今天有同学对接一个支付平台，涉及到RSA的签名和验签。由于对方是java的sdk，翻成c#语言时，搞了半天也没搞定。网上搜的东西都是各种copy还不解决问题。 碰巧，我之前对接过连连银通的网银支付和代付。连连那边提供了c#版的RSA加密算法，立即破了这位同学的难题。在这里也分享出来，以便大家日后备用。
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Security.Cryptography; /// <summary>
/// 类名：RSAFromPkcs8
/// 功能：RSA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：1.0
/// 日期：2013-09-30
/// 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 = "utf-8")
{
byte[] Data = Encoding.GetEncoding(input_charset).GetBytes(content);
RSACryptoServiceProvider rsa = DecodePemPrivateKey(privateKey);
//SHA1 crypto = new SHA1CryptoServiceProvider();
MD5 crypto = new MD5CryptoServiceProvider();
byte[] signData = rsa.SignData(Data, crypto);
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 = "utf-8")
{
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 crypto = new SHA1CryptoServiceProvider();
MD5 crypto = new MD5CryptoServiceProvider();
result = rsaPub.VerifyData(Data, crypto, data);
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);
List<byte> result = new List<byte>();
for (int j = ; j < DataToDecrypt.Length / ; j++)
{
byte[] buf = new byte[];
for (int i = ; i < ; i++)
{
buf[i] = DataToDecrypt[i + * j];
}
result.AddRange(decrypt(buf, privateKey, input_charset));
}
byte[] source = result.ToArray();
char[] asciiChars = new char[Encoding.GetEncoding(input_charset).GetCharCount(source, , source.Length)];
Encoding.GetEncoding(input_charset).GetChars(source, , source.Length, asciiChars, );
return new string(asciiChars);
} #region 内部方法 private static byte[] decrypt(byte[] data, string privateKey, string input_charset)
{
RSACryptoServiceProvider rsa = DecodePemPrivateKey(privateKey);
//SHA1 sh = new SHA1CryptoServiceProvider();
return rsa.Decrypt(data, false);
} 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 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 += ;//
byte[] pemPublicExponent = new byte[];
Array.Copy(keyData, index, pemPublicExponent, , ); index += ;
index += ;//
byte[] pemPrivateExponent = new byte[];
Array.Copy(keyData, index, pemPrivateExponent, , ); index += ;
index += ((int)keyData[index + ] == ? : );//
byte[] pemPrime1 = new byte[];
Array.Copy(keyData, index, pemPrime1, , ); index += ;
index += ((int)keyData[index + ] == ? : );//
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 }