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;
}
}
}