最近开发车辆控制这块，与车上的控制设备进行通信，其中设备向平台注册使用了RSA2048的解密，在网上找了一些加密解密的都是加载XML文件的，公钥(原始的byte[] 294个长度)，私钥，我看C#提供的类库里面有一个加载指数，模数的进行解密的功能所以试着实现了一下，下面上代码：
using System;using System.IO;using System.Security.Cryptography;using System.Text;namespace ConsoleApp2{class Program{ static void Main(string[] args){while (true){var input = Console.ReadLine();#region MyRegion#endregion///公钥string sql = @"MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwNqreCMpgET1BEA/kPZAeaj+xfG2UWTHOkTyV+28AC0BYxQDfKq7HV1RDaLHR5GBIKC1OK+m5thEBVJg27O8uUp95O88McR17mFw9UVQ5w3Zn9ChK93GzmB1ltob3Sm847YW18KyoxDbqbh6MlRy6yt5v/MDpbbs5lEcwME9YmgGVvayfWDMquFqHnX05pEoE05uvAyDj1UtT7ZlMn6TmOzTLpfoGnkADoyB3LraAa6qGkNWa9/fmV3xU11LH141fidO9iG5L5Gx5xw/JEIxTAblXbxqxsWeCBbkNpW4TqtbX5CH1EdhWYxOL060Ujkr1Qe5Zp0TntaKK2lY4RswKQIDAQAB";var rsaa = ConvertFromPemPublicKey(sql);RSACryptoServiceProvider rsab = new RSACryptoServiceProvider();rsab.ImportParameters(rsaa);byte[] sample = rsab.Encrypt(Encoding.Default.GetBytes(input), false);string info = Convert.ToBase64String(sample);Console.WriteLine("加密后:" + info);#region 解密//秘钥byte[] aa = Convert.FromBase64String(info);sql = @"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";var b = DecodeRSAPrivateKey(sql);byte[] vs = b.Decrypt(aa, false);string str = System.Text.Encoding.Default.GetString(vs);Console.WriteLine("解密后:" + str);#endregion}}public static RSACryptoServiceProvider DecodeRSAPrivateKey(string priKey){var privkey = Convert.FromBase64String(priKey);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;} /// <summary> /// 将pem格式公钥(1024 or 2048)转换为RSAParameters /// </summary> /// <param name="pemFileConent">pem公钥内容</param> /// <returns>转换得到的RSAParamenters</returns> public static RSAParameters ConvertFromPemPublicKey(string pemFileConent){if (string.IsNullOrEmpty(pemFileConent)){throw new ArgumentNullException("pemFileConent", "This arg cann't be empty.");}pemFileConent = pemFileConent.Replace("-----BEGIN PUBLIC KEY-----", "").Replace("-----END PUBLIC KEY-----", "").Replace("\n", "").Replace("\r", "");byte[] keyData = Convert.FromBase64String(pemFileConent);bool keySize1024 = (keyData.Length == 162);bool keySize2048 = (keyData.Length == 294);if (!(keySize1024 || keySize2048)){throw new ArgumentException("pem file content is incorrect, Only support the key size is 1024 or 2048");}byte[] pemModulus = (keySize1024 ? new byte[128] : new byte[256]);var pemPublicExponent = new byte[3];Array.Copy(keyData, (keySize1024 ? 29 : 33), pemModulus, 0, (keySize1024 ? 128 : 256));Array.Copy(keyData, (keySize1024 ? 159 : 291), pemPublicExponent, 0, 3);var para = new RSAParameters { Modulus = pemModulus, Exponent = pemPublicExponent };byte[] sss = para.Modulus;return para;}}}
