DSASignatureDeformatter.SetHashAlgorithm(String) Method

Definition

Namespace:

System.Security.Cryptography

Assembly:

System.Security.Cryptography.dll

Source:

DSASignatureDeformatter.cs

Specifies the hash algorithm for the Digital Signature Algorithm (DSA) signature deformatter.

public:
 override void SetHashAlgorithm(System::String ^ strName);

public override void SetHashAlgorithm (string strName);

override this.SetHashAlgorithm : string -> unit

Public Overrides Sub SetHashAlgorithm (strName As String)

Parameters

strName

String

The name of the hash algorithm to use for the signature deformatter.

Exceptions

CryptographicUnexpectedOperationException

The strName parameter does not map to the SHA1 hash algorithm.

Examples

#using <System.dll>

using namespace System;
using namespace System::Security::Cryptography;
int main()
{
   try
   {
      
      //Create a new instance of DSA.
      DSA^ DSA = DSA::Create();
      
      //The hash to sign.
      array<Byte>^Hash = {59,4,248,102,77,97,142,201,210,12,224,93,25,41,100,197,213,134,130,135};
      
      //Create an DSASignatureFormatter object and pass it the 
      //DSA instance to transfer the key information.
      DSASignatureFormatter^ DSAFormatter = gcnew DSASignatureFormatter( DSA );
      
      //Set the hash algorithm to SHA1.
      DSAFormatter->SetHashAlgorithm( "SHA1" );
      
      //Create a signature for HashValue and return it.
      array<Byte>^SignedHash = DSAFormatter->CreateSignature( Hash );
      
      //Create an DSASignatureDeformatter object and pass it the 
      //DSA instance to transfer the key information.
      DSASignatureDeformatter^ DSADeformatter = gcnew DSASignatureDeformatter( DSA );
      
      //Verify the hash and display the results to the console.
      if ( DSADeformatter->VerifySignature( Hash, SignedHash ) )
      {
         Console::WriteLine( "The signature was verified." );
      }
      else
      {
         Console::WriteLine( "The signature was not verified." );
      }
   }
   catch ( CryptographicException^ e ) 
   {
      Console::WriteLine( e->Message );
   }

}

using System;
using System.Security.Cryptography;

class DSASample
{
        
    static void Main()
    {
        try
        {
            //Create a new instance of DSA.
            DSA DSA = DSA.Create();

            //The hash to sign.
            byte[] Hash = {59,4,248,102,77,97,142,201,210,12,224,93,25,41,100,197,213,134,130,135};

            //Create an DSASignatureFormatter object and pass it the 
            //DSA instance to transfer the key information.
            DSASignatureFormatter DSAFormatter = new DSASignatureFormatter(DSA);

            //Set the hash algorithm to SHA1.
            DSAFormatter.SetHashAlgorithm("SHA1");

            //Create a signature for HashValue and return it.
            byte[] SignedHash = DSAFormatter.CreateSignature(Hash);

            //Create an DSASignatureDeformatter object and pass it the 
            //DSA instance to transfer the key information.
            DSASignatureDeformatter DSADeformatter = new DSASignatureDeformatter(DSA);

            //Verify the hash and display the results to the console.
            if(DSADeformatter.VerifySignature(Hash, SignedHash))
            {
                Console.WriteLine("The signature was verified.");
            }
            else
            {
                Console.WriteLine("The signature was not verified.");
            }
        }
        catch(CryptographicException e)
        {
            Console.WriteLine(e.Message);
        }
    }
}

Imports System.Security.Cryptography

 _

Class DSASample


    Shared Sub Main()
        Try
            'Create a new instance of DSA.
            Dim DSA As DSA = DSA.Create()

            'The hash to sign.
            Dim Hash As Byte() = {59, 4, 248, 102, 77, 97, 142, 201, 210, 12, 224, 93, 25, 41, 100, 197, 213, 134, 130, 135}

            'Create an DSASignatureFormatter object and pass it the 
            'DSA instance to transfer the key information.
            Dim DSAFormatter As New DSASignatureFormatter(DSA)

            'Set the hash algorithm to SHA1.
            DSAFormatter.SetHashAlgorithm("SHA1")

            'Create a signature for HashValue and return it.
            Dim SignedHash As Byte() = DSAFormatter.CreateSignature(Hash)

            'Create an DSASignatureDeformatter object and pass it the 
            'DSA instance to transfer the key information.
            Dim DSADeformatter As New DSASignatureDeformatter(DSA)

            'Verify the hash and display the results to the console.
            If DSADeformatter.VerifySignature(Hash, SignedHash) Then
                Console.WriteLine("The signature was verified.")
            Else
                Console.WriteLine("The signature was not verified.")
            End If

        Catch e As CryptographicException
            Console.WriteLine(e.Message)
        End Try
    End Sub
End Class

Notes to Inheritors

This method is not used. The DSA algorithm requires the SHA1 hash algorithm.

See also

• Cryptographic Services