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)
标签：加密,string,RSA,解密,key,elems,new,byte,binr From： https://www.cnblogs.com/onlyou13/p/18089103