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  • PHP_AUTH_USER only known in certain frames

    - by Rob
    Getting very confused by PHP_AUTH_USER. Within my web pages I have .htaccess files in every directory, controlling who can (and cant) see certain folders. In order to further customise the pages I was hoping to use PHP_AUTH_USER within the PHP code, i.e. tailor page contents based on the user. This only seems to work partially. The code snippets below hopefully demonstrate my problems. The main index.php creates a framed page with a menu structure in the top left hand corners, some irrelvant stuff in top right and then the tailor made contents in bottom frame. In top left the user is correctly shown, but in the bottom frame PHP_AUTH_USER doesnt seem to be set anymore (it returns empty and when printing all $HTTP_SERVER_VARS its not listed). Script.php is in a different path, but they all have .htaccess files in them and all other contents is displayed correctly. Why does it not know about PHP_AUTH_USER there? Running version php version 5.2.12 on chrome. index.php <FRAMESET ROWS="35%, *"> <FRAMESET COLS="25%, *"> <FRAME SRC="Menu.php"> <FRAME SRC="Something.php"> </FRAMESET> <FRAME SRC="../OtherPath/Script.php?large=1" name="outputlisting"> </FRAMESET> </FRAMESET> Menu.php <ul> <li>Reporting <ul> <li>Link1 <a href="../OtherPath/Script.php" target="outputlisting">All</a>, <a href="../OtherPath/Script.php?large=1" target="outputlisting">Big</a> </ul> <?php echo 'IP Address: ' . $_SERVER['REMOTE_ADDR'] . '<br />'; echo 'User: ' . $_SERVER['PHP_AUTH_USER']; ?> Script.php <?php echo 'User: ' . $_SERVER['PHP_AUTH_USER']; ?>

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  • Can SQLite file copied successfully on the data folder of an unrooted android device ?

    - by student
    I know that in order to access the data folder on the device, it needs to be rooted. However, if I just want to copy the database from my assets folder to the data folder on my device, will the copying process works on an unrooted phone? The following is my Database Helper class. From logcat, I can verify that the methods call to copyDataBase(), createDataBase() and openDataBase() are returned successfully. However, I got this error message android.database.sqlite.SQLiteException: no such table: TABLE_NAME: when my application is executing rawQuery. I'm suspecting the database file is not copied successfully (cannot be too sure as I do not have access to data folder), yet the method call to copyDatabase() are not throwing any exception. What could it be? Thanks. ps: My device is still unrooted, I hope it is not the main cause of the error. public DatabaseHelper(Context context) { super(context, DB_NAME, null, 1); this.myContext = context; } public void createDataBase() throws IOException{ boolean dbExist = checkDataBase(); String s = new Boolean(dbExist).toString(); Log.d("dbExist", s ); if(dbExist){ //do nothing - database already exist Log.d("createdatabase","DB exists so do nothing"); }else{ this.getReadableDatabase(); try { copyDataBase(); Log.d("copydatabase","Successful return frm method call!"); } catch (IOException e) { throw new Error("Error copying database"); } } } private boolean checkDataBase(){ File dbFile = new File(DB_PATH + DB_NAME); return dbFile.exists(); } private void copyDataBase() throws IOException{ //Open your local db as the input stream InputStream myInput = null; myInput = myContext.getAssets().open(DB_NAME); Log.d("copydatabase","InputStream successful!"); // Path to the just created empty db String outFileName = DB_PATH + DB_NAME; //Open the empty db as the output stream OutputStream myOutput = new FileOutputStream(outFileName); //transfer bytes from the inputfile to the outputfile byte[] buffer = new byte[1024]; int length; while ((length = myInput.read(buffer))>0){ myOutput.write(buffer, 0, length); } //Close the streams myOutput.flush(); myOutput.close(); myInput.close(); } public void openDataBase() throws SQLException{ //Open the database String myPath = DB_PATH + DB_NAME; myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY); } /* @Override public synchronized void close() { if(myDataBase != null) myDataBase.close(); super.close(); }*/ public void close() { // NOTE: openHelper must now be a member of CallDataHelper; // you currently have it as a local in your constructor if (myDataBase != null) { myDataBase.close(); } } @Override public void onCreate(SQLiteDatabase db) { } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { } }

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  • Styling related issue in IE8

    - by Ajith
    I am using a background image to display as a button. The button shows up well in all versions of firefox, chrome, opera etc. However, the image fails to render itself in IE8. Only the image is not being shown, some of the other class styling gets applied such as width, height etc. Even more confounding is that in another page(though a different class and style sheet), an image of similar proportions gets displayed in similar usage. The image format is JPG. I'm copy-pasting the valid style attributes for both cases as shown by firebug below. None of the below buttons are displayed. button classes are applied as class="cart-button login", class="cart-button update", class="cart-button checkout" and class="cart-button continue" and are inside some divs. .cart-button{ height: 28px; cursor: pointer; border: none; float: left; } .cart-button:hover{ background-position: 0 -28px; } .login{ width: 58px; background:url(/../../templates/animalcare/i/login.jpg)no-repeat; margin:0 0 20px 0; clear: both; } .update{ width: 63px; background:url(/../../templates/animalcare/i/update.jpg)no-repeat; margin:0 0 20px 15px; float: left; } .checkout{ width: 77px; background:url(/../../templates/animalcare/i/checkout.jpg)no-repeat; float:right; margin:0 25px 30px 10px; } .continue{ width: 132px; background:url(/../../templates/animalcare/i/continue.jpg)no-repeat; float:right; margin:0 0 30px 0px; } The below is the only image button that gets displayed. It is located inside a table. It is in a different style sheet - hence the path difference. .add-to-cart{ width:102px; height:28px; float:left; background:url(i/add_to_cart.jpg) no-repeat; cursor:pointer; border:none; margin:10px 0 5px 0; } .add-to-cart:hover{ background-position:0 -28px; }

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  • Can I use accepts_nested_attributes_for with checkboxes in a _form to select potential 'links' from a list

    - by Ryan
    In Rails 3: I have the following models: class System has_many :input_modes # name of the table with the join in it has_many :imodes, :through => :input_modes, :source => 'mode', :class_name => "Mode" has_many :output_modes has_many :omodes, :through => :output_modes, :source => 'mode', :class_name => 'Mode' end class InputMode # OutputMode is identical belongs_to :mode belongs_to :system end class Mode ... fields, i.e. name ... end That works nicely and I can assign lists of Modes to imodes and omodes as intended. What I'd like to do is use accepts_nested_attributes_for or some other such magic in the System model and build a view with a set of checkboxes. The set of valid Modes for a given System is defined elsewhere. I'm using checkboxes in the _form view to select which of the valid modes is actually set in imodes and omodes . I don't want to create new Modes from this view, just select from a list of pre-defined Modes. Below is what I'm currently using in my _form view. It generates a list of checkboxes, one for each allowed Mode for the System being edited. If the checkbox is ticked then that Mode is to be included in the imodes list. <% @allowed_modes.each do |mode| %> <li> <%= check_box_tag :imode_ids, mode.id, @system.imodes.include?(modifier), :name => 'imode_ids[]' %> <%= mode.name %> </li> <% end %> Which passes this into the controller in params: { ..., "imode_ids"=>["2", "14"], ... } In the controller#create I extract and assign the Modes that had their corresponding checkboxes ticked and add them to imodes with the following code: @system = System.new(params[:system]) # Note the the empty list that makes sure we clear the # list if none of the checkboxes are ticked if params.has_key?(:imode_ids) imodes = Mode.find(params[:imode_ids]) else imodes = [] end @system.imodes = imodes Once again that all works nicely but I'll have to copy that cludgey code into the other methods in the controller and I'd much prefer to use something more magical if possible. I feel like I've passed off the path of nice clean rails code and into the forest of "hacking around" rails; it works but I don't like it. What should I have done?

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  • Microsoft and jQuery

    - by Rick Strahl
    The jQuery JavaScript library has been steadily getting more popular and with recent developments from Microsoft, jQuery is also getting ever more exposure on the ASP.NET platform including now directly from Microsoft. jQuery is a light weight, open source DOM manipulation library for JavaScript that has changed how many developers think about JavaScript. You can download it and find more information on jQuery on www.jquery.com. For me jQuery has had a huge impact on how I develop Web applications and was probably the main reason I went from dreading to do JavaScript development to actually looking forward to implementing client side JavaScript functionality. It has also had a profound impact on my JavaScript skill level for me by seeing how the library accomplishes things (and often reviewing the terse but excellent source code). jQuery made an uncomfortable development platform (JavaScript + DOM) a joy to work on. Although jQuery is by no means the only JavaScript library out there, its ease of use, small size, huge community of plug-ins and pure usefulness has made it easily the most popular JavaScript library available today. As a long time jQuery user, I’ve been excited to see the developments from Microsoft that are bringing jQuery to more ASP.NET developers and providing more integration with jQuery for ASP.NET’s core features rather than relying on the ASP.NET AJAX library. Microsoft and jQuery – making Friends jQuery is an open source project but in the last couple of years Microsoft has really thrown its weight behind supporting this open source library as a supported component on the Microsoft platform. When I say supported I literally mean supported: Microsoft now offers actual tech support for jQuery as part of their Product Support Services (PSS) as jQuery integration has become part of several of the ASP.NET toolkits and ships in several of the default Web project templates in Visual Studio 2010. The ASP.NET MVC 3 framework (still in Beta) also uses jQuery for a variety of client side support features including client side validation and we can look forward toward more integration of client side functionality via jQuery in both MVC and WebForms in the future. In other words jQuery is becoming an optional but included component of the ASP.NET platform. PSS support means that support staff will answer jQuery related support questions as part of any support incidents related to ASP.NET which provides some piece of mind to some corporate development shops that require end to end support from Microsoft. In addition to including jQuery and supporting it, Microsoft has also been getting involved in providing development resources for extending jQuery’s functionality via plug-ins. Microsoft’s last version of the Microsoft Ajax Library – which is the successor to the native ASP.NET AJAX Library – included some really cool functionality for client templates, databinding and localization. As it turns out Microsoft has rebuilt most of that functionality using jQuery as the base API and provided jQuery plug-ins of these components. Very recently these three plug-ins were submitted and have been approved for inclusion in the official jQuery plug-in repository and been taken over by the jQuery team for further improvements and maintenance. Even more surprising: The jQuery-templates component has actually been approved for inclusion in the next major update of the jQuery core in jQuery V1.5, which means it will become a native feature that doesn’t require additional script files to be loaded. Imagine this – an open source contribution from Microsoft that has been accepted into a major open source project for a core feature improvement. Microsoft has come a long way indeed! What the Microsoft Involvement with jQuery means to you For Microsoft jQuery support is a strategic decision that affects their direction in client side development, but nothing stopped you from using jQuery in your applications prior to Microsoft’s official backing and in fact a large chunk of developers did so readily prior to Microsoft’s announcement. Official support from Microsoft brings a few benefits to developers however. jQuery support in Visual Studio 2010 means built-in support for jQuery IntelliSense, automatically added jQuery scripts in many projects types and a common base for client side functionality that actually uses what most developers are already using. If you have already been using jQuery and were worried about straying from the Microsoft line and their internal Microsoft Ajax Library – worry no more. With official support and the change in direction towards jQuery Microsoft is now following along what most in the ASP.NET community had already been doing by using jQuery, which is likely the reason for Microsoft’s shift in direction in the first place. ASP.NET AJAX and the Microsoft AJAX Library weren’t bad technology – there was tons of useful functionality buried in these libraries. However, these libraries never got off the ground, mainly because early incarnations were squarely aimed at control/component developers rather than application developers. For all the functionality that these controls provided for control developers they lacked in useful and easily usable application developer functionality that was easily accessible in day to day client side development. The result was that even though Microsoft shipped support for these tools in the box (in .NET 3.5 and 4.0), other than for the internal support in ASP.NET for things like the UpdatePanel and the ASP.NET AJAX Control Toolkit as well as some third party vendors, the Microsoft client libraries were largely ignored by the developer community opening the door for other client side solutions. Microsoft seems to be acknowledging developer choice in this case: Many more developers were going down the jQuery path rather than using the Microsoft built libraries and there seems to be little sense in continuing development of a technology that largely goes unused by the majority of developers. Kudos for Microsoft for recognizing this and gracefully changing directions. Note that even though there will be no further development in the Microsoft client libraries they will continue to be supported so if you’re using them in your applications there’s no reason to start running for the exit in a panic and start re-writing everything with jQuery. Although that might be a reasonable choice in some cases, jQuery and the Microsoft libraries work well side by side so that you can leave existing solutions untouched even as you enhance them with jQuery. The Microsoft jQuery Plug-ins – Solid Core Features One of the most interesting developments in Microsoft’s embracing of jQuery is that Microsoft has started contributing to jQuery via standard mechanism set for jQuery developers: By submitting plug-ins. Microsoft took some of the nicest new features of the unpublished Microsoft Ajax Client Library and re-wrote these components for jQuery and then submitted them as plug-ins to the jQuery plug-in repository. Accepted plug-ins get taken over by the jQuery team and that’s exactly what happened with the three plug-ins submitted by Microsoft with the templating plug-in even getting slated to be published as part of the jQuery core in the next major release (1.5). The following plug-ins are provided by Microsoft: jQuery Templates – a client side template rendering engine jQuery Data Link – a client side databinder that can synchronize changes without code jQuery Globalization – provides formatting and conversion features for dates and numbers The first two are ports of functionality that was slated for the Microsoft Ajax Library while functionality for the globalization library provides functionality that was already found in the original ASP.NET AJAX library. To me all three plug-ins address a pressing need in client side applications and provide functionality I’ve previously used in other incarnations, but with more complete implementations. Let’s take a close look at these plug-ins. jQuery Templates http://api.jquery.com/category/plugins/templates/ Client side templating is a key component for building rich JavaScript applications in the browser. Templating on the client lets you avoid from manually creating markup by creating DOM nodes and injecting them individually into the document via code. Rather you can create markup templates – similar to the way you create classic ASP server markup – and merge data into these templates to render HTML which you can then inject into the document or replace existing content with. Output from templates are rendered as a jQuery matched set and can then be easily inserted into the document as needed. Templating is key to minimize client side code and reduce repeated code for rendering logic. Instead a single template can be used in many places for updating and adding content to existing pages. Further if you build pure AJAX interfaces that rely entirely on client rendering of the initial page content, templates allow you to a use a single markup template to handle all rendering of each specific HTML section/element. I’ve used a number of different client rendering template engines with jQuery in the past including jTemplates (a PHP style templating engine) and a modified version of John Resig’s MicroTemplating engine which I built into my own set of libraries because it’s such a commonly used feature in my client side applications. jQuery templates adds a much richer templating model that allows for sub-templates and access to the data items. Like John Resig’s original Micro Template engine, the core basics of the templating engine create JavaScript code which means that templates can include JavaScript code. To give you a basic idea of how templates work imagine I have an application that downloads a set of stock quotes based on a symbol list then displays them in the document. To do this you can create an ‘item’ template that describes how each of the quotes is renderd as a template inside of the document: <script id="stockTemplate" type="text/x-jquery-tmpl"> <div id="divStockQuote" class="errordisplay" style="width: 500px;"> <div class="label">Company:</div><div><b>${Company}(${Symbol})</b></div> <div class="label">Last Price:</div><div>${LastPrice}</div> <div class="label">Net Change:</div><div> {{if NetChange > 0}} <b style="color:green" >${NetChange}</b> {{else}} <b style="color:red" >${NetChange}</b> {{/if}} </div> <div class="label">Last Update:</div><div>${LastQuoteTimeString}</div> </div> </script> The ‘template’ is little more than HTML with some markup expressions inside of it that define the template language. Notice the embedded ${} expressions which reference data from the quote objects returned from an AJAX call on the server. You can embed any JavaScript or value expression in these template expressions. There are also a number of structural commands like {{if}} and {{each}} that provide for rudimentary logic inside of your templates as well as commands ({{tmpl}} and {{wrap}}) for nesting templates. You can find more about the full set of markup expressions available in the documentation. To load up this data you can use code like the following: <script type="text/javascript"> //var Proxy = new ServiceProxy("../PageMethods/PageMethodsService.asmx/"); $(document).ready(function () { $("#btnGetQuotes").click(GetQuotes); }); function GetQuotes() { var symbols = $("#txtSymbols").val().split(","); $.ajax({ url: "../PageMethods/PageMethodsService.asmx/GetStockQuotes", data: JSON.stringify({ symbols: symbols }), // parameter map type: "POST", // data has to be POSTed contentType: "application/json", timeout: 10000, dataType: "json", success: function (result) { var quotes = result.d; var jEl = $("#stockTemplate").tmpl(quotes); $("#quoteDisplay").empty().append(jEl); }, error: function (xhr, status) { alert(status + "\r\n" + xhr.responseText); } }); }; </script> In this case an ASMX AJAX service is called to retrieve the stock quotes. The service returns an array of quote objects. The result is returned as an object with the .d property (in Microsoft service style) that returns the actual array of quotes. The template is applied with: var jEl = $("#stockTemplate").tmpl(quotes); which selects the template script tag and uses the .tmpl() function to apply the data to it. The result is a jQuery matched set of elements that can then be appended to the quote display element in the page. The template is merged against an array in this example. When the result is an array the template is automatically applied to each each array item. If you pass a single data item – like say a stock quote – the template works exactly the same way but is applied only once. Templates also have access to a $data item which provides the current data item and information about the tempalte that is currently executing. This makes it possible to keep context within the context of the template itself and also to pass context from a parent template to a child template which is very powerful. Templates can be evaluated by using the template selector and calling the .tmpl() function on the jQuery matched set as shown above or you can use the static $.tmpl() function to provide a template as a string. This allows you to dynamically create templates in code or – more likely – to load templates from the server via AJAX calls. In short there are options The above shows off some of the basics, but there’s much for functionality available in the template engine. Check the documentation link for more information and links to additional examples. The plug-in download also comes with a number of examples that demonstrate functionality. jQuery templates will become a native component in jQuery Core 1.5, so it’s definitely worthwhile checking out the engine today and get familiar with this interface. As much as I’m stoked about templating becoming part of the jQuery core because it’s such an integral part of many applications, there are also a couple shortcomings in the current incarnation: Lack of Error Handling Currently if you embed an expression that is invalid it’s simply not rendered. There’s no error rendered into the template nor do the various  template functions throw errors which leaves finding of bugs as a runtime exercise. I would like some mechanism – optional if possible – to be able to get error info of what is failing in a template when it’s rendered. No String Output Templates are always rendered into a jQuery matched set and there’s no way that I can see to directly render to a string. String output can be useful for debugging as well as opening up templating for creating non-HTML string output. Limited JavaScript Access Unlike John Resig’s original MicroTemplating Engine which was entirely based on JavaScript code generation these templates are limited to a few structured commands that can ‘execute’. There’s no code execution inside of script code which means you’re limited to calling expressions available in global objects or the data item passed in. This may or may not be a big deal depending on the complexity of your template logic. Error handling has been discussed quite a bit and it’s likely there will be some solution to that particualar issue by the time jQuery templates ship. The others are relatively minor issues but something to think about anyway. jQuery Data Link http://api.jquery.com/category/plugins/data-link/ jQuery Data Link provides the ability to do two-way data binding between input controls and an underlying object’s properties. The typical scenario is linking a textbox to a property of an object and have the object updated when the text in the textbox is changed and have the textbox change when the value in the object or the entire object changes. The plug-in also supports converter functions that can be applied to provide the conversion logic from string to some other value typically necessary for mapping things like textbox string input to say a number property and potentially applying additional formatting and calculations. In theory this sounds great, however in reality this plug-in has some serious usability issues. Using the plug-in you can do things like the following to bind data: person = { firstName: "rick", lastName: "strahl"}; $(document).ready( function() { // provide for two-way linking of inputs $("form").link(person); // bind to non-input elements explicitly $("#objFirst").link(person, { firstName: { name: "objFirst", convertBack: function (value, source, target) { $(target).text(value); } } }); $("#objLast").link(person, { lastName: { name: "objLast", convertBack: function (value, source, target) { $(target).text(value); } } }); }); This code hooks up two-way linking between a couple of textboxes on the page and the person object. The first line in the .ready() handler provides mapping of object to form field with the same field names as properties on the object. Note that .link() does NOT bind items into the textboxes when you call .link() – changes are mapped only when values change and you move out of the field. Strike one. The two following commands allow manual binding of values to specific DOM elements which is effectively a one-way bind. You specify the object and a then an explicit mapping where name is an ID in the document. The converter is required to explicitly assign the value to the element. Strike two. You can also detect changes to the underlying object and cause updates to the input elements bound. Unfortunately the syntax to do this is not very natural as you have to rely on the jQuery data object. To update an object’s properties and get change notification looks like this: function updateFirstName() { $(person).data("firstName", person.firstName + " (code updated)"); } This works fine in causing any linked fields to be updated. In the bindings above both the firstName input field and objFirst DOM element gets updated. But the syntax requires you to use a jQuery .data() call for each property change to ensure that the changes are tracked properly. Really? Sure you’re binding through multiple layers of abstraction now but how is that better than just manually assigning values? The code savings (if any) are going to be minimal. As much as I would like to have a WPF/Silverlight/Observable-like binding mechanism in client script, this plug-in doesn’t help much towards that goal in its current incarnation. While you can bind values, the ‘binder’ is too limited to be really useful. If initial values can’t be assigned from the mappings you’re going to end up duplicating work loading the data using some other mechanism. There’s no easy way to re-bind data with a different object altogether since updates trigger only through the .data members. Finally, any non-input elements have to be bound via code that’s fairly verbose and frankly may be more voluminous than what you might write by hand for manual binding and unbinding. Two way binding can be very useful but it has to be easy and most importantly natural. If it’s more work to hook up a binding than writing a couple of lines to do binding/unbinding this sort of thing helps very little in most scenarios. In talking to some of the developers the feature set for Data Link is not complete and they are still soliciting input for features and functionality. If you have ideas on how you want this feature to be more useful get involved and post your recommendations. As it stands, it looks to me like this component needs a lot of love to become useful. For this component to really provide value, bindings need to be able to be refreshed easily and work at the object level, not just the property level. It seems to me we would be much better served by a model binder object that can perform these binding/unbinding tasks in bulk rather than a tool where each link has to be mapped first. I also find the choice of creating a jQuery plug-in questionable – it seems a standalone object – albeit one that relies on the jQuery library – would provide a more intuitive interface than the current forcing of options onto a plug-in style interface. Out of the three Microsoft created components this is by far the least useful and least polished implementation at this point. jQuery Globalization http://github.com/jquery/jquery-global Globalization in JavaScript applications often gets short shrift and part of the reason for this is that natively in JavaScript there’s little support for formatting and parsing of numbers and dates. There are a number of JavaScript libraries out there that provide some support for globalization, but most are limited to a particular portion of globalization. As .NET developers we’re fairly spoiled by the richness of APIs provided in the framework and when dealing with client development one really notices the lack of these features. While you may not necessarily need to localize your application the globalization plug-in also helps with some basic tasks for non-localized applications: Dealing with formatting and parsing of dates and time values. Dates in particular are problematic in JavaScript as there are no formatters whatsoever except the .toString() method which outputs a verbose and next to useless long string. With the globalization plug-in you get a good chunk of the formatting and parsing functionality that the .NET framework provides on the server. You can write code like the following for example to format numbers and dates: var date = new Date(); var output = $.format(date, "MMM. dd, yy") + "\r\n" + $.format(date, "d") + "\r\n" + // 10/25/2010 $.format(1222.32213, "N2") + "\r\n" + $.format(1222.33, "c") + "\r\n"; alert(output); This becomes even more useful if you combine it with templates which can also include any JavaScript expressions. Assuming the globalization plug-in is loaded you can create template expressions that use the $.format function. Here’s the template I used earlier for the stock quote again with a couple of formats applied: <script id="stockTemplate" type="text/x-jquery-tmpl"> <div id="divStockQuote" class="errordisplay" style="width: 500px;"> <div class="label">Company:</div><div><b>${Company}(${Symbol})</b></div> <div class="label">Last Price:</div> <div>${$.format(LastPrice,"N2")}</div> <div class="label">Net Change:</div><div> {{if NetChange > 0}} <b style="color:green" >${NetChange}</b> {{else}} <b style="color:red" >${NetChange}</b> {{/if}} </div> <div class="label">Last Update:</div> <div>${$.format(LastQuoteTime,"MMM dd, yyyy")}</div> </div> </script> There are also parsing methods that can parse dates and numbers from strings into numbers easily: alert($.parseDate("25.10.2010")); alert($.parseInt("12.222")); // de-DE uses . for thousands separators As you can see culture specific options are taken into account when parsing. The globalization plugin provides rich support for a variety of locales: Get a list of all available cultures Query cultures for culture items (like currency symbol, separators etc.) Localized string names for all calendar related items (days of week, months) Generated off of .NET’s supported locales In short you get much of the same functionality that you already might be using in .NET on the server side. The plugin includes a huge number of locales and an Globalization.all.min.js file that contains the text defaults for each of these locales as well as small locale specific script files that define each of the locale specific settings. It’s highly recommended that you NOT use the huge globalization file that includes all locales, but rather add script references to only those languages you explicitly care about. Overall this plug-in is a welcome helper. Even if you use it with a single locale (like en-US) and do no other localization, you’ll gain solid support for number and date formatting which is a vital feature of many applications. Changes for Microsoft It’s good to see Microsoft coming out of its shell and away from the ‘not-built-here’ mentality that has been so pervasive in the past. It’s especially good to see it applied to jQuery – a technology that has stood in drastic contrast to Microsoft’s own internal efforts in terms of design, usage model and… popularity. It’s great to see that Microsoft is paying attention to what customers prefer to use and supporting the customer sentiment – even if it meant drastically changing course of policy and moving into a more open and sharing environment in the process. The additional jQuery support that has been introduced in the last two years certainly has made lives easier for many developers on the ASP.NET platform. It’s also nice to see Microsoft submitting proposals through the standard jQuery process of plug-ins and getting accepted for various very useful projects. Certainly the jQuery Templates plug-in is going to be very useful to many especially since it will be baked into the jQuery core in jQuery 1.5. I hope we see more of this type of involvement from Microsoft in the future. Kudos!© Rick Strahl, West Wind Technologies, 2005-2010Posted in jQuery  ASP.NET  

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  • Creating a dynamic, extensible C# Expando Object

    - by Rick Strahl
    I love dynamic functionality in a strongly typed language because it offers us the best of both worlds. In C# (or any of the main .NET languages) we now have the dynamic type that provides a host of dynamic features for the static C# language. One place where I've found dynamic to be incredibly useful is in building extensible types or types that expose traditionally non-object data (like dictionaries) in easier to use and more readable syntax. I wrote about a couple of these for accessing old school ADO.NET DataRows and DataReaders more easily for example. These classes are dynamic wrappers that provide easier syntax and auto-type conversions which greatly simplifies code clutter and increases clarity in existing code. ExpandoObject in .NET 4.0 Another great use case for dynamic objects is the ability to create extensible objects - objects that start out with a set of static members and then can add additional properties and even methods dynamically. The .NET 4.0 framework actually includes an ExpandoObject class which provides a very dynamic object that allows you to add properties and methods on the fly and then access them again. For example with ExpandoObject you can do stuff like this:dynamic expand = new ExpandoObject(); expand.Name = "Rick"; expand.HelloWorld = (Func<string, string>) ((string name) => { return "Hello " + name; }); Console.WriteLine(expand.Name); Console.WriteLine(expand.HelloWorld("Dufus")); Internally ExpandoObject uses a Dictionary like structure and interface to store properties and methods and then allows you to add and access properties and methods easily. As cool as ExpandoObject is it has a few shortcomings too: It's a sealed type so you can't use it as a base class It only works off 'properties' in the internal Dictionary - you can't expose existing type data It doesn't serialize to XML or with DataContractSerializer/DataContractJsonSerializer Expando - A truly extensible Object ExpandoObject is nice if you just need a dynamic container for a dictionary like structure. However, if you want to build an extensible object that starts out with a set of strongly typed properties and then allows you to extend it, ExpandoObject does not work because it's a sealed class that can't be inherited. I started thinking about this very scenario for one of my applications I'm building for a customer. In this system we are connecting to various different user stores. Each user store has the same basic requirements for username, password, name etc. But then each store also has a number of extended properties that is available to each application. In the real world scenario the data is loaded from the database in a data reader and the known properties are assigned from the known fields in the database. All unknown fields are then 'added' to the expando object dynamically. In the past I've done this very thing with a separate property - Properties - just like I do for this class. But the property and dictionary syntax is not ideal and tedious to work with. I started thinking about how to represent these extra property structures. One way certainly would be to add a Dictionary, or an ExpandoObject to hold all those extra properties. But wouldn't it be nice if the application could actually extend an existing object that looks something like this as you can with the Expando object:public class User : Westwind.Utilities.Dynamic.Expando { public string Email { get; set; } public string Password { get; set; } public string Name { get; set; } public bool Active { get; set; } public DateTime? ExpiresOn { get; set; } } and then simply start extending the properties of this object dynamically? Using the Expando object I describe later you can now do the following:[TestMethod] public void UserExampleTest() { var user = new User(); // Set strongly typed properties user.Email = "[email protected]"; user.Password = "nonya123"; user.Name = "Rickochet"; user.Active = true; // Now add dynamic properties dynamic duser = user; duser.Entered = DateTime.Now; duser.Accesses = 1; // you can also add dynamic props via indexer user["NickName"] = "AntiSocialX"; duser["WebSite"] = "http://www.west-wind.com/weblog"; // Access strong type through dynamic ref Assert.AreEqual(user.Name,duser.Name); // Access strong type through indexer Assert.AreEqual(user.Password,user["Password"]); // access dyanmically added value through indexer Assert.AreEqual(duser.Entered,user["Entered"]); // access index added value through dynamic Assert.AreEqual(user["NickName"],duser.NickName); // loop through all properties dynamic AND strong type properties (true) foreach (var prop in user.GetProperties(true)) { object val = prop.Value; if (val == null) val = "null"; Console.WriteLine(prop.Key + ": " + val.ToString()); } } As you can see this code somewhat blurs the line between a static and dynamic type. You start with a strongly typed object that has a fixed set of properties. You can then cast the object to dynamic (as I discussed in my last post) and add additional properties to the object. You can also use an indexer to add dynamic properties to the object. To access the strongly typed properties you can use either the strongly typed instance, the indexer or the dynamic cast of the object. Personally I think it's kinda cool to have an easy way to access strongly typed properties by string which can make some data scenarios much easier. To access the 'dynamically added' properties you can use either the indexer on the strongly typed object, or property syntax on the dynamic cast. Using the dynamic type allows all three modes to work on both strongly typed and dynamic properties. Finally you can iterate over all properties, both dynamic and strongly typed if you chose. Lots of flexibility. Note also that by default the Expando object works against the (this) instance meaning it extends the current object. You can also pass in a separate instance to the constructor in which case that object will be used to iterate over to find properties rather than this. Using this approach provides some really interesting functionality when use the dynamic type. To use this we have to add an explicit constructor to the Expando subclass:public class User : Westwind.Utilities.Dynamic.Expando { public string Email { get; set; } public string Password { get; set; } public string Name { get; set; } public bool Active { get; set; } public DateTime? ExpiresOn { get; set; } public User() : base() { } // only required if you want to mix in seperate instance public User(object instance) : base(instance) { } } to allow the instance to be passed. When you do you can now do:[TestMethod] public void ExpandoMixinTest() { // have Expando work on Addresses var user = new User( new Address() ); // cast to dynamicAccessToPropertyTest dynamic duser = user; // Set strongly typed properties duser.Email = "[email protected]"; user.Password = "nonya123"; // Set properties on address object duser.Address = "32 Kaiea"; //duser.Phone = "808-123-2131"; // set dynamic properties duser.NonExistantProperty = "This works too"; // shows default value Address.Phone value Console.WriteLine(duser.Phone); } Using the dynamic cast in this case allows you to access *three* different 'objects': The strong type properties, the dynamically added properties in the dictionary and the properties of the instance passed in! Effectively this gives you a way to simulate multiple inheritance (which is scary - so be very careful with this, but you can do it). How Expando works Behind the scenes Expando is a DynamicObject subclass as I discussed in my last post. By implementing a few of DynamicObject's methods you can basically create a type that can trap 'property missing' and 'method missing' operations. When you access a non-existant property a known method is fired that our code can intercept and provide a value for. Internally Expando uses a custom dictionary implementation to hold the dynamic properties you might add to your expandable object. Let's look at code first. The code for the Expando type is straight forward and given what it provides relatively short. Here it is.using System; using System.Collections.Generic; using System.Linq; using System.Dynamic; using System.Reflection; namespace Westwind.Utilities.Dynamic { /// <summary> /// Class that provides extensible properties and methods. This /// dynamic object stores 'extra' properties in a dictionary or /// checks the actual properties of the instance. /// /// This means you can subclass this expando and retrieve either /// native properties or properties from values in the dictionary. /// /// This type allows you three ways to access its properties: /// /// Directly: any explicitly declared properties are accessible /// Dynamic: dynamic cast allows access to dictionary and native properties/methods /// Dictionary: Any of the extended properties are accessible via IDictionary interface /// </summary> [Serializable] public class Expando : DynamicObject, IDynamicMetaObjectProvider { /// <summary> /// Instance of object passed in /// </summary> object Instance; /// <summary> /// Cached type of the instance /// </summary> Type InstanceType; PropertyInfo[] InstancePropertyInfo { get { if (_InstancePropertyInfo == null && Instance != null) _InstancePropertyInfo = Instance.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly); return _InstancePropertyInfo; } } PropertyInfo[] _InstancePropertyInfo; /// <summary> /// String Dictionary that contains the extra dynamic values /// stored on this object/instance /// </summary> /// <remarks>Using PropertyBag to support XML Serialization of the dictionary</remarks> public PropertyBag Properties = new PropertyBag(); //public Dictionary<string,object> Properties = new Dictionary<string, object>(); /// <summary> /// This constructor just works off the internal dictionary and any /// public properties of this object. /// /// Note you can subclass Expando. /// </summary> public Expando() { Initialize(this); } /// <summary> /// Allows passing in an existing instance variable to 'extend'. /// </summary> /// <remarks> /// You can pass in null here if you don't want to /// check native properties and only check the Dictionary! /// </remarks> /// <param name="instance"></param> public Expando(object instance) { Initialize(instance); } protected virtual void Initialize(object instance) { Instance = instance; if (instance != null) InstanceType = instance.GetType(); } /// <summary> /// Try to retrieve a member by name first from instance properties /// followed by the collection entries. /// </summary> /// <param name="binder"></param> /// <param name="result"></param> /// <returns></returns> public override bool TryGetMember(GetMemberBinder binder, out object result) { result = null; // first check the Properties collection for member if (Properties.Keys.Contains(binder.Name)) { result = Properties[binder.Name]; return true; } // Next check for Public properties via Reflection if (Instance != null) { try { return GetProperty(Instance, binder.Name, out result); } catch { } } // failed to retrieve a property result = null; return false; } /// <summary> /// Property setter implementation tries to retrieve value from instance /// first then into this object /// </summary> /// <param name="binder"></param> /// <param name="value"></param> /// <returns></returns> public override bool TrySetMember(SetMemberBinder binder, object value) { // first check to see if there's a native property to set if (Instance != null) { try { bool result = SetProperty(Instance, binder.Name, value); if (result) return true; } catch { } } // no match - set or add to dictionary Properties[binder.Name] = value; return true; } /// <summary> /// Dynamic invocation method. Currently allows only for Reflection based /// operation (no ability to add methods dynamically). /// </summary> /// <param name="binder"></param> /// <param name="args"></param> /// <param name="result"></param> /// <returns></returns> public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result) { if (Instance != null) { try { // check instance passed in for methods to invoke if (InvokeMethod(Instance, binder.Name, args, out result)) return true; } catch { } } result = null; return false; } /// <summary> /// Reflection Helper method to retrieve a property /// </summary> /// <param name="instance"></param> /// <param name="name"></param> /// <param name="result"></param> /// <returns></returns> protected bool GetProperty(object instance, string name, out object result) { if (instance == null) instance = this; var miArray = InstanceType.GetMember(name, BindingFlags.Public | BindingFlags.GetProperty | BindingFlags.Instance); if (miArray != null && miArray.Length > 0) { var mi = miArray[0]; if (mi.MemberType == MemberTypes.Property) { result = ((PropertyInfo)mi).GetValue(instance,null); return true; } } result = null; return false; } /// <summary> /// Reflection helper method to set a property value /// </summary> /// <param name="instance"></param> /// <param name="name"></param> /// <param name="value"></param> /// <returns></returns> protected bool SetProperty(object instance, string name, object value) { if (instance == null) instance = this; var miArray = InstanceType.GetMember(name, BindingFlags.Public | BindingFlags.SetProperty | BindingFlags.Instance); if (miArray != null && miArray.Length > 0) { var mi = miArray[0]; if (mi.MemberType == MemberTypes.Property) { ((PropertyInfo)mi).SetValue(Instance, value, null); return true; } } return false; } /// <summary> /// Reflection helper method to invoke a method /// </summary> /// <param name="instance"></param> /// <param name="name"></param> /// <param name="args"></param> /// <param name="result"></param> /// <returns></returns> protected bool InvokeMethod(object instance, string name, object[] args, out object result) { if (instance == null) instance = this; // Look at the instanceType var miArray = InstanceType.GetMember(name, BindingFlags.InvokeMethod | BindingFlags.Public | BindingFlags.Instance); if (miArray != null && miArray.Length > 0) { var mi = miArray[0] as MethodInfo; result = mi.Invoke(Instance, args); return true; } result = null; return false; } /// <summary> /// Convenience method that provides a string Indexer /// to the Properties collection AND the strongly typed /// properties of the object by name. /// /// // dynamic /// exp["Address"] = "112 nowhere lane"; /// // strong /// var name = exp["StronglyTypedProperty"] as string; /// </summary> /// <remarks> /// The getter checks the Properties dictionary first /// then looks in PropertyInfo for properties. /// The setter checks the instance properties before /// checking the Properties dictionary. /// </remarks> /// <param name="key"></param> /// /// <returns></returns> public object this[string key] { get { try { // try to get from properties collection first return Properties[key]; } catch (KeyNotFoundException ex) { // try reflection on instanceType object result = null; if (GetProperty(Instance, key, out result)) return result; // nope doesn't exist throw; } } set { if (Properties.ContainsKey(key)) { Properties[key] = value; return; } // check instance for existance of type first var miArray = InstanceType.GetMember(key, BindingFlags.Public | BindingFlags.GetProperty); if (miArray != null && miArray.Length > 0) SetProperty(Instance, key, value); else Properties[key] = value; } } /// <summary> /// Returns and the properties of /// </summary> /// <param name="includeProperties"></param> /// <returns></returns> public IEnumerable<KeyValuePair<string,object>> GetProperties(bool includeInstanceProperties = false) { if (includeInstanceProperties && Instance != null) { foreach (var prop in this.InstancePropertyInfo) yield return new KeyValuePair<string, object>(prop.Name, prop.GetValue(Instance, null)); } foreach (var key in this.Properties.Keys) yield return new KeyValuePair<string, object>(key, this.Properties[key]); } /// <summary> /// Checks whether a property exists in the Property collection /// or as a property on the instance /// </summary> /// <param name="item"></param> /// <returns></returns> public bool Contains(KeyValuePair<string, object> item, bool includeInstanceProperties = false) { bool res = Properties.ContainsKey(item.Key); if (res) return true; if (includeInstanceProperties && Instance != null) { foreach (var prop in this.InstancePropertyInfo) { if (prop.Name == item.Key) return true; } } return false; } } } Although the Expando class supports an indexer, it doesn't actually implement IDictionary or even IEnumerable. It only provides the indexer and Contains() and GetProperties() methods, that work against the Properties dictionary AND the internal instance. The reason for not implementing IDictionary is that a) it doesn't add much value since you can access the Properties dictionary directly and that b) I wanted to keep the interface to class very lean so that it can serve as an entity type if desired. Implementing these IDictionary (or even IEnumerable) causes LINQ extension methods to pop up on the type which obscures the property interface and would only confuse the purpose of the type. IDictionary and IEnumerable are also problematic for XML and JSON Serialization - the XML Serializer doesn't serialize IDictionary<string,object>, nor does the DataContractSerializer. The JavaScriptSerializer does serialize, but it treats the entire object like a dictionary and doesn't serialize the strongly typed properties of the type, only the dictionary values which is also not desirable. Hence the decision to stick with only implementing the indexer to support the user["CustomProperty"] functionality and leaving iteration functions to the publicly exposed Properties dictionary. Note that the Dictionary used here is a custom PropertyBag class I created to allow for serialization to work. One important aspect for my apps is that whatever custom properties get added they have to be accessible to AJAX clients since the particular app I'm working on is a SIngle Page Web app where most of the Web access is through JSON AJAX calls. PropertyBag can serialize to XML and one way serialize to JSON using the JavaScript serializer (not the DCS serializers though). The key components that make Expando work in this code are the Properties Dictionary and the TryGetMember() and TrySetMember() methods. The Properties collection is public so if you choose you can explicitly access the collection to get better performance or to manipulate the members in internal code (like loading up dynamic values form a database). Notice that TryGetMember() and TrySetMember() both work against the dictionary AND the internal instance to retrieve and set properties. This means that user["Name"] works against native properties of the object as does user["Name"] = "RogaDugDog". What's your Use Case? This is still an early prototype but I've plugged it into one of my customer's applications and so far it's working very well. The key features for me were the ability to easily extend the type with values coming from a database and exposing those values in a nice and easy to use manner. I'm also finding that using this type of object for ViewModels works very well to add custom properties to view models. I suspect there will be lots of uses for this - I've been using the extra dictionary approach to extensibility for years - using a dynamic type to make the syntax cleaner is just a bonus here. What can you think of to use this for? Resources Source Code and Tests (GitHub) Also integrated in Westwind.Utilities of the West Wind Web Toolkit West Wind Utilities NuGet© Rick Strahl, West Wind Technologies, 2005-2012Posted in CSharp  .NET  Dynamic Types   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • WCF WS-Security and WSE Nonce Authentication

    - by Rick Strahl
    WCF makes it fairly easy to access WS-* Web Services, except when you run into a service format that it doesn't support. Even then WCF provides a huge amount of flexibility to make the service clients work, however finding the proper interfaces to make that happen is not easy to discover and for the most part undocumented unless you're lucky enough to run into a blog, forum or StackOverflow post on the matter. This is definitely true for the Password Nonce as part of the WS-Security/WSE protocol, which is not natively supported in WCF. Specifically I had a need to create a WCF message on the client that includes a WS-Security header that looks like this from their spec document:<soapenv:Header> <wsse:Security soapenv:mustUnderstand="1" xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd"> <wsse:UsernameToken wsu:Id="UsernameToken-8" xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd"> <wsse:Username>TeStUsErNaMe1</wsse:Username> <wsse:Password Type="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-profile-1.0#PasswordText" >TeStPaSsWoRd1</wsse:Password> <wsse:Nonce EncodingType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0#Base64Binary" >f8nUe3YupTU5ISdCy3X9Gg==</wsse:Nonce> <wsu:Created>2011-05-04T19:01:40.981Z</wsu:Created> </wsse:UsernameToken> </wsse:Security> </soapenv:Header> Specifically, the Nonce and Created keys are what WCF doesn't create or have a built in formatting for. Why is there a nonce? My first thought here was WTF? The username and password are there in clear text, what does the Nonce accomplish? The Nonce and created keys are are part of WSE Security specification and are meant to allow the server to detect and prevent replay attacks. The hashed nonce should be unique per request which the server can store and check for before running another request thus ensuring that a request is not replayed with exactly the same values. Basic ServiceUtl Import - not much Luck The first thing I did when I imported this service with a service reference was to simply import it as a Service Reference. The Add Service Reference import automatically detects that WS-Security is required and appropariately adds the WS-Security to the basicHttpBinding in the config file:<?xml version="1.0" encoding="utf-8" ?> <configuration> <system.serviceModel> <bindings> <basicHttpBinding> <binding name="RealTimeOnlineSoapBinding"> <security mode="Transport" /> </binding> <binding name="RealTimeOnlineSoapBinding1" /> </basicHttpBinding> </bindings> <client> <endpoint address="https://notarealurl.com:443/services/RealTimeOnline" binding="basicHttpBinding" bindingConfiguration="RealTimeOnlineSoapBinding" contract="RealTimeOnline.RealTimeOnline" name="RealTimeOnline" /> </client> </system.serviceModel> </configuration> If if I run this as is using code like this:var client = new RealTimeOnlineClient(); client.ClientCredentials.UserName.UserName = "TheUsername"; client.ClientCredentials.UserName.Password = "ThePassword"; … I get nothing in terms of WS-Security headers. The request is sent, but the the binding expects transport level security to be applied, rather than message level security. To fix this so that a WS-Security message header is sent the security mode can be changed to: <security mode="TransportWithMessageCredential" /> Now if I re-run I at least get a WS-Security header which looks like this:<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" xmlns:u="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd"> <s:Header> <o:Security s:mustUnderstand="1" xmlns:o="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd"> <u:Timestamp u:Id="_0"> <u:Created>2012-11-24T02:55:18.011Z</u:Created> <u:Expires>2012-11-24T03:00:18.011Z</u:Expires> </u:Timestamp> <o:UsernameToken u:Id="uuid-18c215d4-1106-40a5-8dd1-c81fdddf19d3-1"> <o:Username>TheUserName</o:Username> <o:Password Type="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-profile-1.0#PasswordText" >ThePassword</o:Password> </o:UsernameToken> </o:Security> </s:Header> Closer! Now the WS-Security header is there along with a timestamp field (which might not be accepted by some WS-Security expecting services), but there's no Nonce or created timestamp as required by my original service. Using a CustomBinding instead My next try was to go with a CustomBinding instead of basicHttpBinding as it allows a bit more control over the protocol and transport configurations for the binding. Specifically I can explicitly specify the message protocol(s) used. Using configuration file settings here's what the config file looks like:<?xml version="1.0"?> <configuration> <system.serviceModel> <bindings> <customBinding> <binding name="CustomSoapBinding"> <security includeTimestamp="false" authenticationMode="UserNameOverTransport" defaultAlgorithmSuite="Basic256" requireDerivedKeys="false" messageSecurityVersion="WSSecurity10WSTrustFebruary2005WSSecureConversationFebruary2005WSSecurityPolicy11BasicSecurityProfile10"> </security> <textMessageEncoding messageVersion="Soap11"></textMessageEncoding> <httpsTransport maxReceivedMessageSize="2000000000"/> </binding> </customBinding> </bindings> <client> <endpoint address="https://notrealurl.com:443/services/RealTimeOnline" binding="customBinding" bindingConfiguration="CustomSoapBinding" contract="RealTimeOnline.RealTimeOnline" name="RealTimeOnline" /> </client> </system.serviceModel> <startup> <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/> </startup> </configuration> This ends up creating a cleaner header that's missing the timestamp field which can cause some services problems. The WS-Security header output generated with the above looks like this:<s:Header> <o:Security s:mustUnderstand="1" xmlns:o="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd"> <o:UsernameToken u:Id="uuid-291622ca-4c11-460f-9886-ac1c78813b24-1"> <o:Username>TheUsername</o:Username> <o:Password Type="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-profile-1.0#PasswordText" >ThePassword</o:Password> </o:UsernameToken> </o:Security> </s:Header> This is closer as it includes only the username and password. The key here is the protocol for WS-Security:messageSecurityVersion="WSSecurity10WSTrustFebruary2005WSSecureConversationFebruary2005WSSecurityPolicy11BasicSecurityProfile10" which explicitly specifies the protocol version. There are several variants of this specification but none of them seem to support the nonce unfortunately. This protocol does allow for optional omission of the Nonce and created timestamp provided (which effectively makes those keys optional). With some services I tried that requested a Nonce just using this protocol actually worked where the default basicHttpBinding failed to connect, so this is a possible solution for access to some services. Unfortunately for my target service that was not an option. The nonce has to be there. Creating Custom ClientCredentials As it turns out WCF doesn't have support for the Digest Nonce as part of WS-Security, and so as far as I can tell there's no way to do it just with configuration settings. I did a bunch of research on this trying to find workarounds for this, and I did find a couple of entries on StackOverflow as well as on the MSDN forums. However, none of these are particularily clear and I ended up using bits and pieces of several of them to arrive at a working solution in the end. http://stackoverflow.com/questions/896901/wcf-adding-nonce-to-usernametoken http://social.msdn.microsoft.com/Forums/en-US/wcf/thread/4df3354f-0627-42d9-b5fb-6e880b60f8ee The latter forum message is the more useful of the two (the last message on the thread in particular) and it has most of the information required to make this work. But it took some experimentation for me to get this right so I'll recount the process here maybe a bit more comprehensively. In order for this to work a number of classes have to be overridden: ClientCredentials ClientCredentialsSecurityTokenManager WSSecurityTokenizer The idea is that we need to create a custom ClientCredential class to hold the custom properties so they can be set from the UI or via configuration settings. The TokenManager and Tokenizer are mainly required to allow the custom credentials class to flow through the WCF pipeline and eventually provide custom serialization. Here are the three classes required and their full implementations:public class CustomCredentials : ClientCredentials { public CustomCredentials() { } protected CustomCredentials(CustomCredentials cc) : base(cc) { } public override System.IdentityModel.Selectors.SecurityTokenManager CreateSecurityTokenManager() { return new CustomSecurityTokenManager(this); } protected override ClientCredentials CloneCore() { return new CustomCredentials(this); } } public class CustomSecurityTokenManager : ClientCredentialsSecurityTokenManager { public CustomSecurityTokenManager(CustomCredentials cred) : base(cred) { } public override System.IdentityModel.Selectors.SecurityTokenSerializer CreateSecurityTokenSerializer(System.IdentityModel.Selectors.SecurityTokenVersion version) { return new CustomTokenSerializer(System.ServiceModel.Security.SecurityVersion.WSSecurity11); } } public class CustomTokenSerializer : WSSecurityTokenSerializer { public CustomTokenSerializer(SecurityVersion sv) : base(sv) { } protected override void WriteTokenCore(System.Xml.XmlWriter writer, System.IdentityModel.Tokens.SecurityToken token) { UserNameSecurityToken userToken = token as UserNameSecurityToken; string tokennamespace = "o"; DateTime created = DateTime.Now; string createdStr = created.ToString("yyyy-MM-ddThh:mm:ss.fffZ"); // unique Nonce value - encode with SHA-1 for 'randomness' // in theory the nonce could just be the GUID by itself string phrase = Guid.NewGuid().ToString(); var nonce = GetSHA1String(phrase); // in this case password is plain text // for digest mode password needs to be encoded as: // PasswordAsDigest = Base64(SHA-1(Nonce + Created + Password)) // and profile needs to change to //string password = GetSHA1String(nonce + createdStr + userToken.Password); string password = userToken.Password; writer.WriteRaw(string.Format( "<{0}:UsernameToken u:Id=\"" + token.Id + "\" xmlns:u=\"http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd\">" + "<{0}:Username>" + userToken.UserName + "</{0}:Username>" + "<{0}:Password Type=\"http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-profile-1.0#PasswordText\">" + password + "</{0}:Password>" + "<{0}:Nonce EncodingType=\"http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0#Base64Binary\">" + nonce + "</{0}:Nonce>" + "<u:Created>" + createdStr + "</u:Created></{0}:UsernameToken>", tokennamespace)); } protected string GetSHA1String(string phrase) { SHA1CryptoServiceProvider sha1Hasher = new SHA1CryptoServiceProvider(); byte[] hashedDataBytes = sha1Hasher.ComputeHash(Encoding.UTF8.GetBytes(phrase)); return Convert.ToBase64String(hashedDataBytes); } } Realistically only the CustomTokenSerializer has any significant code in. The code there deals with actually serializing the custom credentials using low level XML semantics by writing output into an XML writer. I can't take credit for this code - most of the code comes from the MSDN forum post mentioned earlier - I made a few adjustments to simplify the nonce generation and also added some notes to allow for PasswordDigest generation. Per spec the nonce is nothing more than a unique value that's supposed to be 'random'. I'm thinking that this value can be any string that's unique and a GUID on its own probably would have sufficed. Comments on other posts that GUIDs can be potentially guessed are highly exaggerated to say the least IMHO. To satisfy even that aspect though I added the SHA1 encryption and binary decoding to give a more random value that would be impossible to 'guess'. The original example from the forum post used another level of encoding and decoding to string in between - but that really didn't accomplish anything but extra overhead. The header output generated from this looks like this:<s:Header> <o:Security s:mustUnderstand="1" xmlns:o="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd"> <o:UsernameToken u:Id="uuid-f43d8b0d-0ebb-482e-998d-f544401a3c91-1" xmlns:u="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd"> <o:Username>TheUsername</o:Username> <o:Password Type="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-profile-1.0#PasswordText">ThePassword</o:Password> <o:Nonce EncodingType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0#Base64Binary" >PjVE24TC6HtdAnsf3U9c5WMsECY=</o:Nonce> <u:Created>2012-11-23T07:10:04.670Z</u:Created> </o:UsernameToken> </o:Security> </s:Header> which is exactly as it should be. Password Digest? In my case the password is passed in plain text over an SSL connection, so there's no digest required so I was done with the code above. Since I don't have a service handy that requires a password digest,  I had no way of testing the code for the digest implementation, but here is how this is likely to work. If you need to pass a digest encoded password things are a little bit trickier. The password type namespace needs to change to: http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-profile-1.0#Digest and then the password value needs to be encoded. The format for password digest encoding is this: Base64(SHA-1(Nonce + Created + Password)) and it can be handled in the code above with this code (that's commented in the snippet above): string password = GetSHA1String(nonce + createdStr + userToken.Password); The entire WriteTokenCore method for digest code looks like this:protected override void WriteTokenCore(System.Xml.XmlWriter writer, System.IdentityModel.Tokens.SecurityToken token) { UserNameSecurityToken userToken = token as UserNameSecurityToken; string tokennamespace = "o"; DateTime created = DateTime.Now; string createdStr = created.ToString("yyyy-MM-ddThh:mm:ss.fffZ"); // unique Nonce value - encode with SHA-1 for 'randomness' // in theory the nonce could just be the GUID by itself string phrase = Guid.NewGuid().ToString(); var nonce = GetSHA1String(phrase); string password = GetSHA1String(nonce + createdStr + userToken.Password); writer.WriteRaw(string.Format( "<{0}:UsernameToken u:Id=\"" + token.Id + "\" xmlns:u=\"http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd\">" + "<{0}:Username>" + userToken.UserName + "</{0}:Username>" + "<{0}:Password Type=\"http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-profile-1.0#Digest\">" + password + "</{0}:Password>" + "<{0}:Nonce EncodingType=\"http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0#Base64Binary\">" + nonce + "</{0}:Nonce>" + "<u:Created>" + createdStr + "</u:Created></{0}:UsernameToken>", tokennamespace)); } I had no service to connect to to try out Digest auth - if you end up needing it and get it to work please drop a comment… How to use the custom Credentials The easiest way to use the custom credentials is to create the client in code. Here's a factory method I use to create an instance of my service client:  public static RealTimeOnlineClient CreateRealTimeOnlineProxy(string url, string username, string password) { if (string.IsNullOrEmpty(url)) url = "https://notrealurl.com:443/cows/services/RealTimeOnline"; CustomBinding binding = new CustomBinding(); var security = TransportSecurityBindingElement.CreateUserNameOverTransportBindingElement(); security.IncludeTimestamp = false; security.DefaultAlgorithmSuite = SecurityAlgorithmSuite.Basic256; security.MessageSecurityVersion = MessageSecurityVersion.WSSecurity10WSTrustFebruary2005WSSecureConversationFebruary2005WSSecurityPolicy11BasicSecurityProfile10; var encoding = new TextMessageEncodingBindingElement(); encoding.MessageVersion = MessageVersion.Soap11; var transport = new HttpsTransportBindingElement(); transport.MaxReceivedMessageSize = 20000000; // 20 megs binding.Elements.Add(security); binding.Elements.Add(encoding); binding.Elements.Add(transport); RealTimeOnlineClient client = new RealTimeOnlineClient(binding, new EndpointAddress(url)); // to use full client credential with Nonce uncomment this code: // it looks like this might not be required - the service seems to work without it client.ChannelFactory.Endpoint.Behaviors.Remove<System.ServiceModel.Description.ClientCredentials>(); client.ChannelFactory.Endpoint.Behaviors.Add(new CustomCredentials()); client.ClientCredentials.UserName.UserName = username; client.ClientCredentials.UserName.Password = password; return client; } This returns a service client that's ready to call other service methods. The key item in this code is the ChannelFactory endpoint behavior modification that that first removes the original ClientCredentials and then adds the new one. The ClientCredentials property on the client is read only and this is the way it has to be added.   Summary It's a bummer that WCF doesn't suport WSE Security authentication with nonce values out of the box. From reading the comments in posts/articles while I was trying to find a solution, I found that this feature was omitted by design as this protocol is considered unsecure. While I agree that plain text passwords are rarely a good idea even if they go over secured SSL connection as WSE Security does, there are unfortunately quite a few services (mosly Java services I suspect) that use this protocol. I've run into this twice now and trying to find a solution online I can see that this is not an isolated problem - many others seem to have struggled with this. It seems there are about a dozen questions about this on StackOverflow all with varying incomplete answers. Hopefully this post provides a little more coherent content in one place. Again I marvel at WCF and its breadth of support for protocol features it has in a single tool. And even when it can't handle something there are ways to get it working via extensibility. But at the same time I marvel at how freaking difficult it is to arrive at these solutions. I mean there's no way I could have ever figured this out on my own. It takes somebody working on the WCF team or at least being very, very intricately involved in the innards of WCF to figure out the interconnection of the various objects to do this from scratch. Luckily this is an older problem that has been discussed extensively online and I was able to cobble together a solution from the online content. I'm glad it worked out that way, but it feels dirty and incomplete in that there's a whole learning path that was omitted to get here… Man am I glad I'm not dealing with SOAP services much anymore. REST service security - even when using some sort of federation is a piece of cake by comparison :-) I'm sure once standards bodies gets involved we'll be right back in security standard hell…© Rick Strahl, West Wind Technologies, 2005-2012Posted in WCF  Web Services   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • A Taxonomy of Numerical Methods v1

    - by JoshReuben
    Numerical Analysis – When, What, (but not how) Once you understand the Math & know C++, Numerical Methods are basically blocks of iterative & conditional math code. I found the real trick was seeing the forest for the trees – knowing which method to use for which situation. Its pretty easy to get lost in the details – so I’ve tried to organize these methods in a way that I can quickly look this up. I’ve included links to detailed explanations and to C++ code examples. I’ve tried to classify Numerical methods in the following broad categories: Solving Systems of Linear Equations Solving Non-Linear Equations Iteratively Interpolation Curve Fitting Optimization Numerical Differentiation & Integration Solving ODEs Boundary Problems Solving EigenValue problems Enjoy – I did ! Solving Systems of Linear Equations Overview Solve sets of algebraic equations with x unknowns The set is commonly in matrix form Gauss-Jordan Elimination http://en.wikipedia.org/wiki/Gauss%E2%80%93Jordan_elimination C++: http://www.codekeep.net/snippets/623f1923-e03c-4636-8c92-c9dc7aa0d3c0.aspx Produces solution of the equations & the coefficient matrix Efficient, stable 2 steps: · Forward Elimination – matrix decomposition: reduce set to triangular form (0s below the diagonal) or row echelon form. If degenerate, then there is no solution · Backward Elimination –write the original matrix as the product of ints inverse matrix & its reduced row-echelon matrix à reduce set to row canonical form & use back-substitution to find the solution to the set Elementary ops for matrix decomposition: · Row multiplication · Row switching · Add multiples of rows to other rows Use pivoting to ensure rows are ordered for achieving triangular form LU Decomposition http://en.wikipedia.org/wiki/LU_decomposition C++: http://ganeshtiwaridotcomdotnp.blogspot.co.il/2009/12/c-c-code-lu-decomposition-for-solving.html Represent the matrix as a product of lower & upper triangular matrices A modified version of GJ Elimination Advantage – can easily apply forward & backward elimination to solve triangular matrices Techniques: · Doolittle Method – sets the L matrix diagonal to unity · Crout Method - sets the U matrix diagonal to unity Note: both the L & U matrices share the same unity diagonal & can be stored compactly in the same matrix Gauss-Seidel Iteration http://en.wikipedia.org/wiki/Gauss%E2%80%93Seidel_method C++: http://www.nr.com/forum/showthread.php?t=722 Transform the linear set of equations into a single equation & then use numerical integration (as integration formulas have Sums, it is implemented iteratively). an optimization of Gauss-Jacobi: 1.5 times faster, requires 0.25 iterations to achieve the same tolerance Solving Non-Linear Equations Iteratively find roots of polynomials – there may be 0, 1 or n solutions for an n order polynomial use iterative techniques Iterative methods · used when there are no known analytical techniques · Requires set functions to be continuous & differentiable · Requires an initial seed value – choice is critical to convergence à conduct multiple runs with different starting points & then select best result · Systematic - iterate until diminishing returns, tolerance or max iteration conditions are met · bracketing techniques will always yield convergent solutions, non-bracketing methods may fail to converge Incremental method if a nonlinear function has opposite signs at 2 ends of a small interval x1 & x2, then there is likely to be a solution in their interval – solutions are detected by evaluating a function over interval steps, for a change in sign, adjusting the step size dynamically. Limitations – can miss closely spaced solutions in large intervals, cannot detect degenerate (coinciding) solutions, limited to functions that cross the x-axis, gives false positives for singularities Fixed point method http://en.wikipedia.org/wiki/Fixed-point_iteration C++: http://books.google.co.il/books?id=weYj75E_t6MC&pg=PA79&lpg=PA79&dq=fixed+point+method++c%2B%2B&source=bl&ots=LQ-5P_taoC&sig=lENUUIYBK53tZtTwNfHLy5PEWDk&hl=en&sa=X&ei=wezDUPW1J5DptQaMsIHQCw&redir_esc=y#v=onepage&q=fixed%20point%20method%20%20c%2B%2B&f=false Algebraically rearrange a solution to isolate a variable then apply incremental method Bisection method http://en.wikipedia.org/wiki/Bisection_method C++: http://numericalcomputing.wordpress.com/category/algorithms/ Bracketed - Select an initial interval, keep bisecting it ad midpoint into sub-intervals and then apply incremental method on smaller & smaller intervals – zoom in Adv: unaffected by function gradient à reliable Disadv: slow convergence False Position Method http://en.wikipedia.org/wiki/False_position_method C++: http://www.dreamincode.net/forums/topic/126100-bisection-and-false-position-methods/ Bracketed - Select an initial interval , & use the relative value of function at interval end points to select next sub-intervals (estimate how far between the end points the solution might be & subdivide based on this) Newton-Raphson method http://en.wikipedia.org/wiki/Newton's_method C++: http://www-users.cselabs.umn.edu/classes/Summer-2012/csci1113/index.php?page=./newt3 Also known as Newton's method Convenient, efficient Not bracketed – only a single initial guess is required to start iteration – requires an analytical expression for the first derivative of the function as input. Evaluates the function & its derivative at each step. Can be extended to the Newton MutiRoot method for solving multiple roots Can be easily applied to an of n-coupled set of non-linear equations – conduct a Taylor Series expansion of a function, dropping terms of order n, rewrite as a Jacobian matrix of PDs & convert to simultaneous linear equations !!! Secant Method http://en.wikipedia.org/wiki/Secant_method C++: http://forum.vcoderz.com/showthread.php?p=205230 Unlike N-R, can estimate first derivative from an initial interval (does not require root to be bracketed) instead of inputting it Since derivative is approximated, may converge slower. Is fast in practice as it does not have to evaluate the derivative at each step. Similar implementation to False Positive method Birge-Vieta Method http://mat.iitm.ac.in/home/sryedida/public_html/caimna/transcendental/polynomial%20methods/bv%20method.html C++: http://books.google.co.il/books?id=cL1boM2uyQwC&pg=SA3-PA51&lpg=SA3-PA51&dq=Birge-Vieta+Method+c%2B%2B&source=bl&ots=QZmnDTK3rC&sig=BPNcHHbpR_DKVoZXrLi4nVXD-gg&hl=en&sa=X&ei=R-_DUK2iNIjzsgbE5ID4Dg&redir_esc=y#v=onepage&q=Birge-Vieta%20Method%20c%2B%2B&f=false combines Horner's method of polynomial evaluation (transforming into lesser degree polynomials that are more computationally efficient to process) with Newton-Raphson to provide a computational speed-up Interpolation Overview Construct new data points for as close as possible fit within range of a discrete set of known points (that were obtained via sampling, experimentation) Use Taylor Series Expansion of a function f(x) around a specific value for x Linear Interpolation http://en.wikipedia.org/wiki/Linear_interpolation C++: http://www.hamaluik.com/?p=289 Straight line between 2 points à concatenate interpolants between each pair of data points Bilinear Interpolation http://en.wikipedia.org/wiki/Bilinear_interpolation C++: http://supercomputingblog.com/graphics/coding-bilinear-interpolation/2/ Extension of the linear function for interpolating functions of 2 variables – perform linear interpolation first in 1 direction, then in another. Used in image processing – e.g. texture mapping filter. Uses 4 vertices to interpolate a value within a unit cell. Lagrange Interpolation http://en.wikipedia.org/wiki/Lagrange_polynomial C++: http://www.codecogs.com/code/maths/approximation/interpolation/lagrange.php For polynomials Requires recomputation for all terms for each distinct x value – can only be applied for small number of nodes Numerically unstable Barycentric Interpolation http://epubs.siam.org/doi/pdf/10.1137/S0036144502417715 C++: http://www.gamedev.net/topic/621445-barycentric-coordinates-c-code-check/ Rearrange the terms in the equation of the Legrange interpolation by defining weight functions that are independent of the interpolated value of x Newton Divided Difference Interpolation http://en.wikipedia.org/wiki/Newton_polynomial C++: http://jee-appy.blogspot.co.il/2011/12/newton-divided-difference-interpolation.html Hermite Divided Differences: Interpolation polynomial approximation for a given set of data points in the NR form - divided differences are used to approximately calculate the various differences. For a given set of 3 data points , fit a quadratic interpolant through the data Bracketed functions allow Newton divided differences to be calculated recursively Difference table Cubic Spline Interpolation http://en.wikipedia.org/wiki/Spline_interpolation C++: https://www.marcusbannerman.co.uk/index.php/home/latestarticles/42-articles/96-cubic-spline-class.html Spline is a piecewise polynomial Provides smoothness – for interpolations with significantly varying data Use weighted coefficients to bend the function to be smooth & its 1st & 2nd derivatives are continuous through the edge points in the interval Curve Fitting A generalization of interpolating whereby given data points may contain noise à the curve does not necessarily pass through all the points Least Squares Fit http://en.wikipedia.org/wiki/Least_squares C++: http://www.ccas.ru/mmes/educat/lab04k/02/least-squares.c Residual – difference between observed value & expected value Model function is often chosen as a linear combination of the specified functions Determines: A) The model instance in which the sum of squared residuals has the least value B) param values for which model best fits data Straight Line Fit Linear correlation between independent variable and dependent variable Linear Regression http://en.wikipedia.org/wiki/Linear_regression C++: http://www.oocities.org/david_swaim/cpp/linregc.htm Special case of statistically exact extrapolation Leverage least squares Given a basis function, the sum of the residuals is determined and the corresponding gradient equation is expressed as a set of normal linear equations in matrix form that can be solved (e.g. using LU Decomposition) Can be weighted - Drop the assumption that all errors have the same significance –-> confidence of accuracy is different for each data point. Fit the function closer to points with higher weights Polynomial Fit - use a polynomial basis function Moving Average http://en.wikipedia.org/wiki/Moving_average C++: http://www.codeproject.com/Articles/17860/A-Simple-Moving-Average-Algorithm Used for smoothing (cancel fluctuations to highlight longer-term trends & cycles), time series data analysis, signal processing filters Replace each data point with average of neighbors. Can be simple (SMA), weighted (WMA), exponential (EMA). Lags behind latest data points – extra weight can be given to more recent data points. Weights can decrease arithmetically or exponentially according to distance from point. Parameters: smoothing factor, period, weight basis Optimization Overview Given function with multiple variables, find Min (or max by minimizing –f(x)) Iterative approach Efficient, but not necessarily reliable Conditions: noisy data, constraints, non-linear models Detection via sign of first derivative - Derivative of saddle points will be 0 Local minima Bisection method Similar method for finding a root for a non-linear equation Start with an interval that contains a minimum Golden Search method http://en.wikipedia.org/wiki/Golden_section_search C++: http://www.codecogs.com/code/maths/optimization/golden.php Bisect intervals according to golden ratio 0.618.. Achieves reduction by evaluating a single function instead of 2 Newton-Raphson Method Brent method http://en.wikipedia.org/wiki/Brent's_method C++: http://people.sc.fsu.edu/~jburkardt/cpp_src/brent/brent.cpp Based on quadratic or parabolic interpolation – if the function is smooth & parabolic near to the minimum, then a parabola fitted through any 3 points should approximate the minima – fails when the 3 points are collinear , in which case the denominator is 0 Simplex Method http://en.wikipedia.org/wiki/Simplex_algorithm C++: http://www.codeguru.com/cpp/article.php/c17505/Simplex-Optimization-Algorithm-and-Implemetation-in-C-Programming.htm Find the global minima of any multi-variable function Direct search – no derivatives required At each step it maintains a non-degenerative simplex – a convex hull of n+1 vertices. Obtains the minimum for a function with n variables by evaluating the function at n-1 points, iteratively replacing the point of worst result with the point of best result, shrinking the multidimensional simplex around the best point. Point replacement involves expanding & contracting the simplex near the worst value point to determine a better replacement point Oscillation can be avoided by choosing the 2nd worst result Restart if it gets stuck Parameters: contraction & expansion factors Simulated Annealing http://en.wikipedia.org/wiki/Simulated_annealing C++: http://code.google.com/p/cppsimulatedannealing/ Analogy to heating & cooling metal to strengthen its structure Stochastic method – apply random permutation search for global minima - Avoid entrapment in local minima via hill climbing Heating schedule - Annealing schedule params: temperature, iterations at each temp, temperature delta Cooling schedule – can be linear, step-wise or exponential Differential Evolution http://en.wikipedia.org/wiki/Differential_evolution C++: http://www.amichel.com/de/doc/html/ More advanced stochastic methods analogous to biological processes: Genetic algorithms, evolution strategies Parallel direct search method against multiple discrete or continuous variables Initial population of variable vectors chosen randomly – if weighted difference vector of 2 vectors yields a lower objective function value then it replaces the comparison vector Many params: #parents, #variables, step size, crossover constant etc Convergence is slow – many more function evaluations than simulated annealing Numerical Differentiation Overview 2 approaches to finite difference methods: · A) approximate function via polynomial interpolation then differentiate · B) Taylor series approximation – additionally provides error estimate Finite Difference methods http://en.wikipedia.org/wiki/Finite_difference_method C++: http://www.wpi.edu/Pubs/ETD/Available/etd-051807-164436/unrestricted/EAMPADU.pdf Find differences between high order derivative values - Approximate differential equations by finite differences at evenly spaced data points Based on forward & backward Taylor series expansion of f(x) about x plus or minus multiples of delta h. Forward / backward difference - the sums of the series contains even derivatives and the difference of the series contains odd derivatives – coupled equations that can be solved. Provide an approximation of the derivative within a O(h^2) accuracy There is also central difference & extended central difference which has a O(h^4) accuracy Richardson Extrapolation http://en.wikipedia.org/wiki/Richardson_extrapolation C++: http://mathscoding.blogspot.co.il/2012/02/introduction-richardson-extrapolation.html A sequence acceleration method applied to finite differences Fast convergence, high accuracy O(h^4) Derivatives via Interpolation Cannot apply Finite Difference method to discrete data points at uneven intervals – so need to approximate the derivative of f(x) using the derivative of the interpolant via 3 point Lagrange Interpolation Note: the higher the order of the derivative, the lower the approximation precision Numerical Integration Estimate finite & infinite integrals of functions More accurate procedure than numerical differentiation Use when it is not possible to obtain an integral of a function analytically or when the function is not given, only the data points are Newton Cotes Methods http://en.wikipedia.org/wiki/Newton%E2%80%93Cotes_formulas C++: http://www.siafoo.net/snippet/324 For equally spaced data points Computationally easy – based on local interpolation of n rectangular strip areas that is piecewise fitted to a polynomial to get the sum total area Evaluate the integrand at n+1 evenly spaced points – approximate definite integral by Sum Weights are derived from Lagrange Basis polynomials Leverage Trapezoidal Rule for default 2nd formulas, Simpson 1/3 Rule for substituting 3 point formulas, Simpson 3/8 Rule for 4 point formulas. For 4 point formulas use Bodes Rule. Higher orders obtain more accurate results Trapezoidal Rule uses simple area, Simpsons Rule replaces the integrand f(x) with a quadratic polynomial p(x) that uses the same values as f(x) for its end points, but adds a midpoint Romberg Integration http://en.wikipedia.org/wiki/Romberg's_method C++: http://code.google.com/p/romberg-integration/downloads/detail?name=romberg.cpp&can=2&q= Combines trapezoidal rule with Richardson Extrapolation Evaluates the integrand at equally spaced points The integrand must have continuous derivatives Each R(n,m) extrapolation uses a higher order integrand polynomial replacement rule (zeroth starts with trapezoidal) à a lower triangular matrix set of equation coefficients where the bottom right term has the most accurate approximation. The process continues until the difference between 2 successive diagonal terms becomes sufficiently small. Gaussian Quadrature http://en.wikipedia.org/wiki/Gaussian_quadrature C++: http://www.alglib.net/integration/gaussianquadratures.php Data points are chosen to yield best possible accuracy – requires fewer evaluations Ability to handle singularities, functions that are difficult to evaluate The integrand can include a weighting function determined by a set of orthogonal polynomials. Points & weights are selected so that the integrand yields the exact integral if f(x) is a polynomial of degree <= 2n+1 Techniques (basically different weighting functions): · Gauss-Legendre Integration w(x)=1 · Gauss-Laguerre Integration w(x)=e^-x · Gauss-Hermite Integration w(x)=e^-x^2 · Gauss-Chebyshev Integration w(x)= 1 / Sqrt(1-x^2) Solving ODEs Use when high order differential equations cannot be solved analytically Evaluated under boundary conditions RK for systems – a high order differential equation can always be transformed into a coupled first order system of equations Euler method http://en.wikipedia.org/wiki/Euler_method C++: http://rosettacode.org/wiki/Euler_method First order Runge–Kutta method. Simple recursive method – given an initial value, calculate derivative deltas. Unstable & not very accurate (O(h) error) – not used in practice A first-order method - the local error (truncation error per step) is proportional to the square of the step size, and the global error (error at a given time) is proportional to the step size In evolving solution between data points xn & xn+1, only evaluates derivatives at beginning of interval xn à asymmetric at boundaries Higher order Runge Kutta http://en.wikipedia.org/wiki/Runge%E2%80%93Kutta_methods C++: http://www.dreamincode.net/code/snippet1441.htm 2nd & 4th order RK - Introduces parameterized midpoints for more symmetric solutions à accuracy at higher computational cost Adaptive RK – RK-Fehlberg – estimate the truncation at each integration step & automatically adjust the step size to keep error within prescribed limits. At each step 2 approximations are compared – if in disagreement to a specific accuracy, the step size is reduced Boundary Value Problems Where solution of differential equations are located at 2 different values of the independent variable x à more difficult, because cannot just start at point of initial value – there may not be enough starting conditions available at the end points to produce a unique solution An n-order equation will require n boundary conditions – need to determine the missing n-1 conditions which cause the given conditions at the other boundary to be satisfied Shooting Method http://en.wikipedia.org/wiki/Shooting_method C++: http://ganeshtiwaridotcomdotnp.blogspot.co.il/2009/12/c-c-code-shooting-method-for-solving.html Iteratively guess the missing values for one end & integrate, then inspect the discrepancy with the boundary values of the other end to adjust the estimate Given the starting boundary values u1 & u2 which contain the root u, solve u given the false position method (solving the differential equation as an initial value problem via 4th order RK), then use u to solve the differential equations. Finite Difference Method For linear & non-linear systems Higher order derivatives require more computational steps – some combinations for boundary conditions may not work though Improve the accuracy by increasing the number of mesh points Solving EigenValue Problems An eigenvalue can substitute a matrix when doing matrix multiplication à convert matrix multiplication into a polynomial EigenValue For a given set of equations in matrix form, determine what are the solution eigenvalue & eigenvectors Similar Matrices - have same eigenvalues. Use orthogonal similarity transforms to reduce a matrix to diagonal form from which eigenvalue(s) & eigenvectors can be computed iteratively Jacobi method http://en.wikipedia.org/wiki/Jacobi_method C++: http://people.sc.fsu.edu/~jburkardt/classes/acs2_2008/openmp/jacobi/jacobi.html Robust but Computationally intense – use for small matrices < 10x10 Power Iteration http://en.wikipedia.org/wiki/Power_iteration For any given real symmetric matrix, generate the largest single eigenvalue & its eigenvectors Simplest method – does not compute matrix decomposition à suitable for large, sparse matrices Inverse Iteration Variation of power iteration method – generates the smallest eigenvalue from the inverse matrix Rayleigh Method http://en.wikipedia.org/wiki/Rayleigh's_method_of_dimensional_analysis Variation of power iteration method Rayleigh Quotient Method Variation of inverse iteration method Matrix Tri-diagonalization Method Use householder algorithm to reduce an NxN symmetric matrix to a tridiagonal real symmetric matrix vua N-2 orthogonal transforms     Whats Next Outside of Numerical Methods there are lots of different types of algorithms that I’ve learned over the decades: Data Mining – (I covered this briefly in a previous post: http://geekswithblogs.net/JoshReuben/archive/2007/12/31/ssas-dm-algorithms.aspx ) Search & Sort Routing Problem Solving Logical Theorem Proving Planning Probabilistic Reasoning Machine Learning Solvers (eg MIP) Bioinformatics (Sequence Alignment, Protein Folding) Quant Finance (I read Wilmott’s books – interesting) Sooner or later, I’ll cover the above topics as well.

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  • Toorcon 15 (2013)

    - by danx
    The Toorcon gang (senior staff): h1kari (founder), nfiltr8, and Geo Introduction to Toorcon 15 (2013) A Tale of One Software Bypass of MS Windows 8 Secure Boot Breaching SSL, One Byte at a Time Running at 99%: Surviving an Application DoS Security Response in the Age of Mass Customized Attacks x86 Rewriting: Defeating RoP and other Shinanighans Clowntown Express: interesting bugs and running a bug bounty program Active Fingerprinting of Encrypted VPNs Making Attacks Go Backwards Mask Your Checksums—The Gorry Details Adventures with weird machines thirty years after "Reflections on Trusting Trust" Introduction to Toorcon 15 (2013) Toorcon 15 is the 15th annual security conference held in San Diego. I've attended about a third of them and blogged about previous conferences I attended here starting in 2003. As always, I've only summarized the talks I attended and interested me enough to write about them. Be aware that I may have misrepresented the speaker's remarks and that they are not my remarks or opinion, or those of my employer, so don't quote me or them. Those seeking further details may contact the speakers directly or use The Google. For some talks, I have a URL for further information. A Tale of One Software Bypass of MS Windows 8 Secure Boot Andrew Furtak and Oleksandr Bazhaniuk Yuri Bulygin, Oleksandr ("Alex") Bazhaniuk, and (not present) Andrew Furtak Yuri and Alex talked about UEFI and Bootkits and bypassing MS Windows 8 Secure Boot, with vendor recommendations. They previously gave this talk at the BlackHat 2013 conference. MS Windows 8 Secure Boot Overview UEFI (Unified Extensible Firmware Interface) is interface between hardware and OS. UEFI is processor and architecture independent. Malware can replace bootloader (bootx64.efi, bootmgfw.efi). Once replaced can modify kernel. Trivial to replace bootloader. Today many legacy bootkits—UEFI replaces them most of them. MS Windows 8 Secure Boot verifies everything you load, either through signatures or hashes. UEFI firmware relies on secure update (with signed update). You would think Secure Boot would rely on ROM (such as used for phones0, but you can't do that for PCs—PCs use writable memory with signatures DXE core verifies the UEFI boat loader(s) OS Loader (winload.efi, winresume.efi) verifies the OS kernel A chain of trust is established with a root key (Platform Key, PK), which is a cert belonging to the platform vendor. Key Exchange Keys (KEKs) verify an "authorized" database (db), and "forbidden" database (dbx). X.509 certs with SHA-1/SHA-256 hashes. Keys are stored in non-volatile (NV) flash-based NVRAM. Boot Services (BS) allow adding/deleting keys (can't be accessed once OS starts—which uses Run-Time (RT)). Root cert uses RSA-2048 public keys and PKCS#7 format signatures. SecureBoot — enable disable image signature checks SetupMode — update keys, self-signed keys, and secure boot variables CustomMode — allows updating keys Secure Boot policy settings are: always execute, never execute, allow execute on security violation, defer execute on security violation, deny execute on security violation, query user on security violation Attacking MS Windows 8 Secure Boot Secure Boot does NOT protect from physical access. Can disable from console. Each BIOS vendor implements Secure Boot differently. There are several platform and BIOS vendors. It becomes a "zoo" of implementations—which can be taken advantage of. Secure Boot is secure only when all vendors implement it correctly. Allow only UEFI firmware signed updates protect UEFI firmware from direct modification in flash memory protect FW update components program SPI controller securely protect secure boot policy settings in nvram protect runtime api disable compatibility support module which allows unsigned legacy Can corrupt the Platform Key (PK) EFI root certificate variable in SPI flash. If PK is not found, FW enters setup mode wich secure boot turned off. Can also exploit TPM in a similar manner. One is not supposed to be able to directly modify the PK in SPI flash from the OS though. But they found a bug that they can exploit from User Mode (undisclosed) and demoed the exploit. It loaded and ran their own bootkit. The exploit requires a reboot. Multiple vendors are vulnerable. They will disclose this exploit to vendors in the future. Recommendations: allow only signed updates protect UEFI fw in ROM protect EFI variable store in ROM Breaching SSL, One Byte at a Time Yoel Gluck and Angelo Prado Angelo Prado and Yoel Gluck, Salesforce.com CRIME is software that performs a "compression oracle attack." This is possible because the SSL protocol doesn't hide length, and because SSL compresses the header. CRIME requests with every possible character and measures the ciphertext length. Look for the plaintext which compresses the most and looks for the cookie one byte-at-a-time. SSL Compression uses LZ77 to reduce redundancy. Huffman coding replaces common byte sequences with shorter codes. US CERT thinks the SSL compression problem is fixed, but it isn't. They convinced CERT that it wasn't fixed and they issued a CVE. BREACH, breachattrack.com BREACH exploits the SSL response body (Accept-Encoding response, Content-Encoding). It takes advantage of the fact that the response is not compressed. BREACH uses gzip and needs fairly "stable" pages that are static for ~30 seconds. It needs attacker-supplied content (say from a web form or added to a URL parameter). BREACH listens to a session's requests and responses, then inserts extra requests and responses. Eventually, BREACH guesses a session's secret key. Can use compression to guess contents one byte at-a-time. For example, "Supersecret SupersecreX" (a wrong guess) compresses 10 bytes, and "Supersecret Supersecret" (a correct guess) compresses 11 bytes, so it can find each character by guessing every character. To start the guess, BREACH needs at least three known initial characters in the response sequence. Compression length then "leaks" information. Some roadblocks include no winners (all guesses wrong) or too many winners (multiple possibilities that compress the same). The solutions include: lookahead (guess 2 or 3 characters at-a-time instead of 1 character). Expensive rollback to last known conflict check compression ratio can brute-force first 3 "bootstrap" characters, if needed (expensive) block ciphers hide exact plain text length. Solution is to align response in advance to block size Mitigations length: use variable padding secrets: dynamic CSRF tokens per request secret: change over time separate secret to input-less servlets Future work eiter understand DEFLATE/GZIP HTTPS extensions Running at 99%: Surviving an Application DoS Ryan Huber Ryan Huber, Risk I/O Ryan first discussed various ways to do a denial of service (DoS) attack against web services. One usual method is to find a slow web page and do several wgets. Or download large files. Apache is not well suited at handling a large number of connections, but one can put something in front of it Can use Apache alternatives, such as nginx How to identify malicious hosts short, sudden web requests user-agent is obvious (curl, python) same url requested repeatedly no web page referer (not normal) hidden links. hide a link and see if a bot gets it restricted access if not your geo IP (unless the website is global) missing common headers in request regular timing first seen IP at beginning of attack count requests per hosts (usually a very large number) Use of captcha can mitigate attacks, but you'll lose a lot of genuine users. Bouncer, goo.gl/c2vyEc and www.github.com/rawdigits/Bouncer Bouncer is software written by Ryan in netflow. Bouncer has a small, unobtrusive footprint and detects DoS attempts. It closes blacklisted sockets immediately (not nice about it, no proper close connection). Aggregator collects requests and controls your web proxies. Need NTP on the front end web servers for clean data for use by bouncer. Bouncer is also useful for a popularity storm ("Slashdotting") and scraper storms. Future features: gzip collection data, documentation, consumer library, multitask, logging destroyed connections. Takeaways: DoS mitigation is easier with a complete picture Bouncer designed to make it easier to detect and defend DoS—not a complete cure Security Response in the Age of Mass Customized Attacks Peleus Uhley and Karthik Raman Peleus Uhley and Karthik Raman, Adobe ASSET, blogs.adobe.com/asset/ Peleus and Karthik talked about response to mass-customized exploits. Attackers behave much like a business. "Mass customization" refers to concept discussed in the book Future Perfect by Stan Davis of Harvard Business School. Mass customization is differentiating a product for an individual customer, but at a mass production price. For example, the same individual with a debit card receives basically the same customized ATM experience around the world. Or designing your own PC from commodity parts. Exploit kits are another example of mass customization. The kits support multiple browsers and plugins, allows new modules. Exploit kits are cheap and customizable. Organized gangs use exploit kits. A group at Berkeley looked at 77,000 malicious websites (Grier et al., "Manufacturing Compromise: The Emergence of Exploit-as-a-Service", 2012). They found 10,000 distinct binaries among them, but derived from only a dozen or so exploit kits. Characteristics of Mass Malware: potent, resilient, relatively low cost Technical characteristics: multiple OS, multipe payloads, multiple scenarios, multiple languages, obfuscation Response time for 0-day exploits has gone down from ~40 days 5 years ago to about ~10 days now. So the drive with malware is towards mass customized exploits, to avoid detection There's plenty of evicence that exploit development has Project Manager bureaucracy. They infer from the malware edicts to: support all versions of reader support all versions of windows support all versions of flash support all browsers write large complex, difficult to main code (8750 lines of JavaScript for example Exploits have "loose coupling" of multipe versions of software (adobe), OS, and browser. This allows specific attacks against specific versions of multiple pieces of software. Also allows exploits of more obscure software/OS/browsers and obscure versions. Gave examples of exploits that exploited 2, 3, 6, or 14 separate bugs. However, these complete exploits are more likely to be buggy or fragile in themselves and easier to defeat. Future research includes normalizing malware and Javascript. Conclusion: The coming trend is that mass-malware with mass zero-day attacks will result in mass customization of attacks. x86 Rewriting: Defeating RoP and other Shinanighans Richard Wartell Richard Wartell The attack vector we are addressing here is: First some malware causes a buffer overflow. The malware has no program access, but input access and buffer overflow code onto stack Later the stack became non-executable. The workaround malware used was to write a bogus return address to the stack jumping to malware Later came ASLR (Address Space Layout Randomization) to randomize memory layout and make addresses non-deterministic. The workaround malware used was to jump t existing code segments in the program that can be used in bad ways "RoP" is Return-oriented Programming attacks. RoP attacks use your own code and write return address on stack to (existing) expoitable code found in program ("gadgets"). Pinkie Pie was paid $60K last year for a RoP attack. One solution is using anti-RoP compilers that compile source code with NO return instructions. ASLR does not randomize address space, just "gadgets". IPR/ILR ("Instruction Location Randomization") randomizes each instruction with a virtual machine. Richard's goal was to randomize a binary with no source code access. He created "STIR" (Self-Transofrming Instruction Relocation). STIR disassembles binary and operates on "basic blocks" of code. The STIR disassembler is conservative in what to disassemble. Each basic block is moved to a random location in memory. Next, STIR writes new code sections with copies of "basic blocks" of code in randomized locations. The old code is copied and rewritten with jumps to new code. the original code sections in the file is marked non-executible. STIR has better entropy than ASLR in location of code. Makes brute force attacks much harder. STIR runs on MS Windows (PEM) and Linux (ELF). It eliminated 99.96% or more "gadgets" (i.e., moved the address). Overhead usually 5-10% on MS Windows, about 1.5-4% on Linux (but some code actually runs faster!). The unique thing about STIR is it requires no source access and the modified binary fully works! Current work is to rewrite code to enforce security policies. For example, don't create a *.{exe,msi,bat} file. Or don't connect to the network after reading from the disk. Clowntown Express: interesting bugs and running a bug bounty program Collin Greene Collin Greene, Facebook Collin talked about Facebook's bug bounty program. Background at FB: FB has good security frameworks, such as security teams, external audits, and cc'ing on diffs. But there's lots of "deep, dark, forgotten" parts of legacy FB code. Collin gave several examples of bountied bugs. Some bounty submissions were on software purchased from a third-party (but bounty claimers don't know and don't care). We use security questions, as does everyone else, but they are basically insecure (often easily discoverable). Collin didn't expect many bugs from the bounty program, but they ended getting 20+ good bugs in first 24 hours and good submissions continue to come in. Bug bounties bring people in with different perspectives, and are paid only for success. Bug bounty is a better use of a fixed amount of time and money versus just code review or static code analysis. The Bounty program started July 2011 and paid out $1.5 million to date. 14% of the submissions have been high priority problems that needed to be fixed immediately. The best bugs come from a small % of submitters (as with everything else)—the top paid submitters are paid 6 figures a year. Spammers like to backstab competitors. The youngest sumitter was 13. Some submitters have been hired. Bug bounties also allows to see bugs that were missed by tools or reviews, allowing improvement in the process. Bug bounties might not work for traditional software companies where the product has release cycle or is not on Internet. Active Fingerprinting of Encrypted VPNs Anna Shubina Anna Shubina, Dartmouth Institute for Security, Technology, and Society (I missed the start of her talk because another track went overtime. But I have the DVD of the talk, so I'll expand later) IPsec leaves fingerprints. Using netcat, one can easily visually distinguish various crypto chaining modes just from packet timing on a chart (example, DES-CBC versus AES-CBC) One can tell a lot about VPNs just from ping roundtrips (such as what router is used) Delayed packets are not informative about a network, especially if far away from the network More needed to explore about how TCP works in real life with respect to timing Making Attacks Go Backwards Fuzzynop FuzzyNop, Mandiant This talk is not about threat attribution (finding who), product solutions, politics, or sales pitches. But who are making these malware threats? It's not a single person or group—they have diverse skill levels. There's a lot of fat-fingered fumblers out there. Always look for low-hanging fruit first: "hiding" malware in the temp, recycle, or root directories creation of unnamed scheduled tasks obvious names of files and syscalls ("ClearEventLog") uncleared event logs. Clearing event log in itself, and time of clearing, is a red flag and good first clue to look for on a suspect system Reverse engineering is hard. Disassembler use takes practice and skill. A popular tool is IDA Pro, but it takes multiple interactive iterations to get a clean disassembly. Key loggers are used a lot in targeted attacks. They are typically custom code or built in a backdoor. A big tip-off is that non-printable characters need to be printed out (such as "[Ctrl]" "[RightShift]") or time stamp printf strings. Look for these in files. Presence is not proof they are used. Absence is not proof they are not used. Java exploits. Can parse jar file with idxparser.py and decomile Java file. Java typially used to target tech companies. Backdoors are the main persistence mechanism (provided externally) for malware. Also malware typically needs command and control. Application of Artificial Intelligence in Ad-Hoc Static Code Analysis John Ashaman John Ashaman, Security Innovation Initially John tried to analyze open source files with open source static analysis tools, but these showed thousands of false positives. Also tried using grep, but tis fails to find anything even mildly complex. So next John decided to write his own tool. His approach was to first generate a call graph then analyze the graph. However, the problem is that making a call graph is really hard. For example, one problem is "evil" coding techniques, such as passing function pointer. First the tool generated an Abstract Syntax Tree (AST) with the nodes created from method declarations and edges created from method use. Then the tool generated a control flow graph with the goal to find a path through the AST (a maze) from source to sink. The algorithm is to look at adjacent nodes to see if any are "scary" (a vulnerability), using heuristics for search order. The tool, called "Scat" (Static Code Analysis Tool), currently looks for C# vulnerabilities and some simple PHP. Later, he plans to add more PHP, then JSP and Java. For more information see his posts in Security Innovation blog and NRefactory on GitHub. Mask Your Checksums—The Gorry Details Eric (XlogicX) Davisson Eric (XlogicX) Davisson Sometimes in emailing or posting TCP/IP packets to analyze problems, you may want to mask the IP address. But to do this correctly, you need to mask the checksum too, or you'll leak information about the IP. Problem reports found in stackoverflow.com, sans.org, and pastebin.org are usually not masked, but a few companies do care. If only the IP is masked, the IP may be guessed from checksum (that is, it leaks data). Other parts of packet may leak more data about the IP. TCP and IP checksums both refer to the same data, so can get more bits of information out of using both checksums than just using one checksum. Also, one can usually determine the OS from the TTL field and ports in a packet header. If we get hundreds of possible results (16x each masked nibble that is unknown), one can do other things to narrow the results, such as look at packet contents for domain or geo information. With hundreds of results, can import as CSV format into a spreadsheet. Can corelate with geo data and see where each possibility is located. Eric then demoed a real email report with a masked IP packet attached. Was able to find the exact IP address, given the geo and university of the sender. Point is if you're going to mask a packet, do it right. Eric wouldn't usually bother, but do it correctly if at all, to not create a false impression of security. Adventures with weird machines thirty years after "Reflections on Trusting Trust" Sergey Bratus Sergey Bratus, Dartmouth College (and Julian Bangert and Rebecca Shapiro, not present) "Reflections on Trusting Trust" refers to Ken Thompson's classic 1984 paper. "You can't trust code that you did not totally create yourself." There's invisible links in the chain-of-trust, such as "well-installed microcode bugs" or in the compiler, and other planted bugs. Thompson showed how a compiler can introduce and propagate bugs in unmodified source. But suppose if there's no bugs and you trust the author, can you trust the code? Hell No! There's too many factors—it's Babylonian in nature. Why not? Well, Input is not well-defined/recognized (code's assumptions about "checked" input will be violated (bug/vunerabiliy). For example, HTML is recursive, but Regex checking is not recursive. Input well-formed but so complex there's no telling what it does For example, ELF file parsing is complex and has multiple ways of parsing. Input is seen differently by different pieces of program or toolchain Any Input is a program input executes on input handlers (drives state changes & transitions) only a well-defined execution model can be trusted (regex/DFA, PDA, CFG) Input handler either is a "recognizer" for the inputs as a well-defined language (see langsec.org) or it's a "virtual machine" for inputs to drive into pwn-age ELF ABI (UNIX/Linux executible file format) case study. Problems can arise from these steps (without planting bugs): compiler linker loader ld.so/rtld relocator DWARF (debugger info) exceptions The problem is you can't really automatically analyze code (it's the "halting problem" and undecidable). Only solution is to freeze code and sign it. But you can't freeze everything! Can't freeze ASLR or loading—must have tables and metadata. Any sufficiently complex input data is the same as VM byte code Example, ELF relocation entries + dynamic symbols == a Turing Complete Machine (TM). @bxsays created a Turing machine in Linux from relocation data (not code) in an ELF file. For more information, see Rebecca "bx" Shapiro's presentation from last year's Toorcon, "Programming Weird Machines with ELF Metadata" @bxsays did same thing with Mach-O bytecode Or a DWARF exception handling data .eh_frame + glibc == Turning Machine X86 MMU (IDT, GDT, TSS): used address translation to create a Turning Machine. Page handler reads and writes (on page fault) memory. Uses a page table, which can be used as Turning Machine byte code. Example on Github using this TM that will fly a glider across the screen Next Sergey talked about "Parser Differentials". That having one input format, but two parsers, will create confusion and opportunity for exploitation. For example, CSRs are parsed during creation by cert requestor and again by another parser at the CA. Another example is ELF—several parsers in OS tool chain, which are all different. Can have two different Program Headers (PHDRs) because ld.so parses multiple PHDRs. The second PHDR can completely transform the executable. This is described in paper in the first issue of International Journal of PoC. Conclusions trusting computers not only about bugs! Bugs are part of a problem, but no by far all of it complex data formats means bugs no "chain of trust" in Babylon! (that is, with parser differentials) we need to squeeze complexity out of data until data stops being "code equivalent" Further information See and langsec.org. USENIX WOOT 2013 (Workshop on Offensive Technologies) for "weird machines" papers and videos.

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  • Scrum in 5 Minutes

    - by Stephen.Walther
    The goal of this blog entry is to explain the basic concepts of Scrum in less than five minutes. You learn how Scrum can help a team of developers to successfully complete a complex software project. Product Backlog and the Product Owner Imagine that you are part of a team which needs to create a new website – for example, an e-commerce website. You have an overwhelming amount of work to do. You need to build (or possibly buy) a shopping cart, install an SSL certificate, create a product catalog, create a Facebook page, and at least a hundred other things that you have not thought of yet. According to Scrum, the first thing you should do is create a list. Place the highest priority items at the top of the list and the lower priority items lower in the list. For example, creating the shopping cart and buying the domain name might be high priority items and creating a Facebook page might be a lower priority item. In Scrum, this list is called the Product Backlog. How do you prioritize the items in the Product Backlog? Different stakeholders in the project might have different priorities. Gary, your division VP, thinks that it is crucial that the e-commerce site has a mobile app. Sally, your direct manager, thinks taking advantage of new HTML5 features is much more important. Multiple people are pulling you in different directions. According to Scrum, it is important that you always designate one person, and only one person, as the Product Owner. The Product Owner is the person who decides what items should be added to the Product Backlog and the priority of the items in the Product Backlog. The Product Owner could be the customer who is paying the bills, the project manager who is responsible for delivering the project, or a customer representative. The critical point is that the Product Owner must always be a single person and that single person has absolute authority over the Product Backlog. Sprints and the Sprint Backlog So now the developer team has a prioritized list of items and they can start work. The team starts implementing the first item in the Backlog — the shopping cart — and the team is making good progress. Unfortunately, however, half-way through the work of implementing the shopping cart, the Product Owner changes his mind. The Product Owner decides that it is much more important to create the product catalog before the shopping cart. With some frustration, the team switches their developmental efforts to focus on implementing the product catalog. However, part way through completing this work, once again the Product Owner changes his mind about the highest priority item. Getting work done when priorities are constantly shifting is frustrating for the developer team and it results in lower productivity. At the same time, however, the Product Owner needs to have absolute authority over the priority of the items which need to get done. Scrum solves this conflict with the concept of Sprints. In Scrum, a developer team works in Sprints. At the beginning of a Sprint the developers and the Product Owner agree on the items from the backlog which they will complete during the Sprint. This subset of items from the Product Backlog becomes the Sprint Backlog. During the Sprint, the Product Owner is not allowed to change the items in the Sprint Backlog. In other words, the Product Owner cannot shift priorities on the developer team during the Sprint. Different teams use Sprints of different lengths such as one month Sprints, two-week Sprints, and one week Sprints. For high-stress, time critical projects, teams typically choose shorter sprints such as one week sprints. For more mature projects, longer one month sprints might be more appropriate. A team can pick whatever Sprint length makes sense for them just as long as the team is consistent. You should pick a Sprint length and stick with it. Daily Scrum During a Sprint, the developer team needs to have meetings to coordinate their work on completing the items in the Sprint Backlog. For example, the team needs to discuss who is working on what and whether any blocking issues have been discovered. Developers hate meetings (well, sane developers hate meetings). Meetings take developers away from their work of actually implementing stuff as opposed to talking about implementing stuff. However, a developer team which never has meetings and never coordinates their work also has problems. For example, Fred might get stuck on a programming problem for days and never reach out for help even though Tom (who sits in the cubicle next to him) has already solved the very same problem. Or, both Ted and Fred might have started working on the same item from the Sprint Backlog at the same time. In Scrum, these conflicting needs – limiting meetings but enabling team coordination – are resolved with the idea of the Daily Scrum. The Daily Scrum is a meeting for coordinating the work of the developer team which happens once a day. To keep the meeting short, each developer answers only the following three questions: 1. What have you done since yesterday? 2. What do you plan to do today? 3. Any impediments in your way? During the Daily Scrum, developers are not allowed to talk about issues with their cat, do demos of their latest work, or tell heroic stories of programming problems overcome. The meeting must be kept short — typically about 15 minutes. Issues which come up during the Daily Scrum should be discussed in separate meetings which do not involve the whole developer team. Stories and Tasks Items in the Product or Sprint Backlog – such as building a shopping cart or creating a Facebook page – are often referred to as User Stories or Stories. The Stories are created by the Product Owner and should represent some business need. Unlike the Product Owner, the developer team needs to think about how a Story should be implemented. At the beginning of a Sprint, the developer team takes the Stories from the Sprint Backlog and breaks the stories into tasks. For example, the developer team might take the Create a Shopping Cart story and break it into the following tasks: · Enable users to add and remote items from shopping cart · Persist the shopping cart to database between visits · Redirect user to checkout page when Checkout button is clicked During the Daily Scrum, members of the developer team volunteer to complete the tasks required to implement the next Story in the Sprint Backlog. When a developer talks about what he did yesterday or plans to do tomorrow then the developer should be referring to a task. Stories are owned by the Product Owner and a story is all about business value. In contrast, the tasks are owned by the developer team and a task is all about implementation details. A story might take several days or weeks to complete. A task is something which a developer can complete in less than a day. Some teams get lazy about breaking stories into tasks. Neglecting to break stories into tasks can lead to “Never Ending Stories” If you don’t break a story into tasks, then you can’t know how much of a story has actually been completed because you don’t have a clear idea about the implementation steps required to complete the story. Scrumboard During the Daily Scrum, the developer team uses a Scrumboard to coordinate their work. A Scrumboard contains a list of the stories for the current Sprint, the tasks associated with each Story, and the state of each task. The developer team uses the Scrumboard so everyone on the team can see, at a glance, what everyone is working on. As a developer works on a task, the task moves from state to state and the state of the task is updated on the Scrumboard. Common task states are ToDo, In Progress, and Done. Some teams include additional task states such as Needs Review or Needs Testing. Some teams use a physical Scrumboard. In that case, you use index cards to represent the stories and the tasks and you tack the index cards onto a physical board. Using a physical Scrumboard has several disadvantages. A physical Scrumboard does not work well with a distributed team – for example, it is hard to share the same physical Scrumboard between Boston and Seattle. Also, generating reports from a physical Scrumboard is more difficult than generating reports from an online Scrumboard. Estimating Stories and Tasks Stakeholders in a project, the people investing in a project, need to have an idea of how a project is progressing and when the project will be completed. For example, if you are investing in creating an e-commerce site, you need to know when the site can be launched. It is not enough to just say that “the project will be done when it is done” because the stakeholders almost certainly have a limited budget to devote to the project. The people investing in the project cannot determine the business value of the project unless they can have an estimate of how long it will take to complete the project. Developers hate to give estimates. The reason that developers hate to give estimates is that the estimates are almost always completely made up. For example, you really don’t know how long it takes to build a shopping cart until you finish building a shopping cart, and at that point, the estimate is no longer useful. The problem is that writing code is much more like Finding a Cure for Cancer than Building a Brick Wall. Building a brick wall is very straightforward. After you learn how to add one brick to a wall, you understand everything that is involved in adding a brick to a wall. There is no additional research required and no surprises. If, on the other hand, I assembled a team of scientists and asked them to find a cure for cancer, and estimate exactly how long it will take, they would have no idea. The problem is that there are too many unknowns. I don’t know how to cure cancer, I need to do a lot of research here, so I cannot even begin to estimate how long it will take. So developers hate to provide estimates, but the Product Owner and other product stakeholders, have a legitimate need for estimates. Scrum resolves this conflict by using the idea of Story Points. Different teams use different units to represent Story Points. For example, some teams use shirt sizes such as Small, Medium, Large, and X-Large. Some teams prefer to use Coffee Cup sizes such as Tall, Short, and Grande. Finally, some teams like to use numbers from the Fibonacci series. These alternative units are converted into a Story Point value. Regardless of the type of unit which you use to represent Story Points, the goal is the same. Instead of attempting to estimate a Story in hours (which is doomed to failure), you use a much less fine-grained measure of work. A developer team is much more likely to be able to estimate that a Story is Small or X-Large than the exact number of hours required to complete the story. So you can think of Story Points as a compromise between the needs of the Product Owner and the developer team. When a Sprint starts, the developer team devotes more time to thinking about the Stories in a Sprint and the developer team breaks the Stories into Tasks. In Scrum, you estimate the work required to complete a Story by using Story Points and you estimate the work required to complete a task by using hours. The difference between Stories and Tasks is that you don’t create a task until you are just about ready to start working on a task. A task is something that you should be able to create within a day, so you have a much better chance of providing an accurate estimate of the work required to complete a task than a story. Burndown Charts In Scrum, you use Burndown charts to represent the remaining work on a project. You use Release Burndown charts to represent the overall remaining work for a project and you use Sprint Burndown charts to represent the overall remaining work for a particular Sprint. You create a Release Burndown chart by calculating the remaining number of uncompleted Story Points for the entire Product Backlog every day. The vertical axis represents Story Points and the horizontal axis represents time. A Sprint Burndown chart is similar to a Release Burndown chart, but it focuses on the remaining work for a particular Sprint. There are two different types of Sprint Burndown charts. You can either represent the remaining work in a Sprint with Story Points or with task hours (the following image, taken from Wikipedia, uses hours). When each Product Backlog Story is completed, the Release Burndown chart slopes down. When each Story or task is completed, the Sprint Burndown chart slopes down. Burndown charts typically do not always slope down over time. As new work is added to the Product Backlog, the Release Burndown chart slopes up. If new tasks are discovered during a Sprint, the Sprint Burndown chart will also slope up. The purpose of a Burndown chart is to give you a way to track team progress over time. If, halfway through a Sprint, the Sprint Burndown chart is still climbing a hill then you know that you are in trouble. Team Velocity Stakeholders in a project always want more work done faster. For example, the Product Owner for the e-commerce site wants the website to launch before tomorrow. Developers tend to be overly optimistic. Rarely do developers acknowledge the physical limitations of reality. So Project stakeholders and the developer team often collude to delude themselves about how much work can be done and how quickly. Too many software projects begin in a state of optimism and end in frustration as deadlines zoom by. In Scrum, this problem is overcome by calculating a number called the Team Velocity. The Team Velocity is a measure of the average number of Story Points which a team has completed in previous Sprints. Knowing the Team Velocity is important during the Sprint Planning meeting when the Product Owner and the developer team work together to determine the number of stories which can be completed in the next Sprint. If you know the Team Velocity then you can avoid committing to do more work than the team has been able to accomplish in the past, and your team is much more likely to complete all of the work required for the next Sprint. Scrum Master There are three roles in Scrum: the Product Owner, the developer team, and the Scrum Master. I’v e already discussed the Product Owner. The Product Owner is the one and only person who maintains the Product Backlog and prioritizes the stories. I’ve also described the role of the developer team. The members of the developer team do the work of implementing the stories by breaking the stories into tasks. The final role, which I have not discussed, is the role of the Scrum Master. The Scrum Master is responsible for ensuring that the team is following the Scrum process. For example, the Scrum Master is responsible for making sure that there is a Daily Scrum meeting and that everyone answers the standard three questions. The Scrum Master is also responsible for removing (non-technical) impediments which the team might encounter. For example, if the team cannot start work until everyone installs the latest version of Microsoft Visual Studio then the Scrum Master has the responsibility of working with management to get the latest version of Visual Studio as quickly as possible. The Scrum Master can be a member of the developer team. Furthermore, different people can take on the role of the Scrum Master over time. The Scrum Master, however, cannot be the same person as the Product Owner. Using SonicAgile SonicAgile (SonicAgile.com) is an online tool which you can use to manage your projects using Scrum. You can use the SonicAgile Product Backlog to create a prioritized list of stories. You can estimate the size of the Stories using different Story Point units such as Shirt Sizes and Coffee Cup sizes. You can use SonicAgile during the Sprint Planning meeting to select the Stories that you want to complete during a particular Sprint. You can configure Sprints to be any length of time. SonicAgile calculates Team Velocity automatically and displays a warning when you add too many stories to a Sprint. In other words, it warns you when it thinks you are overcommitting in a Sprint. SonicAgile also includes a Scrumboard which displays the list of Stories selected for a Sprint and the tasks associated with each story. You can drag tasks from one task state to another. Finally, SonicAgile enables you to generate Release Burndown and Sprint Burndown charts. You can use these charts to view the progress of your team. To learn more about SonicAgile, visit SonicAgile.com. Summary In this post, I described many of the basic concepts of Scrum. You learned how a Product Owner uses a Product Backlog to create a prioritized list of tasks. I explained why work is completed in Sprints so the developer team can be more productive. I also explained how a developer team uses the daily scrum to coordinate their work. You learned how the developer team uses a Scrumboard to see, at a glance, who is working on what and the state of each task. I also discussed Burndown charts. You learned how you can use both Release and Sprint Burndown charts to track team progress in completing a project. Finally, I described the crucial role of the Scrum Master – the person who is responsible for ensuring that the rules of Scrum are being followed. My goal was not to describe all of the concepts of Scrum. This post was intended to be an introductory overview. For a comprehensive explanation of Scrum, I recommend reading Ken Schwaber’s book Agile Project Management with Scrum: http://www.amazon.com/Agile-Project-Management-Microsoft-Professional/dp/073561993X/ref=la_B001H6ODMC_1_1?ie=UTF8&qid=1345224000&sr=1-1

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  • ASP.NET Frameworks and Raw Throughput Performance

    - by Rick Strahl
    A few days ago I had a curious thought: With all these different technologies that the ASP.NET stack has to offer, what's the most efficient technology overall to return data for a server request? When I started this it was mere curiosity rather than a real practical need or result. Different tools are used for different problems and so performance differences are to be expected. But still I was curious to see how the various technologies performed relative to each just for raw throughput of the request getting to the endpoint and back out to the client with as little processing in the actual endpoint logic as possible (aka Hello World!). I want to clarify that this is merely an informal test for my own curiosity and I'm sharing the results and process here because I thought it was interesting. It's been a long while since I've done any sort of perf testing on ASP.NET, mainly because I've not had extremely heavy load requirements and because overall ASP.NET performs very well even for fairly high loads so that often it's not that critical to test load performance. This post is not meant to make a point  or even come to a conclusion which tech is better, but just to act as a reference to help understand some of the differences in perf and give a starting point to play around with this yourself. I've included the code for this simple project, so you can play with it and maybe add a few additional tests for different things if you like. Source Code on GitHub I looked at this data for these technologies: ASP.NET Web API ASP.NET MVC WebForms ASP.NET WebPages ASMX AJAX Services  (couldn't get AJAX/JSON to run on IIS8 ) WCF Rest Raw ASP.NET HttpHandlers It's quite a mixed bag, of course and the technologies target different types of development. What started out as mere curiosity turned into a bit of a head scratcher as the results were sometimes surprising. What I describe here is more to satisfy my curiosity more than anything and I thought it interesting enough to discuss on the blog :-) First test: Raw Throughput The first thing I did is test raw throughput for the various technologies. This is the least practical test of course since you're unlikely to ever create the equivalent of a 'Hello World' request in a real life application. The idea here is to measure how much time a 'NOP' request takes to return data to the client. So for this request I create the simplest Hello World request that I could come up for each tech. Http Handler The first is the lowest level approach which is an HTTP handler. public class Handler : IHttpHandler { public void ProcessRequest(HttpContext context) { context.Response.ContentType = "text/plain"; context.Response.Write("Hello World. Time is: " + DateTime.Now.ToString()); } public bool IsReusable { get { return true; } } } WebForms Next I added a couple of ASPX pages - one using CodeBehind and one using only a markup page. The CodeBehind page simple does this in CodeBehind without any markup in the ASPX page: public partial class HelloWorld_CodeBehind : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { Response.Write("Hello World. Time is: " + DateTime.Now.ToString() ); Response.End(); } } while the Markup page only contains some static output via an expression:<%@ Page Language="C#" AutoEventWireup="false" CodeBehind="HelloWorld_Markup.aspx.cs" Inherits="AspNetFrameworksPerformance.HelloWorld_Markup" %> Hello World. Time is <%= DateTime.Now %> ASP.NET WebPages WebPages is the freestanding Razor implementation of ASP.NET. Here's the simple HelloWorld.cshtml page:Hello World @DateTime.Now WCF REST WCF REST was the token REST implementation for ASP.NET before WebAPI and the inbetween step from ASP.NET AJAX. I'd like to forget that this technology was ever considered for production use, but I'll include it here. Here's an OperationContract class: [ServiceContract(Namespace = "")] [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] public class WcfService { [OperationContract] [WebGet] public Stream HelloWorld() { var data = Encoding.Unicode.GetBytes("Hello World" + DateTime.Now.ToString()); var ms = new MemoryStream(data); // Add your operation implementation here return ms; } } WCF REST can return arbitrary results by returning a Stream object and a content type. The code above turns the string result into a stream and returns that back to the client. ASP.NET AJAX (ASMX Services) I also wanted to test ASP.NET AJAX services because prior to WebAPI this is probably still the most widely used AJAX technology for the ASP.NET stack today. Unfortunately I was completely unable to get this running on my Windows 8 machine. Visual Studio 2012  removed adding of ASP.NET AJAX services, and when I tried to manually add the service and configure the script handler references it simply did not work - I always got a SOAP response for GET and POST operations. No matter what I tried I always ended up getting XML results even when explicitly adding the ScriptHandler. So, I didn't test this (but the code is there - you might be able to test this on a Windows 7 box). ASP.NET MVC Next up is probably the most popular ASP.NET technology at the moment: MVC. Here's the small controller: public class MvcPerformanceController : Controller { public ActionResult Index() { return View(); } public ActionResult HelloWorldCode() { return new ContentResult() { Content = "Hello World. Time is: " + DateTime.Now.ToString() }; } } ASP.NET WebAPI Next up is WebAPI which looks kind of similar to MVC. Except here I have to use a StringContent result to return the response: public class WebApiPerformanceController : ApiController { [HttpGet] public HttpResponseMessage HelloWorldCode() { return new HttpResponseMessage() { Content = new StringContent("Hello World. Time is: " + DateTime.Now.ToString(), Encoding.UTF8, "text/plain") }; } } Testing Take a minute to think about each of the technologies… and take a guess which you think is most efficient in raw throughput. The fastest should be pretty obvious, but the others - maybe not so much. The testing I did is pretty informal since it was mainly to satisfy my curiosity - here's how I did this: I used Apache Bench (ab.exe) from a full Apache HTTP installation to run and log the test results of hitting the server. ab.exe is a small executable that lets you hit a URL repeatedly and provides counter information about the number of requests, requests per second etc. ab.exe and the batch file are located in the \LoadTests folder of the project. An ab.exe command line  looks like this: ab.exe -n100000 -c20 http://localhost/aspnetperf/api/HelloWorld which hits the specified URL 100,000 times with a load factor of 20 concurrent requests. This results in output like this:   It's a great way to get a quick and dirty performance summary. Run it a few times to make sure there's not a large amount of varience. You might also want to do an IISRESET to clear the Web Server. Just make sure you do a short test run to warm up the server first - otherwise your first run is likely to be skewed downwards. ab.exe also allows you to specify headers and provide POST data and many other things if you want to get a little more fancy. Here all tests are GET requests to keep it simple. I ran each test: 100,000 iterations Load factor of 20 concurrent connections IISReset before starting A short warm up run for API and MVC to make sure startup cost is mitigated Here is the batch file I used for the test: IISRESET REM make sure you add REM C:\Program Files (x86)\Apache Software Foundation\Apache2.2\bin REM to your path so ab.exe can be found REM Warm up ab.exe -n100 -c20 http://localhost/aspnetperf/MvcPerformance/HelloWorldJsonab.exe -n100 -c20 http://localhost/aspnetperf/api/HelloWorldJson ab.exe -n100 -c20 http://localhost/AspNetPerf/WcfService.svc/HelloWorld ab.exe -n100000 -c20 http://localhost/aspnetperf/handler.ashx > handler.txt ab.exe -n100000 -c20 http://localhost/aspnetperf/HelloWorld_CodeBehind.aspx > AspxCodeBehind.txt ab.exe -n100000 -c20 http://localhost/aspnetperf/HelloWorld_Markup.aspx > AspxMarkup.txt ab.exe -n100000 -c20 http://localhost/AspNetPerf/WcfService.svc/HelloWorld > Wcf.txt ab.exe -n100000 -c20 http://localhost/aspnetperf/MvcPerformance/HelloWorldCode > Mvc.txt ab.exe -n100000 -c20 http://localhost/aspnetperf/api/HelloWorld > WebApi.txt I ran each of these tests 3 times and took the average score for Requests/second, with the machine otherwise idle. I did see a bit of variance when running many tests but the values used here are the medians. Part of this has to do with the fact I ran the tests on my local machine - result would probably more consistent running the load test on a separate machine hitting across the network. I ran these tests locally on my laptop which is a Dell XPS with quad core Sandibridge I7-2720QM @ 2.20ghz and a fast SSD drive on Windows 8. CPU load during tests ran to about 70% max across all 4 cores (IOW, it wasn't overloading the machine). Ideally you can try running these tests on a separate machine hitting the local machine. If I remember correctly IIS 7 and 8 on client OSs don't throttle so the performance here should be Results Ok, let's cut straight to the chase. Below are the results from the tests… It's not surprising that the handler was fastest. But it was a bit surprising to me that the next fastest was WebForms and especially Web Forms with markup over a CodeBehind page. WebPages also fared fairly well. MVC and WebAPI are a little slower and the slowest by far is WCF REST (which again I find surprising). As mentioned at the start the raw throughput tests are not overly practical as they don't test scripting performance for the HTML generation engines or serialization performances of the data engines. All it really does is give you an idea of the raw throughput for the technology from time of request to reaching the endpoint and returning minimal text data back to the client which indicates full round trip performance. But it's still interesting to see that Web Forms performs better in throughput than either MVC, WebAPI or WebPages. It'd be interesting to try this with a few pages that actually have some parsing logic on it, but that's beyond the scope of this throughput test. But what's also amazing about this test is the sheer amount of traffic that a laptop computer is handling. Even the slowest tech managed 5700 requests a second, which is one hell of a lot of requests if you extrapolate that out over a 24 hour period. Remember these are not static pages, but dynamic requests that are being served. Another test - JSON Data Service Results The second test I used a JSON result from several of the technologies. I didn't bother running WebForms and WebPages through this test since that doesn't make a ton of sense to return data from the them (OTOH, returning text from the APIs didn't make a ton of sense either :-) In these tests I have a small Person class that gets serialized and then returned to the client. The Person class looks like this: public class Person { public Person() { Id = 10; Name = "Rick"; Entered = DateTime.Now; } public int Id { get; set; } public string Name { get; set; } public DateTime Entered { get; set; } } Here are the updated handler classes that use Person: Handler public class Handler : IHttpHandler { public void ProcessRequest(HttpContext context) { var action = context.Request.QueryString["action"]; if (action == "json") JsonRequest(context); else TextRequest(context); } public void TextRequest(HttpContext context) { context.Response.ContentType = "text/plain"; context.Response.Write("Hello World. Time is: " + DateTime.Now.ToString()); } public void JsonRequest(HttpContext context) { var json = JsonConvert.SerializeObject(new Person(), Formatting.None); context.Response.ContentType = "application/json"; context.Response.Write(json); } public bool IsReusable { get { return true; } } } This code adds a little logic to check for a action query string and route the request to an optional JSON result method. To generate JSON, I'm using the same JSON.NET serializer (JsonConvert.SerializeObject) used in Web API to create the JSON response. WCF REST   [ServiceContract(Namespace = "")] [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] public class WcfService { [OperationContract] [WebGet] public Stream HelloWorld() { var data = Encoding.Unicode.GetBytes("Hello World " + DateTime.Now.ToString()); var ms = new MemoryStream(data); // Add your operation implementation here return ms; } [OperationContract] [WebGet(ResponseFormat=WebMessageFormat.Json,BodyStyle=WebMessageBodyStyle.WrappedRequest)] public Person HelloWorldJson() { // Add your operation implementation here return new Person(); } } For WCF REST all I have to do is add a method with the Person result type.   ASP.NET MVC public class MvcPerformanceController : Controller { // // GET: /MvcPerformance/ public ActionResult Index() { return View(); } public ActionResult HelloWorldCode() { return new ContentResult() { Content = "Hello World. Time is: " + DateTime.Now.ToString() }; } public JsonResult HelloWorldJson() { return Json(new Person(), JsonRequestBehavior.AllowGet); } } For MVC all I have to do for a JSON response is return a JSON result. ASP.NET internally uses JavaScriptSerializer. ASP.NET WebAPI public class WebApiPerformanceController : ApiController { [HttpGet] public HttpResponseMessage HelloWorldCode() { return new HttpResponseMessage() { Content = new StringContent("Hello World. Time is: " + DateTime.Now.ToString(), Encoding.UTF8, "text/plain") }; } [HttpGet] public Person HelloWorldJson() { return new Person(); } [HttpGet] public HttpResponseMessage HelloWorldJson2() { var response = new HttpResponseMessage(HttpStatusCode.OK); response.Content = new ObjectContent<Person>(new Person(), GlobalConfiguration.Configuration.Formatters.JsonFormatter); return response; } } Testing and Results To run these data requests I used the following ab.exe commands:REM JSON RESPONSES ab.exe -n100000 -c20 http://localhost/aspnetperf/Handler.ashx?action=json > HandlerJson.txt ab.exe -n100000 -c20 http://localhost/aspnetperf/MvcPerformance/HelloWorldJson > MvcJson.txt ab.exe -n100000 -c20 http://localhost/aspnetperf/api/HelloWorldJson > WebApiJson.txt ab.exe -n100000 -c20 http://localhost/AspNetPerf/WcfService.svc/HelloWorldJson > WcfJson.txt The results from this test run are a bit interesting in that the WebAPI test improved performance significantly over returning plain string content. Here are the results:   The performance for each technology drops a little bit except for WebAPI which is up quite a bit! From this test it appears that WebAPI is actually significantly better performing returning a JSON response, rather than a plain string response. Snag with Apache Benchmark and 'Length Failures' I ran into a little snag with Apache Benchmark, which was reporting failures for my Web API requests when serializing. As the graph shows performance improved significantly from with JSON results from 5580 to 6530 or so which is a 15% improvement (while all others slowed down by 3-8%). However, I was skeptical at first because the WebAPI test reports showed a bunch of errors on about 10% of the requests. Check out this report: Notice the Failed Request count. What the hey? Is WebAPI failing on roughly 10% of requests when sending JSON? Turns out: No it's not! But it took some sleuthing to figure out why it reports these failures. At first I thought that Web API was failing, and so to make sure I re-ran the test with Fiddler attached and runiisning the ab.exe test by using the -X switch: ab.exe -n100 -c10 -X localhost:8888 http://localhost/aspnetperf/api/HelloWorldJson which showed that indeed all requests where returning proper HTTP 200 results with full content. However ab.exe was reporting the errors. After some closer inspection it turned out that the dates varying in size altered the response length in dynamic output. For example: these two results: {"Id":10,"Name":"Rick","Entered":"2012-09-04T10:57:24.841926-10:00"} {"Id":10,"Name":"Rick","Entered":"2012-09-04T10:57:24.8519262-10:00"} are different in length for the number which results in 68 and 69 bytes respectively. The same URL produces different result lengths which is what ab.exe reports. I didn't notice at first bit the same is happening when running the ASHX handler with JSON.NET result since it uses the same serializer that varies the milliseconds. Moral: You can typically ignore Length failures in Apache Benchmark and when in doubt check the actual output with Fiddler. Note that the other failure values are accurate though. Another interesting Side Note: Perf drops over Time As I was running these tests repeatedly I was finding that performance steadily dropped from a startup peak to a 10-15% lower stable level. IOW, with Web API I'd start out with around 6500 req/sec and in subsequent runs it keeps dropping until it would stabalize somewhere around 5900 req/sec occasionally jumping lower. For these tests this is why I did the IIS RESET and warm up for individual tests. This is a little puzzling. Looking at Process Monitor while the test are running memory very quickly levels out as do handles and threads, on the first test run. Subsequent runs everything stays stable, but the performance starts going downwards. This applies to all the technologies - Handlers, Web Forms, MVC, Web API - curious to see if others test this and see similar results. Doing an IISRESET then resets everything and performance starts off at peak again… Summary As I stated at the outset, these were informal to satiate my curiosity not to prove that any technology is better or even faster than another. While there clearly are differences in performance the differences (other than WCF REST which was by far the slowest and the raw handler which was by far the highest) are relatively minor, so there is no need to feel that any one technology is a runaway standout in raw performance. Choosing a technology is about more than pure performance but also about the adequateness for the job and the easy of implementation. The strengths of each technology will make for any minor performance difference we see in these tests. However, to me it's important to get an occasional reality check and compare where new technologies are heading. Often times old stuff that's been optimized and designed for a time of less horse power can utterly blow the doors off newer tech and simple checks like this let you compare. Luckily we're seeing that much of the new stuff performs well even in V1.0 which is great. To me it was very interesting to see Web API perform relatively badly with plain string content, which originally led me to think that Web API might not be properly optimized just yet. For those that caught my Tweets late last week regarding WebAPI's slow responses was with String content which is in fact considerably slower. Luckily where it counts with serialized JSON and XML WebAPI actually performs better. But I do wonder what would make generic string content slower than serialized code? This stresses another point: Don't take a single test as the final gospel and don't extrapolate out from a single set of tests. Certainly Twitter can make you feel like a fool when you post something immediate that hasn't been fleshed out a little more <blush>. Egg on my face. As a result I ended up screwing around with this for a few hours today to compare different scenarios. Well worth the time… I hope you found this useful, if not for the results, maybe for the process of quickly testing a few requests for performance and charting out a comparison. Now onwards with more serious stuff… Resources Source Code on GitHub Apache HTTP Server Project (ab.exe is part of the binary distribution)© Rick Strahl, West Wind Technologies, 2005-2012Posted in ASP.NET  Web Api   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Using TPL and PLINQ to raise performance of feed aggregator

    - by DigiMortal
    In this posting I will show you how to use Task Parallel Library (TPL) and PLINQ features to boost performance of simple RSS-feed aggregator. I will use here only very basic .NET classes that almost every developer starts from when learning parallel programming. Of course, we will also measure how every optimization affects performance of feed aggregator. Feed aggregator Our feed aggregator works as follows: Load list of blogs Download RSS-feed Parse feed XML Add new posts to database Our feed aggregator is run by task scheduler after every 15 minutes by example. We will start our journey with serial implementation of feed aggregator. Second step is to use task parallelism and parallelize feeds downloading and parsing. And our last step is to use data parallelism to parallelize database operations. We will use Stopwatch class to measure how much time it takes for aggregator to download and insert all posts from all registered blogs. After every run we empty posts table in database. Serial aggregation Before doing parallel stuff let’s take a look at serial implementation of feed aggregator. All tasks happen one after other. internal class FeedClient {     private readonly INewsService _newsService;     private const int FeedItemContentMaxLength = 255;       public FeedClient()     {          ObjectFactory.Initialize(container =>          {              container.PullConfigurationFromAppConfig = true;          });           _newsService = ObjectFactory.GetInstance<INewsService>();     }       public void Execute()     {         var blogs = _newsService.ListPublishedBlogs();           for (var index = 0; index <blogs.Count; index++)         {              ImportFeed(blogs[index]);         }     }       private void ImportFeed(BlogDto blog)     {         if(blog == null)             return;         if (string.IsNullOrEmpty(blog.RssUrl))             return;           var uri = new Uri(blog.RssUrl);         SyndicationContentFormat feedFormat;           feedFormat = SyndicationDiscoveryUtility.SyndicationContentFormatGet(uri);           if (feedFormat == SyndicationContentFormat.Rss)             ImportRssFeed(blog);         if (feedFormat == SyndicationContentFormat.Atom)             ImportAtomFeed(blog);                 }       private void ImportRssFeed(BlogDto blog)     {         var uri = new Uri(blog.RssUrl);         var feed = RssFeed.Create(uri);           foreach (var item in feed.Channel.Items)         {             SaveRssFeedItem(item, blog.Id, blog.CreatedById);         }     }       private void ImportAtomFeed(BlogDto blog)     {         var uri = new Uri(blog.RssUrl);         var feed = AtomFeed.Create(uri);           foreach (var item in feed.Entries)         {             SaveAtomFeedEntry(item, blog.Id, blog.CreatedById);         }     } } Serial implementation of feed aggregator downloads and inserts all posts with 25.46 seconds. Task parallelism Task parallelism means that separate tasks are run in parallel. You can find out more about task parallelism from MSDN page Task Parallelism (Task Parallel Library) and Wikipedia page Task parallelism. Although finding parts of code that can run safely in parallel without synchronization issues is not easy task we are lucky this time. Feeds import and parsing is perfect candidate for parallel tasks. We can safely parallelize feeds import because importing tasks doesn’t share any resources and therefore they don’t also need any synchronization. After getting the list of blogs we iterate through the collection and start new TPL task for each blog feed aggregation. internal class FeedClient {     private readonly INewsService _newsService;     private const int FeedItemContentMaxLength = 255;       public FeedClient()     {          ObjectFactory.Initialize(container =>          {              container.PullConfigurationFromAppConfig = true;          });           _newsService = ObjectFactory.GetInstance<INewsService>();     }       public void Execute()     {         var blogs = _newsService.ListPublishedBlogs();                var tasks = new Task[blogs.Count];           for (var index = 0; index <blogs.Count; index++)         {             tasks[index] = new Task(ImportFeed, blogs[index]);             tasks[index].Start();         }           Task.WaitAll(tasks);     }       private void ImportFeed(object blogObject)     {         if(blogObject == null)             return;         var blog = (BlogDto)blogObject;         if (string.IsNullOrEmpty(blog.RssUrl))             return;           var uri = new Uri(blog.RssUrl);         SyndicationContentFormat feedFormat;           feedFormat = SyndicationDiscoveryUtility.SyndicationContentFormatGet(uri);           if (feedFormat == SyndicationContentFormat.Rss)             ImportRssFeed(blog);         if (feedFormat == SyndicationContentFormat.Atom)             ImportAtomFeed(blog);                }       private void ImportRssFeed(BlogDto blog)     {          var uri = new Uri(blog.RssUrl);          var feed = RssFeed.Create(uri);           foreach (var item in feed.Channel.Items)          {              SaveRssFeedItem(item, blog.Id, blog.CreatedById);          }     }     private void ImportAtomFeed(BlogDto blog)     {         var uri = new Uri(blog.RssUrl);         var feed = AtomFeed.Create(uri);           foreach (var item in feed.Entries)         {             SaveAtomFeedEntry(item, blog.Id, blog.CreatedById);         }     } } You should notice first signs of the power of TPL. We made only minor changes to our code to parallelize blog feeds aggregating. On my machine this modification gives some performance boost – time is now 17.57 seconds. Data parallelism There is one more way how to parallelize activities. Previous section introduced task or operation based parallelism, this section introduces data based parallelism. By MSDN page Data Parallelism (Task Parallel Library) data parallelism refers to scenario in which the same operation is performed concurrently on elements in a source collection or array. In our code we have independent collections we can process in parallel – imported feed entries. As checking for feed entry existence and inserting it if it is missing from database doesn’t affect other entries the imported feed entries collection is ideal candidate for parallelization. internal class FeedClient {     private readonly INewsService _newsService;     private const int FeedItemContentMaxLength = 255;       public FeedClient()     {          ObjectFactory.Initialize(container =>          {              container.PullConfigurationFromAppConfig = true;          });           _newsService = ObjectFactory.GetInstance<INewsService>();     }       public void Execute()     {         var blogs = _newsService.ListPublishedBlogs();                var tasks = new Task[blogs.Count];           for (var index = 0; index <blogs.Count; index++)         {             tasks[index] = new Task(ImportFeed, blogs[index]);             tasks[index].Start();         }           Task.WaitAll(tasks);     }       private void ImportFeed(object blogObject)     {         if(blogObject == null)             return;         var blog = (BlogDto)blogObject;         if (string.IsNullOrEmpty(blog.RssUrl))             return;           var uri = new Uri(blog.RssUrl);         SyndicationContentFormat feedFormat;           feedFormat = SyndicationDiscoveryUtility.SyndicationContentFormatGet(uri);           if (feedFormat == SyndicationContentFormat.Rss)             ImportRssFeed(blog);         if (feedFormat == SyndicationContentFormat.Atom)             ImportAtomFeed(blog);                }       private void ImportRssFeed(BlogDto blog)     {         var uri = new Uri(blog.RssUrl);         var feed = RssFeed.Create(uri);           feed.Channel.Items.AsParallel().ForAll(a =>         {             SaveRssFeedItem(a, blog.Id, blog.CreatedById);         });      }        private void ImportAtomFeed(BlogDto blog)      {         var uri = new Uri(blog.RssUrl);         var feed = AtomFeed.Create(uri);           feed.Entries.AsParallel().ForAll(a =>         {              SaveAtomFeedEntry(a, blog.Id, blog.CreatedById);         });      } } We did small change again and as the result we parallelized checking and saving of feed items. This change was data centric as we applied same operation to all elements in collection. On my machine I got better performance again. Time is now 11.22 seconds. Results Let’s visualize our measurement results (numbers are given in seconds). As we can see then with task parallelism feed aggregation takes about 25% less time than in original case. When adding data parallelism to task parallelism our aggregation takes about 2.3 times less time than in original case. More about TPL and PLINQ Adding parallelism to your application can be very challenging task. You have to carefully find out parts of your code where you can safely go to parallel processing and even then you have to measure the effects of parallel processing to find out if parallel code performs better. If you are not careful then troubles you will face later are worse than ones you have seen before (imagine error that occurs by average only once per 10000 code runs). Parallel programming is something that is hard to ignore. Effective programs are able to use multiple cores of processors. Using TPL you can also set degree of parallelism so your application doesn’t use all computing cores and leaves one or more of them free for host system and other processes. And there are many more things in TPL that make it easier for you to start and go on with parallel programming. In next major version all .NET languages will have built-in support for parallel programming. There will be also new language constructs that support parallel programming. Currently you can download Visual Studio Async to get some idea about what is coming. Conclusion Parallel programming is very challenging but good tools offered by Visual Studio and .NET Framework make it way easier for us. In this posting we started with feed aggregator that imports feed items on serial mode. With two steps we parallelized feed importing and entries inserting gaining 2.3 times raise in performance. Although this number is specific to my test environment it shows clearly that parallel programming may raise the performance of your application significantly.

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  • Dynamically loading Assemblies to reduce Runtime Depencies

    - by Rick Strahl
    I've been working on a request to the West Wind Application Configuration library to add JSON support. The config library is a very easy to use code-first approach to configuration: You create a class that holds the configuration data that inherits from a base configuration class, and then assign a persistence provider at runtime that determines where and how the configuration data is store. Currently the library supports .NET Configuration stores (web.config/app.config), XML files, SQL records and string storage.About once a week somebody asks me about JSON support and I've deflected this question for the longest time because frankly I think that JSON as a configuration store doesn't really buy a heck of a lot over XML. Both formats require the user to perform some fixup of the plain configuration data - in XML into XML tags, with JSON using JSON delimiters for properties and property formatting rules. Sure JSON is a little less verbose and maybe a little easier to read if you have hierarchical data, but overall the differences are pretty minor in my opinion. And yet - the requests keep rolling in.Hard Link Issues in a Component LibraryAnother reason I've been hesitant is that I really didn't want to pull in a dependency on an external JSON library - in this case JSON.NET - into the core library. If you're not using JSON.NET elsewhere I don't want a user to have to require a hard dependency on JSON.NET unless they want to use the JSON feature. JSON.NET is also sensitive to versions and doesn't play nice with multiple versions when hard linked. For example, when you have a reference to V4.4 in your project but the host application has a reference to version 4.5 you can run into assembly load problems. NuGet's Update-Package can solve some of this *if* you can recompile, but that's not ideal for a component that's supposed to be just plug and play. This is no criticism of JSON.NET - this really applies to any dependency that might change.  So hard linking the DLL can be problematic for a number reasons, but the primary reason is to not force loading of JSON.NET unless you actually need it when you use the JSON configuration features of the library.Enter Dynamic LoadingSo rather than adding an assembly reference to the project, I decided that it would be better to dynamically load the DLL at runtime and then use dynamic typing to access various classes. This allows me to run without a hard assembly reference and allows more flexibility with version number differences now and in the future.But there are also a couple of downsides:No assembly reference means only dynamic access - no compiler type checking or IntellisenseRequirement for the host application to have reference to JSON.NET or else get runtime errorsThe former is minor, but the latter can be problematic. Runtime errors are always painful, but in this case I'm willing to live with this. If you want to use JSON configuration settings JSON.NET needs to be loaded in the project. If this is a Web project, it'll likely be there already.So there are a few things that are needed to make this work:Dynamically create an instance and optionally attempt to load an Assembly (if not loaded)Load types into dynamic variablesUse Reflection for a few tasks like statics/enumsThe dynamic keyword in C# makes the formerly most difficult Reflection part - method calls and property assignments - fairly painless. But as cool as dynamic is it doesn't handle all aspects of Reflection. Specifically it doesn't deal with object activation, truly dynamic (string based) member activation or accessing of non instance members, so there's still a little bit of work left to do with Reflection.Dynamic Object InstantiationThe first step in getting the process rolling is to instantiate the type you need to work with. This might be a two step process - loading the instance from a string value, since we don't have a hard type reference and potentially having to load the assembly. Although the host project might have a reference to JSON.NET, that instance might have not been loaded yet since it hasn't been accessed yet. In ASP.NET this won't be a problem, since ASP.NET preloads all referenced assemblies on AppDomain startup, but in other executable project, assemblies are just in time loaded only when they are accessed.Instantiating a type is a two step process: Finding the type reference and then activating it. Here's the generic code out of my ReflectionUtils library I use for this:/// <summary> /// Creates an instance of a type based on a string. Assumes that the type's /// </summary> /// <param name="typeName">Common name of the type</param> /// <param name="args">Any constructor parameters</param> /// <returns></returns> public static object CreateInstanceFromString(string typeName, params object[] args) { object instance = null; Type type = null; try { type = GetTypeFromName(typeName); if (type == null) return null; instance = Activator.CreateInstance(type, args); } catch { return null; } return instance; } /// <summary> /// Helper routine that looks up a type name and tries to retrieve the /// full type reference in the actively executing assemblies. /// </summary> /// <param name="typeName"></param> /// <returns></returns> public static Type GetTypeFromName(string typeName) { Type type = null; // Let default name binding find it type = Type.GetType(typeName, false); if (type != null) return type; // look through assembly list var assemblies = AppDomain.CurrentDomain.GetAssemblies(); // try to find manually foreach (Assembly asm in assemblies) { type = asm.GetType(typeName, false); if (type != null) break; } return type; } To use this for loading JSON.NET I have a small factory function that instantiates JSON.NET and sets a bunch of configuration settings on the generated object. The startup code also looks for failure and tries loading up the assembly when it fails since that's the main reason the load would fail. Finally it also caches the loaded instance for reuse (according to James the JSON.NET instance is thread safe and quite a bit faster when cached). Here's what the factory function looks like in JsonSerializationUtils:/// <summary> /// Dynamically creates an instance of JSON.NET /// </summary> /// <param name="throwExceptions">If true throws exceptions otherwise returns null</param> /// <returns>Dynamic JsonSerializer instance</returns> public static dynamic CreateJsonNet(bool throwExceptions = true) { if (JsonNet != null) return JsonNet; lock (SyncLock) { if (JsonNet != null) return JsonNet; // Try to create instance dynamic json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); if (json == null) { try { var ass = AppDomain.CurrentDomain.Load("Newtonsoft.Json"); json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); } catch (Exception ex) { if (throwExceptions) throw; return null; } } if (json == null) return null; json.ReferenceLoopHandling = (dynamic) ReflectionUtils.GetStaticProperty("Newtonsoft.Json.ReferenceLoopHandling", "Ignore"); // Enums as strings in JSON dynamic enumConverter = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.Converters.StringEnumConverter"); json.Converters.Add(enumConverter); JsonNet = json; } return JsonNet; }This code's purpose is to return a fully configured JsonSerializer instance. As you can see the code tries to create an instance and when it fails tries to load the assembly, and then re-tries loading.Once the instance is loaded some configuration occurs on it. Specifically I set the ReferenceLoopHandling option to not blow up immediately when circular references are encountered. There are a host of other small config setting that might be useful to set, but the default seem to be good enough in recent versions. Note that I'm setting ReferenceLoopHandling which requires an Enum value to be set. There's no real easy way (short of using the cardinal numeric value) to set a property or pass parameters from static values or enums. This means I still need to use Reflection to make this work. I'm using the same ReflectionUtils class I previously used to handle this for me. The function looks up the type and then uses Type.InvokeMember() to read the static property.Another feature I need is have Enum values serialized as strings rather than numeric values which is the default. To do this I can use the StringEnumConverter to convert enums to strings by adding it to the Converters collection.As you can see there's still a bit of Reflection to be done even in C# 4+ with dynamic, but with a few helpers this process is relatively painless.Doing the actual JSON ConversionFinally I need to actually do my JSON conversions. For the Utility class I need serialization that works for both strings and files so I created four methods that handle these tasks two each for serialization and deserialization for string and file.Here's what the File Serialization looks like:/// <summary> /// Serializes an object instance to a JSON file. /// </summary> /// <param name="value">the value to serialize</param> /// <param name="fileName">Full path to the file to write out with JSON.</param> /// <param name="throwExceptions">Determines whether exceptions are thrown or false is returned</param> /// <param name="formatJsonOutput">if true pretty-formats the JSON with line breaks</param> /// <returns>true or false</returns> public static bool SerializeToFile(object value, string fileName, bool throwExceptions = false, bool formatJsonOutput = false) { dynamic writer = null; FileStream fs = null; try { Type type = value.GetType(); var json = CreateJsonNet(throwExceptions); if (json == null) return false; fs = new FileStream(fileName, FileMode.Create); var sw = new StreamWriter(fs, Encoding.UTF8); writer = Activator.CreateInstance(JsonTextWriterType, sw); if (formatJsonOutput) writer.Formatting = (dynamic)Enum.Parse(FormattingType, "Indented"); writer.QuoteChar = '"'; json.Serialize(writer, value); } catch (Exception ex) { Debug.WriteLine("JsonSerializer Serialize error: " + ex.Message); if (throwExceptions) throw; return false; } finally { if (writer != null) writer.Close(); if (fs != null) fs.Close(); } return true; }You can see more of the dynamic invocation in this code. First I grab the dynamic JsonSerializer instance using the CreateJsonNet() method shown earlier which returns a dynamic. I then create a JsonTextWriter and configure a couple of enum settings on it, and then call Serialize() on the serializer instance with the JsonTextWriter that writes the output to disk. Although this code is dynamic it's still fairly short and readable.For full circle operation here's the DeserializeFromFile() version:/// <summary> /// Deserializes an object from file and returns a reference. /// </summary> /// <param name="fileName">name of the file to serialize to</param> /// <param name="objectType">The Type of the object. Use typeof(yourobject class)</param> /// <param name="binarySerialization">determines whether we use Xml or Binary serialization</param> /// <param name="throwExceptions">determines whether failure will throw rather than return null on failure</param> /// <returns>Instance of the deserialized object or null. Must be cast to your object type</returns> public static object DeserializeFromFile(string fileName, Type objectType, bool throwExceptions = false) { dynamic json = CreateJsonNet(throwExceptions); if (json == null) return null; object result = null; dynamic reader = null; FileStream fs = null; try { fs = new FileStream(fileName, FileMode.Open, FileAccess.Read); var sr = new StreamReader(fs, Encoding.UTF8); reader = Activator.CreateInstance(JsonTextReaderType, sr); result = json.Deserialize(reader, objectType); reader.Close(); } catch (Exception ex) { Debug.WriteLine("JsonNetSerialization Deserialization Error: " + ex.Message); if (throwExceptions) throw; return null; } finally { if (reader != null) reader.Close(); if (fs != null) fs.Close(); } return result; }This code is a little more compact since there are no prettifying options to set. Here JsonTextReader is created dynamically and it receives the output from the Deserialize() operation on the serializer.You can take a look at the full JsonSerializationUtils.cs file on GitHub to see the rest of the operations, but the string operations are very similar - the code is fairly repetitive.These generic serialization utilities isolate the dynamic serialization logic that has to deal with the dynamic nature of JSON.NET, and any code that uses these functions is none the wiser that JSON.NET is dynamically loaded.Using the JsonSerializationUtils WrapperThe final consumer of the SerializationUtils wrapper is an actual ConfigurationProvider, that is responsible for handling reading and writing JSON values to and from files. The provider is simple a small wrapper around the SerializationUtils component and there's very little code to make this work now:The whole provider looks like this:/// <summary> /// Reads and Writes configuration settings in .NET config files and /// sections. Allows reading and writing to default or external files /// and specification of the configuration section that settings are /// applied to. /// </summary> public class JsonFileConfigurationProvider<TAppConfiguration> : ConfigurationProviderBase<TAppConfiguration> where TAppConfiguration: AppConfiguration, new() { /// <summary> /// Optional - the Configuration file where configuration settings are /// stored in. If not specified uses the default Configuration Manager /// and its default store. /// </summary> public string JsonConfigurationFile { get { return _JsonConfigurationFile; } set { _JsonConfigurationFile = value; } } private string _JsonConfigurationFile = string.Empty; public override bool Read(AppConfiguration config) { var newConfig = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfiguration)) as TAppConfiguration; if (newConfig == null) { if(Write(config)) return true; return false; } DecryptFields(newConfig); DataUtils.CopyObjectData(newConfig, config, "Provider,ErrorMessage"); return true; } /// <summary> /// Return /// </summary> /// <typeparam name="TAppConfig"></typeparam> /// <returns></returns> public override TAppConfig Read<TAppConfig>() { var result = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfig)) as TAppConfig; if (result != null) DecryptFields(result); return result; } /// <summary> /// Write configuration to XmlConfigurationFile location /// </summary> /// <param name="config"></param> /// <returns></returns> public override bool Write(AppConfiguration config) { EncryptFields(config); bool result = JsonSerializationUtils.SerializeToFile(config, JsonConfigurationFile,false,true); // Have to decrypt again to make sure the properties are readable afterwards DecryptFields(config); return result; } }This incidentally demonstrates how easy it is to create a new provider for the West Wind Application Configuration component. Simply implementing 3 methods will do in most cases.Note this code doesn't have any dynamic dependencies - all that's abstracted away in the JsonSerializationUtils(). From here on, serializing JSON is just a matter of calling the static methods on the SerializationUtils class.Already, there are several other places in some other tools where I use JSON serialization this is coming in very handy. With a couple of lines of code I was able to add JSON.NET support to an older AJAX library that I use replacing quite a bit of code that was previously in use. And for any other manual JSON operations (in a couple of apps I use JSON Serialization for 'blob' like document storage) this is also going to be handy.Performance?Some of you might be thinking that using dynamic and Reflection can't be good for performance. And you'd be right… In performing some informal testing it looks like the performance of the native code is nearly twice as fast as the dynamic code. Most of the slowness is attributable to type lookups. To test I created a native class that uses an actual reference to JSON.NET and performance was consistently around 85-90% faster with the referenced code. That being said though - I serialized 10,000 objects in 80ms vs. 45ms so this isn't hardly slouchy. For the configuration component speed is not that important because both read and write operations typically happen once on first access and then every once in a while. But for other operations - say a serializer trying to handle AJAX requests on a Web Server one would be well served to create a hard dependency.Dynamic Loading - Worth it?On occasion dynamic loading makes sense. But there's a price to be paid in added code complexity and a performance hit. But for some operations that are not pivotal to a component or application and only used under certain circumstances dynamic loading can be beneficial to avoid having to ship extra files and loading down distributions. These days when you create new projects in Visual Studio with 30 assemblies before you even add your own code, trying to keep file counts under control seems a good idea. It's not the kind of thing you do on a regular basis, but when needed it can be a useful tool. Hopefully some of you find this information useful…© Rick Strahl, West Wind Technologies, 2005-2013Posted in .NET  C#   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Dynamically loading Assemblies to reduce Runtime Dependencies

    - by Rick Strahl
    I've been working on a request to the West Wind Application Configuration library to add JSON support. The config library is a very easy to use code-first approach to configuration: You create a class that holds the configuration data that inherits from a base configuration class, and then assign a persistence provider at runtime that determines where and how the configuration data is store. Currently the library supports .NET Configuration stores (web.config/app.config), XML files, SQL records and string storage.About once a week somebody asks me about JSON support and I've deflected this question for the longest time because frankly I think that JSON as a configuration store doesn't really buy a heck of a lot over XML. Both formats require the user to perform some fixup of the plain configuration data - in XML into XML tags, with JSON using JSON delimiters for properties and property formatting rules. Sure JSON is a little less verbose and maybe a little easier to read if you have hierarchical data, but overall the differences are pretty minor in my opinion. And yet - the requests keep rolling in.Hard Link Issues in a Component LibraryAnother reason I've been hesitant is that I really didn't want to pull in a dependency on an external JSON library - in this case JSON.NET - into the core library. If you're not using JSON.NET elsewhere I don't want a user to have to require a hard dependency on JSON.NET unless they want to use the JSON feature. JSON.NET is also sensitive to versions and doesn't play nice with multiple versions when hard linked. For example, when you have a reference to V4.4 in your project but the host application has a reference to version 4.5 you can run into assembly load problems. NuGet's Update-Package can solve some of this *if* you can recompile, but that's not ideal for a component that's supposed to be just plug and play. This is no criticism of JSON.NET - this really applies to any dependency that might change.  So hard linking the DLL can be problematic for a number reasons, but the primary reason is to not force loading of JSON.NET unless you actually need it when you use the JSON configuration features of the library.Enter Dynamic LoadingSo rather than adding an assembly reference to the project, I decided that it would be better to dynamically load the DLL at runtime and then use dynamic typing to access various classes. This allows me to run without a hard assembly reference and allows more flexibility with version number differences now and in the future.But there are also a couple of downsides:No assembly reference means only dynamic access - no compiler type checking or IntellisenseRequirement for the host application to have reference to JSON.NET or else get runtime errorsThe former is minor, but the latter can be problematic. Runtime errors are always painful, but in this case I'm willing to live with this. If you want to use JSON configuration settings JSON.NET needs to be loaded in the project. If this is a Web project, it'll likely be there already.So there are a few things that are needed to make this work:Dynamically create an instance and optionally attempt to load an Assembly (if not loaded)Load types into dynamic variablesUse Reflection for a few tasks like statics/enumsThe dynamic keyword in C# makes the formerly most difficult Reflection part - method calls and property assignments - fairly painless. But as cool as dynamic is it doesn't handle all aspects of Reflection. Specifically it doesn't deal with object activation, truly dynamic (string based) member activation or accessing of non instance members, so there's still a little bit of work left to do with Reflection.Dynamic Object InstantiationThe first step in getting the process rolling is to instantiate the type you need to work with. This might be a two step process - loading the instance from a string value, since we don't have a hard type reference and potentially having to load the assembly. Although the host project might have a reference to JSON.NET, that instance might have not been loaded yet since it hasn't been accessed yet. In ASP.NET this won't be a problem, since ASP.NET preloads all referenced assemblies on AppDomain startup, but in other executable project, assemblies are just in time loaded only when they are accessed.Instantiating a type is a two step process: Finding the type reference and then activating it. Here's the generic code out of my ReflectionUtils library I use for this:/// <summary> /// Creates an instance of a type based on a string. Assumes that the type's /// </summary> /// <param name="typeName">Common name of the type</param> /// <param name="args">Any constructor parameters</param> /// <returns></returns> public static object CreateInstanceFromString(string typeName, params object[] args) { object instance = null; Type type = null; try { type = GetTypeFromName(typeName); if (type == null) return null; instance = Activator.CreateInstance(type, args); } catch { return null; } return instance; } /// <summary> /// Helper routine that looks up a type name and tries to retrieve the /// full type reference in the actively executing assemblies. /// </summary> /// <param name="typeName"></param> /// <returns></returns> public static Type GetTypeFromName(string typeName) { Type type = null; // Let default name binding find it type = Type.GetType(typeName, false); if (type != null) return type; // look through assembly list var assemblies = AppDomain.CurrentDomain.GetAssemblies(); // try to find manually foreach (Assembly asm in assemblies) { type = asm.GetType(typeName, false); if (type != null) break; } return type; } To use this for loading JSON.NET I have a small factory function that instantiates JSON.NET and sets a bunch of configuration settings on the generated object. The startup code also looks for failure and tries loading up the assembly when it fails since that's the main reason the load would fail. Finally it also caches the loaded instance for reuse (according to James the JSON.NET instance is thread safe and quite a bit faster when cached). Here's what the factory function looks like in JsonSerializationUtils:/// <summary> /// Dynamically creates an instance of JSON.NET /// </summary> /// <param name="throwExceptions">If true throws exceptions otherwise returns null</param> /// <returns>Dynamic JsonSerializer instance</returns> public static dynamic CreateJsonNet(bool throwExceptions = true) { if (JsonNet != null) return JsonNet; lock (SyncLock) { if (JsonNet != null) return JsonNet; // Try to create instance dynamic json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); if (json == null) { try { var ass = AppDomain.CurrentDomain.Load("Newtonsoft.Json"); json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); } catch (Exception ex) { if (throwExceptions) throw; return null; } } if (json == null) return null; json.ReferenceLoopHandling = (dynamic) ReflectionUtils.GetStaticProperty("Newtonsoft.Json.ReferenceLoopHandling", "Ignore"); // Enums as strings in JSON dynamic enumConverter = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.Converters.StringEnumConverter"); json.Converters.Add(enumConverter); JsonNet = json; } return JsonNet; }This code's purpose is to return a fully configured JsonSerializer instance. As you can see the code tries to create an instance and when it fails tries to load the assembly, and then re-tries loading.Once the instance is loaded some configuration occurs on it. Specifically I set the ReferenceLoopHandling option to not blow up immediately when circular references are encountered. There are a host of other small config setting that might be useful to set, but the default seem to be good enough in recent versions. Note that I'm setting ReferenceLoopHandling which requires an Enum value to be set. There's no real easy way (short of using the cardinal numeric value) to set a property or pass parameters from static values or enums. This means I still need to use Reflection to make this work. I'm using the same ReflectionUtils class I previously used to handle this for me. The function looks up the type and then uses Type.InvokeMember() to read the static property.Another feature I need is have Enum values serialized as strings rather than numeric values which is the default. To do this I can use the StringEnumConverter to convert enums to strings by adding it to the Converters collection.As you can see there's still a bit of Reflection to be done even in C# 4+ with dynamic, but with a few helpers this process is relatively painless.Doing the actual JSON ConversionFinally I need to actually do my JSON conversions. For the Utility class I need serialization that works for both strings and files so I created four methods that handle these tasks two each for serialization and deserialization for string and file.Here's what the File Serialization looks like:/// <summary> /// Serializes an object instance to a JSON file. /// </summary> /// <param name="value">the value to serialize</param> /// <param name="fileName">Full path to the file to write out with JSON.</param> /// <param name="throwExceptions">Determines whether exceptions are thrown or false is returned</param> /// <param name="formatJsonOutput">if true pretty-formats the JSON with line breaks</param> /// <returns>true or false</returns> public static bool SerializeToFile(object value, string fileName, bool throwExceptions = false, bool formatJsonOutput = false) { dynamic writer = null; FileStream fs = null; try { Type type = value.GetType(); var json = CreateJsonNet(throwExceptions); if (json == null) return false; fs = new FileStream(fileName, FileMode.Create); var sw = new StreamWriter(fs, Encoding.UTF8); writer = Activator.CreateInstance(JsonTextWriterType, sw); if (formatJsonOutput) writer.Formatting = (dynamic)Enum.Parse(FormattingType, "Indented"); writer.QuoteChar = '"'; json.Serialize(writer, value); } catch (Exception ex) { Debug.WriteLine("JsonSerializer Serialize error: " + ex.Message); if (throwExceptions) throw; return false; } finally { if (writer != null) writer.Close(); if (fs != null) fs.Close(); } return true; }You can see more of the dynamic invocation in this code. First I grab the dynamic JsonSerializer instance using the CreateJsonNet() method shown earlier which returns a dynamic. I then create a JsonTextWriter and configure a couple of enum settings on it, and then call Serialize() on the serializer instance with the JsonTextWriter that writes the output to disk. Although this code is dynamic it's still fairly short and readable.For full circle operation here's the DeserializeFromFile() version:/// <summary> /// Deserializes an object from file and returns a reference. /// </summary> /// <param name="fileName">name of the file to serialize to</param> /// <param name="objectType">The Type of the object. Use typeof(yourobject class)</param> /// <param name="binarySerialization">determines whether we use Xml or Binary serialization</param> /// <param name="throwExceptions">determines whether failure will throw rather than return null on failure</param> /// <returns>Instance of the deserialized object or null. Must be cast to your object type</returns> public static object DeserializeFromFile(string fileName, Type objectType, bool throwExceptions = false) { dynamic json = CreateJsonNet(throwExceptions); if (json == null) return null; object result = null; dynamic reader = null; FileStream fs = null; try { fs = new FileStream(fileName, FileMode.Open, FileAccess.Read); var sr = new StreamReader(fs, Encoding.UTF8); reader = Activator.CreateInstance(JsonTextReaderType, sr); result = json.Deserialize(reader, objectType); reader.Close(); } catch (Exception ex) { Debug.WriteLine("JsonNetSerialization Deserialization Error: " + ex.Message); if (throwExceptions) throw; return null; } finally { if (reader != null) reader.Close(); if (fs != null) fs.Close(); } return result; }This code is a little more compact since there are no prettifying options to set. Here JsonTextReader is created dynamically and it receives the output from the Deserialize() operation on the serializer.You can take a look at the full JsonSerializationUtils.cs file on GitHub to see the rest of the operations, but the string operations are very similar - the code is fairly repetitive.These generic serialization utilities isolate the dynamic serialization logic that has to deal with the dynamic nature of JSON.NET, and any code that uses these functions is none the wiser that JSON.NET is dynamically loaded.Using the JsonSerializationUtils WrapperThe final consumer of the SerializationUtils wrapper is an actual ConfigurationProvider, that is responsible for handling reading and writing JSON values to and from files. The provider is simple a small wrapper around the SerializationUtils component and there's very little code to make this work now:The whole provider looks like this:/// <summary> /// Reads and Writes configuration settings in .NET config files and /// sections. Allows reading and writing to default or external files /// and specification of the configuration section that settings are /// applied to. /// </summary> public class JsonFileConfigurationProvider<TAppConfiguration> : ConfigurationProviderBase<TAppConfiguration> where TAppConfiguration: AppConfiguration, new() { /// <summary> /// Optional - the Configuration file where configuration settings are /// stored in. If not specified uses the default Configuration Manager /// and its default store. /// </summary> public string JsonConfigurationFile { get { return _JsonConfigurationFile; } set { _JsonConfigurationFile = value; } } private string _JsonConfigurationFile = string.Empty; public override bool Read(AppConfiguration config) { var newConfig = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfiguration)) as TAppConfiguration; if (newConfig == null) { if(Write(config)) return true; return false; } DecryptFields(newConfig); DataUtils.CopyObjectData(newConfig, config, "Provider,ErrorMessage"); return true; } /// <summary> /// Return /// </summary> /// <typeparam name="TAppConfig"></typeparam> /// <returns></returns> public override TAppConfig Read<TAppConfig>() { var result = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfig)) as TAppConfig; if (result != null) DecryptFields(result); return result; } /// <summary> /// Write configuration to XmlConfigurationFile location /// </summary> /// <param name="config"></param> /// <returns></returns> public override bool Write(AppConfiguration config) { EncryptFields(config); bool result = JsonSerializationUtils.SerializeToFile(config, JsonConfigurationFile,false,true); // Have to decrypt again to make sure the properties are readable afterwards DecryptFields(config); return result; } }This incidentally demonstrates how easy it is to create a new provider for the West Wind Application Configuration component. Simply implementing 3 methods will do in most cases.Note this code doesn't have any dynamic dependencies - all that's abstracted away in the JsonSerializationUtils(). From here on, serializing JSON is just a matter of calling the static methods on the SerializationUtils class.Already, there are several other places in some other tools where I use JSON serialization this is coming in very handy. With a couple of lines of code I was able to add JSON.NET support to an older AJAX library that I use replacing quite a bit of code that was previously in use. And for any other manual JSON operations (in a couple of apps I use JSON Serialization for 'blob' like document storage) this is also going to be handy.Performance?Some of you might be thinking that using dynamic and Reflection can't be good for performance. And you'd be right… In performing some informal testing it looks like the performance of the native code is nearly twice as fast as the dynamic code. Most of the slowness is attributable to type lookups. To test I created a native class that uses an actual reference to JSON.NET and performance was consistently around 85-90% faster with the referenced code. This will change though depending on the size of objects serialized - the larger the object the more processing time is spent inside the actual dynamically activated components and the less difference there will be. Dynamic code is always slower, but how much it really affects your application primarily depends on how frequently the dynamic code is called in relation to the non-dynamic code executing. In most situations where dynamic code is used 'to get the process rolling' as I do here the overhead is small enough to not matter.All that being said though - I serialized 10,000 objects in 80ms vs. 45ms so this is hardly slouchy performance. For the configuration component speed is not that important because both read and write operations typically happen once on first access and then every once in a while. But for other operations - say a serializer trying to handle AJAX requests on a Web Server one would be well served to create a hard dependency.Dynamic Loading - Worth it?Dynamic loading is not something you need to worry about but on occasion dynamic loading makes sense. But there's a price to be paid in added code  and a performance hit which depends on how frequently the dynamic code is accessed. But for some operations that are not pivotal to a component or application and are only used under certain circumstances dynamic loading can be beneficial to avoid having to ship extra files adding dependencies and loading down distributions. These days when you create new projects in Visual Studio with 30 assemblies before you even add your own code, trying to keep file counts under control seems like a good idea. It's not the kind of thing you do on a regular basis, but when needed it can be a useful option in your toolset… © Rick Strahl, West Wind Technologies, 2005-2013Posted in .NET  C#   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • How to shoot yourself in the foot (DO NOT Read in the office)

    - by TATWORTH
    Originally posted on: http://geekswithblogs.net/TATWORTH/archive/2013/06/21/how-to-shoot-yourself-in-the-foot-do-not-read.aspxLet me make it absolutely clear - the following is:merely collated by your Geek from http://www.codeproject.com/Lounge.aspx?msg=3917012#xx3917012xxvery, very very funny so you read it in the presence of others at your own riskso here is the list - you have been warned!C You shoot yourself in the foot.   C++ You accidently create a dozen instances of yourself and shoot them all in the foot. Providing emergency medical assistance is impossible since you can't tell which are bitwise copies and which are just pointing at others and saying "That's me, over there."   FORTRAN You shoot yourself in each toe, iteratively, until you run out of toes, then you read in the next foot and repeat. If you run out of bullets, you continue anyway because you have no exception-handling facility.   Modula-2 After realizing that you can't actually accomplish anything in this language, you shoot yourself in the head.   COBOL USEing a COLT 45 HANDGUN, AIM gun at LEG.FOOT, THEN place ARM.HAND.FINGER on HANDGUN.TRIGGER and SQUEEZE. THEN return HANDGUN to HOLSTER. CHECK whether shoelace needs to be retied.   Lisp You shoot yourself in the appendage which holds the gun with which you shoot yourself in the appendage which holds the gun with which you shoot yourself in the appendage which holds...   BASIC Shoot yourself in the foot with a water pistol. On big systems, continue until entire lower body is waterlogged.   Forth Foot yourself in the shoot.   APL You shoot yourself in the foot; then spend all day figuring out how to do it in fewer characters.   Pascal The compiler won't let you shoot yourself in the foot.   Snobol If you succeed, shoot yourself in the left foot. If you fail, shoot yourself in the right foot.   HyperTalk Put the first bullet of the gun into foot left of leg of you. Answer the result.   Prolog You tell your program you want to be shot in the foot. The program figures out how to do it, but the syntax doesn't allow it to explain.   370 JCL You send your foot down to MIS with a 4000-page document explaining how you want it to be shot. Three years later, your foot comes back deep-fried.   FORTRAN-77 You shoot yourself in each toe, iteratively, until you run out of toes, then you read in the next foot and repeat. If you run out of bullets, you continue anyway because you still can't do exception-processing.   Modula-2 (alternative) You perform a shooting on what might be currently a foot with what might be currently a bullet shot by what might currently be a gun.   BASIC (compiled) You shoot yourself in the foot with a BB using a SCUD missile launcher.   Visual Basic You'll really only appear to have shot yourself in the foot, but you'll have so much fun doing it that you won't care.   Forth (alternative) BULLET DUP3 * GUN LOAD FOOT AIM TRIGGER PULL BANG! EMIT DEAD IF DROP ROT THEN (This takes about five bytes of memory, executes in two to ten clock cycles on any processor and can be used to replace any existing function of the language as well as in any future words). (Welcome to bottom up programming - where you, too, can perform compiler pre-processing instead of writing code)   APL (alternative) You hear a gunshot and there's a hole in your foot, but you don't remember enough linear algebra to understand what happened. or @#&^$%&%^ foot   Pascal (alternative) Same as Modula-2 except that the bullet is not the right type for the gun and your hand is blown off.   Snobol (alternative) You grab your foot with your hand, then rewrite your hand to be a bullet. The act of shooting the original foot then changes your hand/bullet into yet another foot (a left foot).   Prolog (alternative) You attempt to shoot yourself in the foot, but the bullet, failing to find its mark, backtracks to the gun, which then explodes in your face.   COMAL You attempt to shoot yourself in the foot with a water pistol, but the bore is clogged, and the pressure build-up blows apart both the pistol and your hand. or draw_pistol aim_at_foot(left) pull_trigger hop(swearing)   Scheme As Lisp, but none of the other appendages are aware of this happening.   Algol You shoot yourself in the foot with a musket. The musket is aesthetically fascinating and the wound baffles the adolescent medic in the emergency room.   Ada If you are dumb enough to actually use this language, the United States Department of Defense will kidnap you, stand you up in front of a firing squad and tell the soldiers, "Shoot at the feet." or The Department of Defense shoots you in the foot after offering you a blindfold and a last cigarette. or After correctly packaging your foot, you attempt to concurrently load the gun, pull the trigger, scream and shoot yourself in the foot. When you try, however, you discover that your foot is of the wrong type. or After correctly packing your foot, you attempt to concurrently load the gun, pull the trigger, scream, and confidently aim at your foot knowing it is safe. However the cordite in the round does an Unchecked Conversion, fires and shoots you in the foot anyway.   Eiffel   You create a GUN object, two FOOT objects and a BULLET object. The GUN passes both the FOOT objects a reference to the BULLET. The FOOT objects increment their hole counts and forget about the BULLET. A little demon then drives a garbage truck over your feet and grabs the bullet (both of it) on the way. Smalltalk You spend so much time playing with the graphics and windowing system that your boss shoots you in the foot, takes away your workstation and makes you develop in COBOL on a character terminal. or You send the message shoot to gun, with selectors bullet and myFoot. A window pops up saying Gunpowder doesNotUnderstand: spark. After several fruitless hours spent browsing the methods for Trigger, FiringPin and IdealGas, you take the easy way out and create ShotFoot, a subclass of Foot with an additional instance variable bulletHole. Object Oriented Pascal You perform a shooting on what might currently be a foot with what might currently be a bullet fired from what might currently be a gun.   PL/I You consume all available system resources, including all the offline bullets. The Data Processing & Payroll Department doubles its size, triples its budget, acquires four new mainframes and drops the original one on your foot. Postscript foot bullets 6 locate loadgun aim gun shoot showpage or It takes the bullet ten minutes to travel from the gun to your foot, by which time you're long since gone out to lunch. The text comes out great, though.   PERL You stab yourself in the foot repeatedly with an incredibly large and very heavy Swiss Army knife. or You pick up the gun and begin to load it. The gun and your foot begin to grow to huge proportions and the world around you slows down, until the gun fires. It makes a tiny hole, which you don't feel. Assembly Language You crash the OS and overwrite the root disk. The system administrator arrives and shoots you in the foot. After a moment of contemplation, the administrator shoots himself in the foot and then hops around the room rabidly shooting at everyone in sight. or You try to shoot yourself in the foot only to discover you must first reinvent the gun, the bullet, and your foot.or The bullet travels to your foot instantly, but it took you three weeks to load the round and aim the gun.   BCPL You shoot yourself somewhere in the leg -- you can't get any finer resolution than that. Concurrent Euclid You shoot yourself in somebody else's foot.   Motif You spend days writing a UIL description of your foot, the trajectory, the bullet and the intricate scrollwork on the ivory handles of the gun. When you finally get around to pulling the trigger, the gun jams.   Powerbuilder While attempting to load the gun you discover that the LoadGun system function is buggy; as a work around you tape the bullet to the outside of the gun and unsuccessfully attempt to fire it with a nail. In frustration you club your foot with the butt of the gun and explain to your client that this approximates the functionality of shooting yourself in the foot and that the next version of Powerbuilder will fix it.   Standard ML By the time you get your code to typecheck, you're using a shoot to foot yourself in the gun.   MUMPS You shoot 583149 AK-47 teflon-tipped, hollow-point, armour-piercing bullets into even-numbered toes on odd-numbered feet of everyone in the building -- with one line of code. Three weeks later you shoot yourself in the head rather than try to modify that line.   Java You locate the Gun class, but discover that the Bullet class is abstract, so you extend it and write the missing part of the implementation. Then you implement the ShootAble interface for your foot, and recompile the Foot class. The interface lets the bullet call the doDamage method on the Foot, so the Foot can damage itself in the most effective way. Now you run the program, and call the doShoot method on the instance of the Gun class. First the Gun creates an instance of Bullet, which calls the doFire method on the Gun. The Gun calls the hit(Bullet) method on the Foot, and the instance of Bullet is passed to the Foot. But this causes an IllegalHitByBullet exception to be thrown, and you die.   Unix You shoot yourself in the foot or % ls foot.c foot.h foot.o toe.c toe.o % rm * .o rm: .o: No such file or directory % ls %   370 JCL (alternative) You shoot yourself in the head just thinking about it.   DOS JCL You first find the building you're in in the phone book, then find your office number in the corporate phone book. Then you have to write this down, then describe, in cubits, your exact location, in relation to the door (right hand side thereof). Then you need to write down the location of the gun (loading it is a proprietary utility), then you load it, and the COBOL program, and run them, and, with luck, it may be run tonight.   VMS   $ MOUNT/DENSITY=.45/LABEL=BULLET/MESSAGE="BYE" BULLET::BULLET$GUN SYS$BULLET $ SET GUN/LOAD/SAFETY=OFF/SIGHT=NONE/HAND=LEFT/CHAMBER=1/ACTION=AUTOMATIC/ LOG/ALL/FULL SYS$GUN_3$DUA3:[000000]GUN.GNU $ SHOOT/LOG/AUTO SYS$GUN SYS$SYSTEM:[FOOT]FOOT.FOOT   %DCL-W-ACTIMAGE, error activating image GUN -CLI-E-IMGNAME, image file $3$DUA240:[GUN]GUN.EXE;1 -IMGACT-F-NOTNATIVE, image is not an OpenVMS Alpha AXP image or %SYS-F-FTSHT, foot shot (fifty lines of traceback omitted) sh,csh, etc You can't remember the syntax for anything, so you spend five hours reading manual pages, then your foot falls asleep. You shoot the computer and switch to C.   Apple System 7 Double click the gun icon and a window giving a selection for guns, target areas, plus balloon help with medical remedies, and assorted sound effects. Click "shoot" button and a small bomb appears with note "Error of Type 1 has occurred."   Windows 3.1 Double click the gun icon and wait. Eventually a window opens giving a selection for guns, target areas, plus balloon help with medical remedies, and assorted sound effects. Click "shoot" button and a small box appears with note "Unable to open Shoot.dll, check that path is correct."   Windows 95 Your gun is not compatible with this OS and you must buy an upgrade and install it before you can continue. Then you will be informed that you don't have enough memory.   CP/M I remember when shooting yourself in the foot with a BB gun was a big deal.   DOS You finally found the gun, but can't locate the file with the foot for the life of you.   MSDOS You shoot yourself in the foot, but can unshoot yourself with add-on software.   Access You try to point the gun at your foot, but it shoots holes in all your Borland distribution diskettes instead.   Paradox Not only can you shoot yourself in the foot, your users can too.   dBase You squeeze the trigger, but the bullet moves so slowly that by the time your foot feels the pain, you've forgotten why you shot yourself anyway. or You buy a gun. Bullets are only available from another company and are promised to work so you buy them. Then you find out that the next version of the gun is the one scheduled to actually shoot bullets.   DBase IV, V1.0 You pull the trigger, but it turns out that the gun was a poorly designed hand grenade and the whole building blows up.   SQL You cut your foot off, send it out to a service bureau and when it returns, it has a hole in it but will no longer fit the attachment at the end of your leg. or Insert into Foot Select Bullet >From Gun.Hand Where Chamber = 'LOADED' And Trigger = 'PULLED'   Clipper You grab a bullet, get ready to insert it in the gun so that you can shoot yourself in the foot and discover that the gun that the bullets fits has not yet been built, but should be arriving in the mail _REAL_SOON_NOW_. Oracle The menus for coding foot_shooting have not been implemented yet and you can't do foot shooting in SQL.   English You put your foot in your mouth, then bite it off. (For those who don't know, English is a McDonnell Douglas/PICK query language which allegedly requires 110% of system resources to run happily.) Revelation [an implementation of the PICK Operating System] You'll be able to shoot yourself in the foot just as soon as you figure out what all these bullets are for.   FlagShip Starting at the top of your head, you aim the gun at yourself repeatedly until, half an hour later, the gun is finally pointing at your foot and you pull the trigger. A new foot with a hole in it appears but you can't work out how to get rid of the old one and your gun doesn't work anymore.   FidoNet You put your foot in your mouth, then echo it internationally.   PicoSpan [a UNIX-based computer conferencing system] You can't shoot yourself in the foot because you're not a host. or (host variation) Whenever you shoot yourself in the foot, someone opens a topic in policy about it.   Internet You put your foot in your mouth, shoot it, then spam the bullet so that everybody gets shot in the foot.   troff rmtroff -ms -Hdrwp | lpr -Pwp2 & .*place bullet in footer .B .NR FT +3i .in 4 .bu Shoot! .br .sp .in -4 .br .bp NR HD -2i .*   Genetic Algorithms You create 10,000 strings describing the best way to shoot yourself in the foot. By the time the program produces the optimal solution, humans have evolved wings and the problem is moot.   CSP (Communicating Sequential Processes) You only fail to shoot everything that isn't your foot.   MS-SQL Server MS-SQL Server’s gun comes pre-loaded with an unlimited supply of Teflon coated bullets, and it only has two discernible features: the muzzle and the trigger. If that wasn't enough, MS-SQL Server also puts the gun in your hand, applies local anesthetic to the skin of your forefinger and stitches it to the gun's trigger. Meanwhile, another process has set up a spinal block to numb your lower body. It will then proceeded to surgically remove your foot, cryogenically freeze it for preservation, and attach it to the muzzle of the gun so that no matter where you aim, you will shoot your foot. In order to avoid shooting yourself in the foot, you need to unstitch your trigger finger, remove your foot from the muzzle of the gun, and have it surgically reattached. Then you probably want to get some crutches and go out to buy a book on SQL Server Performance Tuning.   Sybase Sybase's gun requires assembly, and you need to go out and purchase your own clip and bullets to load the gun. Assembly is complicated by the fact that Sybase has hidden the gun behind a big stack of reference manuals, but it hasn't told you where that stack is. While you were off finding the gun, assembling it, buying bullets, etc., Sybase was also busy surgically removing your foot and cryogenically freezing it for preservation. Instead of attaching it to the muzzle of the gun, though, it packed your foot on dry ice and sent it UPS-Ground to an unnamed hookah bar somewhere in the middle east. In order to shoot your foot, you must modify your gun with a GPS system for targeting and hire some guy named "Indy" to find the hookah bar and wire the coordinates back to you. By this time, you've probably become so daunted at the tasks stand between you and shooting your foot that you hire a guy who's read all the books on Sybase to help you shoot your foot. If you're lucky, he'll be smart enough both to find your foot and to stop you from shooting it.   Magic software You spend 1 week looking up the correct syntax for GUN. When you find it, you realise that GUN will not let you shoot in your own foot. It will allow you to shoot almost anything but your foot. You then decide to build your own gun. You can't use the standard barrel since this will only allow for standard bullets, which will not fire if the barrel is pointed at your foot. After four weeks, you have created your own custom gun. It blows up in your hand without warning, because you failed to initialise the safety catch and it doesn't know whether the initial state is "0", 0, NULL, "ZERO", 0.0, 0,0, "0.0", or "0,00". You fix the problem with your remaining hand by nesting 12 safety catches, and then decide to build the gun without safety catch. You then shoot the management and retire to a happy life where you code in languages that will allow you to shoot your foot in under 10 days.FirefoxLets you shoot yourself in as many feet as you'd like, while using multiple great addons! IEA moving target in terms of standard ammunition size and doesn't always work properly with non-Microsoft ammunition, so sometimes you shoot something other than your foot. However, it's the corporate world's standard foot-shooting apparatus. Hackers seem to enjoy rigging websites up to trigger cascading foot-shooting failures. Windows 98 About the same as Windows 95 in terms of overall bullet capacity and triggering mechanisms. Includes updated DirectShot API. A new version was released later on to support USB guns, Windows 98 SE.WPF:You get your baseball glove and a ball and you head out to your backyard, where you throw balls to your pitchback. Then your unkempt-haired-cargo-shorts-and-sandals-with-white-socks-wearing neighbor uses XAML to sculpt your arm into a gun, the ball into a bullet and the pitchback into your foot. By now, however, only the neighbor can get it to work and he's only around from 6:30 PM - 3:30 AM. LOGO: You very carefully lay out the trajectory of the bullet. Then you start the gun, which fires very slowly. You walk precisely to the point where the bullet will travel and wait, but just before it gets to you, your class time is up and one of the other kids has already used the system to hack into Sony's PS3 network. Flash: Someone has designed a beautiful-looking gun that anyone can shoot their feet with for free. It weighs six hundred pounds. All kinds of people are shooting themselves in the feet, and sending the link to everyone else so that they can too. That is, except for the criminals, who are all stealing iOS devices that the gun won't work with.APL: Its (mostly) all greek to me. Lisp: Place ((gun in ((hand sight (foot then shoot))))) (Lots of Insipid Stupid Parentheses)Apple OS/X and iOS Once a year, Steve Jobs returns from sick leave to tell millions of unwavering fans how they will be able to shoot themselves in the foot differently this year. They retweet and blog about it ad nauseam, and wait in line to be the first to experience "shoot different".Windows ME Usually fails, even at shooting you in the foot. Yo dawg, I heard you like shooting yourself in the foot. So I put a gun in your gun, so you can shoot yourself in the foot while you shoot yourself in the foot. (Okay, I'm not especially proud of this joke.) Windows 2000 Now you really do have to log in, before you are allowed to shoot yourself in the foot.Windows XPYou thought you learned your lesson: Don't use Windows ME. Then, along came this new creature, built on top of Windows NT! So you spend the next couple days installing antivirus software, patches and service packs, just so you can get that driver to install, and then proceed to shoot yourself in the foot. Windows Vista Newer! Glossier! Shootier! Windows 7 The bullets come out a lot smoother. Active Directory Each bullet now has an attached Bullet Identifier, and can be uniquely identified. Policies can be applied to dictate fragmentation, and the gun will occasionally have a confusing delay after the trigger has been pulled. PythonYou try to use import foot; foot.shoot() only to realize that's only available in 3.0, to which you can't yet upgrade from 2.7 because of all those extension libs lacking support. Solaris Shoots best when used on SPARC hardware, but still runs the trigger GUI under Java. After weeks of learning the appropriate STOP command to prevent the trigger from automatically being pressed on boot, you think you've got it under control. Then the one time you ever use dtrace, it hits a bug that fires the gun. MySQL The feature that allows you to shoot yourself in the foot has been in development for about 6 years, and they are adding it into the next version, which is coming out REAL SOON NOW, promise! But you can always check it out of source control and try it yourself (just not in any environment where data integrity is important because it will probably explode.) PostgreSQLAllows you to have a smug look on your face while you shoot yourself in the foot, because those MySQL guys STILL don't have that feature. NoSQL Barrel? Who needs a barrel? Just put the bullet on your foot, and strike it with a hammer. See? It's so much simpler and more efficient that way. You can even strike multiple bullets in one swing if you swing with a good enough arc, because hammers are easy to use. Getting them to synchronize is a little difficult, though.Eclipse There are about a dozen different packages for shooting yourself in the foot, with weird interdependencies on outdated components. Once you finally navigate the morass and get one installed, you then have something to look at while you shoot yourself in the foot with that package: You can watch the screen redraw.Outlook Makes it really easy to let everyone know you shot yourself in the foot!Shooting yourself in the foot using delegates.You really need to shoot yourself in the foot but you hate firearms (you don't want any dependency on the specifics of shooting) so you delegate it to somebody else. You don't care how it is done as long is shooting your foot. You can do it asynchronously in case you know you may faint so you are called back/slapped in the face by your shooter/friend (or background worker) when everything is done.C#You prepare the gun and the bullet, carefully modeling all of the physics of a bullet traveling through a foot. Just before you're about to pull the trigger, you stumble on System.Windows.BodyParts.Foot.ShootAt(System.Windows.Firearms.IGun gun) in the extended framework, realize you just wasted the entire afternoon, and shoot yourself in the head.PHP<?phprequire("foot_safety_check.php");?><!DOCTYPE HTML><html><head> <!--Lower!--><title>Shooting me in the foot</title></head> <body> <!--LOWER!!!--><leg> <!--OK, I made this one up...--><footer><?php echo (dungSift($_SERVER['HTTP_USER_AGENT'], "ie"))?("Your foot is safe, but you might want to wear a hard hat!"):("<div class=\"shot\">BANG!</div>"); ?></footer></leg> </body> </html>

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  • Run CGI in IIS 7 to work with GET without Requiring POST Request

    - by Mohamed Meligy
    I'm trying to migrate an old CGI application from an existing Windows 2003 server (IIS 6.0) where it works just fine to a new Windows 2008 server with IIS 7.0 where we're getting the following problem: After setting up the module handler and everything, I find that I can only access the CGI application (rdbweb.exe) file if I'm calling it via POST request (form submit from another page). If I just try to type in the URL of the file (issuing a GET request) I get the following error: HTTP Error 502.2 - Bad Gateway The specified CGI application misbehaved by not returning a complete set of HTTP headers. The headers it did return are "Exception EInOutError in module rdbweb.exe at 00039B44. I/O error 6. ". This is a very old application for one of our clients. When we tried to call the vendor they said we need to pay ~ $3000 annual support fee in order to start the talk about it. Of course I'm trying to avoid that! Note that: If we create a normal HTML form that submits to "rdbweb.exe", we get the CGI working normally. We can't use this as workaround though because some pages in the application link to "rdbweb.exe" with normal link not form submit. If we run "rdbweb.exe". from a Console (Command Prompt) Window not IIS, we get the normal HTML we'd typically expect, no problem. We have tried the following: Ensuring the CGI module mapped to "rdbweb.exe".in IIS has all permissions (read, write, execute) enabled and also all verbs are allowed not just specific ones, also tried allowing GET, POST explicitely. Ensuring the application bool has "enable 32 bit applications" set to true. Ensuring the website runs with an account that has full permissions on the "rdbweb.exe".file and whole website (although we know it "read", "execute" should be enough). Ensuring the machine wide IIS setting for "ISAPI and CGI Restrictions" has the full path to "rdbweb.exe".allowed. Making sure we have the latest Windows Updates (for IIS6 we found knowledge base articles stating bugs that require hot fixes for IIS6, but nothing similar was found for IIS7). Changing the module from CGI to Fast CGI, not working also Now the only remaining possibility we have instigated is the following Microsoft Knowledge Base article:http://support.microsoft.com/kb/145661 - Which is about: CGI Error: The specified CGI application misbehaved by not returning a complete set of HTTP headers. The headers it did return are: the article suggests the following solution: Modify the source code for the CGI application header output. The following is an example of a correct header: print "HTTP/1.0 200 OK\n"; print "Content-Type: text/html\n\n\n"; Unfortunately we do not have the source to try this out, and I'm not sure anyway whether this is the issue we're having. Can you help me with this problem? Is there a way to make the application work without requiring POST request? Note that on the old IIS6 server the application is working just fine, and I could not find any special IIS configuration that I may want to try its equivalent on IIS7.

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  • HTTP 500 Internal Server Error on IIS 7.5 with MVC3

    - by Tor Haugen
    I am trying to install an MVC3 application on our production server with no luck. The application is from a 3rd party (compiled), and so debugging is not available to me. Besides, I strongly suspect the error occurs before any code in the site has a chance to execute. Our staging server is - as far as I can determine - set up excactly like the production server. Both run Windows Server 2008 Standard R2, both also run a Sharepoint 2010 site (though this install doesn't touch that in any way). IIS is version 7.5, and .NET Framework 4.0 (required by the MVC app) is (recently) installed (by me, with a reboot after). The application is very small and simple and, as far as I can tell sticks to fairly standard functionality - including forms authentication (ie. it doesnt' pull any dirty tricks). The error message shown in the browser is very general: HTTP Error 500.0 - Internal Server Error An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur. The bit about 'An error message detailing the cause' being in the application event log seems to be just speculation - a pious hope that whatever code actually caused the error will log it. Nothing useful is to be found in the event log (only the very same message, logged by IIS). Module: AspNetInitClrHostFailureModule Notification: BeginRequest Handler: StaticFile Error Code: 0x80070002 Requested URL: http://xxxxxx.xxxxxx.xx:80/ Physical Path: C:\Xxxxxxx\Prod\WebClient Logon Method: Not yet determined Logon User: Not yet determined Using Failed Request Tracing, I have been able to track the error (as also indicated above) to the AspNetInitClrHostFailureModule: 103. -NOTIFY_MODULE_START ModuleName AspNetInitClrHostFailureModule Notification 1 fIsPostNotification false Notification BEGIN_REQUEST 104. -SET_RESPONSE_ERROR_DESCRIPTION ErrorDescription An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur. 105. -MODULE_SET_RESPONSE_ERROR_STATUS ModuleName AspNetInitClrHostFailureModule Notification 1 HttpStatus 500 HttpReason Internal Server Error HttpSubStatus 0 ErrorCode 2147942402 ConfigExceptionInfo Notification BEGIN_REQUEST ErrorCode The system cannot find the file specified. (0x80070002) So there you have it. Seemingly, the AspNetInitClrHostFailureModule fails to find some file. So some questions are: What is the AspNetInitClrHostFailureModule? It is not listed in the fairly exhausting list of modules configurable in IIS manager for the site. I have had no success googling it either. Maybe it's secret.. I access the root URL of the site. This is supposed to be redirected to /Account/LogOn by the FormsAuthenticationModule. Why then is the handler StaticFile? Is that a clue? I have tried removing the infamous system.webserver/modules/runAllManagedModulesForAllRequests attribute, and that makes the error go away (but MVC not actually working, of course). I am prepared to specify all necessary modules manually if that's what it takes, but if the AspNetInitClrHostFailureModule is actually needed, I will be just as stuck. Does anyone know, or can anyone direct me to someone who knows, exactly what modules a typical MVC3 application actually needs? This question might well be a duplicate of this one, but he didn't get any useful answer, and also asked less specific questions. So I'll have my own go. Hoping for some help here :) Edit: I have now tried setting up a trivial MVC 3 project on the server. I created a new project using the MVC Application template, compiled it and deployed it to the server. It behaves in exactly the same way. The server simply cannot run MVC 3 projects.

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  • Cannot get libcurl-devl on OpenSUSE 11.3

    - by Dai
    I have a server running OpenSUSE 11.3 that I can't really upgrade to a newer version of OpenSUSE (it's a managed appliance). I have some PHP shell scripts that need to run on the server that have a dependency on both cURL and OpenSSL. I discovered that the PHP 5.3.3 binaries on the server did not include OpenSSL but did include cURL I downloaded the latest PHP sources, extracted them, and ran ./configure --with-openssl --with-zlib --with-bcmath --with-curl --with-readline --with-libxml --enable-sockets This failed: the configure script complained that it couldn't find cURL: checking for cURL support... yes checking for cURL in default path... not found configure: error: Please reinstall the libcurl distribution - easy.h should be in /include/curl/ I tried to install libcurl by running zypper install libcurl-devl This failed too: doom:~/phpworksite/php-5.5.15 # zypper install libcurl-devl Loading repository data... Warning: Repository 'Updates for openSUSE 11.3 11.3-1.82' appears to outdated. Consider using a different mirror or server. Warning: Repository 'openSUSE_11.3_Updates' appears to outdated. Consider using a different mirror or server. Reading installed packages... 'libcurl-devl' not found in package names. Trying capabilities. No provider of 'libcurl-devl' found. Resolving package dependencies... Nothing to do. However, libcurl-devl is listed when I run zypper search curl. doom:~/phpworksite/php-5.5.15 # zypper search curl Loading repository data... Warning: Repository 'Updates for openSUSE 11.3 11.3-1.82' appears to outdated. Consider using a different mirror or server. Warning: Repository 'openSUSE_11.3_Updates' appears to outdated. Consider using a different mirror or server. Reading installed packages... S | Name | Summary | Type --+-----------------------------+----------------------------------------------------------+-------- i | curl | A Tool for Transferring Data from URLs | package | curlftpfs | Filesystem for mounting FTP hosts using FUSE and libcurl | package | libcurl-devel | A Tool for Transferring Data from URLs | package i | libcurl4 | cURL shared library version 4 | package i | perl-WWW-Curl | Perl extension interface for libcurl | package i | php5-curl | PHP5 Extension Module | package | python-curl | Python module interface to the cURL library | package | python-curl-doc | Documentation for python-curl | package | xmms2-plugin-curl | Curl Support for xmms2 | package | xmms2-plugin-curl-debuginfo | Debug information for package xmms2-plugin-curl | package doom:~/phpworksite/php-5.5.15 # Here are the current repositories. doom:~/phpworksite/php-5.5.15 # zypper repos # | Alias | Name | Enabled | Refresh ---+----------------------------------------------+----------------------------------------------+---------+-------- 1 | PHP_extensions_(openSUSE_11.3) | PHP_extensions_(openSUSE_11.3) | No | Yes 2 | Packman_11.3 | Packman_11.3 | Yes | Yes 3 | Updates for openSUSE 11.3 11.3-1.82 | Updates for openSUSE 11.3 11.3-1.82 | Yes | Yes 4 | openSUSE_11.3_OSS | openSUSE_11.3_OSS | Yes | Yes 5 | openSUSE_11.3_Updates | openSUSE_11.3_Updates | Yes | Yes 6 | openSUSE_BuildService_-_devel:languages:perl | openSUSE_BuildService_-_devel:languages:perl | No | Yes 7 | repo-debug | openSUSE-11.3-Debug | No | Yes 8 | repo-non-oss | openSUSE-11.3-Non-Oss | Yes | Yes 9 | repo-oss | openSUSE-11.3-Oss | Yes | Yes 10 | repo-source | openSUSE-11.3-Source | No | Yes BTW, I did try building PHP without cURL, however it broke a lot of things, so apparently I really need cURL. My question: how can I install libcurl-devl (or just install cURL) so that I can build PHP?

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  • Pig_Cassandra integration caused - ERROR 1070: Could not resolve CassandraStorage using imports:

    - by Le Dude
    I'm following basic Pig, Cassandra, Hadoop installation. Everything works just fine as a stand alone. No error. However when I tried to run the example file provided by Pig_cassandra example, I got this error. [root@localhost pig]# /opt/cassandra/apache-cassandra-1.1.6/examples/pig/bin/pig_cassandra -x local -x local /opt/cassandra/apache-cassandra-1.1.6/examples/pig/example-script.pig Using /opt/pig/pig-0.10.0/pig-0.10.0-withouthadoop.jar. 2012-10-24 21:14:58,551 [main] INFO org.apache.pig.Main - Apache Pig version 0.10.0 (r1328203) compiled Apr 19 2012, 22:54:12 2012-10-24 21:14:58,552 [main] INFO org.apache.pig.Main - Logging error messages to: /opt/pig/pig_1351138498539.log 2012-10-24 21:14:59,004 [main] INFO org.apache.pig.backend.hadoop.executionengine.HExecutionEngine - Connecting to hadoop file system at: file:/// 2012-10-24 21:14:59,472 [main] ERROR org.apache.pig.tools.grunt.Grunt - ERROR 1070: Could not resolve CassandraStorage using imports: [, org.apache.pig.builtin., org.apache.pig.impl.builtin.] Details at logfile: /opt/pig/pig_1351138498539.log Here is the log file Pig Stack Trace --------------- ERROR 1070: Could not resolve CassandraStorage using imports: [, org.apache.pig.builtin., org.apache.pig.impl.builtin.] org.apache.pig.impl.logicalLayer.FrontendException: ERROR 1000: Error during parsing. Could not resolve CassandraStorage using imports: [, org.apache.pig.builtin., org.apache.pig.impl.builtin.] at org.apache.pig.PigServer$Graph.parseQuery(PigServer.java:1597) at org.apache.pig.PigServer$Graph.registerQuery(PigServer.java:1540) at org.apache.pig.PigServer.registerQuery(PigServer.java:540) at org.apache.pig.tools.grunt.GruntParser.processPig(GruntParser.java:970) at org.apache.pig.tools.pigscript.parser.PigScriptParser.parse(PigScriptParser.java:386) at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:189) at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:165) at org.apache.pig.tools.grunt.Grunt.exec(Grunt.java:84) at org.apache.pig.Main.run(Main.java:555) at org.apache.pig.Main.main(Main.java:111) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at org.apache.hadoop.util.RunJar.main(RunJar.java:156) Caused by: Failed to parse: Cannot instantiate: CassandraStorage at org.apache.pig.parser.QueryParserDriver.parse(QueryParserDriver.java:184) at org.apache.pig.PigServer$Graph.parseQuery(PigServer.java:1589) ... 14 more Caused by: java.lang.RuntimeException: Cannot instantiate: CassandraStorage at org.apache.pig.impl.PigContext.instantiateFuncFromSpec(PigContext.java:510) at org.apache.pig.parser.LogicalPlanBuilder.validateFuncSpec(LogicalPlanBuilder.java:791) at org.apache.pig.parser.LogicalPlanBuilder.buildFuncSpec(LogicalPlanBuilder.java:780) at org.apache.pig.parser.LogicalPlanGenerator.func_clause(LogicalPlanGenerator.java:4583) at org.apache.pig.parser.LogicalPlanGenerator.load_clause(LogicalPlanGenerator.java:3115) at org.apache.pig.parser.LogicalPlanGenerator.op_clause(LogicalPlanGenerator.java:1291) at org.apache.pig.parser.LogicalPlanGenerator.general_statement(LogicalPlanGenerator.java:789) at org.apache.pig.parser.LogicalPlanGenerator.statement(LogicalPlanGenerator.java:507) at org.apache.pig.parser.LogicalPlanGenerator.query(LogicalPlanGenerator.java:382) at org.apache.pig.parser.QueryParserDriver.parse(QueryParserDriver.java:175) ... 15 more Caused by: org.apache.pig.backend.executionengine.ExecException: ERROR 1070: Could not resolve CassandraStorage using imports: [, org.apache.pig.builtin., org.apache.pig.impl.builtin.] at org.apache.pig.impl.PigContext.resolveClassName(PigContext.java:495) at org.apache.pig.impl.PigContext.instantiateFuncFromSpec(PigContext.java:507) ... 24 more ================================================================================ I googled around and got to this point from other stackoverflow user that identified the potential problem but not the solution. Cassandra and pig integration cause error during startup I believe my configuration is correct and the path has already been defined properly. I didn't change anything in the pig_cassandra file. I'm not quite sure how to proceed from here. Please help?

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  • IIS 7.5 + Windows Server 2008 R2 + ASP.NET 4.0 HTTP 500 Error?

    - by Dave
    Hi, I'm having an issue I cannot track down and I have looked through the forums and not found anything that sheds any light. I have a fresh install of a Server 2008 R2 Web that I am trying to load an application I created and tested on a Windows 7 machine running IIS 7.5 using ASP.NET 4.0. Everything works fine on the dev machine. But when I used the Web Deployment tool to move it to the server, I now get a HTTP 500 error without a lot of information: Module AspNetInitClrHostFailureModule Notification BeginRequest Handler StaticFile Error Code 0x80070002 Requested URL http://192.168.1.83:80/ Physical Path C:\JustStreamIt Logon Method Not yet determined Logon User Not yet determined Failed Request Tracing Log Directory C:\inetpub\logs\FailedReqLogFiles And in my trace file I get: view trace Warning -SET_RESPONSE_ERROR_DESCRIPTION ErrorDescription An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur. view trace Warning -MODULE_SET_RESPONSE_ERROR_STATUS ModuleName AspNetInitClrHostFailureModule Notification 1 HttpStatus 500 HttpReason Internal Server Error HttpSubStatus 0 ErrorCode 2147942402 ConfigExceptionInfo Notification BEGIN_REQUEST ErrorCode The system cannot find the file specified. (0x80070002) And I get the following in the Application Log: Log Name: Application Source: Microsoft-Windows-IIS-W3SVC-WP Date: 5/28/2010 2:08:10 PM Event ID: 2299 Task Category: None Level: Error Keywords: Classic User: N/A Computer: win-ltfkdo1dnfp Description: An application has reported as being unhealthy. The worker process will now request a recycle. Reason given: An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur. . The data is the error. Event Xml: <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> <System> <Provider Name="Microsoft-Windows-IIS-W3SVC-WP" Guid="{670080D9-742A-4187-8D16-41143D1290BD}" EventSourceName="W3SVC-WP" /> <EventID Qualifiers="49152">2299</EventID> <Version>0</Version> <Level>2</Level> <Task>0</Task> <Opcode>0</Opcode> <Keywords>0x80000000000000</Keywords> <TimeCreated SystemTime="2010-05-28T21:08:10.000000000Z" /> <EventRecordID>1663</EventRecordID> <Correlation /> <Execution ProcessID="0" ThreadID="0" /> <Channel>Application</Channel> <Computer>win-ltfkdo1dnfp</Computer> <Security /> </System> <EventData> <Data Name="Reason">An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur. </Data> <Binary>02000780</Binary> </EventData> </Event> Anyone have a suggestion about where I should start looking?

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  • Connecting debian and windows via IPsec VPN with Racoon and ipsec-tools

    - by Michi Qne
    I've some trouble with the IPsec configuration on my debian server (6 squeeze). This server should connect via IPsec VPN to an windows server, which is protected by an firewall. I've used racoon and ipsec-tools and this tutorial http://wiki.debian.org/IPsec. However, I am not quite sure, if this tutorial fits to my purpose, because of some differences: my Host and my gateway are the same server. So I don't have two different ip addresses. I guess, that's not a problem the other server is an windows system behind a firewall. Hopefully, not a problem the subnet of the windows system is /32 not /24. So I change it to /32. I worked through the tutorial step by step, but I wasn't able to route the ip. The following command didn't work for me: ip route add to 172.16.128.100/32 via XXX.XXX.XXX.XXX src XXX.XXX.XXX.XXX So I tried the following instead: ip route add to 172.16.128.100 .., which obviously not solved the problem. The next problem is the compression. The windows doesn't use a compression, but 'compression_algorithm none;' doesn't work with my racoon. So the current value is 'compression_algorithm deflate;' So my current result looks like this: When I am trying to ping the windows host (ping 172.16.128.100), I receive the following error message from ping: ping: sendmsg: Operation not permitted And racoon logs: racoon: ERROR: failed to get sainfo. After googling for a while I came to no conclusion, what's the solution. Does this error message mean that the first phase of IPsec works? I am thankful for any advice. I guess my configs might be helpful. My racoon.conf looks like this: path pre_shared_key "/etc/racoon/psk.txt"; remote YYY.YYY.YYY.YYY { exchange_mode main; proposal { lifetime time 8 hour; encryption_algorithm 3des; hash_algorithm sha1; authentication_method pre_shared_key; dh_group 2; } } sainfo address XXX.XXX.XXX.XXX/32 any address 172.16.128.100/32 any { pfs_group 2; lifetime time 8 hour; encryption_algorithm aes 256; authentication_algorithm hmac_sha1; compression_algorithm deflate; } And my ipsec-tools.conf looks like this: flush; spdflush; spdadd XXX.XXX.XXX.XXX/32 172.16.128.100/32 any -P out ipsec esp/tunnel/XXX.XXX.XXX.XXX-YYY.YYY.YYY.YYY/require; spdadd 172.16.128.100/32 XXX.XXX.XXX.XXX/32 any -P in ipsec esp/tunnel/YYY.YYY.YYY.YYY-XXX.XXX.XXX.XXX/require; If anyone has an advice, that would be awesome. Thanks in Advance. Greets, Michael It was a simple copy-and-paste error in an ip address.

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  • /etc/rc.local not being run on Ubuntu Desktop Install

    - by loosecannon
    I have been trying to get sphinx to run at boot, so I added some lines to /etc/rc.local but nothing happens when I start up. If i run it manually it works however. /etc/init.d/rc.local start works fine as does /etc/rc.local It's listed in the default runlevel and is all executable but it does not work. I am considering writing a separate init.d script to do the same thing but that's a lot of work for a simple task dumbledore:/etc/init.d# ls -l rc* -rwxr-xr-x 1 root root 8863 2009-09-07 13:58 rc -rwxr-xr-x 1 root root 801 2009-09-07 13:58 rc.local -rwxr-xr-x 1 root root 117 2009-09-07 13:58 rcS dumbledore:/etc/init.d# ls /etc/rc.local -l -rwxr-xr-x 1 root root 491 2011-05-14 16:13 /etc/rc.local dumbledore:/etc/init.d# runlevel N 2 dumbledore:/etc/init.d# ls /etc/rc2.d/ -l total 4 lrwxrwxrwx 1 root root 18 2011-04-22 18:53 K08vmware -> /etc/init.d/vmware -rw-r--r-- 1 root root 677 2011-03-28 15:10 README lrwxrwxrwx 1 root root 18 2011-04-22 18:53 S19vmware -> /etc/init.d/vmware lrwxrwxrwx 1 root root 18 2011-05-15 14:09 S20ddclient -> ../init.d/ddclient lrwxrwxrwx 1 root root 20 2011-03-10 18:00 S20fancontrol -> ../init.d/fancontrol lrwxrwxrwx 1 root root 20 2011-03-10 18:00 S20kerneloops -> ../init.d/kerneloops lrwxrwxrwx 1 root root 27 2011-03-10 18:00 S20speech-dispatcher -> ../init.d/speech-dispatcher lrwxrwxrwx 1 root root 19 2011-03-10 18:00 S25bluetooth -> ../init.d/bluetooth lrwxrwxrwx 1 root root 20 2011-03-10 18:00 S50pulseaudio -> ../init.d/pulseaudio lrwxrwxrwx 1 root root 15 2011-03-10 18:00 S50rsync -> ../init.d/rsync lrwxrwxrwx 1 root root 15 2011-03-10 18:00 S50saned -> ../init.d/saned lrwxrwxrwx 1 root root 19 2011-03-10 18:00 S70dns-clean -> ../init.d/dns-clean lrwxrwxrwx 1 root root 18 2011-03-10 18:00 S70pppd-dns -> ../init.d/pppd-dns lrwxrwxrwx 1 root root 14 2011-05-07 11:22 S75sudo -> ../init.d/sudo lrwxrwxrwx 1 root root 24 2011-03-10 18:00 S90binfmt-support -> ../init.d/binfmt-support lrwxrwxrwx 1 root root 17 2011-05-12 21:18 S91apache2 -> ../init.d/apache2 lrwxrwxrwx 1 root root 22 2011-03-10 18:00 S99acpi-support -> ../init.d/acpi-support lrwxrwxrwx 1 root root 21 2011-03-10 18:00 S99grub-common -> ../init.d/grub-common lrwxrwxrwx 1 root root 18 2011-03-10 18:00 S99ondemand -> ../init.d/ondemand lrwxrwxrwx 1 root root 18 2011-03-10 18:00 S99rc.local -> ../init.d/rc.local dumbledore:/etc/init.d# cat /etc/rc.local #!/bin/sh -e # # rc.local # # This script is executed at the end of each multiuser runlevel. # Make sure that the script will "exit 0" on success or any other # value on error. # # In order to enable or disable this script just change the execution # bits. # # By default this script does nothing. # Start sphinx daemon for rails app on startup # Added 2011-05-13 # Cannon Matthews cd /var/www/extemp /usr/bin/rake ts:config /usr/bin/rake ts:start touch ./tmp/ohyeah cd - exit 0 dumbledore:/etc/init.d# cat /etc/init.d/rc.local #! /bin/sh ### BEGIN INIT INFO # Provides: rc.local # Required-Start: $remote_fs $syslog $all # Required-Stop: # Default-Start: 2 3 4 5 # Default-Stop: # Short-Description: Run /etc/rc.local if it exist ### END INIT INFO PATH=/sbin:/usr/sbin:/bin:/usr/bin . /lib/init/vars.sh . /lib/lsb/init-functions do_start() { if [ -x /etc/rc.local ]; then [ "$VERBOSE" != no ] && log_begin_msg "Running local boot scripts (/etc/rc.local)" /etc/rc.local ES=$? [ "$VERBOSE" != no ] && log_end_msg $ES return $ES fi } case "$1" in start) do_start ;; restart|reload|force-reload) echo "Error: argument '$1' not supported" >&2 exit 3 ;; stop) ;; *) echo "Usage: $0 start|stop" >&2 exit 3 ;; esac

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  • GMail suspects confirmation email in stealing personal information

    - by Dennis Gorelik
    When user registers on my web site, web site sends user email confirmation link. Subject: Please confirm your email address Body:Please open this link in your browser to confirm your email address: http://www.postjobfree.com/a/c301718062444f96ba0e358ea833c9b3 This link will expire on: 6/9/2012 8:04:07 PM EST. If my web site sends that email to GMaill (either @gmail.com or another domain that's handled by Google Apps) and that user never emailed to email -- then GMail not only puts the email to spam folder, but also adds prominent red warning:Be careful with this message. Similar messages were used to steal people's personal information. Unless you trust the sender, don't click links or reply with personal information. Learn more That warning really scares many of my users, so they are afraid to open that link and confirm their email. What can I do about it? Ideally I would like that message end up in user's inbox, not spam folder. But at least how do I prevent that scary message? IP address of my mailing server is not blacklisted: http://www.mxtoolbox.com/SuperTool.aspx?action=blacklist%3a208.43.198.72 I use SPF and DKIM signature. Below is the email that ended up in spam folder with that scary red message. Delivered-To: [email protected] Received: by 10.112.84.98 with SMTP id x2csp36568lby; Fri, 8 Jun 2012 17:04:15 -0700 (PDT) Received: by 10.60.25.6 with SMTP id y6mr9110318oef.42.1339200255375; Fri, 08 Jun 2012 17:04:15 -0700 (PDT) Return-Path: Received: from smtp.postjobfree.com (smtp.postjobfree.com. [208.43.198.72]) by mx.google.com with ESMTP id v8si6058193oev.44.2012.06.08.17.04.14; Fri, 08 Jun 2012 17:04:15 -0700 (PDT) Received-SPF: pass (google.com: domain of [email protected] designates 208.43.198.72 as permitted sender) client-ip=208.43.198.72; Authentication-Results: mx.google.com; spf=pass (google.com: domain of [email protected] designates 208.43.198.72 as permitted sender) [email protected]; dkim=pass [email protected] DomainKey-Signature: a=rsa-sha1; c=nofws; q=dns; d=postjobfree.com; s=postjobfree.com; h= received:message-id:mime-version:from:to:date:subject:content-type; b=TCip/3hP1WWViWB1cdAzMFPjyi/aUKXQbuSTVpEO7qr8x3WdMFhJCqZciA69S0HB4 Koatk2cQQ3fOilr4ledCgZYemLSJgwa/ZRhObnqgPHAglkBy8/RAwkrwaE0GjLKup 0XI6G2wPlh+ReR+inkMwhCPHFInmvrh4evlBx/VlA= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=postjobfree.com; s=postjobfree.com; h=content-type:subject:date:to:from:mime-version:message-id; bh=N59EIgRECIlAnd41LY4HY/OFI+v1p7t5M9yP+3FsKXY=; b=J3/BdZmpjzP4I6GA4ntmi4REu5PpOcmyzEL+6i7y7LaTR8tuc2h7fdW4HaMPlB7za Lj4NJPed61ErumO66eG4urd1UfyaRDtszWeuIbcIUqzwYpnMZ8ytaj8DPcWPE3JYj oKhcYyiVbgiFjLujib3/2k2PqDIrNutRH9Ln7puz4= Received: from sv3035 (sv3035 [208.43.198.72]) by smtp.postjobfree.com with SMTP; Fri, 8 Jun 2012 20:04:07 -0400 Message-ID: MIME-Version: 1.0 From: "PostJobFree Notification" To: [email protected] Date: 8 Jun 2012 20:04:07 -0400 Subject: Please confirm your email address Content-Type: multipart/alternative; boundary=--boundary_107_ffa6a9ea-01dc-40f5-a50c-4c3b3d113f08 ----boundary_107_ffa6a9ea-01dc-40f5-a50c-4c3b3d113f08 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Please open this link in your browser to confirm your email addre= ss: =0D=0Ahttp://www.postjobfree.com/a/c301718062444f96ba0e358ea8= 33c9b3 =0D=0AThis link will expire on: 6/9/2012 8:04:07 PM EST. =0D=0A ----boundary_107_ffa6a9ea-01dc-40f5-a50c-4c3b3d113f08 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: base64 PGh0bWw+PGhlYWQ+PG1ldGEgaHR0cC1lcXVpdj1Db250ZW50LVR5cGUgY29udGVu dD0idGV4dC9odG1sOyBjaGFyc2V0PXV0Zi04Ij48L2hlYWQ+DQo8Ym9keT48ZGl2 Pg0KUGxlYXNlIG9wZW4gdGhpcyBsaW5rIGluIHlvdXIgYnJvd3NlciB0byBjb25m aXJtIHlvdXIgZW1haWwgYWRkcmVzczo8YnIgLz48YSBocmVmPSJodHRwOi8vd3d3 LnBvc3Rqb2JmcmVlLmNvbS9hL2MzMDE3MTgwNjI0NDRmOTZiYTBlMzU4ZWE4MzNj OWIzIj5odHRwOi8vd3d3LnBvc3Rqb2JmcmVlLmNvbS9hL2MzMDE3MTgwNjI0NDRm OTZiYTBlMzU4ZWE4MzNjOWIzPC9hPjxiciAvPlRoaXMgbGluayB3aWxsIGV4cGly ZSBvbjogNi85LzIwMTIgODowNDowNyBQTSBFU1QuPGJyIC8+DQo8L2Rpdj48L2Jv ZHk+PC9odG1sPg== ----boundary_107_ffa6a9ea-01dc-40f5-a50c-4c3b3d113f08--

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  • nginx: How can I set proxy_* directives only for matching URIs?

    - by Artem Russakovskii
    I've been at this for hours and I can't figure out a clean solution. Basically, I have an nginx proxy setup, which works really well, but I'd like to handle a few urls more manually. Specifically, there are 2-3 locations for which I'd like to set proxy_ignore_headers to Set-Cookie to force nginx to cache them (nginx doesn't cache responses with Set-Cookie as per http://wiki.nginx.org/HttpProxyModule#proxy_ignore_headers). So for these locations, all I'd like to do is set proxy_ignore_headers Set-Cookie; I've tried everything I could think of outside of setting up and duplicating every config value, but nothing works. I tried: Nesting location directives, hoping the inner location which matches on my files would just set this value and inherit the rest, but that wasn't the case - it seemed to ignore anything set in the outer location, most notably proxy_pass and I end up with a 404). Specifying the proxy_cache_valid directive in an if block that matches on $request_uri, but nginx complains that it's not allowed ("proxy_cache_valid" directive is not allowed here). Specifying a variable equal to "Set-Cookie" in an if block, and then trying to set proxy_cache_valid to that variable later, but nginx isn't allowing variables for this case and throws up. It should be so simple - modifying/appending a single directive for some requests, and yet I haven't been able to make nginx do that. What am I missing here? Is there at least a way to wrap common directives in a reusable block and have multiple location blocks refer to it, after adding their own unique bits? Thank you. Just for reference, the main location / block is included below, together with my failed proxy_ignore_headers directive for a specific URI. location / { # Setup var defaults set $no_cache ""; # If non GET/HEAD, don't cache & mark user as uncacheable for 1 second via cookie if ($request_method !~ ^(GET|HEAD)$) { set $no_cache "1"; } if ($http_user_agent ~* '(iphone|ipod|ipad|aspen|incognito|webmate|android|dream|cupcake|froyo|blackberry|webos|s8000|bada)') { set $mobile_request '1'; set $no_cache "1"; } # feed crawlers, don't want these to get stuck with a cached version, especially if it caches a 302 back to themselves (infinite loop) if ($http_user_agent ~* '(FeedBurner|FeedValidator|MediafedMetrics)') { set $no_cache "1"; } # Drop no cache cookie if need be # (for some reason, add_header fails if included in prior if-block) if ($no_cache = "1") { add_header Set-Cookie "_mcnc=1; Max-Age=17; Path=/"; add_header X-Microcachable "0"; } # Bypass cache if no-cache cookie is set, these are absolutely critical for Wordpress installations that don't use JS comments if ($http_cookie ~* "(_mcnc|comment_author_|wordpress_(?!test_cookie)|wp-postpass_)") { set $no_cache "1"; } if ($request_uri ~* wpsf-(img|js)\.php) { proxy_ignore_headers Set-Cookie; } # Bypass cache if flag is set proxy_no_cache $no_cache; proxy_cache_bypass $no_cache; # under no circumstances should there ever be a retry of a POST request, or any other request for that matter proxy_next_upstream off; proxy_read_timeout 86400s; # Point nginx to the real app/web server proxy_pass http://localhost; # Set cache zone proxy_cache microcache; # Set cache key to include identifying components proxy_cache_key $scheme$host$request_method$request_uri$mobile_request; # Only cache valid HTTP 200 responses for this long proxy_cache_valid 200 15s; #proxy_cache_min_uses 3; # Serve from cache if currently refreshing proxy_cache_use_stale updating timeout; # Send appropriate headers through proxy_set_header Host $host; # no need for this proxy_set_header X-Real-IP $remote_addr; # no need for this proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; # Set files larger than 1M to stream rather than cache proxy_max_temp_file_size 1M; access_log /var/log/nginx/androidpolice-microcache.log custom; }

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  • OpenSwan IPSec phase #2 complications

    - by XXL
    Phase #1 (IKE) succeeds without any problems (verified at the target host). Phase #2 (IPSec), however, is erroneous at some point (apparently due to misconfiguration on localhost). This should be an IPSec-only connection. I am using OpenSwan on Debian. The error log reads the following (the actual IP-addr. of the remote endpoint has been modified): pluto[30868]: "x" #2: initiating Quick Mode PSK+ENCRYPT+PFS+UP+IKEv2ALLOW+SAREFTRACK {using isakmp#1 msgid:5ece82ee proposal=AES(12)_256-SHA1(2)_160 pfsgroup=OAKLEY_GROUP_DH22} pluto[30868]: "x" #1: ignoring informational payload, type NO_PROPOSAL_CHOSEN msgid=00000000 pluto[30868]: "x" #1: received and ignored informational message pluto[30868]: "x" #1: the peer proposed: 0.0.0.0/0:0/0 - 0.0.0.0/0:0/0 pluto[30868]: "x" #3: responding to Quick Mode proposal {msgid:a4f5a81c} pluto[30868]: "x" #3: us: 192.168.1.76<192.168.1.76[+S=C] pluto[30868]: "x" #3: them: 222.222.222.222<222.222.222.222[+S=C]===10.196.0.0/17 pluto[30868]: "x" #3: transition from state STATE_QUICK_R0 to state STATE_QUICK_R1 pluto[30868]: "x" #3: STATE_QUICK_R1: sent QR1, inbound IPsec SA installed, expecting QI2 pluto[30868]: "x" #1: ignoring informational payload, type NO_PROPOSAL_CHOSEN msgid=00000000 pluto[30868]: "x" #1: received and ignored informational message pluto[30868]: "x" #3: next payload type of ISAKMP Hash Payload has an unknown value: 97 X pluto[30868]: "x" #3: malformed payload in packet pluto[30868]: | payload malformed after IV I am behind NAT and this is all coming from wlan2. Here are the details: default via 192.168.1.254 dev wlan2 proto static 169.254.0.0/16 dev wlan2 scope link metric 1000 192.168.1.0/24 dev wlan2 proto kernel scope link src 192.168.1.76 metric 2 Output of ipsec verify: Checking your system to see if IPsec got installed and started correctly: Version check and ipsec on-path [OK] Linux Openswan U2.6.37/K3.2.0-24-generic (netkey) Checking for IPsec support in kernel [OK] SAref kernel support [N/A] NETKEY: Testing XFRM related proc values [OK] [OK] [OK] Checking that pluto is running [OK] Pluto listening for IKE on udp 500 [OK] Pluto listening for NAT-T on udp 4500 [OK] Two or more interfaces found, checking IP forwarding [OK] Checking NAT and MASQUERADEing [OK] Checking for 'ip' command [OK] Checking /bin/sh is not /bin/dash [WARNING] Checking for 'iptables' command [OK] Opportunistic Encryption Support [DISABLED] This is what happens when I run ipsec auto --up x: 104 "x" #1: STATE_MAIN_I1: initiate 003 "x" #1: received Vendor ID payload [RFC 3947] method set to=109 106 "x" #1: STATE_MAIN_I2: sent MI2, expecting MR2 003 "x" #1: received Vendor ID payload [Cisco-Unity] 003 "x" #1: received Vendor ID payload [Dead Peer Detection] 003 "x" #1: ignoring unknown Vendor ID payload [502099ff84bd4373039074cf56649aad] 003 "x" #1: received Vendor ID payload [XAUTH] 003 "x" #1: NAT-Traversal: Result using RFC 3947 (NAT-Traversal): i am NATed 108 "x" #1: STATE_MAIN_I3: sent MI3, expecting MR3 004 "x" #1: STATE_MAIN_I4: ISAKMP SA established {auth=OAKLEY_PRESHARED_KEY cipher=aes_128 prf=oakley_sha group=modp1024} 117 "x" #2: STATE_QUICK_I1: initiate 010 "x" #2: STATE_QUICK_I1: retransmission; will wait 20s for response 010 "x" #2: STATE_QUICK_I1: retransmission; will wait 40s for response 031 "x" #2: max number of retransmissions (2) reached STATE_QUICK_I1. No acceptable response to our first Quick Mode message: perhaps peer likes no proposal 000 "x" #2: starting keying attempt 2 of at most 3, but releasing whack I have enabled NAT traversal in ipsec.conf accordingly. Here are the settings relative to the connection in question: version 2.0 config setup plutoopts="--perpeerlog" plutoopts="--interface=wlan2" dumpdir=/var/run/pluto/ nat_traversal=yes virtual_private=%v4:10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/12 oe=off protostack=netkey conn x authby=secret pfs=yes auto=add phase2alg=aes256-sha1;dh22 keyingtries=3 ikelifetime=8h type=transport left=192.168.1.76 leftsubnet=192.168.1.0/24 leftprotoport=0/0 right=222.222.222.222 rightsubnet=10.196.0.0/17 rightprotoport=0/0 Here are the specs provided by the other end that must be met for Phase #2: encryption algorithm: AES (128 or 256 bit) hash algorithm: SHA local ident1 (addr/mask/prot/port): (10.196.0.0/255.255.128.0/0/0) local ident2 (addr/mask/prot/port): (10.241.0.0/255.255.0.0/0/0) remote ident (addr/mask/prot/port): (x.x.x.x/x.x.x.x/0/0) (internal network or localhost) Security association lifetime: 4608000 kilobytes/3600 seconds PFS: DH group2 So, finally, what might be the cause of the issue that I am experiencing? Thank you.

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