RSAPKCS1SignatureFormatter.CreateSignature(Byte[]) Method

Reference

Definition

Namespace:: System.Security.Cryptography

Assembly:: System.Security.Cryptography.Algorithms.dll

Assembly:: System.Security.Cryptography.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Source:: RSAPKCS1SignatureFormatter.cs

Source:: RSAPKCS1SignatureFormatter.cs

Source:: RSAPKCS1SignatureFormatter.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Creates the RSA PKCS #1 signature for the specified data.

public:
 override cli::array <System::Byte> ^ CreateSignature(cli::array <System::Byte> ^ rgbHash);

public override byte[] CreateSignature (byte[] rgbHash);

override this.CreateSignature : byte[] -> byte[]

Public Overrides Function CreateSignature (rgbHash As Byte()) As Byte()

Parameters

rgbHash: Byte[]

The data to be signed.

Returns

Byte[]

The digital signature for rgbHash.

Exceptions

CryptographicUnexpectedOperationException

The key is null.

-or-

The hash algorithm is null.

ArgumentNullException

The rgbHash parameter is null.

Examples

The following example demonstrates how to create a PKCS #1 version 1.5 signature.

using System;
using System.Security.Cryptography;

class RSASample
{

    static void Main()
    {
        try
        {
            //Create a new instance of RSA.
            using (RSA rsa = RSA.Create())
            {
                //The hash to sign.
                byte[] hash;
                using (SHA256 sha256 = SHA256.Create())
                {
                    byte[] data = new byte[] { 59, 4, 248, 102, 77, 97, 142, 201, 210, 12, 224, 93, 25, 41, 100, 197, 213, 134, 130, 135 };
                    hash = sha256.ComputeHash(data);
                }

                //Create an RSASignatureFormatter object and pass it the 
                //RSA instance to transfer the key information.
                RSAPKCS1SignatureFormatter RSAFormatter = new RSAPKCS1SignatureFormatter(rsa);

                //Set the hash algorithm to SHA256.
                RSAFormatter.SetHashAlgorithm("SHA256");

                //Create a signature for HashValue and return it.
                byte[] SignedHash = RSAFormatter.CreateSignature(hash);
            }
        }
        catch (CryptographicException e)
        {
            Console.WriteLine(e.Message);
        }
    }
}

Imports System.Security.Cryptography

Friend Class RSASample

    Shared Sub Main()
        Try
            'Create a new instance of RSA.
            Using rsa As RSA = RSA.Create()
                'The hash to sign.
                Dim hash() As Byte
                Using sha256 As SHA256 = SHA256.Create()
                    Dim data() As Byte = { 59, 4, 248, 102, 77, 97, 142, 201, 210, 12, 224, 93, 25, 41, 100, 197, 213, 134, 130, 135 }
                    hash = sha256.ComputeHash(data)
                End Using

                'Create an RSASignatureFormatter object and pass it the 
                'RSA to transfer the key information.
                Dim RSAFormatter As New RSAPKCS1SignatureFormatter(rsa)

                'Set the hash algorithm to SHA256.
                RSAFormatter.SetHashAlgorithm("SHA256")

                'Create a signature for HashValue and return it.
                Dim SignedHash() As Byte = RSAFormatter.CreateSignature(hash)
            End Using

        Catch e As CryptographicException
            Console.WriteLine(e.Message)
        End Try
    End Sub

End Class

Remarks

You must specify a key and a hash algorithm before calling this method.

Applies to

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