Was this page helpful?
Your feedback about this content is important. Let us know what you think.
Additional feedback?
1500 characters remaining
SetHashAlgorithm Method
Collapse the table of content
Expand the table of content

DSASignatureDeformatter.SetHashAlgorithm Method

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

[Visual Basic]
Overrides Public Sub SetHashAlgorithm( _
   ByVal strName As String _
)
[C#]
public override void SetHashAlgorithm(
 string strName
);
[C++]
public: void SetHashAlgorithm(
 String* strName
);
[JScript]
public override function SetHashAlgorithm(
   strName : String
);

Parameters

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

Exceptions

Exception Type Condition
CryptographicUnexpectedOperationException The strName parameter does not map to the SHA1 hash algorithm.

Remarks

Notes to Implementers:  This method is not used. The DSA algorithm requires the SHA1 hash algorithm.

Example

[Visual Basic] 
Imports System
Imports System.Security.Cryptography

 _

Class DSASample


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

            '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 
            'DSACryptoServiceProvider 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 
            'DSACryptoServiceProvider 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

[C#] 
using System;
using System.Security.Cryptography;

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

            //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 
            //DSACryptoServiceProvider 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 
            //DSACryptoServiceProvider 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);
        }
    }

}

[C++] 
#using <mscorlib.dll>
#using <System.dll>

using namespace System;
using namespace System::Security::Cryptography;

int main() {
    try {
        //Create a new instance of DSACryptoServiceProvider.
        DSACryptoServiceProvider* DSA = new DSACryptoServiceProvider();

        //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 
        //DSACryptoServiceProvider to transfer the key information.
        DSASignatureFormatter* DSAFormatter = new DSASignatureFormatter(DSA);

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

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

        //Create an DSASignatureDeformatter object and pass it the 
        //DSACryptoServiceProvider 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(S"The signature was verified.");
        } else {
            Console::WriteLine(S"The signature was not verified.");
        }
    } catch (CryptographicException* e) {
        Console::WriteLine(e->Message);
    }
}

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also

DSASignatureDeformatter Class | DSASignatureDeformatter Members | System.Security.Cryptography Namespace | Cryptographic Services

Show:
© 2015 Microsoft