RSAPKCS1SignatureDeformatter Class

Definition

Verifies an RSA PKCS #1 version 1.5 signature.

C#
[System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
public class RSAPKCS1SignatureDeformatter : System.Security.Cryptography.AsymmetricSignatureDeformatter
C#
public class RSAPKCS1SignatureDeformatter : System.Security.Cryptography.AsymmetricSignatureDeformatter
C#
[System.Runtime.InteropServices.ComVisible(true)]
public class RSAPKCS1SignatureDeformatter : System.Security.Cryptography.AsymmetricSignatureDeformatter
Inheritance
RSAPKCS1SignatureDeformatter
Attributes

Examples

The following example demonstrates how to use the VerifySignature method to verify a signature.

C#
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);
                //Create an RSAPKCS1SignatureDeformatter object and pass it the  
                //RSA instance to transfer the key information.
                RSAPKCS1SignatureDeformatter RSADeformatter = new RSAPKCS1SignatureDeformatter(rsa);
                RSADeformatter.SetHashAlgorithm("SHA256");
                //Verify the hash and display the results to the console. 
                if (RSADeformatter.VerifySignature(hash, signedHash))
                {
                    Console.WriteLine("The signature was verified.");
                }
                else
                {
                    Console.WriteLine("The signature was not verified.");
                }
            }
        }
        catch (CryptographicException e)
        {
            Console.WriteLine(e.Message);
        }
    }
}

Remarks

This class is used to verify a digital signature made with the RSA algorithm.

Use RSAPKCS1SignatureFormatter to create digital signatures with the RSA algorithm.

Constructors

RSAPKCS1SignatureDeformatter()

Initializes a new instance of the RSAPKCS1SignatureDeformatter class.

RSAPKCS1SignatureDeformatter(AsymmetricAlgorithm)

Initializes a new instance of the RSAPKCS1SignatureDeformatter class with the specified key.

Methods

Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetType()

Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
SetHashAlgorithm(String)

Sets the hash algorithm to use for verifying the signature.

SetKey(AsymmetricAlgorithm)

Sets the public key to use for verifying the signature.

ToString()

Returns a string that represents the current object.

(Inherited from Object)
VerifySignature(Byte[], Byte[])

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

VerifySignature(HashAlgorithm, Byte[])

Verifies the signature from the specified hash value.

(Inherited from AsymmetricSignatureDeformatter)

Applies to

Product Versions
.NET Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 2.0, 2.1

See also