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SignatureDescription Class

Contains information about the properties of a digital signature.

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

[ComVisibleAttribute(true)]
public ref class SignatureDescription

The SignatureDescription type exposes the following members.

  NameDescription
Public methodSignatureDescription()Initializes a new instance of the SignatureDescription class.
Public methodSignatureDescription(SecurityElement)Initializes a new instance of the SignatureDescription class from the specified SecurityElement.
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  NameDescription
Public propertyDeformatterAlgorithmGets or sets the deformatter algorithm for the signature description.
Public propertyDigestAlgorithmGets or sets the digest algorithm for the signature description.
Public propertyFormatterAlgorithmGets or sets the formatter algorithm for the signature description.
Public propertyKeyAlgorithmGets or sets the key algorithm for the signature description.
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  NameDescription
Public methodCreateDeformatterCreates an AsymmetricSignatureDeformatter instance with the specified key using the DeformatterAlgorithm property.
Public methodCreateDigestCreates a HashAlgorithm instance using the DigestAlgorithm property.
Public methodCreateFormatterCreates an AsymmetricSignatureFormatter instance with the specified key using the FormatterAlgorithm property.
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 the default hash function. (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 code example demonstrates how to use members of the SignatureDescription class.

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

ref class SignatureDescriptionImpl
{
public:
   [STAThread]
   static void Main()
   {
      // Create a digital signature based on RSA encryption.
      SignatureDescription^ rsaSignature = CreateRSAPKCS1Signature();
      ShowProperties( rsaSignature );

      // Create a digital signature based on DSA encryption.
      SignatureDescription^ dsaSignature = CreateDSASignature();
      ShowProperties( dsaSignature );

      // Create a HashAlgorithm using the digest algorithm of the signature.
      HashAlgorithm^ hashAlgorithm = dsaSignature->CreateDigest();

      Console::WriteLine( L"\nHash algorithm for the DigestAlgorithm property:"
         L" {0}", hashAlgorithm );

      // Create an AsymmetricSignatureFormatter instance using the DSA key.
      DSA^ dsa = DSA::Create();
      AsymmetricSignatureFormatter^ asymmetricFormatter = CreateDSAFormatter( dsa );

      // Create an AsymmetricSignatureDeformatter instance using the 
      // DSA key.
      AsymmetricSignatureDeformatter^ asymmetricDeformatter =
         CreateDSADeformatter( dsa );
      Console::WriteLine( L"This sample completed successfully; "
         L"press Enter to exit." );
      Console::ReadLine();
   }

private:
   // Create a SignatureDescription for RSA encryption. 
   static SignatureDescription^ CreateRSAPKCS1Signature()
   {
      SignatureDescription^ signatureDescription = gcnew SignatureDescription;

      // Set the key algorithm property for RSA encryption.
      signatureDescription->KeyAlgorithm = L"System.Security.Cryptography.RSACryptoServiceProvider";

      // Set the digest algorithm for RSA encryption using the 
      // SHA1 provider.
      signatureDescription->DigestAlgorithm = L"System.Security.Cryptography.SHA1CryptoServiceProvider";

      // Set the formatter algorithm with the RSAPKCS1 formatter.
      signatureDescription->FormatterAlgorithm = L"System.Security.Cryptography.RSAPKCS1SignatureFormatter";

      // Set the formatter algorithm with the RSAPKCS1 deformatter.
      signatureDescription->DeformatterAlgorithm = L"System.Security.Cryptography.RSAPKCS1SignatureDeformatter";

      return signatureDescription;
   }

   // Create a SignatureDescription using a constructed SecurityElement for 
   // DSA encryption. 
   static SignatureDescription^ CreateDSASignature()
   {
      SecurityElement^ securityElement = gcnew SecurityElement( L"DSASignature" );
      // Create new security elements for the four algorithms.
      securityElement->AddChild( gcnew SecurityElement(
         L"Key",L"System.Security.Cryptography.DSACryptoServiceProvider" ) );
      securityElement->AddChild( gcnew SecurityElement(
         L"Digest",L"System.Security.Cryptography.SHA1CryptoServiceProvider" ) );
      securityElement->AddChild( gcnew SecurityElement(
         L"Formatter",L"System.Security.Cryptography.DSASignatureFormatter" ) );
      securityElement->AddChild( gcnew SecurityElement(
         L"Deformatter",L"System.Security.Cryptography.DSASignatureDeformatter" ) );
      SignatureDescription^ signatureDescription =
         gcnew SignatureDescription( securityElement );

      return signatureDescription;
   }

   // Create a signature formatter for DSA encryption. 
   static AsymmetricSignatureFormatter^ CreateDSAFormatter( DSA^ dsa )
   {
      // Create a DSA signature formatter for encryption.
      SignatureDescription^ signatureDescription =
         gcnew SignatureDescription;
      signatureDescription->FormatterAlgorithm =
         L"System.Security.Cryptography.DSASignatureFormatter";
      AsymmetricSignatureFormatter^ asymmetricFormatter =
         signatureDescription->CreateFormatter( dsa );

      Console::WriteLine( L"\nCreated formatter : {0}",
         asymmetricFormatter );
      return asymmetricFormatter;
   }

   // Create a signature deformatter for DSA decryption. 
   static AsymmetricSignatureDeformatter^ CreateDSADeformatter( DSA^ dsa )
   {
      // Create a DSA signature deformatter to verify the signature.
      SignatureDescription^ signatureDescription =
         gcnew SignatureDescription;
      signatureDescription->DeformatterAlgorithm =
         L"System.Security.Cryptography.DSASignatureDeformatter";
      AsymmetricSignatureDeformatter^ asymmetricDeformatter =
         signatureDescription->CreateDeformatter( dsa );

      Console::WriteLine( L"\nCreated deformatter : {0}",
         asymmetricDeformatter );
      return asymmetricDeformatter;
   }

   // Display to the console the properties of the specified 
   // SignatureDescription. 
   static void ShowProperties( SignatureDescription^ signatureDescription )
   {
      // Retrieve the class path for the specified SignatureDescription.
      String^ classDescription = signatureDescription->ToString();

      String^ deformatterAlgorithm = signatureDescription->DeformatterAlgorithm;
      String^ formatterAlgorithm = signatureDescription->FormatterAlgorithm;
      String^ digestAlgorithm = signatureDescription->DigestAlgorithm;
      String^ keyAlgorithm = signatureDescription->KeyAlgorithm;
      Console::WriteLine( L"\n** {0} **", classDescription );
      Console::WriteLine( L"DeformatterAlgorithm : {0}", deformatterAlgorithm );
      Console::WriteLine( L"FormatterAlgorithm : {0}", formatterAlgorithm );
      Console::WriteLine( L"DigestAlgorithm : {0}", digestAlgorithm );
      Console::WriteLine( L"KeyAlgorithm : {0}", keyAlgorithm );
   }
};

int main()
{
   SignatureDescriptionImpl::Main();
}

// 
// This sample produces the following output: 
// 
// ** System.Security.Cryptography.SignatureDescription ** 
// DeformatterAlgorithm : System.Security.Cryptography. 
// RSAPKCS1SignatureDeformatter 
// 
// FormatterAlgorithm : System.Security.Cryptography. 
// RSAPKCS1SignatureFormatter 
// DigestAlgorithm : System.Security.Cryptography.SHA1CryptoServiceProvider 
// KeyAlgorithm : System.Security.Cryptography.RSACryptoServiceProvider 
// 
// ** System.Security.Cryptography.SignatureDescription ** 
// DeformatterAlgorithm : System.Security.Cryptography.DSASignatureDeformatter 
// FormatterAlgorithm : System.Security.Cryptography.DSASignatureFormatter 
// DigestAlgorithm : System.Security.Cryptography.SHA1CryptoServiceProvider 
// KeyAlgorithm : System.Security.Cryptography.DSACryptoServiceProvider 
// 
// Hash algorithm for the DigestAlgorithm property: 
// System.Security.Cryptography.SH 
// A1CryptoServiceProvider 
// 
// Created formatter : System.Security.Cryptography.DSASignatureFormatter 
// 
// Created deformatter : System.Security.Cryptography.DSASignatureDeformatter 
// This sample completed successfully; press Enter to exit.

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

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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