银联手机支付(.Net Csharp)，3DES加密解密，RSA加密解密，RSA私钥加密公钥解密，.Net RSA 3DES C#

前段时间做的银联支付，折腾了好久，拼凑的一些代码，有需要的朋友可以参考，本人.Net新手，不保证准确性！

这个银联手机支付没有SDK提供，技术支持也没有.Net的，真心不好搞！

RSA加解密，这里有个麻烦就是私钥加密/公钥解密；

3DES加解密，这里有个问题是所用的密钥长度不一样，银联向我们发送报文时密钥用32字节长度的，我们.Net最多用24字节，办法是直接取密钥前24字节就行了；

下面是RSA算法的加解密，用到一个BigInteger类(http://www.codeproject.com/csharp/biginteger.asp)：

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Security.Cryptography.X509Certificates;using System.Security.Cryptography;namespace Kad.ThridParty.ChinaPayWap{    /// <summary>    /// 非对称RSA加解密，私钥加密/公钥解密    /// 仅用于银联Wap支付报文收发    /// By : EnVon(E旺) 2013-08-20    /// </summary>    internal class RSAHelper    {        /// <summary>        /// RSA加密（用私钥加密哟）        /// </summary>        /// <param name="key">私钥</param>        /// <param name="data">待加密的数据</param>        /// <returns></returns>        public static byte[] Encrypt(String key, byte[] data)        {            //由密钥xml取得RSA对象            RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();            rsa.FromXmlString(key);            //取得加密时使用的2个参数            RSAParameters par = rsa.ExportParameters(true);            BigInteger mod = new BigInteger(par.Modulus);            BigInteger ep = new BigInteger(par.D);            //计算填充长度            int mLen = par.Modulus.Length;            int fLen = mLen - data.Length - 3;            //组建bytes            List<byte> lis = new List<byte>();            lis.Add(0x00);            lis.Add(0x01);//兼容java            for (int i = 0; i < fLen; i++) lis.Add(0xff);            lis.Add(0x00);            lis.AddRange(data);            byte[] bytes = lis.ToArray();            //加密就这么简单？            BigInteger m = new BigInteger(bytes);            BigInteger c = m.modPow(ep, mod);            return c.getBytes();        }        /// <summary>        /// RSA解密（用公钥解密哟）        /// </summary>        /// <param name="key">公钥</param>        /// <param name="data">待解密的数据</param>        /// <returns></returns>        public static byte[] Decrypt(String key, byte[] data)        {            //由密钥xml取得RSA对象            RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();            rsa.FromXmlString(key);            //取得解密时使用的2个参数            RSAParameters par = rsa.ExportParameters(false);            BigInteger mod = new BigInteger(par.Modulus);            BigInteger ep = new BigInteger(par.Exponent);            //解密？            BigInteger m = new BigInteger(data);            BigInteger c = m.modPow(ep, mod);            byte[] bytes = c.getBytes();            //去掉填充域（头部可能填充了一段0xff）            byte flag = 0;            for (int i = 1/*我从1开始啦*/; i < bytes.Length; i++)            {                if (bytes[i] == flag && i != (bytes.Length - 1))                {                    byte[] retBytes = new byte[bytes.Length - i - 1];                    Array.Copy(bytes, i + 1, retBytes, 0, retBytes.Length);                    return retBytes;                }            }            return bytes;        }        /// <summary>        /// 取得证书私钥        /// </summary>        /// <param name="pfxPath">证书的绝对路径</param>        /// <param name="password">访问证书的密码</param>        /// <returns></returns>        public static String GetPrivateKey(string pfxPath, string password)        {            X509Certificate2 pfx = new X509Certificate2(pfxPath, password, X509KeyStorageFlags.Exportable);            string privateKey = pfx.PrivateKey.ToXmlString(true);            return privateKey;        }        /// <summary>        /// 取得证书的公钥        /// </summary>        /// <param name="cerPath">证书的绝对路径</param>        /// <returns></returns>        public static String GetPublicKey(string cerPath)        {            X509Certificate2 cer = new X509Certificate2(cerPath);            string publicKey = cer.PublicKey.Key.ToXmlString(false);            return publicKey;        }    }}

下面是3DES的代码：

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Security.Cryptography;namespace Kad.ThridParty.ChinaPayWap{    /// <summary>    /// 对称加密3DES加解密，代码来源于网络    /// </summary>    internal class TripleDESHelper    {        /// <summary>        /// 加密        /// </summary>        /// <param name="toEncrypt">要加密的字符串，即明文</param>        /// <param name="key">公共密钥</param>        /// <param name="useHashing">是否使用MD5生成机密秘钥</param>        /// <returns>加密后的字符串，即密文</returns>        public static string Encrypt(string toEncrypt, string key, bool useHashing)        {            try            {                byte[] keyArray;                byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);                if (useHashing)                {                    MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();                    keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));                }                else                    keyArray = UTF8Encoding.UTF8.GetBytes(key);                TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();                tdes.Key = keyArray;                tdes.Mode = CipherMode.ECB;                tdes.Padding = PaddingMode.PKCS7;                ICryptoTransform cTransform = tdes.CreateEncryptor();                byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);                return Convert.ToBase64String(resultArray, 0, resultArray.Length);            }            catch            {            }            return string.Empty;        }        public static string Encrypt(byte[] toEncryptArray, string key, bool useHashing)        {            try            {                byte[] keyArray;                //byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);                if (useHashing)                {                    MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();                    keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));                }                else                    keyArray = UTF8Encoding.UTF8.GetBytes(key);                TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();                tdes.Key = keyArray;                tdes.Mode = CipherMode.ECB;                tdes.Padding = PaddingMode.PKCS7;                ICryptoTransform cTransform = tdes.CreateEncryptor();                byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);                return Convert.ToBase64String(resultArray, 0, resultArray.Length);            }            catch            {            }            return string.Empty;        }        /// <summary>        /// 解密        /// </summary>        /// <param name="toDecrypt">要解密的字符串，即密文</param>        /// <param name="key">公共密钥</param>        /// <param name="useHashing">是否使用MD5生成机密密钥</param>        /// <returns>解密后的字符串，即明文</returns>        public static string Decrypt(string toDecrypt, string key, bool useHashing)        {            try            {                byte[] keyArray;                byte[] toEncryptArray = Convert.FromBase64String(toDecrypt);                if (useHashing)                {                    MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();                    keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));                }                else                    keyArray = UTF8Encoding.UTF8.GetBytes(key);                TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();                tdes.Key = keyArray;                tdes.Mode = CipherMode.ECB;                tdes.Padding = PaddingMode.PKCS7;                ICryptoTransform cTransform = tdes.CreateDecryptor();                byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);                return UTF8Encoding.UTF8.GetString(resultArray);            }            catch            {            }            return string.Empty;        }        public static string Decrypt(byte[] toEncryptArray, string key, bool useHashing)        {            try            {                byte[] keyArray;                //byte[] toEncryptArray = Convert.FromBase64String(toDecrypt);                if (useHashing)                {                    MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();                    keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));                }                else                    keyArray = UTF8Encoding.UTF8.GetBytes(key);                TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();                tdes.Key = keyArray;                tdes.Mode = CipherMode.ECB;                tdes.Padding = PaddingMode.PKCS7;                ICryptoTransform cTransform = tdes.CreateDecryptor();                byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);                return UTF8Encoding.UTF8.GetString(resultArray);            }            catch            {            }            return string.Empty;        }    }}

文章出处：http://blog.csdn.net/envon123/article/details/12388205