SignatureDescription Class

 
System_CAPS_noteNote

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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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