DSASignatureDeformatter Class

Definition

Namespace:

System.Security.Cryptography

Assembly:

System.Security.Cryptography.dll

Source:

DSASignatureDeformatter.cs

Verifies a Digital Signature Algorithm (DSA) PKCS#1 v1.5 signature.

public ref class DSASignatureDeformatter : System::Security::Cryptography::AsymmetricSignatureDeformatter

public class DSASignatureDeformatter : System.Security.Cryptography.AsymmetricSignatureDeformatter

type DSASignatureDeformatter = class
    inherit AsymmetricSignatureDeformatter

Public Class DSASignatureDeformatter
Inherits AsymmetricSignatureDeformatter

Inheritance

Object

AsymmetricSignatureDeformatter

DSASignatureDeformatter

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

Remarks

Important

The creators of the DSA algorithm have withdrawn their support for it. Consider using the RSA class or the ECDsa class instead of the DSA class. Use DSA only for compatibility with legacy applications and data.

Constructors

DSASignatureDeformatter()	Initializes a new instance of the DSASignatureDeformatter class.
DSASignatureDeformatter(AsymmetricAlgorithm)	Initializes a new instance of the DSASignatureDeformatter class with the specified key.

Methods

Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
SetHashAlgorithm(String)	Specifies the hash algorithm for the Digital Signature Algorithm (DSA) signature deformatter.
SetKey(AsymmetricAlgorithm)	Specifies the key to be used for the Digital Signature Algorithm (DSA) signature deformatter.
ToString()	Returns a string that represents the current object. (Inherited from Object)
VerifySignature(Byte[], Byte[])	Verifies the Digital Signature Algorithm (DSA) signature on the data.
VerifySignature(HashAlgorithm, Byte[])	Verifies the signature from the specified hash value. (Inherited from AsymmetricSignatureDeformatter)

See also

• Cryptographic Services