SM2的非对称加解密java工具类

由于工作原因需要对原有加密方式RSA已不适用,要支持国密SM2

maven依赖


    org.bouncycastle
	bcprov-jdk15on
	1.54

java实现如下

import java.math.BigInteger;
import java.security.SecureRandom;
import java.util.Arrays;

import org.bouncycastle.crypto.DerivationFunction;
import org.bouncycastle.crypto.digests.SHA256Digest;
import org.bouncycastle.crypto.digests.ShortenedDigest;
import org.bouncycastle.crypto.generators.KDF1BytesGenerator;
import org.bouncycastle.crypto.params.ISO18033KDFParameters;
import org.bouncycastle.math.ec.ECCurve;
import org.bouncycastle.math.ec.ECPoint;

/**
 * 	 说	明:SM2的非对称加解密工具类,椭圆曲线方程为:y^2=x^3+ax+b 使用Fp-256
 * 
 * @author 作者名:冯龙淼
 * 		   E-mail:[email protected]
 * 
 * @version 版   本  号:1.0.
* 创建时间:2018年3月6日 上午9:40:53 */ public class SM2Util { /** 素数p */ private static final BigInteger p = new BigInteger("FFFFFFFE" + "FFFFFFFF" + "FFFFFFFF" + "FFFFFFFF" + "FFFFFFFF" + "00000000" + "FFFFFFFF" + "FFFFFFFF", 16); /** 系数a */ private static final BigInteger a = new BigInteger("FFFFFFFE" + "FFFFFFFF" + "FFFFFFFF" + "FFFFFFFF" + "FFFFFFFF" + "00000000" + "FFFFFFFF" + "FFFFFFFC", 16); /** 系数b */ private static final BigInteger b = new BigInteger("28E9FA9E" + "9D9F5E34" + "4D5A9E4B" + "CF6509A7" + "F39789F5" + "15AB8F92" + "DDBCBD41" + "4D940E93", 16); /** 坐标x */ private static final BigInteger xg = new BigInteger("32C4AE2C" + "1F198119" + "5F990446" + "6A39C994" + "8FE30BBF" + "F2660BE1" + "715A4589" + "334C74C7", 16); /** 坐标y */ private static final BigInteger yg = new BigInteger("BC3736A2" + "F4F6779C" + "59BDCEE3" + "6B692153" + "D0A9877C" + "C62A4740" + "02DF32E5" + "2139F0A0", 16); /** 基点G, G=(xg,yg),其介记为n */ private static final BigInteger n = new BigInteger("FFFFFFFE" + "FFFFFFFF" + "FFFFFFFF" + "FFFFFFFF" + "7203DF6B" + "21C6052B" + "53BBF409" + "39D54123", 16); private static SecureRandom random = new SecureRandom(); private ECCurve.Fp curve; private ECPoint G; public static String printHexString(byte[] b) { StringBuilder builder = new StringBuilder(); for (int i = 0; i < b.length; i++) { String hex = Integer.toHexString(b[i] & 0xFF); if (hex.length() == 1) { builder.append('0'+hex); hex = '0' + hex; } // System.out.print(hex.toUpperCase()); System.out.print(hex.toUpperCase()); builder.append(hex); } System.out.println(); return builder.toString(); } public BigInteger random(BigInteger max) { BigInteger r = new BigInteger(256, random); // int count = 1; while (r.compareTo(max) >= 0) { r = new BigInteger(128, random); // count++; } // System.out.println("count: " + count); return r; } private boolean allZero(byte[] buffer) { for (int i = 0; i < buffer.length; i++) { if (buffer[i] != 0) return false; } return true; } /** * 加密 * @param input 待加密消息M * @param publicKey 公钥 * @return byte[] 加密后的字节数组 */ public byte[] encrypt(String input, ECPoint publicKey) { System.out.println("publicKey is: "+publicKey); byte[] inputBuffer = input.getBytes(); printHexString(inputBuffer); /* 1 产生随机数k,k属于[1, n-1] */ BigInteger k = random(n); System.out.print("k: "); printHexString(k.toByteArray()); /* 2 计算椭圆曲线点C1 = [k]G = (x1, y1) */ ECPoint C1 = G.multiply(k); byte[] C1Buffer = C1.getEncoded(false); System.out.print("C1: "); printHexString(C1Buffer); // 3 计算椭圆曲线点 S = [h]Pb * curve没有指定余因子,h为空 // BigInteger h = curve.getCofactor(); System.out.print("h: "); // printHexString(h.toByteArray()); if (publicKey != null) { ECPoint // result = publicKey.multiply(h); if (!result.isInfinity()) { // System.out.println("pass"); } else { // System.err.println("计算椭圆曲线点 S = [h]Pb失败"); return null; } } /* 4 计算 [k]PB = (x2, y2) */ ECPoint kpb = publicKey.multiply(k).normalize(); /* 5 计算 t = KDF(x2||y2, klen) */ byte[] kpbBytes = kpb.getEncoded(false); DerivationFunction kdf = new KDF1BytesGenerator(new ShortenedDigest( new SHA256Digest(), 20)); byte[] t = new byte[inputBuffer.length]; kdf.init(new ISO18033KDFParameters(kpbBytes)); kdf.generateBytes(t, 0, t.length); if (allZero(t)) { System.err.println("all zero"); } /* 6 计算C2=M^t */ byte[] C2 = new byte[inputBuffer.length]; for (int i = 0; i < inputBuffer.length; i++) { C2[i] = (byte) (inputBuffer[i] ^ t[i]); } /* 7 计算C3 = Hash(x2 || M || y2) */ byte[] C3 = calculateHash(kpb.getXCoord().toBigInteger(), inputBuffer, kpb.getYCoord().toBigInteger()); /* 8 输出密文 C=C1 || C2 || C3 */ byte[] encryptResult = new byte[C1Buffer.length + C2.length + C3.length]; System.arraycopy(C1Buffer, 0, encryptResult, 0, C1Buffer.length); System.arraycopy(C2, 0, encryptResult, C1Buffer.length, C2.length); System.arraycopy(C3, 0, encryptResult, C1Buffer.length + C2.length, C3.length); System.out.print("密文: "); printHexString(encryptResult); return encryptResult; } public void decrypt(byte[] encryptData, BigInteger privateKey) { System.out.println("privateKey is: "+privateKey); System.out.println("encryptData length: " + encryptData.length); byte[] C1Byte = new byte[65]; System.arraycopy(encryptData, 0, C1Byte, 0, C1Byte.length); ECPoint C1 = curve.decodePoint(C1Byte).normalize(); /* 计算[dB]C1 = (x2, y2) */ ECPoint dBC1 = C1.multiply(privateKey).normalize(); /* 计算t = KDF(x2 || y2, klen) */ byte[] dBC1Bytes = dBC1.getEncoded(false); DerivationFunction kdf = new KDF1BytesGenerator(new ShortenedDigest( new SHA256Digest(), 20)); int klen = encryptData.length - 65 - 20; System.out.println("klen = " + klen); byte[] t = new byte[klen]; kdf.init(new ISO18033KDFParameters(dBC1Bytes)); kdf.generateBytes(t, 0, t.length); if (allZero(t)) { System.err.println("all zero"); } /* 5 计算M'=C2^t */ byte[] M = new byte[klen]; for (int i = 0; i < M.length; i++) { M[i] = (byte) (encryptData[C1Byte.length + i] ^ t[i]); } /* 6 计算 u = Hash(x2 || M' || y2) 判断 u == C3是否成立 */ byte[] C3 = new byte[20]; System.arraycopy(encryptData, encryptData.length - 20, C3, 0, 20); byte[] u = calculateHash(dBC1.getXCoord().toBigInteger(), M, dBC1 .getYCoord().toBigInteger()); if (Arrays.equals(u, C3)) { System.out.println("解密成功"); System.out.println("M' = " + new String(M)); } else { System.out.print("u = "); printHexString(u); System.out.print("C3 = "); printHexString(C3); System.err.println("解密验证失败"); } } private byte[] calculateHash(BigInteger x2, byte[] M, BigInteger y2) { ShortenedDigest digest = new ShortenedDigest(new SHA256Digest(), 20); byte[] buf = x2.toByteArray(); digest.update(buf, 0, buf.length); digest.update(M, 0, M.length); buf = y2.toByteArray(); digest.update(buf, 0, buf.length); buf = new byte[20]; digest.doFinal(buf, 0); return buf; } private boolean between(BigInteger param, BigInteger min, BigInteger max) { if (param.compareTo(min) >= 0 && param.compareTo(max) < 0) { return true; } else { return false; } } /** * 公钥校验 * @param publicKey 公钥 * @return boolean true或false */ private boolean checkPublicKey(ECPoint publicKey) { if (!publicKey.isInfinity()) { BigInteger x = publicKey.getXCoord().toBigInteger(); BigInteger y = publicKey.getYCoord().toBigInteger(); if (between(x, new BigInteger("0"), p) && between(y, new BigInteger("0"), p)) { BigInteger xResult = x.pow(3).add(a.multiply(x)).add(b).mod(p); System.out.println("xResult: " + xResult.toString()); BigInteger yResult = y.pow(2).mod(p); System.out.println("yResult: " + yResult.toString()); if (yResult.equals(xResult) && publicKey.multiply(n).isInfinity()) { return true; } } return false; } else { return false; } } /** * 获得公私钥对 * @return */ public SM2KeyPair generateKeyPair() { BigInteger d = random(n.subtract(new BigInteger("1"))); SM2KeyPair keyPair = new SM2KeyPair(G.multiply(d).normalize(), d); if (checkPublicKey(keyPair.getPublicKey())) { System.out.println("generate key successfully"); return keyPair; } else { System.err.println("generate key failed"); return null; } } public SM2Util() { curve = new ECCurve.Fp(p, // q a, // a b); // b G = curve.createPoint(xg, yg); } }

import java.math.BigInteger;

import org.bouncycastle.math.ec.ECPoint;

/**
 * 	 说	明:SM2公私钥实体类
 * 
 * @author 作者名:冯龙淼
 * 		   E-mail:[email protected]
 * 
 * @version 版   本  号:1.0.
* 创建时间:2018年3月6日 上午9:43:56 */ public class SM2KeyPair { /** 公钥 */ private ECPoint publicKey; /** 私钥 */ private BigInteger privateKey; SM2KeyPair(ECPoint publicKey, BigInteger privateKey) { this.publicKey = publicKey; this.privateKey = privateKey; } public ECPoint getPublicKey() { return publicKey; } public BigInteger getPrivateKey() { return privateKey; } }

import java.util.Arrays;

/**
 * 	 说	明:SM2非对称加解密工具类测试
 * @author 作者名:冯龙淼
 * 		   E-mail:[email protected]
 * 
 * @version 版   本  号:1.0.
* 创建时间:2018年3月6日 下午5:20:56 */ public class SM2UtilTest { /** 元消息串 */ private static String M = "哈哈哈,&*&…………&、、//\\!@#$%^&*()物品woyebuzhidaowozijiqiaodesha!@#$%^&*())))))ooooooooppppppppppppppppppplllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkffffffffffffffffffffffffffffffffffffff"; public static void main(String[] args) { SM2Util sm2 = new SM2Util(); SM2KeyPair keyPair = sm2.generateKeyPair(); byte[] data = sm2.encrypt(M,keyPair.getPublicKey()); System.out.println("data is:"+Arrays.toString(data)); sm2.decrypt(data, keyPair.getPrivateKey());//71017045908707391874054405929626258767106914144911649587813342322113806533034 } }

 

 

 

 

 

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