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KeySizes Class

Determines the set of valid key sizes for the symmetric cryptographic algorithms.

System.Object
  System.Security.Cryptography.KeySizes

Namespace:  System.Security.Cryptography
Assembly:  mscorlib (in mscorlib.dll)

[ComVisibleAttribute(true)]
public sealed class KeySizes

The KeySizes type exposes the following members.

  NameDescription
Public methodKeySizesInitializes a new instance of the KeySizes class with the specified key values.
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  NameDescription
Public propertyMaxSizeSpecifies the maximum key size in bits.
Public propertyMinSizeSpecifies the minimum key size in bits.
Public propertySkipSizeSpecifies the interval between valid key sizes in bits.
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  NameDescription
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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The following example shows the use of members of the KeySizes class.


using System;
using System.Security.Cryptography;

namespace Contoso
{
    class KeySizesMembers
    {
        [STAThread]
        static void Main(string[] args)
        {
            // Initializes a new instance of the KeySizes class with the
            // specified key values.
            int minSize = 64;
            int maxSize = 1024;
            int skipSize = 64;
            KeySizes keySizes = new KeySizes(minSize, maxSize, skipSize);

            // Show the values of the keys.
            ShowKeys(new KeySizes[1]{keySizes}, "Custom Keys");

            // Create a new symmetric algorithm and display its key values.
            SymmetricAlgorithm rijn = SymmetricAlgorithm.Create();
            ShowKeys(rijn.LegalKeySizes, rijn.ToString());
            Console.WriteLine("rijn.blocksize:" + rijn.BlockSize);

            // Create a new RSA algorithm and display its key values.
            RSACryptoServiceProvider rsaCSP = 
                new RSACryptoServiceProvider(384);
            ShowKeys(rsaCSP.LegalKeySizes, rsaCSP.ToString());
            Console.WriteLine("RSACryptoServiceProvider KeySize = " + 
                rsaCSP.KeySize);

            Console.WriteLine("This sample completed successfully; " +
                "press Enter to exit.");
            Console.ReadLine();
        }

        // Display specified KeySize properties to the console.
        private static void ShowKeys(KeySizes[] keySizes, string objectName)
        {
            // Retrieve the first KeySizes in the array.
            KeySizes firstKeySize = keySizes[0];

            // Retrieve the minimum key size in bits.
            int minKeySize = firstKeySize.MinSize;

            // Retrieve the maximum key size in bits.
            int maxKeySize = firstKeySize.MaxSize;

            // Retrieve the interval between valid key size in bits.
            int skipKeySize = firstKeySize.SkipSize;

            Console.Write("\n KeySizes retrieved from the ");
            Console.WriteLine(objectName + " object.");
            Console.WriteLine("Minimum key size bits: " + minKeySize);
            Console.WriteLine("Maximum key size bits: " + maxKeySize);
            Console.WriteLine("Interval between key size bits: " + 
                skipKeySize);
        }
	}
}
//
// This sample produces the following output:
//
// KeySizes retrieved from the Custom Keys object.
// Minimum key size bits: 64
// Maximum key size bits: 1024
// Interval between key size bits: 64
// 
// KeySizes retrieved from the System.Security.Cryptography.RijndaelManaged
// object.
// Minimum key size bits: 128
// Maximum key size bits: 256
// Interval between key size bits: 64
// rijn.blocksize:128
// 
// KeySizes retrieved from the
// System.Security.Cryptography.RSACryptoServiceProvider object.
// Minimum key size bits: 384
// Maximum key size bits: 16384
// Interval between key size bits: 8
// RSACryptoServiceProvider KeySize = 384
// This sample completed successfully; press Enter to exit.


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

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.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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