用RSA c#签名和验证签名

我最近发布了关于使用RSA加密大数据的问题，我终于完成了这一点，现在我正在继续使用用户的私钥实现签名并使用相应的公钥进行验证。然而，每当我比较签名数据和原始消息时，我基本上只得到false返回。我希望你们中的一些人能看到我做错了什么。

代码如下:

public static string SignData(string message, RSAParameters privateKey)
    {
        //// The array to store the signed message in bytes
        byte[] signedBytes;
        using (var rsa = new RSACryptoServiceProvider())
        {
            //// Write the message to a byte array using UTF8 as the encoding.
            var encoder = new UTF8Encoding();
            byte[] originalData = encoder.GetBytes(message);
            try
            {
                //// Import the private key used for signing the message
                rsa.ImportParameters(privateKey);
                //// Sign the data, using SHA512 as the hashing algorithm 
                signedBytes = rsa.SignData(originalData, CryptoConfig.MapNameToOID("SHA512"));
            }
            catch (CryptographicException e)
            {
                Console.WriteLine(e.Message);
                return null;
            }
            finally
            {
                //// Set the keycontainer to be cleared when rsa is garbage collected.
                rsa.PersistKeyInCsp = false;
            }
        }
        //// Convert the a base64 string before returning
        return Convert.ToBase64String(signedBytes);
    }

所以这是第一步，签名数据，接下来我要验证数据:

public static bool VerifyData(string originalMessage, string signedMessage, RSAParameters publicKey)
    {
        bool success = false;
        using (var rsa = new RSACryptoServiceProvider())
        {
            byte[] bytesToVerify = Convert.FromBase64String(originalMessage);
            byte[] signedBytes = Convert.FromBase64String(signedMessage);
            try
            {
                rsa.ImportParameters(publicKey);
                SHA512Managed Hash = new SHA512Managed();
                byte[] hashedData = Hash.ComputeHash(signedBytes);
                success = rsa.VerifyData(bytesToVerify, CryptoConfig.MapNameToOID("SHA512"), signedBytes);
            }
            catch (CryptographicException e)
            {
                Console.WriteLine(e.Message);
            }
            finally
            {
                rsa.PersistKeyInCsp = false;
            }
        }
        return success;
    }

下面是测试客户端:

public static void Main(string[] args)
    {
        PublicKeyInfrastructure pki = new PublicKeyInfrastructure();
        Cryptograph crypto = new Cryptograph();
        RSAParameters privateKey = crypto.GenerateKeys("email@email.com");
        const string PlainText = "This is really sent by me, really!";
        RSAParameters publicKey = crypto.GetPublicKey("email@email.com");
        string encryptedText = Cryptograph.Encrypt(PlainText, publicKey);
        Console.WriteLine("This is the encrypted Text:" + "'n " + encryptedText);
        string decryptedText = Cryptograph.Decrypt(encryptedText, privateKey);
        Console.WriteLine("This is the decrypted text: " + decryptedText);
        string messageToSign = encryptedText;
        string signedMessage = Cryptograph.SignData(messageToSign, privateKey);
        //// Is this message really, really, REALLY sent by me?
        bool success = Cryptograph.VerifyData(messageToSign, signedMessage, publicKey);
        Console.WriteLine("Is this message really, really, REALLY sent by me? " + success);
    }

我这里漏了一个步骤吗?根据Cryptography API和示例，我不应该手动计算任何散列，因为我在方法调用本身中提供了算法。

public static bool VerifyData(string originalMessage, string signedMessage, RSAParameters publicKey)
{
    bool success = false;
    using (var rsa = new RSACryptoServiceProvider())
    {
        //Don't do this, do the same as you did in SignData:
        //byte[] bytesToVerify = Convert.FromBase64String(originalMessage);
        var encoder = new UTF8Encoding();
        byte[] bytesToVerify = encoder.GetBytes(originalMessage);
        byte[] signedBytes = Convert.FromBase64String(signedMessage);
        try
        ...