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  • Telerik Extensions for ASP.NET MVC Q1 2010 is out!

    Today we shipped the Q1 2010 release out of the door. Go download the open source or if you are a licensed customer download it from your client.net account.   What is new on the MVC front is: No longer in BETA New components TreeView, NumericTextBox components, Calendar, DatePicker New features Grid grouping, Grid editing, Grid localization Using jQuery 1.4.2 Lots of bug fixes   The rest is mentioned in the release notes.   Breaking changes from Q1 2010 Futures!!! There is one breaking change since the Q1 2010 Futures release. The Toolbar method of the GridBuilder has been renamed to ToolBar: <%= Html.Telerik().Grid(Model) //.Toolbar(commands => commands.Insert()) <- Old .ToolBar(commands => commands.Insert()) // <- New%> For a complete list of changed API of the grid check the changes and backward compatibility help topic.   By the way if you still havent cast your vote for a new product or feature do it now! We will soon start development for Q2 2010.Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • The DOS DEBUG Environment

    - by MarkPearl
    Today I thought I would go back in time and have a look at the DEBUG command that has been available since the beginning of dawn in DOS, MS-DOS and Microsoft Windows. up to today I always knew it was there, but had no clue on how to use it so for those that are interested this might be a great geek party trick to pull out when you want the awe the younger generation and want to show them what “real” programming is about. But wait, you will have to do it relatively quickly as it seems like DEBUG was finally dumped from the Windows group in Windows 7. Not to worry, pull out that Windows XP box which will get you even more geek points and you can still poke DEBUG a bit. So, for those that are interested and want to find out a bit about the history of DEBUG read the wiki link here. That all put aside, lets get our hands dirty.. How to Start DEBUG in Windows Make sure your version of Windows supports DEBUG. Open up a console window Make a directory where you want to play with debug – in my instance I called it C221 Enter the directory and type Debug You will get a response with a – as illustrated in the image below…   The commands available in DEBUG There are several commands available in DEBUG. The most common ones are A (Assemble) R (Register) T (Trace) G (Go) D (Dump or Display) U (Unassemble) E (Enter) P (Proceed) N (Name) L (Load) W (Write) H (Hexadecimal) I (Input) O (Output) Q (Quit) I am not going to cover all these commands, but what I will do is go through a few of them briefly. A is for Assemble Command (to write code) The A command translates assembly language statements into machine code. It is quite useful for writing small assembly programs. Below I have written a very basic assembly program. The code typed out is as follows mov ax,0015 mov cx,0023 sub cx,ax mov [120],al mov cl,[120]A nop R is for Register (to jump to a point in memory) The r command turns out to be one of the most frequent commands you will use in DEBUG. It allows you to view the contents of registers and to change their values. It can be used with the following combinations… R – Displays the contents of all the registers R f – Displays the flags register R register_name – Displays the contents of a specific register All three methods are illustrated in the image above T is for Trace (To execute a program step by step) The t command allows us to execute the program step by step. Before we can trace the program we need to point back to the beginning of the program. We do this by typing in r ip, which moves us back to memory point 100. We then type trace which executes the first line of code (line 100) (As shown in the image below starting from the red arrow). You can see from the above image that the register AX now contains 0015 as per our instruction mov ax,0015 You can also see that the IP points to line 0103 which has the MOV CX,0023 command If we type t again it will now execute the second line of the program which moves 23 in the cx register. Again, we can see that the line of code was executed and that the CX register now holds the value of 23. What I would like to highlight now is the section underlined in red. These are the status flags. The ones we are going to look at now are 1st (NV), 4th (PL), 5th (NZ) & 8th (NC) NV means no overflow, the alternate would be OV PL means that the sign of the previous arithmetic operation was Plus, the alternate would be NG (Negative) NZ means that the results of the previous arithmetic operation operation was Not Zero, the alternate would be ZR NC means that No final Carry resulted from the previous arithmetic operation. CY means that there was a final Carry. We could now follow this process of entering the t command until the entire program is executed line by line. G is for Go (To execute a program up to a certain line number) So we have looked at executing a program line by line, which is fine if your program is minuscule BUT totally unpractical if we have any decent sized program. A quicker way to run some lines of code is to use the G command. The ‘g’ command executes a program up to a certain specified point. It can be used in connection with the the reset IP command. You would set your initial point and then run the G command with the line you want to end on. P is for Proceed (Similar to trace but slightly more streamlined) Another command similar to trace is the proceed command. All that the p command does is if it is called and it encounters a CALL, INT or LOOP command it terminates the program execution. In the example below I modified our example program to include an int 20 at the end of it as illustrated in the image below… Then when executing the code when I encountered the int 20 command I typed the P command and the program terminated normally (illustrated below). D is for Dump (or for those more polite Display) So, we have all these assembly lines of code, but if you have ever opened up an exe or com file in a text/hex editor, it looks nothing like assembly code. The D command is a way that we can see what our code looks like in memory (or in a hex editor). If we examined the image above, we can see that Debug is storing our assembly code with each instruction following immediately after the previous one. For instance in memory address 110 we have int and 111 we have 20. If we examine the dump of memory we can see at memory point 110 CD is stored and at memory point 111 20 is stored. U is for Unassemble (or Convert Machine code to Assembly Code) So up to now we have gone through a bunch of commands, but probably one of the most useful is the U command. Let’s say we don’t understand machine code so well and so instead we want to see it in its equivalent assembly code. We can type the U command followed by the start memory point, followed by the end memory point and it will show us the assembly code equivalent of the machine code. E is for a bunch of things… The E command can be used for a bunch of things… One example is to enter data or machine code instructions directly into memory. It can also be used to display the contents of memory locations. I am not going to worry to much about it in this post. N / L / W is for Name, Load & Write So we have written out assembly code in debug, and now we want to save it to disk, or write it as a com file or load it. This is where the N, L & W command come in handy. The n command is used to give a name to the executable program file and is pretty simple to use. The w command is a bit trickier. It saves to disk all the memory between point bx and point cx so you need to specify the bx memory address and the cx memory address for it to write your code. Let’s look at an example illustrated below. You do this by calling the r command followed by the either bx or cx. We can then go to the directory where we were working and will see the new file with the name we specified. The L command is relatively simple. You would first specify the name of the file you would like to load using the N command, and then call the L command. Q is for Quit The last command that I am going to write about in this post is the Q command. Simply put, calling the Q command exits DEBUG. Commands we did not Cover Out of the standard DEBUG commands we covered A, T, G, D, U, E, P, R, N, L & W. The ones we did not cover were H, I & O – I might make mention of these in a later post, but for the basics they are not really needed. Some Useful Resources Please note this post is based on the COS2213 handouts for UNISA A Guide to DEBUG - http://mirror.href.com/thestarman/asm/debug/debug.htm#NT

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  • SQL SERVER – Faster SQL Server Databases and Applications – Power and Control with SafePeak Caching Options

    - by Pinal Dave
    Update: This blog post is written based on the SafePeak, which is available for free download. Today, I’d like to examine more closely one of my preferred technologies for accelerating SQL Server databases, SafePeak. Safepeak’s software provides a variety of advanced data caching options, techniques and tools to accelerate the performance and scalability of SQL Server databases and applications. I’d like to look more closely at some of these options, as some of these capabilities could help you address lagging database and performance on your systems. To better understand the available options, it is best to start by understanding the difference between the usual “Basic Caching” vs. SafePeak’s “Dynamic Caching”. Basic Caching Basic Caching (or the stale and static cache) is an ability to put the results from a query into cache for a certain period of time. It is based on TTL, or Time-to-live, and is designed to stay in cache no matter what happens to the data. For example, although the actual data can be modified due to DML commands (update/insert/delete), the cache will still hold the same obsolete query data. Meaning that with the Basic Caching is really static / stale cache.  As you can tell, this approach has its limitations. Dynamic Caching Dynamic Caching (or the non-stale cache) is an ability to put the results from a query into cache while maintaining the cache transaction awareness looking for possible data modifications. The modifications can come as a result of: DML commands (update/insert/delete), indirect modifications due to triggers on other tables, executions of stored procedures with internal DML commands complex cases of stored procedures with multiple levels of internal stored procedures logic. When data modification commands arrive, the caching system identifies the related cache items and evicts them from cache immediately. In the dynamic caching option the TTL setting still exists, although its importance is reduced, since the main factor for cache invalidation (or cache eviction) become the actual data updates commands. Now that we have a basic understanding of the differences between “basic” and “dynamic” caching, let’s dive in deeper. SafePeak: A comprehensive and versatile caching platform SafePeak comes with a wide range of caching options. Some of SafePeak’s caching options are automated, while others require manual configuration. Together they provide a complete solution for IT and Data managers to reach excellent performance acceleration and application scalability for  a wide range of business cases and applications. Automated caching of SQL Queries: Fully/semi-automated caching of all “read” SQL queries, containing any types of data, including Blobs, XMLs, Texts as well as all other standard data types. SafePeak automatically analyzes the incoming queries, categorizes them into SQL Patterns, identifying directly and indirectly accessed tables, views, functions and stored procedures; Automated caching of Stored Procedures: Fully or semi-automated caching of all read” stored procedures, including procedures with complex sub-procedure logic as well as procedures with complex dynamic SQL code. All procedures are analyzed in advance by SafePeak’s  Metadata-Learning process, their SQL schemas are parsed – resulting with a full understanding of the underlying code, objects dependencies (tables, views, functions, sub-procedures) enabling automated or semi-automated (manually review and activate by a mouse-click) cache activation, with full understanding of the transaction logic for cache real-time invalidation; Transaction aware cache: Automated cache awareness for SQL transactions (SQL and in-procs); Dynamic SQL Caching: Procedures with dynamic SQL are pre-parsed, enabling easy cache configuration, eliminating SQL Server load for parsing time and delivering high response time value even in most complicated use-cases; Fully Automated Caching: SQL Patterns (including SQL queries and stored procedures) that are categorized by SafePeak as “read and deterministic” are automatically activated for caching; Semi-Automated Caching: SQL Patterns categorized as “Read and Non deterministic” are patterns of SQL queries and stored procedures that contain reference to non-deterministic functions, like getdate(). Such SQL Patterns are reviewed by the SafePeak administrator and in usually most of them are activated manually for caching (point and click activation); Fully Dynamic Caching: Automated detection of all dependent tables in each SQL Pattern, with automated real-time eviction of the relevant cache items in the event of “write” commands (a DML or a stored procedure) to one of relevant tables. A default setting; Semi Dynamic Caching: A manual cache configuration option enabling reducing the sensitivity of specific SQL Patterns to “write” commands to certain tables/views. An optimization technique relevant for cases when the query data is either known to be static (like archive order details), or when the application sensitivity to fresh data is not critical and can be stale for short period of time (gaining better performance and reduced load); Scheduled Cache Eviction: A manual cache configuration option enabling scheduling SQL Pattern cache eviction based on certain time(s) during a day. A very useful optimization technique when (for example) certain SQL Patterns can be cached but are time sensitive. Example: “select customers that today is their birthday”, an SQL with getdate() function, which can and should be cached, but the data stays relevant only until 00:00 (midnight); Parsing Exceptions Management: Stored procedures that were not fully parsed by SafePeak (due to too complex dynamic SQL or unfamiliar syntax), are signed as “Dynamic Objects” with highest transaction safety settings (such as: Full global cache eviction, DDL Check = lock cache and check for schema changes, and more). The SafePeak solution points the user to the Dynamic Objects that are important for cache effectiveness, provides easy configuration interface, allowing you to improve cache hits and reduce cache global evictions. Usually this is the first configuration in a deployment; Overriding Settings of Stored Procedures: Override the settings of stored procedures (or other object types) for cache optimization. For example, in case a stored procedure SP1 has an “insert” into table T1, it will not be allowed to be cached. However, it is possible that T1 is just a “logging or instrumentation” table left by developers. By overriding the settings a user can allow caching of the problematic stored procedure; Advanced Cache Warm-Up: Creating an XML-based list of queries and stored procedure (with lists of parameters) for periodically automated pre-fetching and caching. An advanced tool allowing you to handle more rare but very performance sensitive queries pre-fetch them into cache allowing high performance for users’ data access; Configuration Driven by Deep SQL Analytics: All SQL queries are continuously logged and analyzed, providing users with deep SQL Analytics and Performance Monitoring. Reduce troubleshooting from days to minutes with database objects and SQL Patterns heat-map. The performance driven configuration helps you to focus on the most important settings that bring you the highest performance gains. Use of SafePeak SQL Analytics allows continuous performance monitoring and analysis, easy identification of bottlenecks of both real-time and historical data; Cloud Ready: Available for instant deployment on Amazon Web Services (AWS). As you can see, there are many options to configure SafePeak’s SQL Server database and application acceleration caching technology to best fit a lot of situations. If you’re not familiar with their technology, they offer free-trial software you can download that comes with a free “help session” to help get you started. You can access the free trial here. Also, SafePeak is available to use on Amazon Cloud. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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  • Visual Studio 2010 tip: Cut empty lines

    - by koevoeter
    How many times you wanted to move 2 lines by cut and pasting them, but the line you cut last is actually a blank line and your actual code is removed from the clipboard? Visual Studio 2010 has an option that keeps cutting blank lines from overwriting the clipboard. Go and uncheck this one: Tools » Options » Text Editor » All Languages » General » Apply Cut or Copy commands to blank lines when there is no selection Extra (related) tip The (free) Visual Studio 2010 extension Visual Studio 2010 Pro Power Tools contains (apart from a bunch of other handy features) the commands Edit.MoveLineUp and Edit.MoveLineDown to do whatever they say they do and maps them automatically to keyboard shortcuts Alt+Up & Alt+Down. Resharper (not-free) has similar commands for moving lines, by default mapped to Ctrl+Alt+Shift+Up/Down.

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  • Get and Set property accessors are ‘actually’ methods

    - by nmarun
    Well, they are ‘special’ methods, but they indeed are methods. See the class below: 1: public class Person 2: { 3: private string _name; 4:  5: public string Name 6: { 7: get 8: { 9: return _name; 10: } 11: set 12: { 13: if (value == "aaa") 14: { 15: throw new ArgumentException("Invalid Name"); 16: } 17: _name = value; 18: } 19: } 20:  21: public void Save() 22: { 23: Console.WriteLine("Saving..."); 24: } 25: } Ok, so a class with a field, a property with the get and set accessors and a method. Now my calling code says: 1: static void Main() 2: { 3: try 4: { 5: Person person1 = new Person 6: { 7: Name = "aaa", 8: }; 9:  10: } 11: catch (Exception ex) 12: { 13: Console.WriteLine(ex.Message); 14: Console.WriteLine(ex.StackTrace); 15: Console.WriteLine("--------------------"); 16: } 17: } When the code is run, you’ll get the following exception message displayed: Now, you see the first line of the stack trace where it says that the exception was thrown in the method set_Name(String value). Wait a minute, we have not declared any method with that name in our Person class. Oh no, we actually have. When you create a property, this is what happens behind the screen. The CLR creates two methods for each get and set property accessor. Let’s look at the signature once again: set_Name(String value) This also tells you where the ‘value’ keyword comes from in our set property accessor. You’re actually wiring up a method parameter to a field. 1: set 2: { 3: if (value == "aaa") 4: { 5: throw new ArgumentException("Invalid Name"); 6: } 7: _name = value; 8: } Digging deeper on this, I ran the ILDasm tool and this is what I see: We see the ‘free’ constructor (named .ctor) that the compiler gives us, the _name field, the Name property and the Save method. We also see the get_Name and set_Name methods. In order to compare the Save and the set_Name methods, I double-clicked on the two methods and this is what I see: The ‘.method’ keyword tells that both Save and set_Name are both methods (no guessing there!). Seeing the set_Name method as a public method did kinda surprise me. So I said, why can’t I do a person1.set_Name(“abc”) since it is declared as public. This cannot be done because the get_Name and set_Name methods have an extra attribute called ‘specialname’. This attribute is used to identify an IL (Intermediate Language) token that can be treated with special care by the .net language. So the thumb-rule is that any method with the ‘specialname’ attribute cannot be generally called / invoked by the user (a simple test using intellisense proves this). Their functionality is exposed through other ways. In our case, this is done through the property itself. The same concept gets extended to constructors as well making them special methods too. These so-called ‘special’ methods can be identified through reflection. 1: static void ReflectOnPerson() 2: { 3: Type personType = typeof(Person); 4:  5: MethodInfo[] methods = personType.GetMethods(); 6:  7: for (int i = 0; i < methods.Length; i++) 8: { 9: Console.Write("Method: {0}", methods[i].Name); 10: // Determine whether or not each method is a special name. 11: if (methods[i].IsSpecialName) 12: { 13: Console.Write(" has 'SpecialName' attribute"); 14: } 15: Console.WriteLine(); 16: } 17: } Line 11 shows the ‘IsSpecialName’ boolean property. So a method with a ‘specialname’ attribute gets mapped to the IsSpecialName property. The output is displayed as: Wuhuuu! There they are.. our special guests / methods. Verdict: Getting to know the internals… helps!

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  • frame lock networking

    - by kochol
    I'm developing an RTS game and I want to add multiplayer support to my game. I picked the easiest technique to implement for start frame locking technique. I used server client networking architecture (I think it's my first mistake I think using peer to peer is a better one for this) On game update every clients send their commands and maybe receive some command then render the frame and wait for all clients to send their update complete message then all of them can go for the next frame. I send commands and all logic is calculated on the clients based on commands but the clients can go out of sync easily. Every AI controlled units make different decisions on each clients What I have to do to sync my game? Do you suggest me a better network architecture or technique?

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  • 8 Ways to Tweak and Configure Sudo on Ubuntu

    - by Chris Hoffman
    Like most things on Linux, the sudo command is very configurable. You can have sudo run specific commands without asking for a password, restrict specific users to only approved commands, log commands run with sudo, and more. The sudo command’s behavior is controlled by the /etc/sudoers file on your system. This command must be edited with the visudo command, which performs syntax-checking to ensure you don’t accidentally break the file. HTG Explains: What Is Windows RT and What Does It Mean To Me? HTG Explains: How Windows 8′s Secure Boot Feature Works & What It Means for Linux Hack Your Kindle for Easy Font Customization

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  • mysql does not start or work

    - by Artem Moskalev
    Recently I installed LAMP with tasksel. Then I remember I issued some commands to get into the mysql console - it worked. Right now I checked - apache and php modules work perfectly. But as for mysql - whatever commands I issue - it does not start the console. It writes: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' How can I fix it and start mysql? Why did this happen? Where is it installed (I used the default location for the installation), because I dont understand what is started when I issue the commands?

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  • How to get working cups command line tools on Server 14.04

    - by Nick
    It looks like some of the commands like lpr and lprm have broken versions that don't work with cups. These commands worked properly on 10.04. lpr for cups has an -o option, but no lpr is intalled when cups is installed, and the lpr installed with apt-get install lpr does not have the -o option and does not appear to be the cups version of lpr. man lpr shows BSD General Commands Manual at the top, where man lpr on the Ubuntu 10.04 server said Apple, inc in the same spot. which leads me to believe the "wrong" lpr is in the "lpr" package or package names got moved around. There is also a lprng package, but trying to install it wants to remove cups and cups-client. lprm also returns lprm: PrinterName: unknown printer when PrinterName is in fact a valid printer installed with cups and does appear in lpstat -t. How do I get the proper cups versions of lpr working on Server 14.04?

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  • Oracle Data Integrator Demo Webcast - Next Webcast - November 21st, 2013

    - by Javier Puerta
    Oracle Data Integrator Demo Webcast Next Webcast - November 21st, 2013 The ODI Product Management team will be hosting a demonstration webcast of Oracle Data Integrator regularly. We will be showing baseline functionality, and covering special topics as requested by our customers. Attendance to these webcasts is open to customers and partners Webcast Format The same format for the Webcast will be followed for each presentation: 05 minutes - Background & Overview 30 minutes - Introduction to ODI Features 15 minutes - Drill-Down into Special Topics 10 minutes - Questions and Answers Next Webcast Special Topics Oracle Data Integrator 12c Webcast Details Thursday November 21st 2013, 10:00 AM PST | 1:00 PM EST | 6:00 PM CET (1 hour) Web Conference Link: 594 942 837 (https://oracleconferencing.webex.com) Dial-In Number: AMER: 1-866-682-4770 (More Numbers) Phone Meeting ID/Passcode: 3096713/505638 More information on Oracle Data Integrator (ODI) Learn more about Oracle Data Integrator. Download Oracle Data Integrator 12c. Oracle Data Integrator Webcast Archive Copyright © 2013, Oracle. All rights reserved. Contact Us | Legal Notices and Terms of Use | Privacy Statement

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  • ScreenManagement how do I had different controls?

    - by DiasFrancisco
    I saw a question here using DataTemplates with WPF for ScreenManagement, I was curious and I gave it a try I think the ideia is amazing and very clean. Though I'm new to WPF and I read a lot of times that almost everything should be made in XAML and very little should be "coded behind". My questions resolves about using the datatemplate ideia, WHERE should the code that calls the transitions be? where should I define which commands are avaiable in which screens. For example: [ScreenA] Commands: Pressing B - Goes to state B Pressing ESC - Exits [ScreenB] Commands: Pressing A - Goes to state A Pressing SPACE - Exits where do I define the keyEventHandlers? and where do I call the next screen? I'm doing this as an hobby for learning and "if you are learning, better learn it right" :) Thank you for your time.

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  • trouble detecing huawei EC156 in ubuntu 12.04

    - by naina
    the data card is never detected automatically...its detected only when i fire a lsusb. Later i give modeswitch commands etc etc...then the device works fine..i can easily use internet...but once i disconnect from the net, its impossible to reestablish the connection...to reconnect i have to type all the commands, starting with lsusb, in the terminal again..ie every time i want a connection i have to sit and type 5-6 commands in the terminal before i can get through. what can be done to get automatic net connection as soon as i plug in the data card...please help...

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  • Search engine bots accessing strange URLs

    - by casasoft
    We have ELMAH enabled on our site and get errors whenever a Page Not Found error is triggered on the website. We have recently redesigned a new website and so we understand that search engine robots might have previously indexed pages which they try to access and result in a Page Not Found errors. For this reason, we have set up permanent redirects for such previously indexed pages to the respective new pages. The website in mention is www.chambercollege.com and for example, a previously indexed URL was www.chambercollege.com/special-offers.aspx. This page is no longer accessible so we have created the necessary permanent redirect to redirect to the respective page on www.chambercollege.com/en/content/special-offers-161/. Now we are starting to receive Page Not Found errors of search engine bots (e.g. MSN bot) trying to access the URL www.chambercollege.com/special-offers.aspx/images/shadow_right.jpg/. Any idea how could a search engine make up that strange URL and whether you have any suggestions of what to do best?

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  • Tools to diagnose Ubuntu problems

    - by Luis Alvarado
    Over time a user will have several problems with Ubuntu as any other OS in the world. What tools and terminal commands exist in Ubuntu to help diagnose how the problem occurred and help solve it if it can be done. Problems like: Ubuntu Freezes after X time or when using Y app Ubuntu rebooted/hibernated/suspended all by itself Ubuntu not showing video or video has problems Ubuntu not making any sound or sound has problems Ubuntu not reading X drive (Pen drive, Internal Drive, External Drive...) Ubuntu slow Ubuntu not working with X hardware when connected Ubuntu network problem Normally there is a couple of GUI tools or Terminal commands that Ubuntu experts typically mention first to use to do a first diagnosis of this. What GUI tools (in case the problem is not related to video or limits the user from using the GUI) and Terminal commands (In case GUI is not working) can a user use to diagnose and help himself to how to find/fix the problem.

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  • First Typemock Academy - 4 days from now

    This April 27th marks a special occasion for Typemock the first Typemock Partner Conference is about to take place in Oslo, Norway. Some special treats are expected (including a very cool after party), and Uncle Bob Martin and myself will be doing a special Q&A video conference live with the attendees as part of it. Attendance is by invite only, but you can see if youre eligible by going to this page and filling out your details. ...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • How can I estimate the entropy of a password?

    - by Wug
    Having read various resources about password strength I'm trying to create an algorithm that will provide a rough estimation of how much entropy a password has. I'm trying to create an algorithm that's as comprehensive as possible. At this point I only have pseudocode, but the algorithm covers the following: password length repeated characters patterns (logical) different character spaces (LC, UC, Numeric, Special, Extended) dictionary attacks It does NOT cover the following, and SHOULD cover it WELL (though not perfectly): ordering (passwords can be strictly ordered by output of this algorithm) patterns (spatial) Can anyone provide some insight on what this algorithm might be weak to? Specifically, can anyone think of situations where feeding a password to the algorithm would OVERESTIMATE its strength? Underestimations are less of an issue. The algorithm: // the password to test password = ? length = length(password) // unique character counts from password (duplicates discarded) uqlca = number of unique lowercase alphabetic characters in password uquca = number of uppercase alphabetic characters uqd = number of unique digits uqsp = number of unique special characters (anything with a key on the keyboard) uqxc = number of unique special special characters (alt codes, extended-ascii stuff) // algorithm parameters, total sizes of alphabet spaces Nlca = total possible number of lowercase letters (26) Nuca = total uppercase letters (26) Nd = total digits (10) Nsp = total special characters (32 or something) Nxc = total extended ascii characters that dont fit into other categorys (idk, 50?) // algorithm parameters, pw strength growth rates as percentages (per character) flca = entropy growth factor for lowercase letters (.25 is probably a good value) fuca = EGF for uppercase letters (.4 is probably good) fd = EGF for digits (.4 is probably good) fsp = EGF for special chars (.5 is probably good) fxc = EGF for extended ascii chars (.75 is probably good) // repetition factors. few unique letters == low factor, many unique == high rflca = (1 - (1 - flca) ^ uqlca) rfuca = (1 - (1 - fuca) ^ uquca) rfd = (1 - (1 - fd ) ^ uqd ) rfsp = (1 - (1 - fsp ) ^ uqsp ) rfxc = (1 - (1 - fxc ) ^ uqxc ) // digit strengths strength = ( rflca * Nlca + rfuca * Nuca + rfd * Nd + rfsp * Nsp + rfxc * Nxc ) ^ length entropybits = log_base_2(strength) A few inputs and their desired and actual entropy_bits outputs: INPUT DESIRED ACTUAL aaa very pathetic 8.1 aaaaaaaaa pathetic 24.7 abcdefghi weak 31.2 H0ley$Mol3y_ strong 72.2 s^fU¬5ü;y34G< wtf 88.9 [a^36]* pathetic 97.2 [a^20]A[a^15]* strong 146.8 xkcd1** medium 79.3 xkcd2** wtf 160.5 * these 2 passwords use shortened notation, where [a^N] expands to N a's. ** xkcd1 = "Tr0ub4dor&3", xkcd2 = "correct horse battery staple" The algorithm does realize (correctly) that increasing the alphabet size (even by one digit) vastly strengthens long passwords, as shown by the difference in entropy_bits for the 6th and 7th passwords, which both consist of 36 a's, but the second's 21st a is capitalized. However, they do not account for the fact that having a password of 36 a's is not a good idea, it's easily broken with a weak password cracker (and anyone who watches you type it will see it) and the algorithm doesn't reflect that. It does, however, reflect the fact that xkcd1 is a weak password compared to xkcd2, despite having greater complexity density (is this even a thing?). How can I improve this algorithm? Addendum 1 Dictionary attacks and pattern based attacks seem to be the big thing, so I'll take a stab at addressing those. I could perform a comprehensive search through the password for words from a word list and replace words with tokens unique to the words they represent. Word-tokens would then be treated as characters and have their own weight system, and would add their own weights to the password. I'd need a few new algorithm parameters (I'll call them lw, Nw ~= 2^11, fw ~= .5, and rfw) and I'd factor the weight into the password as I would any of the other weights. This word search could be specially modified to match both lowercase and uppercase letters as well as common character substitutions, like that of E with 3. If I didn't add extra weight to such matched words, the algorithm would underestimate their strength by a bit or two per word, which is OK. Otherwise, a general rule would be, for each non-perfect character match, give the word a bonus bit. I could then perform simple pattern checks, such as searches for runs of repeated characters and derivative tests (take the difference between each character), which would identify patterns such as 'aaaaa' and '12345', and replace each detected pattern with a pattern token, unique to the pattern and length. The algorithmic parameters (specifically, entropy per pattern) could be generated on the fly based on the pattern. At this point, I'd take the length of the password. Each word token and pattern token would count as one character; each token would replace the characters they symbolically represented. I made up some sort of pattern notation, but it includes the pattern length l, the pattern order o, and the base element b. This information could be used to compute some arbitrary weight for each pattern. I'd do something better in actual code. Modified Example: Password: 1234kitty$$$$$herpderp Tokenized: 1 2 3 4 k i t t y $ $ $ $ $ h e r p d e r p Words Filtered: 1 2 3 4 @W5783 $ $ $ $ $ @W9001 @W9002 Patterns Filtered: @P[l=4,o=1,b='1'] @W5783 @P[l=5,o=0,b='$'] @W9001 @W9002 Breakdown: 3 small, unique words and 2 patterns Entropy: about 45 bits, as per modified algorithm Password: correcthorsebatterystaple Tokenized: c o r r e c t h o r s e b a t t e r y s t a p l e Words Filtered: @W6783 @W7923 @W1535 @W2285 Breakdown: 4 small, unique words and no patterns Entropy: 43 bits, as per modified algorithm The exact semantics of how entropy is calculated from patterns is up for discussion. I was thinking something like: entropy(b) * l * (o + 1) // o will be either zero or one The modified algorithm would find flaws with and reduce the strength of each password in the original table, with the exception of s^fU¬5ü;y34G<, which contains no words or patterns.

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  • In choosing a service-oriented architecture framework that needs to work with .NET and with Java, what to look for?

    - by cm007
    I planning to write an application in which there will be a service (call it A) listening for particular commands. This service will then relay those commands to other services (call them B and C) which are written, respectively, in .NET and Java (service A chooses which of service B or C to which to relay depending on the contents of the request to service A). I am looking for a framework that will allow for interoperability with both .NET and with Java, for example WCF or JAX-WS, or writing a custom framework (e.g., JSON REST commands over HTTP, similar to http://code.google.com/p/selenium/wiki/JsonWireProtocol). What questions/aspects should I consider in deciding?

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  • concurrency::accelerator_view

    - by Daniel Moth
    Overview We saw previously that accelerator represents a target for our C++ AMP computation or memory allocation and that there is a notion of a default accelerator. We ended that post by introducing how one can obtain accelerator_view objects from an accelerator object through the accelerator class's default_view property and the create_view method. The accelerator_view objects can be thought of as handles to an accelerator. You can also construct an accelerator_view given another accelerator_view (through the copy constructor or the assignment operator overload). Speaking of operator overloading, you can also compare (for equality and inequality) two accelerator_view objects between them to determine if they refer to the same underlying accelerator. We'll see later that when we use concurrency::array objects, the allocation of data takes place on an accelerator at array construction time, so there is a constructor overload that accepts an accelerator_view object. We'll also see later that a new concurrency::parallel_for_each function overload can take an accelerator_view object, so it knows on what target to execute the computation (represented by a lambda that the parallel_for_each also accepts). Beyond normal usage, accelerator_view is a quality of service concept that offers isolation to multiple "consumers" of an accelerator. If in your code you are accessing the accelerator from multiple threads (or, in general, from different parts of your app), then you'll want to create separate accelerator_view objects for each thread. flush, wait, and queuing_mode When you create an accelerator_view via the create_view method of the accelerator, you pass in an option of immediate or deferred, which are the two members of the queuing_mode enum. At any point you can access this value from the queuing_mode property of the accelerator_view. When the queuing_mode value is immediate (which is the default), any commands sent to the device such as kernel invocations and data transfers (e.g. parallel_for_each and copy, as we'll see in future posts), will get submitted as soon as the runtime sees fit (that is the definition of immediate). When the value of queuing_mode is deferred, the commands will be batched up. To send all buffered commands to the device for execution, there is a non-blocking flush method that you can call. If you wish to block until all the commands have been sent, there is a wait method you can call. Deferring is a more advanced scenario aimed at performance gains when you are submitting many device commands and you want to avoid the tiny overhead of flushing/submitting each command separately. Querying information Just like accelerator, accelerator_view exposes the is_debug and version properties. In fact, you can always access the accelerator object from the accelerator property on the accelerator_view class to access the accelerator interface we looked at previously. Interop with D3D (aka DX) In a later post I'll show an example of an app that uses C++ AMP to compute data that is used in pixel shaders. In those scenarios, you can benefit by integrating C++ AMP into your graphics pipeline and one of the building blocks for that is being able to use the same device context from both the compute kernel and the other shaders. You can do that by going from accelerator_view to device context (and vice versa), through part of our interop API in amp.h: *get_device, create_accelerator_view. More on those in a later post. Comments about this post by Daniel Moth welcome at the original blog.

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  • C# UserControl Custom Properties

    - by kjward
    i am creating a usercontrol which provides all of the common validations for a range of textbox styles: alpha, number, decimal, SSN, etc. so, when a developer using this control selects the alpha style, they can also select another property which defines a string of special characters that could also be allowed during validation. but when the decimal style, for instance, is selected, i'd like to simply disable the special characters property so it is not settable when a style is selected that doesn't allow special characters. how can i achieve this goal? thanks

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  • php regex for strong password validation

    - by Jason
    Hello, I've seen around the web the following regex (?=^.{8,}$)((?=.*\d)|(?=.*\W+))(?![.\n])(?=.*[A-Z])(?=.*[a-z]).*$ which validates only if the string: * contain at least (1) upper case letter * contain at least (1) lower case letter * contain at least (1) number or special character * contain at least (8) characters in length I'd like to know how to convert this regex so that it checks the string to * contain at least (2) upper case letter * contain at least (2) lower case letter * contain at least (2) digits * contain at least (2) special character * contain at least (8) characters in length well if it contains at least 2 upper,lower,digits and special chars then I wouldn't need the 8 characters length. special characters include: `~!@#$%^&*()_-+=[]\|{};:'".,/<? thanks in advance.

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  • Remove a keyboard shortcut binding in Visual Studio using Macros

    - by Pete
    Hi. I have a lot of custom keyboard shortcuts set up. To avoid having to set them up every time I install a new visual studio (happens quite a lot currectly, with VS2010 being in beta/RC) I have created a macro, that sets up all my custom commands, like this: DTE.Commands.Item("ReSharper.ReSharper_UnitTest_RunSolution").Bindings = "Global::Ctrl+T, Ctrl+A" My main problem is that Ctrl+T is set up to map to the transpose char command by default. So I want to remove that default value in my macro. I have tried the following two lines, but both throw an exception DTE.Commands.Item("Edit.CharTranspose").Bindings = "" DTE.Commands.Item("Edit.CharTranspose").Bindings = Nothing Although they kind of work, because they actually remove the binding ;) But I would prefer the solution that doesn't throw an exception. How is that done?

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  • How to get entire input string in Lex and Yacc?

    - by DevDevDev
    OK, so here is the deal. In my language I have some commands, say XYZ 3 5 GGB 8 9 HDH 8783 33 And in my Lex file XYZ { return XYZ; } GGB { return GGB; } HDH { return HDH; } [0-9]+ { yylval.ival = atoi(yytext); return NUMBER; } \n { return EOL; } In my yacc file start : commands ; commands : command | command EOL commands ; command : xyz | ggb | hdh ; xyz : XYZ NUMBER NUMBER { /* Do something with the numbers */ } ; etc. etc. etc. etc. My question is, how can I get the entire text XYZ 3 5 GGB 8 9 HDH 8783 33 Into commands while still returning the NUMBERs? Also when my Lex returns a STRING [0-9a-zA-Z]+, and I want to do verification on it's length, should I do it like rule: STRING STRING { if (strlen($1) < 5 ) /* Do some shit else error */ } or actually have a token in my Lex that returns different tokens depending on length?

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  • jQuery Corners and IE Problems

    - by Tom
    Hi Guys, I am using "malsups" jQuery corner plugin - http://jquery.malsup.com/corner/ - and having a bit of nightmare of a time with IE. Basically I have <ol><li> <span class="main"> <span class="test1"></span> <span class="test2"></span> <span class="test3"> <span id="test4"></span> <span id="special" class="special"> <span class="test4">TEXT</span> </span> </span> </li></ol> Basically, in IE when I try and make the id="special" have rounded corners - i get a distorted view. I think its something related to problems with referencing li elements using jQuery('#special').corner('5px'); Could anyone help :) ?

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  • How to find DLL EntryPoint?

    - by Kovu
    Hi, simple question: How I can find out commands for a DLLImport in C#.Net and / or the Entry Points of the DLL? Background: I will use the MobileDevice-Libary from ITunes to send commands to an Iphone. I know round about 90% of the DLL-Commands from another open source project, but there are still 10% left, and I need a command of this 10%.

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  • Problem with starting OpenOffice service (soffice) from Java (command working in commandline, but no

    - by Shervin
    I want to exceute a simple command which works from the shell but doesn't work from Java. This is the command I want to execute, which works fine: soffice -headless "-accept=socket,host=localhost,port=8100;urp;" This is the code I am excecuting from Java trying to run this command: String[] commands = new String[] {"soffice","-headless","\"-accept=socket,host=localhost,port=8100;urp;\""}; Process process = Runtime.getRuntime().exec(commands) int code = process.waitFor(); if(code == 0) System.out.println("Commands executed successfully"); When I run this program I get "Commands executed successfully". However the process is not running when the program finishes. Is it possible that the JVM kills the program after it has run? Why doesn't this work?

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