c#
using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Security.Cryptography; using System.Text; using System.Threading.Tasks; namespace Common { public class RSA { /// <summary> /// RSA公钥加密 /// </summary> /// <param name="publickey">公钥</param> /// <param name="content">待加密字符串</param> /// <param name="input_charset">编码格式，UTF-8</param> /// <returns></returns> public static string RasEncrypt(string publickey, string content, string input_charset) { RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(); byte[] cipherbytes; rsa.ImportParameters(ConvertFromPublicKey(publickey)); cipherbytes = rsa.Encrypt(Encoding.GetEncoding(input_charset).GetBytes(content), false); return Convert.ToBase64String(cipherbytes); } /// <summary> /// RSA私钥解密 /// </summary> /// <param name="resData">RSA加密后字符串</param> /// <param name="privateKey">私钥</param> /// <param name="input_charset">编码格式，UTF-8</param> /// <returns>明文</returns> public static string RsaDecrypt(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 decrypt(byte[] data, string privateKey, string input_charset) { string result = ""; RSACryptoServiceProvider rsa = DecodePemPrivateKey(privateKey); using (var sh = SHA1.Create()) { 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); return result; } } private static RSACryptoServiceProvider DecodePemPrivateKey(String pemstr) { RSACryptoServiceProvider rsa = DecodeRSAPrivateKey(Convert.FromBase64String(pemstr)); return rsa; } 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 ----- CspParameters CspParameters = new CspParameters(); CspParameters.Flags = CspProviderFlags.UseMachineKeyStore; RSACryptoServiceProvider RSA = new RSACryptoServiceProvider(1024, CspParameters); 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 { return null; } finally { binr.Dispose(); } } 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 生成的Pem private static RSAParameters ConvertFromPublicKey(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]); byte[] pemPublicExponent = new byte[3]; Array.Copy(keyData, (keySize1024 ? 29 : 33), pemModulus, 0, (keySize1024 ? 128 : 256)); Array.Copy(keyData, (keySize1024 ? 159 : 291), pemPublicExponent, 0, 3); RSAParameters para = new RSAParameters(); para.Modulus = pemModulus; para.Exponent = pemPublicExponent; return para; } #endregion } }
对应python版本：
from Crypto.PublicKey import RSA from Crypto.Cipher import PKCS1_v1_5 import base64 # 生成 RSA 密钥对 key = RSA.generate(2048) # 获取公钥和私钥 public_key = key.publickey().export_key() private_key = key.export_key() print("Public key:", public_key.decode()) print("Private key:", private_key.decode()) # 加密函数 def rsa_encrypt(message, public_key): rsa_key = RSA.import_key(public_key) cipher = PKCS1_v1_5.new(rsa_key) encrypted_message = cipher.encrypt(message.encode()) return base64.b64encode(encrypted_message) # 解密函数 def rsa_decrypt(ciphertext, private_key): rsa_key = RSA.import_key(private_key) cipher = PKCS1_v1_5.new(rsa_key) decrypted_message = cipher.decrypt(base64.b64decode(ciphertext), None) return decrypted_message.decode() # 要加密的消息 message = "Hello, this is a secret message!" # 使用公钥加密消息 encrypted_message = rsa_encrypt(message, public_key) print("Encrypted message:", encrypted_message) # 使用私钥解密消息 decrypted_message = rsa_decrypt(encrypted_message, private_key) print("Decrypted message:", decrypted_message)
