c# 使用 java的 rsa 进行签名

     /// <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);
             SHA256 sh = new SHA256CryptoServiceProvider();
             //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();
             SHA256 sh = new SHA256CryptoServiceProvider();
             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 = ; j < DataToDecrypt.Length / ; j++)
             {
                 byte[] buf = new byte[];
                 for (int i = ; i < ; i++)
                 {

                     buf[i] = DataToDecrypt[i +  * 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, , source.Length)];
             Encoding.GetEncoding(input_charset).GetChars(source, , source.Length, asciiChars, );
             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;
             }
             else
                 return null;
         }

         private static RSACryptoServiceProvider DecodePemPrivateKey(String pemstr)
         {
             byte[] pkcs8privatekey;
             pkcs8privatekey = Convert.FromBase64String(pemstr);
             if (pkcs8privatekey != null)
             {
                 RSACryptoServiceProvider rsa = DecodePrivateKeyInfo(pkcs8privatekey);
                 return rsa;
             }
             else
                 return 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[];

             MemoryStream mem = new MemoryStream(pkcs8);
             int lenstream = (int)mem.Length;
             BinaryReader binr = new BinaryReader(mem);    //wrap Memory Stream with BinaryReader for easy reading
             byte bt = ;
             ushort twobytes = ;

             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 byte
                 else if (twobytes == 0x8230)
                     binr.ReadInt16();    //advance 2 bytes
                 else
                     return null;

                 bt = binr.ReadByte();
                 if (bt != 0x02)
                     return null;

                 twobytes = binr.ReadUInt16();

                 if (twobytes != 0x0001)
                     return null;

                 seq = binr.ReadBytes();        //read the Sequence OID
                 if (!CompareBytearrays(seq, SeqOID))    //make sure Sequence for OID is correct
                     return null;

                 bt = binr.ReadByte();
                 if (bt != 0x04)    //expect an Octet string
                     return null;

                 bt = binr.ReadByte();        //read next byte, or next 2 bytes is  0x81 or 0x82; otherwise bt is the byte count
                 if (bt == 0x81)
                     binr.ReadByte();
                 else
                     if (bt == 0x82)
                     binr.ReadUInt16();
                 //------ at this stage, the remaining sequence should be the RSA private key  

                 byte[] 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 = ;
             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[];
             // ---------  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 reading
             byte bt = ;
             ushort twobytes = ;

             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 byte
                 else if (twobytes == 0x8230)
                     binr.ReadInt16();   //advance 2 bytes
                 else
                     return null;

                 seq = binr.ReadBytes();       //read the Sequence OID
                 if (!CompareBytearrays(seq, SeqOID))    //make sure Sequence for OID is correct
                     return 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 byte
                 else if (twobytes == 0x8203)
                     binr.ReadInt16();   //advance 2 bytes
                 else
                     return null;

                 bt = binr.ReadByte();
                 if (bt != 0x00)     //expect null byte next
                     return 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 byte
                 else if (twobytes == 0x8230)
                     binr.ReadInt16();   //advance 2 bytes
                 else
                     return 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 modulus
                 else if (twobytes == 0x8202)
                 {
                     highbyte = binr.ReadByte(); //advance 2 bytes
                     lowbyte = binr.ReadByte();
                 }
                 else
                     return null;
                 byte[] modint = { lowbyte, highbyte, 0x00, 0x00 };   //reverse byte order since asn.1 key uses big endian order
                 int modsize = BitConverter.ToInt32(modint, );

                 byte firstbyte = binr.ReadByte();
                 binr.BaseStream.Seek(-, SeekOrigin.Current);

                 if (firstbyte == 0x00)
                 {   //if first byte (highest order) of modulus is zero, don't include it
                     binr.ReadByte();    //skip this null byte
                     modsize -= ;   //reduce modulus buffer size by 1
                 }

                 byte[] modulus = binr.ReadBytes(modsize);   //read the modulus bytes  

                 if (binr.ReadByte() != 0x02)            //expect an Integer for the exponent data
                     return 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 reading
             byte bt = ;
             ushort twobytes = ;
             int elems = ;
             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 byte
                 else if (twobytes == 0x8230)
                     binr.ReadInt16();    //advance 2 bytes
                 else
                     return null;

                 twobytes = binr.ReadUInt16();
                 if (twobytes != 0x0102)    //version number
                     return 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 = ;
             byte lowbyte = 0x00;
             byte highbyte = 0x00;
             int count = ;
             bt = binr.ReadByte();
             if (bt != 0x02)        //expect integer
                 return ;
             bt = binr.ReadByte();

             if (bt == 0x81)
                 count = binr.ReadByte();    // data size in next byte
             else
                 if (bt == 0x82)
             {
                 highbyte = binr.ReadByte();    // data size in next 2 bytes
                 lowbyte = binr.ReadByte();
                 byte[] modint = { lowbyte, highbyte, 0x00, 0x00 };
                 count = BitConverter.ToInt32(modint, );
             }
             else
             {
                 count = bt;        // we already have the data size
             }

             while (binr.ReadByte() == 0x00)
             {    //remove high order zeros in data
                 count -= ;
             }
             binr.BaseStream.Seek(-, SeekOrigin.Current);        //last ReadByte wasn't a removed zero, so back up a byte
             return count;
         }

         #endregion

         #region 解析.net 生成的Pem
         private static RSAParameters ConvertFromPublicKey(string pemFileConent)
         {

             byte[] keyData = Convert.FromBase64String(pemFileConent);
             if (keyData.Length < )
             {
                 throw new ArgumentException("pem file content is incorrect.");
             }
             byte[] pemModulus = new byte[];
             byte[] pemPublicExponent = new byte[];
             Array.Copy(keyData, , pemModulus, , );
             Array.Copy(keyData, , pemPublicExponent, , );
             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 < )
             {
                 throw new ArgumentException("pem file content is incorrect.");
             }

             int index = ;
             byte[] pemModulus = new byte[];
             Array.Copy(keyData, index, pemModulus, , );

             index += ;
             index += ;//141
             byte[] pemPublicExponent = new byte[];
             Array.Copy(keyData, index, pemPublicExponent, , );

             index += ;
             index += ;//148
             byte[] pemPrivateExponent = new byte[];
             Array.Copy(keyData, index, pemPrivateExponent, , );

             index += ;
             index += ((int)keyData[index + ] ==  ?  : );//279
             byte[] pemPrime1 = new byte[];
             Array.Copy(keyData, index, pemPrime1, , );

             index += ;
             index += ((int)keyData[index + ] ==  ?  : );//346
             byte[] pemPrime2 = new byte[];
             Array.Copy(keyData, index, pemPrime2, , );

             index += ;
             index += ((int)keyData[index + ] ==  ?  : );//412/413
             byte[] pemExponent1 = new byte[];
             Array.Copy(keyData, index, pemExponent1, , );

             index += ;
             index += ((int)keyData[index + ] ==  ?  : );//479/480
             byte[] pemExponent2 = new byte[];
             Array.Copy(keyData, index, pemExponent2, , );

             index += ;
             index += ((int)keyData[index + ] ==  ?  : );//545/546
             byte[] pemCoefficient = new byte[];
             Array.Copy(keyData, index, pemCoefficient, , );

             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

     }

调用代码

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();
        }
    }
}  

转载自 http://blog.csdn.net/hjqqingqing/article/details/9272103