SignatureDescription Class
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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 class SignatureDescription

NameDescription
System_CAPS_pubmethodSignatureDescription()

Initializes a new instance of the SignatureDescription class.

System_CAPS_pubmethodSignatureDescription(SecurityElement)

Initializes a new instance of the SignatureDescription class from the specified SecurityElement.

NameDescription
System_CAPS_pubpropertyDeformatterAlgorithm

Gets or sets the deformatter algorithm for the signature description.

System_CAPS_pubpropertyDigestAlgorithm

Gets or sets the digest algorithm for the signature description.

System_CAPS_pubpropertyFormatterAlgorithm

Gets or sets the formatter algorithm for the signature description.

System_CAPS_pubpropertyKeyAlgorithm

Gets or sets the key algorithm for the signature description.

NameDescription
System_CAPS_pubmethodCreateDeformatter(AsymmetricAlgorithm)

Creates an AsymmetricSignatureDeformatter instance with the specified key using the DeformatterAlgorithm property.

System_CAPS_pubmethodCreateDigest()

Creates a HashAlgorithm instance using the DigestAlgorithm property.

System_CAPS_pubmethodCreateFormatter(AsymmetricAlgorithm)

Creates an AsymmetricSignatureFormatter instance with the specified key using the FormatterAlgorithm property.

System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_protmethodFinalize()

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_protmethodMemberwiseClone()

Creates a shallow copy of the current Object.(Inherited from Object.)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

The following code example demonstrates how to use members of the SignatureDescription class.

using System;
using System.Security;
using System.Security.Cryptography;

class SignatureDescriptionImpl
{
    [STAThread]
    static void Main(string[] args)
    {
        // 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("\nHash algorithm for the DigestAlgorithm property:"
            + " " + hashAlgorithm.ToString());

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

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

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

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

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

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

        return signatureDescription;
    }

    // Create a SignatureDescription using a constructed SecurityElement for 
    // DSA encryption.
    private static SignatureDescription CreateDSASignature()
    {
        SecurityElement securityElement = new SecurityElement("DSASignature");

        // Create new security elements for the four algorithms.
        securityElement.AddChild(new SecurityElement(
            "Key",
            "System.Security.Cryptography.DSACryptoServiceProvider"));
        securityElement.AddChild(new SecurityElement(
            "Digest",
            "System.Security.Cryptography.SHA1CryptoServiceProvider")); 
        securityElement.AddChild(new SecurityElement(
            "Formatter",
            "System.Security.Cryptography.DSASignatureFormatter"));
        securityElement.AddChild(new SecurityElement(
            "Deformatter",
            "System.Security.Cryptography.DSASignatureDeformatter"));

        SignatureDescription signatureDescription = 
            new SignatureDescription(securityElement);

        return signatureDescription;
    }

    // Create a signature formatter for DSA encryption.
    private static AsymmetricSignatureFormatter CreateDSAFormatter(DSA dsa)
    {
        // Create a DSA signature formatter for encryption.
        SignatureDescription signatureDescription = 
            new SignatureDescription();
        signatureDescription.FormatterAlgorithm =
            "System.Security.Cryptography.DSASignatureFormatter";

        AsymmetricSignatureFormatter asymmetricFormatter =
            signatureDescription.CreateFormatter(dsa);

        Console.WriteLine("\nCreated formatter : " + 
            asymmetricFormatter.ToString());
        return asymmetricFormatter;
    }

    // Create a signature deformatter for DSA decryption.
    private static AsymmetricSignatureDeformatter CreateDSADeformatter(
        DSA dsa)
    {
        // Create a DSA signature deformatter to verify the signature.
        SignatureDescription signatureDescription = 
            new SignatureDescription();
        signatureDescription.DeformatterAlgorithm =
            "System.Security.Cryptography.DSASignatureDeformatter";

        AsymmetricSignatureDeformatter asymmetricDeformatter =
            signatureDescription.CreateDeformatter(dsa);

        Console.WriteLine("\nCreated deformatter : " + 
            asymmetricDeformatter.ToString());
        return asymmetricDeformatter;
    }

    // Display to the console the properties of the specified
    // SignatureDescription.
    private 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("\n** " + classDescription + " **");
        Console.WriteLine("DeformatterAlgorithm : " + deformatterAlgorithm);
        Console.WriteLine("FormatterAlgorithm : " + formatterAlgorithm);
        Console.WriteLine("DigestAlgorithm : " + digestAlgorithm);
        Console.WriteLine("KeyAlgorithm : " + keyAlgorithm);
    }
}
//
// 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
Available since 1.1

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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