小编典典

使用RSA C#签名和验证签名

c#

我最近发布了有关使用RSA加密大数据的问题,我终于完成了,现在我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。但是,每当我比较签名数据和原始消息时,我基本上只会得到false返回。我希望你们中的一些人可以看到我做错了什么。

这是代码:

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,对数据进行签名,接下来我继续验证数据:

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;
    }

这是测试客户端:

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);

    }

我在这里错过了一步吗?根据密码学API和那里的示例,我不应该手动计算任何哈希,因为我在方法调用本身中提供了算法。

任何帮助将不胜感激。


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2020-05-19

共1个答案

小编典典

您的问题是VerifyData方法的开始:

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
        ...

由于某些原因,您切换到FromBase64String而不是UTF8Encoding.GetBytes

2020-05-19