C# RSA加密解密及RSA签名和验证

1、RSA加密解密

(1)获取密钥，这里是产生密钥，实际应用中可以从各种存储介质上读取密钥

(2)加密

(3)解密

2、RSA签名和验证

(1)获取密钥，这里是产生密钥，实际应用中可以从各种存储介质上读取密钥

(2)获取待签名的Hash码

(3)获取签名的字符串

(4)验证

3、公钥与私钥的理解

(1)私钥用来进行解密和签名，是给自己用的。

(2)公钥由本人公开，用于加密和验证签名，是给别人用的。

(3)当该用户发送文件时，用私钥签名，别人用他给的公钥验证签名，可以保证该信息是由他发送的。当该用户接受文件时，别人用他的公钥加密，他用私钥解密，可以保证该信息只能由他接收到。

class RSACryption
{        
    #region RSA 加密解密

    #region RSA 的密钥产生
    /// <summary>
    /// RSA产生密钥
    /// </summary>
    /// <param name="xmlKeys">私钥</param>
    /// <param name="xmlPublicKey">公钥</param>
    public void RSAKey(out string xmlKeys, out string xmlPublicKey)
    {
        try
        {
            System.Security.Cryptography.RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
            xmlKeys = rsa.ToXmlString(true);
            xmlPublicKey = rsa.ToXmlString(false);
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
    #endregion

    #region RSA加密函数
    //############################################################################## 
    //RSA 方式加密 
    //KEY必须是XML的形式,返回的是字符串 
    //该加密方式有长度限制的！
    //############################################################################## 
       
    /// <summary>
    /// RSA的加密函数
    /// </summary>
    /// <param name="xmlPublicKey">公钥</param>
    /// <param name="encryptString">待加密的字符串</param>
    /// <returns></returns>
    public string RSAEncrypt(string xmlPublicKey, string encryptString)
    {
        try
        {
            byte[] PlainTextBArray;
            byte[] CypherTextBArray;
            string Result;
            System.Security.Cryptography.RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
            rsa.FromXmlString(xmlPublicKey);
            PlainTextBArray = (new UnicodeEncoding()).GetBytes(encryptString);
            CypherTextBArray = rsa.Encrypt(PlainTextBArray, false);
            Result = Convert.ToBase64String(CypherTextBArray);
            return Result;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }        
    /// <summary>
    /// RSA的加密函数 
    /// </summary>
    /// <param name="xmlPublicKey">公钥</param>
    /// <param name="EncryptString">待加密的字节数组</param>
    /// <returns></returns>
    public string RSAEncrypt(string xmlPublicKey, byte[] EncryptString)
    {
        try
        {
            byte[] CypherTextBArray;
            string Result;
            System.Security.Cryptography.RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
            rsa.FromXmlString(xmlPublicKey);
            CypherTextBArray = rsa.Encrypt(EncryptString, false);
            Result = Convert.ToBase64String(CypherTextBArray);
            return Result;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
    #endregion

    #region RSA的解密函数        
    /// <summary>
    /// RSA的解密函数
    /// </summary>
    /// <param name="xmlPrivateKey">私钥</param>
    /// <param name="decryptString">待解密的字符串</param>
    /// <returns></returns>
    public string RSADecrypt(string xmlPrivateKey, string decryptString)
    {
        try
        {
            byte[] PlainTextBArray;
            byte[] DypherTextBArray;
            string Result;
            System.Security.Cryptography.RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
            rsa.FromXmlString(xmlPrivateKey);
            PlainTextBArray = Convert.FromBase64String(decryptString);
            DypherTextBArray = rsa.Decrypt(PlainTextBArray, false);
            Result = (new UnicodeEncoding()).GetString(DypherTextBArray);
            return Result;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }        
    /// <summary>
    /// RSA的解密函数 
    /// </summary>
    /// <param name="xmlPrivateKey">私钥</param>
    /// <param name="DecryptString">待解密的字节数组</param>
    /// <returns></returns>
    public string RSADecrypt(string xmlPrivateKey, byte[] DecryptString)
    {
        try
        {
            byte[] DypherTextBArray;
            string Result;
            System.Security.Cryptography.RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
            rsa.FromXmlString(xmlPrivateKey);
            DypherTextBArray = rsa.Decrypt(DecryptString, false);
            Result = (new UnicodeEncoding()).GetString(DypherTextBArray);
            return Result;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
    #endregion

    #endregion

    #region RSA数字签名

    #region 获取Hash描述表        
    /// <summary>
    /// 获取Hash描述表
    /// </summary>
    /// <param name="strSource">待签名的字符串</param>
    /// <param name="HashData">Hash描述</param>
    /// <returns></returns>
    public bool GetHash(string strSource, ref byte[] HashData)
    {
        try
        {               
            byte[] Buffer;
            System.Security.Cryptography.HashAlgorithm MD5 = System.Security.Cryptography.HashAlgorithm.Create("MD5");
            Buffer = System.Text.Encoding.GetEncoding("GB2312").GetBytes(strSource);
            HashData = MD5.ComputeHash(Buffer);
            return true;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

    /// <summary>
    /// 获取Hash描述表
    /// </summary>
    /// <param name="strSource">待签名的字符串</param>
    /// <param name="strHashData">Hash描述</param>
    /// <returns></returns>
    public bool GetHash(string strSource, ref string strHashData)
    {
        try
        {
            //从字符串中取得Hash描述 
            byte[] Buffer;
            byte[] HashData;
            System.Security.Cryptography.HashAlgorithm MD5 = System.Security.Cryptography.HashAlgorithm.Create("MD5");
            Buffer = System.Text.Encoding.GetEncoding("GB2312").GetBytes(strSource);
            HashData = MD5.ComputeHash(Buffer);
            strHashData = Convert.ToBase64String(HashData);
            return true;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

    /// <summary>
    /// 获取Hash描述表
    /// </summary>
    /// <param name="objFile">待签名的文件</param>
    /// <param name="HashData">Hash描述</param>
    /// <returns></returns>
    public bool GetHash(System.IO.FileStream objFile, ref byte[] HashData)
    {
        try
        {
            //从文件中取得Hash描述 
            System.Security.Cryptography.HashAlgorithm MD5 = System.Security.Cryptography.HashAlgorithm.Create("MD5");
            HashData = MD5.ComputeHash(objFile);
            objFile.Close();
            return true;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

    /// <summary>
    /// 获取Hash描述表
    /// </summary>
    /// <param name="objFile">待签名的文件</param>
    /// <param name="strHashData">Hash描述</param>
    /// <returns></returns>
    public bool GetHash(System.IO.FileStream objFile, ref string strHashData)
    {
        try
        {
            //从文件中取得Hash描述 
            byte[] HashData;
            System.Security.Cryptography.HashAlgorithm MD5 = System.Security.Cryptography.HashAlgorithm.Create("MD5");
            HashData = MD5.ComputeHash(objFile);
            objFile.Close();
            strHashData = Convert.ToBase64String(HashData);
            return true;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
    #endregion

    #region RSA签名
    /// <summary>
    /// RSA签名
    /// </summary>
    /// <param name="strKeyPrivate">私钥</param>
    /// <param name="HashbyteSignature">待签名Hash描述</param>
    /// <param name="EncryptedSignatureData">签名后的结果</param>
    /// <returns></returns>
    public bool SignatureFormatter(string strKeyPrivate, byte[] HashbyteSignature, ref byte[] EncryptedSignatureData)
    {
        try
        {
            System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();

            RSA.FromXmlString(strKeyPrivate);
            System.Security.Cryptography.RSAPKCS1SignatureFormatter RSAFormatter = new System.Security.Cryptography.RSAPKCS1SignatureFormatter(RSA);
            //设置签名的算法为MD5 
            RSAFormatter.SetHashAlgorithm("MD5");
            //执行签名 
            EncryptedSignatureData = RSAFormatter.CreateSignature(HashbyteSignature);
            return true;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

    /// <summary>
    /// RSA签名
    /// </summary>
    /// <param name="strKeyPrivate">私钥</param>
    /// <param name="HashbyteSignature">待签名Hash描述</param>
    /// <param name="m_strEncryptedSignatureData">签名后的结果</param>
    /// <returns></returns>
    public bool SignatureFormatter(string strKeyPrivate, byte[] HashbyteSignature, ref string strEncryptedSignatureData)
    {
        try
        {
            byte[] EncryptedSignatureData;
            System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();
            RSA.FromXmlString(strKeyPrivate);
            System.Security.Cryptography.RSAPKCS1SignatureFormatter RSAFormatter = new System.Security.Cryptography.RSAPKCS1SignatureFormatter(RSA);
            //设置签名的算法为MD5 
            RSAFormatter.SetHashAlgorithm("MD5");
            //执行签名 
            EncryptedSignatureData = RSAFormatter.CreateSignature(HashbyteSignature);
            strEncryptedSignatureData = Convert.ToBase64String(EncryptedSignatureData);
            return true;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

    /// <summary>
    /// RSA签名
    /// </summary>
    /// <param name="strKeyPrivate">私钥</param>
    /// <param name="strHashbyteSignature">待签名Hash描述</param>
    /// <param name="EncryptedSignatureData">签名后的结果</param>
    /// <returns></returns>
    public bool SignatureFormatter(string strKeyPrivate, string strHashbyteSignature, ref byte[] EncryptedSignatureData)
    {
        try
        {
            byte[] HashbyteSignature;

            HashbyteSignature = Convert.FromBase64String(strHashbyteSignature);
            System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();

            RSA.FromXmlString(strKeyPrivate);
            System.Security.Cryptography.RSAPKCS1SignatureFormatter RSAFormatter = new System.Security.Cryptography.RSAPKCS1SignatureFormatter(RSA);
            //设置签名的算法为MD5 
            RSAFormatter.SetHashAlgorithm("MD5");
            //执行签名 
            EncryptedSignatureData = RSAFormatter.CreateSignature(HashbyteSignature);

            return true;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

    /// <summary>
    /// RSA签名
    /// </summary>
    /// <param name="strKeyPrivate">私钥</param>
    /// <param name="strHashbyteSignature">待签名Hash描述</param>
    /// <param name="strEncryptedSignatureData">签名后的结果</param>
    /// <returns></returns>
    public bool SignatureFormatter(string strKeyPrivate, string strHashbyteSignature, ref string strEncryptedSignatureData)
    {
        try
        {
            byte[] HashbyteSignature;
            byte[] EncryptedSignatureData;
            HashbyteSignature = Convert.FromBase64String(strHashbyteSignature);
            System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();
            RSA.FromXmlString(strKeyPrivate);
            System.Security.Cryptography.RSAPKCS1SignatureFormatter RSAFormatter = new System.Security.Cryptography.RSAPKCS1SignatureFormatter(RSA);
            //设置签名的算法为MD5 
            RSAFormatter.SetHashAlgorithm("MD5");
            //执行签名 
            EncryptedSignatureData = RSAFormatter.CreateSignature(HashbyteSignature);
            strEncryptedSignatureData = Convert.ToBase64String(EncryptedSignatureData);
            return true;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
    #endregion

    #region RSA 签名验证
    /// <summary>
    /// RSA签名验证
    /// </summary>
    /// <param name="strKeyPublic">公钥</param>
    /// <param name="HashbyteDeformatter">Hash描述</param>
    /// <param name="DeformatterData">签名后的结果</param>
    /// <returns></returns>
    public bool SignatureDeformatter(string strKeyPublic, byte[] HashbyteDeformatter, byte[] DeformatterData)
    {
        try
        {
            System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();
            RSA.FromXmlString(strKeyPublic);
            System.Security.Cryptography.RSAPKCS1SignatureDeformatter RSADeformatter = new System.Security.Cryptography.RSAPKCS1SignatureDeformatter(RSA);
            //指定解密的时候HASH算法为MD5 
            RSADeformatter.SetHashAlgorithm("MD5");
            if (RSADeformatter.VerifySignature(HashbyteDeformatter, DeformatterData))
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
    /// <summary>
    /// RSA签名验证
    /// </summary>
    /// <param name="strKeyPublic">公钥</param>
    /// <param name="strHashbyteDeformatter">Hash描述</param>
    /// <param name="DeformatterData">签名后的结果</param>
    /// <returns></returns>
    public bool SignatureDeformatter(string strKeyPublic, string strHashbyteDeformatter, byte[] DeformatterData)
    {
        try
        {
            byte[] HashbyteDeformatter;
            HashbyteDeformatter = Convert.FromBase64String(strHashbyteDeformatter);
            System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();
            RSA.FromXmlString(strKeyPublic);
            System.Security.Cryptography.RSAPKCS1SignatureDeformatter RSADeformatter = new System.Security.Cryptography.RSAPKCS1SignatureDeformatter(RSA);
            //指定解密的时候HASH算法为MD5 
            RSADeformatter.SetHashAlgorithm("MD5");
            if (RSADeformatter.VerifySignature(HashbyteDeformatter, DeformatterData))
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
    /// <summary>
    /// RSA签名验证
    /// </summary>
    /// <param name="strKeyPublic">公钥</param>
    /// <param name="HashbyteDeformatter">Hash描述</param>
    /// <param name="strDeformatterData">签名后的结果</param>
    /// <returns></returns>
    public bool SignatureDeformatter(string strKeyPublic, byte[] HashbyteDeformatter, string strDeformatterData)
    {
        try
        {
            byte[] DeformatterData;
            System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();
            RSA.FromXmlString(strKeyPublic);
            System.Security.Cryptography.RSAPKCS1SignatureDeformatter RSADeformatter = new System.Security.Cryptography.RSAPKCS1SignatureDeformatter(RSA);
            //指定解密的时候HASH算法为MD5 
            RSADeformatter.SetHashAlgorithm("MD5");
            DeformatterData = Convert.FromBase64String(strDeformatterData);
            if (RSADeformatter.VerifySignature(HashbyteDeformatter, DeformatterData))
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
    /// <summary>
    /// RSA签名验证
    /// </summary>
    /// <param name="strKeyPublic">公钥</param>
    /// <param name="strHashbyteDeformatter">Hash描述</param>
    /// <param name="strDeformatterData">签名后的结果</param>
    /// <returns></returns>
    public bool SignatureDeformatter(string strKeyPublic, string strHashbyteDeformatter, string strDeformatterData)
    {
        try
        {
            byte[] DeformatterData;
            byte[] HashbyteDeformatter;
            HashbyteDeformatter = Convert.FromBase64String(strHashbyteDeformatter);
            System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();
            RSA.FromXmlString(strKeyPublic);
            System.Security.Cryptography.RSAPKCS1SignatureDeformatter RSADeformatter = new System.Security.Cryptography.RSAPKCS1SignatureDeformatter(RSA);
            //指定解密的时候HASH算法为MD5 
            RSADeformatter.SetHashAlgorithm("MD5");
            DeformatterData = Convert.FromBase64String(strDeformatterData);
            if (RSADeformatter.VerifySignature(HashbyteDeformatter, DeformatterData))
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
    #endregion
    #endregion 
}