RSA加解密工具类

Posted 2020-11-26 zt2710

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Java 实现

import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;

import javax.crypto.Cipher;

import org.apache.commons.codec.binary.Base64;

/**
* RSA 加解密工具类
*
* @author ZT ** 秘钥对可以在在线生成网站获取(http://web.chacuo.net/netrsakeypair)
* 在线生成非对称加密公钥私钥对、在线生成公私钥对、RSA Key pair create、生成RSA密钥对选择秘钥位数：1024
* 秘钥格式：PKCS#8
*
*/
public class RSACryptUtil {

/**
* 获取公钥
*
* @return
*/
public static String getPubliceKey() {
// rsa_public_key.pem内容
String publickey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDLK6Hw+RE///HKM1zukQTao/ybdm7RpbQ2bvDTHtDWysx46vIC4wosNZwP3bmxEpzq8f6B3jZeqtcoxCWfVNi1S1FNjyKpC55xmjzrCTNUe9mSgKwyoGU/kHpR4FyXTgP02XkuDXXJrODlDQQg0UNrgbkA9BboLxdxkZLsp1tshQIDAQAB";

publickey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCssD8md1gI0kA6TVOQtggtvBrSH+N/q5/+grs7LSXT2P7UzVeuN1SdETZdt+386D/3K/k8aJmQILc0HoEjHUIopbdEP318odCnmytveenZCdCtq8/9n1HUcmAUDEVS03F6z51DUvjMfKKSqdc66vhagVciamOmFQNdZJu3jZXjlQIDAQAB";
return publickey;
}

/**
* 获取私钥
*
* @return
*/
public static String getPrivateKey() {
String privatekey = "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";

privatekey = "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";
return privatekey;
}

private static Map<Integer, String> keyMap = new HashMap<Integer, String>(); // 用于封装随机产生的公钥与私钥

public static void main(String[] args) throws Exception {
// 生成公钥和私钥
genKeyPair();
// 加密字符串
String message = "aaabbbb";
System.out.println("随机生成的公钥为:" + keyMap.get(0));
System.out.println("随机生成的私钥为:" + keyMap.get(1));
String messageEn = encrypt(message, keyMap.get(0));
System.out.println(message + " 加密后的字符串为:" + messageEn);
String messageDe = decrypt(messageEn, keyMap.get(1));
System.out.println("还原后的字符串为:" + messageDe);
}

/**
* 随机生成密钥对
*
* @throws NoSuchAlgorithmException
*/
public static void genKeyPair() throws NoSuchAlgorithmException {
// KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
// 初始化密钥对生成器，密钥大小为96-1024位
keyPairGen.initialize(1024, new SecureRandom());
// 生成一个密钥对，保存在keyPair中
KeyPair keyPair = keyPairGen.generateKeyPair();
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate(); // 得到私钥
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); // 得到公钥
String publicKeyString = new String(Base64.encodeBase64(publicKey.getEncoded()));
// 得到私钥字符串
String privateKeyString = new String(Base64.encodeBase64((privateKey.getEncoded())));
// 将公钥和私钥保存到Map
keyMap.put(0, publicKeyString); // 0表示公钥
keyMap.put(1, privateKeyString); // 1表示私钥
}

/**
* RSA公钥加密
*
* @param str 加密字符串
* @param publicKey 公钥
* @return 密文
* @throws Exception 加密过程中的异常信息
*/
public static String encrypt(String str, String publicKey) throws Exception {
// base64编码的公钥
byte[] decoded = Base64.decodeBase64(publicKey);
RSAPublicKey pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA")
.generatePublic(new X509EncodedKeySpec(decoded));
// RSA加密
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.ENCRYPT_MODE, pubKey);
String outStr = Base64.encodeBase64String(cipher.doFinal(str.getBytes("UTF-8")));
return outStr;
}

/**
* RSA私钥解密
* @param str 加密字符串
* @param privateKey 私钥
* @return 铭文
* @throws Exception 解密过程中的异常信息
*/
public static String decrypt(String str, String privateKey) throws Exception {
// 64位解码加密后的字符串
byte[] inputByte = Base64.decodeBase64(str.getBytes("UTF-8"));
// base64编码的私钥
byte[] decoded = Base64.decodeBase64(privateKey);
RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA")
.generatePrivate(new PKCS8EncodedKeySpec(decoded));
// RSA解密
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.DECRYPT_MODE, priKey);
String outStr = new String(cipher.doFinal(inputByte));
return outStr;
}

}

C# 实现

using System;

using System.Collections.Generic;

using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Web;

namespace BS.Data
{
/// <summary>
/// 类名：RSACrypt
/// 功能：RSA加密、解密、签名、验签
/// </summary>
public class RSACrypt
{

/***
* 秘钥对可以在在线生成网站获取(http://web.chacuo.net/netrsakeypair)
* 在线生成非对称加密公钥私钥对、在线生成公私钥对、RSA Key pair create、生成RSA密钥对
* 选择秘钥位数：1024
* 秘钥格式：PKCS#8
*/

/// <summary>
/// 获取公钥
/// </summary>
/// <returns></returns>
public static string getPubliceKey()
{
//rsa_public_key.pem内容
string publickey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDLK6Hw+RE///HKM1zukQTao/ybdm7RpbQ2bvDTHtDWysx46vIC4wosNZwP3bmxEpzq8f6B3jZeqtcoxCWfVNi1S1FNjyKpC55xmjzrCTNUe9mSgKwyoGU/kHpR4FyXTgP02XkuDXXJrODlDQQg0UNrgbkA9BboLxdxkZLsp1tshQIDAQAB";

/// <summary>
/// 获取私钥
/// </summary>
/// <returns></returns>
public static string getPrivateKey()
{
string privatekey = "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";

/// <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);
SHA1 sh = new SHA1CryptoServiceProvider();
byte[] signData = rsa.SignData(Data, sh);
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)
{
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 sh = new SHA1CryptoServiceProvider();
result = rsaPub.VerifyData(Data, sh, data);
return result;
}

/// <summary>
/// 加密 (注意：同一个数据每次加密生成的结果数据不一样,私钥都可以完成解密)
/// </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.ASCII.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;
}

private static string encrypt(byte[] data, string publicKey, string input_charset)
{
RSACryptoServiceProvider rsa = DecodePemPublicKey(publicKey);
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);
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);
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);
byte bt = 0;
ushort twobytes = 0;

try
{
twobytes = binr.ReadUInt16();
if (twobytes == 0x8130)
binr.ReadByte();
else if (twobytes == 0x8230)
binr.ReadInt16();
else
return null;

bt = binr.ReadByte();
if (bt != 0x02)
return null;

twobytes = binr.ReadUInt16();

if (twobytes != 0x0001)
return null;

seq = binr.ReadBytes(15);
if (!CompareBytearrays(seq, SeqOID))
return null;

bt = binr.ReadByte();
if (bt != 0x04)
return null;

bt = binr.ReadByte();
if (bt == 0x81)
binr.ReadByte();
else
if (bt == 0x82)
binr.ReadUInt16();

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)
{
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(publickey);
BinaryReader binr = new BinaryReader(mem);
byte bt = 0;
ushort twobytes = 0;

try
{

twobytes = binr.ReadUInt16();
if (twobytes == 0x8130)
binr.ReadByte();
else if (twobytes == 0x8230)
binr.ReadInt16();
else
return null;

seq = binr.ReadBytes(15);
if (!CompareBytearrays(seq, SeqOID))
return null;

twobytes = binr.ReadUInt16();
if (twobytes == 0x8103)
binr.ReadByte();
else if (twobytes == 0x8203)
binr.ReadInt16();
else
return null;

bt = binr.ReadByte();
if (bt != 0x00)
return null;

twobytes = binr.ReadUInt16();
if (twobytes == 0x8130)
binr.ReadByte();
else if (twobytes == 0x8230)
binr.ReadInt16();
else
return null;

twobytes = binr.ReadUInt16();
byte lowbyte = 0x00;
byte highbyte = 0x00;

if (twobytes == 0x8102)
lowbyte = binr.ReadByte();
else if (twobytes == 0x8202)
{
highbyte = binr.ReadByte();
lowbyte = binr.ReadByte();
}
else
return null;
byte[] modint = { lowbyte, highbyte, 0x00, 0x00 };
int modsize = BitConverter.ToInt32(modint, 0);

byte firstbyte = binr.ReadByte();
binr.BaseStream.Seek(-1, SeekOrigin.Current);

if (firstbyte == 0x00)
{
binr.ReadByte();
modsize -= 1;
}

byte[] modulus = binr.ReadBytes(modsize);

if (binr.ReadByte() != 0x02)
return null;
int expbytes = (int)binr.ReadByte();
byte[] exponent = binr.ReadBytes(expbytes);

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;

MemoryStream mem = new MemoryStream(privkey);
BinaryReader binr = new BinaryReader(mem);
byte bt = 0;
ushort twobytes = 0;
int elems = 0;
try
{
twobytes = binr.ReadUInt16();
if (twobytes == 0x8130)
binr.ReadByte();
else if (twobytes == 0x8230)
binr.ReadInt16();
else
return null;

twobytes = binr.ReadUInt16();
if (twobytes != 0x0102)
return null;
bt = binr.ReadByte();
if (bt != 0x00)
return null;

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);

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)
return 0;
bt = binr.ReadByte();

if (bt == 0x81)
count = binr.ReadByte();
else
if (bt == 0x82)
{
highbyte = binr.ReadByte();
lowbyte = binr.ReadByte();
byte[] modint = { lowbyte, highbyte, 0x00, 0x00 };
count = BitConverter.ToInt32(modint, 0);
}
else
{
count = bt;
}

while (binr.ReadByte() == 0x00)
{
count -= 1;
}
binr.BaseStream.Seek(-1, SeekOrigin.Current);
return count;
}

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;
byte[] pemPublicExponent = new byte[3];
Array.Copy(keyData, index, pemPublicExponent, 0, 3);

index += 3;
index += 4;
byte[] pemPrivateExponent = new byte[128];
Array.Copy(keyData, index, pemPrivateExponent, 0, 128);

index += 128;
index += ((int)keyData[index + 1] == 64 ? 2 : 3);
byte[] pemPrime1 = new byte[64];
Array.Copy(keyData, index, pemPrime1, 0, 64);

index += 64;
index += ((int)keyData[index + 1] == 64 ? 2 : 3);//346
byte[] pemPrime2 = new byte[64];
Array.Copy(keyData, index, pemPrime2, 0, 64);

index += 64;
index += ((int)keyData[index + 1] == 64 ? 2 : 3);
byte[] pemExponent1 = new byte[64];
Array.Copy(keyData, index, pemExponent1, 0, 64);

index += 64;
index += ((int)keyData[index + 1] == 64 ? 2 : 3);
byte[] pemExponent2 = new byte[64];
Array.Copy(keyData, index, pemExponent2, 0, 64);

index += 64;
index += ((int)keyData[index + 1] == 64 ? 2 : 3);
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;
}

}

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