之前在催收系统中使用C#解密银行使用java rsa 发过来的加密数据一直出现乱码，今天无意中解决了；
using System; using System.IO; using System.Security.Cryptography; using System.Text; public class RSAFromPkc8 { /// <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); MD5 sh = new MD5CryptoServiceProvider();//这里也可以使用MD5加密方式 //SHA1 sh = new SHA1CryptoServiceProvider(); byte[] signData = rsa.SignData(Data, sh); string str = Convert.ToBase64String(signData); //str = str.Replace("+", "%2B"); return str; } /// <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); MD5 sh = new MD5CryptoServiceProvider();//这里可以使用MD5加密方式 //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.GetEncoding(input_charset).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); //MD5 sh = new MD5CryptoServiceProvider();//这里也可以使用MD5加密方式 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); //MD5 sh = new MD5CryptoServiceProvider();//这里也可以替换使用MD5方式 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; } 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[15]; 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 = 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 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(15); //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 = 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 reading byte 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 byte } else if (twobytes == 0x8230) { binr.ReadInt16(); //advance 2 bytes } else { return null; } seq = binr.ReadBytes(15); //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, 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 it binr.ReadByte(); //skip this null byte modsize -= 1; //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 = 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 = 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 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 = 0; byte lowbyte = 0x00; byte highbyte = 0x00; int count = 0; bt = binr.ReadByte(); if (bt != 0x02) //expect integer { return 0; } 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, 0); } else { count = bt; // we already have the data size } while (binr.ReadByte() == 0x00) { //remove high order zeros in data count -= 1; } binr.BaseStream.Seek(-1, 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 < 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;//141 byte[] pemPublicExponent = new byte[3]; Array.Copy(keyData, index, pemPublicExponent, 0, 3); index += 3; index += 4;//148 byte[] pemPrivateExponent = new byte[128]; Array.Copy(keyData, index, pemPrivateExponent, 0, 128); index += 128; index += (keyData[index + 1] == 64 ? 2 : 3);//279 byte[] pemPrime1 = new byte[64]; Array.Copy(keyData, index, pemPrime1, 0, 64); index += 64; index += (keyData[index + 1] == 64 ? 2 : 3);//346 byte[] pemPrime2 = new byte[64]; Array.Copy(keyData, index, pemPrime2, 0, 64); index += 64; index += (keyData[index + 1] == 64 ? 2 : 3);//412/413 byte[] pemExponent1 = new byte[64]; Array.Copy(keyData, index, pemExponent1, 0, 64); index += 64; index += (keyData[index + 1] == 64 ? 2 : 3);//479/480 byte[] pemExponent2 = new byte[64]; Array.Copy(keyData, index, pemExponent2, 0, 64); index += 64; index += (keyData[index + 1] == 64 ? 2 : 3);//545/546 byte[] 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 }