关于rsa非对称加密、解密、签名、验签

关于rsa加密有私钥、公钥

私钥：对外不公开，供自己签名对外输出，对传入的数据进行解密。

公钥：对外公开，供外部人员对数据进行加密传出，然后对传入数据进行验签。

rsa对数据加密有长度限制，若长度可控的情况下，建议转换byte[]进行分段加密传输，

若对于大文件的传输：

建议一：

使用des、aes进行加密大文件，将des/aes的密钥使用rsa加密，使用(https/http)传输，这样既能保证数据安全性也能提高性能。

建议二：

双向签名验签，将大文件进行签名，将签名和文件base64之后使用https一同传输。

建议二中的方式数据安全性则有https负责进行保护，数据的完整性则有签名进行保护，防止数据篡改，

二中方法自己可以针对每个用户都分配一个私钥供用户进行签名，自己这端需要存储每个用户的公钥进行验签，这样保证多个用户情况之下数据安全性。

测试数据：

            var xmlprikey ="";
            var xmlpubkey ="";
            rsa = new RSACryption();
            //待处理字符串
            var str="hello成功啊啊！￥%……&*（!@#$%^&*()@#$%^&*()_}::{>>?}{>?{?";
            var strlen= str.Length;
            rsa.RSAKey(out  xmlprikey, out  xmlpubkey);
            //加密
            var rsaencrypt=  rsa.RSAEncrypt(xmlpubkey, str);
            //解密
            var rsadecrypt = rsa.RSADecrypt(xmlprikey, rsaencrypt);
            //获取hash描述
            var gethash="";
            //获取hash值是否成功
            var hashbool= rsa.GetHash(str, ref gethash);
            //签名之后的数据
            var strEncryptedSignatureData ="";
            //rsa签名
            rsa.SignatureFormatter(xmlprikey,gethash, ref strEncryptedSignatureData);
            //rsa验签
            var SignatureDeformatter =rsa.SignatureDeformatter(xmlpubkey, gethash, strEncryptedSignatureData);
            //加密之后数据
            var strEnc="gVVqccxkEIQxMfkXxAmHup9/c0ZMhQzqLJpdrLwysaIaE+o/GFtINp6Q7o1eI4HOIxfdU7/9VEKdPEXakspooXVcH4GZkgWFRhe5VkM7Wj71RiUiEHa+o/H78Fn4q7B0JaiJjiUwfTIr0GHP5nMkPvYDiBZVfzuBARJCcjkrXVM=";
            var strEncLen= strEnc.Length;   

rsa类库：

    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 sha = System.Security.Cryptography.HashAlgorithm.Create("SHA1");
                Buffer = Encoding.UTF8.GetBytes(strSource);
                HashData = sha.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 sha = System.Security.Cryptography.HashAlgorithm.Create("SHA1");
                Buffer = Encoding.UTF8.GetBytes(strSource);
                HashData = sha.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 sha = System.Security.Cryptography.HashAlgorithm.Create("SHA1");
                HashData = sha.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 sha = System.Security.Cryptography.HashAlgorithm.Create("SHA1");
                HashData = sha.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("SHA1");
                //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("SHA1");
                //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("SHA1");
                //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("SHA1");
                //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SHA1 
                RSADeformatter.SetHashAlgorithm("SHA1");
                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SHA1 
                RSADeformatter.SetHashAlgorithm("SHA1");
                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SHA1 
                RSADeformatter.SetHashAlgorithm("SHA1");
                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SHA1 
                RSADeformatter.SetHashAlgorithm("SHA1");
                DeformatterData = Convert.FromBase64String(strDeformatterData);
                if (RSADeformatter.VerifySignature(HashbyteDeformatter, DeformatterData))
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        #endregion

        #endregion

    }

 原创地址:http://www.cnblogs.com/sydeveloper/archive/2012/08/11/2633624.html