RSA算法代码：

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Security.Cryptography;namespace RSA.Class
{/// <summary>/// 类名：RSAFromPkcs8/// 功能：RSA加密、解密、签名、验签/// 详细：该类对Java生成的密钥进行解密和签名以及验签专用类，不需要修改/// 版本：3.0/// 日期：2013-07-08/// 说明：/// 以下代码只是为了方便商户测试而提供的样例代码，商户可以根据自己网站的需要，按照技术文档编写,并非一定要使用该代码。/// </summary>public sealed class RSAFromPkcs8{/// <summary>/// 签名/// </summary>/// <param name="content">待签名字符串</param>/// <param name="privateKey">私钥</param>/// <param name="input_charset">编码格式</param>/// <returns>签名后字符串</returns>public static string sign(string content, string privateKey, string input_charset){byte[] Data = Encoding.GetEncoding(input_charset).GetBytes(content);RSACryptoServiceProvider rsa = DecodePemPrivateKey(privateKey);SHA1 sh = new SHA1CryptoServiceProvider();byte[] signData = rsa.SignData(Data, sh);return Convert.ToBase64String(signData);}/// <summary>/// 验签/// </summary>/// <param name="content">待验签字符串</param>/// <param name="signedString">签名</param>/// <param name="publicKey">公钥</param>/// <param name="input_charset">编码格式</param>/// <returns>true(通过)，false(不通过)</returns>public static bool verify(string content, string signedString, string publicKey, string input_charset){bool result = false;byte[] Data = Encoding.GetEncoding(input_charset).GetBytes(content);byte[] data = Convert.FromBase64String(signedString);RSAParameters paraPub = ConvertFromPublicKey(publicKey);RSACryptoServiceProvider rsaPub = new RSACryptoServiceProvider();rsaPub.ImportParameters(paraPub);SHA1 sh = new SHA1CryptoServiceProvider();result = rsaPub.VerifyData(Data, sh, data);return result;}/// <summary>/// 加密/// </summary>/// <param name="resData">需要加密的字符串</param>/// <param name="publicKey">公钥</param>/// <param name="input_charset">编码格式</param>/// <returns>明文</returns>public static string encryptData(string resData, string publicKey, string input_charset){byte[] DataToEncrypt = Encoding.ASCII.GetBytes(resData);string result = encrypt(DataToEncrypt, publicKey, input_charset);return result;}/// <summary>/// 解密/// </summary>/// <param name="resData">加密字符串</param>/// <param name="privateKey">私钥</param>/// <param name="input_charset">编码格式</param>/// <returns>明文</returns>public static string decryptData(string resData, string privateKey, string input_charset){byte[] DataToDecrypt = Convert.FromBase64String(resData);string result = "";for (int j = 0; j < DataToDecrypt.Length / 128; j++){byte[] buf = new byte[128];for (int i = 0; i < 128; i++){buf[i] = DataToDecrypt[i + 128 * j];}result += decrypt(buf, privateKey, input_charset);}return result;}#region 内部方法private static string encrypt(byte[] data, string publicKey, string input_charset){RSACryptoServiceProvider rsa = DecodePemPublicKey(publicKey);SHA1 sh = new SHA1CryptoServiceProvider();byte[] result = rsa.Encrypt(data, false);return Convert.ToBase64String(result);}private static string decrypt(byte[] data, string privateKey, string input_charset){string result = "";RSACryptoServiceProvider rsa = DecodePemPrivateKey(privateKey);SHA1 sh = new SHA1CryptoServiceProvider();byte[] source = rsa.Decrypt(data, false);char[] asciiChars = new char[Encoding.GetEncoding(input_charset).GetCharCount(source, 0, source.Length)];Encoding.GetEncoding(input_charset).GetChars(source, 0, source.Length, asciiChars, 0);result = new string(asciiChars);//result = ASCIIEncoding.ASCII.GetString(source);return result;}private static RSACryptoServiceProvider DecodePemPublicKey(String pemstr){byte[] pkcs8publickkey;pkcs8publickkey = Convert.FromBase64String(pemstr);if (pkcs8publickkey != null){RSACryptoServiceProvider rsa = DecodeRSAPublicKey(pkcs8publickkey);return rsa;}elsereturn null;}private static RSACryptoServiceProvider DecodePemPrivateKey(String pemstr){byte[] pkcs8privatekey;pkcs8privatekey = Convert.FromBase64String(pemstr);if (pkcs8privatekey != null){RSACryptoServiceProvider rsa = DecodePrivateKeyInfo(pkcs8privatekey);return rsa;}elsereturn null;}private static RSACryptoServiceProvider DecodePrivateKeyInfo(byte[] pkcs8){byte[] SeqOID = { 0x30, 0x0D, 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x01, 0x01, 0x05, 0x00 };byte[] seq = new byte[15];MemoryStream mem = new MemoryStream(pkcs8);int lenstream = (int)mem.Length;BinaryReader binr = new BinaryReader(mem);    //wrap Memory Stream with BinaryReader for easy readingbyte bt = 0;ushort twobytes = 0;try{twobytes = binr.ReadUInt16();if (twobytes == 0x8130)    //data read as little endian order (actual data order for Sequence is 30 81)binr.ReadByte();    //advance 1 byteelse if (twobytes == 0x8230)binr.ReadInt16();    //advance 2 byteselsereturn null;bt = binr.ReadByte();if (bt != 0x02)return null;twobytes = binr.ReadUInt16();if (twobytes != 0x0001)return null;seq = binr.ReadBytes(15);        //read the Sequence OIDif (!CompareBytearrays(seq, SeqOID))    //make sure Sequence for OID is correctreturn null;bt = binr.ReadByte();if (bt != 0x04)    //expect an Octet stringreturn null;bt = binr.ReadByte();        //read next byte, or next 2 bytes is  0x81 or 0x82; otherwise bt is the byte countif (bt == 0x81)binr.ReadByte();elseif (bt == 0x82)binr.ReadUInt16();//------ at this stage, the remaining sequence should be the RSA private keybyte[] rsaprivkey = binr.ReadBytes((int)(lenstream - mem.Position));RSACryptoServiceProvider rsacsp = DecodeRSAPrivateKey(rsaprivkey);return rsacsp;}catch (Exception){return null;}finally { binr.Close(); }}private static bool CompareBytearrays(byte[] a, byte[] b){if (a.Length != b.Length)return false;int i = 0;foreach (byte c in a){if (c != b[i])return false;i++;}return true;}private static RSACryptoServiceProvider DecodeRSAPublicKey(byte[] publickey){// encoded OID sequence for  PKCS #1 rsaEncryption szOID_RSA_RSA = "1.2.840.113549.1.1.1"byte[] SeqOID = { 0x30, 0x0D, 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x01, 0x01, 0x05, 0x00 };byte[] seq = new byte[15];// ---------  Set up stream to read the asn.1 encoded SubjectPublicKeyInfo blob  ------MemoryStream mem = new MemoryStream(publickey);BinaryReader binr = new BinaryReader(mem);    //wrap Memory Stream with BinaryReader for easy readingbyte bt = 0;ushort twobytes = 0;try{twobytes = binr.ReadUInt16();if (twobytes == 0x8130) //data read as little endian order (actual data order for Sequence is 30 81)binr.ReadByte();    //advance 1 byteelse if (twobytes == 0x8230)binr.ReadInt16();   //advance 2 byteselsereturn null;seq = binr.ReadBytes(15);       //read the Sequence OIDif (!CompareBytearrays(seq, SeqOID))    //make sure Sequence for OID is correctreturn null;twobytes = binr.ReadUInt16();if (twobytes == 0x8103) //data read as little endian order (actual data order for Bit String is 03 81)binr.ReadByte();    //advance 1 byteelse if (twobytes == 0x8203)binr.ReadInt16();   //advance 2 byteselsereturn null;bt = binr.ReadByte();if (bt != 0x00)     //expect null byte nextreturn null;twobytes = binr.ReadUInt16();if (twobytes == 0x8130) //data read as little endian order (actual data order for Sequence is 30 81)binr.ReadByte();    //advance 1 byteelse if (twobytes == 0x8230)binr.ReadInt16();   //advance 2 byteselsereturn null;twobytes = binr.ReadUInt16();byte lowbyte = 0x00;byte highbyte = 0x00;if (twobytes == 0x8102) //data read as little endian order (actual data order for Integer is 02 81)lowbyte = binr.ReadByte();  // read next bytes which is bytes in moduluselse if (twobytes == 0x8202){highbyte = binr.ReadByte(); //advance 2 byteslowbyte = binr.ReadByte();}elsereturn null;byte[] modint = { lowbyte, highbyte, 0x00, 0x00 };   //reverse byte order since asn.1 key uses big endian orderint modsize = BitConverter.ToInt32(modint, 0);byte firstbyte = binr.ReadByte();binr.BaseStream.Seek(-1, SeekOrigin.Current);if (firstbyte == 0x00){   //if first byte (highest order) of modulus is zero, don't include itbinr.ReadByte();    //skip this null bytemodsize -= 1;   //reduce modulus buffer size by 1
                }byte[] modulus = binr.ReadBytes(modsize);   //read the modulus bytesif (binr.ReadByte() != 0x02)            //expect an Integer for the exponent datareturn null;int expbytes = (int)binr.ReadByte();        // should only need one byte for actual exponent data (for all useful values)byte[] exponent = binr.ReadBytes(expbytes);// ------- create RSACryptoServiceProvider instance and initialize with public key -----RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();RSAParameters RSAKeyInfo = new RSAParameters();RSAKeyInfo.Modulus = modulus;RSAKeyInfo.Exponent = exponent;RSA.ImportParameters(RSAKeyInfo);return RSA;}catch (Exception){return null;}finally { binr.Close(); }}private static RSACryptoServiceProvider DecodeRSAPrivateKey(byte[] privkey){byte[] MODULUS, E, D, P, Q, DP, DQ, IQ;// ---------  Set up stream to decode the asn.1 encoded RSA private key  ------MemoryStream mem = new MemoryStream(privkey);BinaryReader binr = new BinaryReader(mem);    //wrap Memory Stream with BinaryReader for easy readingbyte bt = 0;ushort twobytes = 0;int elems = 0;try{twobytes = binr.ReadUInt16();if (twobytes == 0x8130)    //data read as little endian order (actual data order for Sequence is 30 81)binr.ReadByte();    //advance 1 byteelse if (twobytes == 0x8230)binr.ReadInt16();    //advance 2 byteselsereturn null;twobytes = binr.ReadUInt16();if (twobytes != 0x0102)    //version numberreturn null;bt = binr.ReadByte();if (bt != 0x00)return null;//------  all private key components are Integer sequences ----elems = GetIntegerSize(binr);MODULUS = binr.ReadBytes(elems);elems = GetIntegerSize(binr);E = binr.ReadBytes(elems);elems = GetIntegerSize(binr);D = binr.ReadBytes(elems);elems = GetIntegerSize(binr);P = binr.ReadBytes(elems);elems = GetIntegerSize(binr);Q = binr.ReadBytes(elems);elems = GetIntegerSize(binr);DP = binr.ReadBytes(elems);elems = GetIntegerSize(binr);DQ = binr.ReadBytes(elems);elems = GetIntegerSize(binr);IQ = binr.ReadBytes(elems);// ------- create RSACryptoServiceProvider instance and initialize with public key -----RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();RSAParameters RSAparams = new RSAParameters();RSAparams.Modulus = MODULUS;RSAparams.Exponent = E;RSAparams.D = D;RSAparams.P = P;RSAparams.Q = Q;RSAparams.DP = DP;RSAparams.DQ = DQ;RSAparams.InverseQ = IQ;RSA.ImportParameters(RSAparams);return RSA;}catch (Exception){return null;}finally { binr.Close(); }}private static int GetIntegerSize(BinaryReader binr){byte bt = 0;byte lowbyte = 0x00;byte highbyte = 0x00;int count = 0;bt = binr.ReadByte();if (bt != 0x02)        //expect integerreturn 0;bt = binr.ReadByte();if (bt == 0x81)count = binr.ReadByte();    // data size in next byteelseif (bt == 0x82){highbyte = binr.ReadByte();    // data size in next 2 byteslowbyte = binr.ReadByte();byte[] modint = { lowbyte, highbyte, 0x00, 0x00 };count = BitConverter.ToInt32(modint, 0);}else{count = bt;        // we already have the data size
                }while (binr.ReadByte() == 0x00){    //remove high order zeros in datacount -= 1;}binr.BaseStream.Seek(-1, SeekOrigin.Current);        //last ReadByte wasn't a removed zero, so back up a bytereturn count;}#endregion#region 解析.net 生成的Pemprivate static RSAParameters ConvertFromPublicKey(string pemFileConent){byte[] keyData = Convert.FromBase64String(pemFileConent);if (keyData.Length < 162){throw new ArgumentException("pem file content is incorrect.");}byte[] pemModulus = new byte[128];byte[] pemPublicExponent = new byte[3];Array.Copy(keyData, 29, pemModulus, 0, 128);Array.Copy(keyData, 159, pemPublicExponent, 0, 3);RSAParameters para = new RSAParameters();para.Modulus = pemModulus;para.Exponent = pemPublicExponent;return para;}private static RSAParameters ConvertFromPrivateKey(string pemFileConent){byte[] keyData = Convert.FromBase64String(pemFileConent);if (keyData.Length < 609){throw new ArgumentException("pem file content is incorrect.");}int index = 11;byte[] pemModulus = new byte[128];Array.Copy(keyData, index, pemModulus, 0, 128);index += 128;index += 2;//141byte[] pemPublicExponent = new byte[3];Array.Copy(keyData, index, pemPublicExponent, 0, 3);index += 3;index += 4;//148byte[] pemPrivateExponent = new byte[128];Array.Copy(keyData, index, pemPrivateExponent, 0, 128);index += 128;index += ((int)keyData[index + 1] == 64 ? 2 : 3);//279byte[] pemPrime1 = new byte[64];Array.Copy(keyData, index, pemPrime1, 0, 64);index += 64;index += ((int)keyData[index + 1] == 64 ? 2 : 3);//346byte[] pemPrime2 = new byte[64];Array.Copy(keyData, index, pemPrime2, 0, 64);index += 64;index += ((int)keyData[index + 1] == 64 ? 2 : 3);//412/413byte[] pemExponent1 = new byte[64];Array.Copy(keyData, index, pemExponent1, 0, 64);index += 64;index += ((int)keyData[index + 1] == 64 ? 2 : 3);//479/480byte[] pemExponent2 = new byte[64];Array.Copy(keyData, index, pemExponent2, 0, 64);index += 64;index += ((int)keyData[index + 1] == 64 ? 2 : 3);//545/546byte[] pemCoefficient = new byte[64];Array.Copy(keyData, index, pemCoefficient, 0, 64);RSAParameters para = new RSAParameters();para.Modulus = pemModulus;para.Exponent = pemPublicExponent;para.D = pemPrivateExponent;para.P = pemPrime1;para.Q = pemPrime2;para.DP = pemExponent1;para.DQ = pemExponent2;para.InverseQ = pemCoefficient;return para;}#endregion}
}

RSA算法测试代码：

using System;
using System.Collections.Generic;
using System.Text;
using RSA.Class;namespace payapi_demo.RSA
{class TestRSA{static void Main(string[] arg){/**RSA加密测试,RSA中的密钥对通过SSL工具生成，生成命令如下：* 1 生成RSA私钥：* openssl genrsa -out rsa_private_key.pem 1024*2 生成RSA公钥* openssl rsa -in rsa_private_key.pem -pubout -out rsa_public_key.pem** 3 将RSA私钥转换成PKCS8格式* openssl pkcs8 -topk8 -inform PEM -in rsa_private_key.pem -outform PEM -nocrypt -out rsa_pub_pk8.pem** 直接打开rsa_private_key.pem和rsa_pub_pk8.pem文件就可以获取密钥对内容，获取密钥对内容组成字符串时，注意将换行符删除* */string publickey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDzOqfNunFxFtCZPlq7fO/jWwjqmTvAooVBB4y87BizSZ9dl/F7FpAxYc6MmX2TqivCvvORXgdlYdFWAhzXOnIUv9OGG///WPLe9TMs9kIwAZ/APUXauvC01oFLnYkzwPlAh0tQ1Au9arTE/OG1V1dKgf8BXHLPhKL4BmGBEUZBtQIDAQAB";string privatekey = "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";//加密字符串string data = "yibao";Console.WriteLine("加密前字符串内容："+data);//加密string encrypteddata = RSAFromPkcs8.encryptData(data, publickey, "UTF-8");Console.WriteLine("加密后的字符串为：" + encrypteddata);Console.WriteLine("解密后的字符串内容：" + RSAFromPkcs8.decryptData(encrypteddata, privatekey, "UTF-8"));Console.WriteLine("***********");//解密string endata = "LpnnvnfA72VnyjboX/OsCPO6FOFXeEnnsKkI7aAEQyVAPfCTfQ43ZYVZVqnADDPMW7VhBXJWyQMAGw2Fh9sS/XLHmO5XW94Yehci6JrJMynePgtIiDysjNA+UlgSTC/MlResNrBm/4MMSPvq0qLwScgpZDynhLsVZk+EQ6G8wgA=";string datamw = RSAFromPkcs8.decryptData(endata, privatekey, "UTF-8");Console.WriteLine("静态加密后的字符串为：" + endata);Console.WriteLine("解密后的字符串内容：" + datamw);//签名string signdata = "YB010000001441234567286038508081299";Console.WriteLine("签名前的字符串内容：" + signdata);string sign = RSAFromPkcs8.sign(signdata, privatekey, "UTF-8");Console.WriteLine("签名后的字符串：" + sign);Console.ReadLine();}}
}