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RSAPKCS1SignatureDeformatter Class
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RSAPKCS1SignatureDeformatter Class

Verifies an RSA PKCS #1 version 1.5 signature.


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

public class RSAPKCS1SignatureDeformatter : AsymmetricSignatureDeformatter

The RSAPKCS1SignatureDeformatter type exposes the following members.

Public methodRSAPKCS1SignatureDeformatter()Initializes a new instance of the RSAPKCS1SignatureDeformatter class.
Public methodRSAPKCS1SignatureDeformatter(AsymmetricAlgorithm)Initializes a new instance of the RSAPKCS1SignatureDeformatter class with the specified key.

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 methodSetHashAlgorithmSets the hash algorithm to use for verifying the signature. (Overrides AsymmetricSignatureDeformatter.SetHashAlgorithm(String).)
Public methodSetKeySets the public key to use for verifying the signature. (Overrides AsymmetricSignatureDeformatter.SetKey(AsymmetricAlgorithm).)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Public methodVerifySignature(Byte[], Byte[])Verifies the RSA PKCS#1 signature for the specified data. (Overrides AsymmetricSignatureDeformatter.VerifySignature(Byte[], Byte[]).)
Public methodVerifySignature(HashAlgorithm, Byte[])Verifies the signature from the specified hash value. (Inherited from AsymmetricSignatureDeformatter.)

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

Use RSAPKCS1SignatureFormatter to create digital signatures with the RSA algorithm.

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

using System;
using System.Security.Cryptography;

class RSASample

    static void Main()
            //Create a new instance of RSACryptoServiceProvider. 
            using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider())
                //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  
                //RSACryptoServiceProvider to transfer the key information.
                RSAPKCS1SignatureFormatter RSAFormatter = new RSAPKCS1SignatureFormatter(rsa);

                //Set the hash algorithm to SHA256.

                //Create a signature for HashValue and return it. 
                byte[] signedHash = RSAFormatter.CreateSignature(hash);
                //Create an RSAPKCS1SignatureDeformatter object and pass it the   
                //RSACryptoServiceProvider to transfer the key information.
                RSAPKCS1SignatureDeformatter RSADeformatter = new RSAPKCS1SignatureDeformatter(rsa);
                //Verify the hash and display the results to the console.  
                if (RSADeformatter.VerifySignature(hash, signedHash))
                    Console.WriteLine("The signature was verified.");
                    Console.WriteLine("The signature was not verified.");

        catch (CryptographicException e)


.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

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
© 2015 Microsoft