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RNGCryptoServiceProvider Class
Visual Studio 2010
Implements a cryptographic Random Number Generator (RNG) using the implementation provided by the cryptographic service provider (CSP). This class cannot be inherited.
System::Object
System.Security.Cryptography::RandomNumberGenerator
System.Security.Cryptography::RNGCryptoServiceProvider
System.Security.Cryptography::RandomNumberGenerator
System.Security.Cryptography::RNGCryptoServiceProvider
Assembly: mscorlib (in mscorlib.dll)
The RNGCryptoServiceProvider type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | RNGCryptoServiceProvider() | Initializes a new instance of the RNGCryptoServiceProvider class. |
![]() | RNGCryptoServiceProvider(array<Byte>) | Initializes a new instance of the RNGCryptoServiceProvider class. |
![]() | RNGCryptoServiceProvider(CspParameters) | Initializes a new instance of the RNGCryptoServiceProvider class with the specified parameters. |
![]() | RNGCryptoServiceProvider(String) | Initializes a new instance of the RNGCryptoServiceProvider class. |
| Name | Description | |
|---|---|---|
![]() | Dispose() | When overridden in a derived class, releases all resources used by the current instance of the RandomNumberGenerator class. (Inherited from RandomNumberGenerator.) |
![]() | Dispose(Boolean) | When overridden in a derived class, releases the unmanaged resources used by the RandomNumberGenerator and optionally releases the managed resources. (Inherited from RandomNumberGenerator.) |
![]() | Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
![]() | GetBytes | Fills an array of bytes with a cryptographically strong sequence of random values. (Overrides RandomNumberGenerator::GetBytes(array<Byte>).) |
![]() | GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
![]() | GetNonZeroBytes | Fills an array of bytes with a cryptographically strong sequence of random nonzero values. (Overrides RandomNumberGenerator::GetNonZeroBytes(array<Byte>).) |
![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
The following code example shows how to create a random number with the RNGCryptoServiceProvider class.
//The following sample uses the Cryptography class to simulate the roll of a dice. using namespace System; using namespace System::IO; using namespace System::Text; using namespace System::Security::Cryptography; ref class RNGCSP { public: // Main method. static void Main() { const int totalRolls = 25000; array<int>^ results = gcnew array<int>(6); // Roll the dice 25000 times and display // the results to the console. for (int x = 0; x < totalRolls; x++) { Byte roll = RollDice((Byte)results->Length); results[roll - 1]++; } for (int i = 0; i < results->Length; ++i) { Console::WriteLine("{0}: {1} ({2:p1})", i + 1, results[i], (double)results[i] / (double)totalRolls); } } // This method simulates a roll of the dice. The input parameter is the // number of sides of the dice. static Byte RollDice(Byte numberSides) { if (numberSides <= 0) throw gcnew ArgumentOutOfRangeException("numberSides"); // Create a new instance of the RNGCryptoServiceProvider. RNGCryptoServiceProvider^ rngCsp = gcnew RNGCryptoServiceProvider(); // Create a byte array to hold the random value. array<Byte>^ randomNumber = gcnew array<Byte>(1); do { // Fill the array with a random value. rngCsp->GetBytes(randomNumber); } while (!IsFairRoll(randomNumber[0], numberSides)); // Return the random number mod the number // of sides. The possible values are zero- // based, so we add one. return (Byte)((randomNumber[0] % numberSides) + 1); } private: static bool IsFairRoll(Byte roll, Byte numSides) { // There are MaxValue / numSides full sets of numbers that can come up // in a single byte. For instance, if we have a 6 sided die, there are // 42 full sets of 1-6 that come up. The 43rd set is incomplete. int fullSetsOfValues = Byte::MaxValue / numSides; // If the roll is within this range of fair values, then we let it continue. // In the 6 sided die case, a roll between 0 and 251 is allowed. (We use // < rather than <= since the = portion allows through an extra 0 value). // 252 through 255 would provide an extra 0, 1, 2, 3 so they are not fair // to use. return roll < numSides * fullSetsOfValues; } }; int main() { RNGCSP::Main(); }
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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