国密：生成SM2秘钥、加解密及加验签

柔情只为你懂 2024-04-01 19:00 90阅读 0赞

国密改造已经持续了很长时间了，相信很多从事金融科技类的程序猿都遇到过这个需求。这篇文章就为大家带来笔者对于国密改造的一些经验，主要是代码层面，有兴趣的同学可以研究下国密的算法模型！

注：本文所用到的工具类并非笔者所写！

**目录**

一、国密简述

二、依赖准备

三、SM2算法应用

1、生成SM2公私钥

工具类

测试Demo

2、数据加解密

--------------------

## 一、国密简述 ##

国密——国家密码局制定的国家密码算法。主要包含SM1、SM2、SM3、SM4几种方式。

SM1：对称加密，且算法不公开，使用硬件加密，本文不做叙述；

SM2：非对称加密，签名以及生成秘钥速度优于RSA，基于ECC算法，运算效率更高，且更安全；

SM3：摘要，国产杂凑算法，生成长度为256比特，优于MD5以及SHA-1算法；

SM4： 无线局域网标准的分组数据算法。对称加密，密钥长度和分组长度均为128位；

## 注意 ##

生成SM2 公钥是130 位 前面多了04两个标识符，注意区分！

## 二、依赖准备 ##

国密主要用到下面的包

<dependency>
                <groupId>org.bouncycastle</groupId>
                <artifactId>bcpkix-jdk15on</artifactId>
                <version>1.57</version>
            </dependency>

一定注意版本。实际项目中笔者发现项目其他子工程用到1.56版本的包，所以选择了低版本。

## 三、SM2算法应用 ##

### 1、生成SM2公私钥 ###

#### 工具类 ####

package cn.test.encrypt.utils.sm2;
    
    
    import org.bouncycastle.crypto.generators.ECKeyPairGenerator;
    import org.bouncycastle.crypto.params.ECDomainParameters;
    import org.bouncycastle.crypto.params.ECKeyGenerationParameters;
    import org.bouncycastle.math.ec.ECCurve;
    import org.bouncycastle.math.ec.ECFieldElement;
    import org.bouncycastle.math.ec.ECFieldElement.Fp;
    import org.bouncycastle.math.ec.ECPoint;
    
    import java.math.BigInteger;
    import java.security.SecureRandom;
    
    public class SM2 {
    
        //国密参数
        public static String[] ecc_param = {
                "FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFF",
                "FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFC",
                "28E9FA9E9D9F5E344D5A9E4BCF6509A7F39789F515AB8F92DDBCBD414D940E93",
                "FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFF7203DF6B21C6052B53BBF40939D54123",
                "32C4AE2C1F1981195F9904466A39C9948FE30BBFF2660BE1715A4589334C74C7",
                "BC3736A2F4F6779C59BDCEE36B692153D0A9877CC62A474002DF32E52139F0A0"
        };
    
        public static SM2 Instance()
        {
            return new SM2();
        }
    
        public final BigInteger ecc_p;
        public final BigInteger ecc_a;
        public final BigInteger ecc_b;
        public final BigInteger ecc_n;
        public final BigInteger ecc_gx;
        public final BigInteger ecc_gy;
        public final ECCurve ecc_curve;
        public final ECPoint ecc_point_g;
        public final ECDomainParameters ecc_bc_spec;
        public final ECKeyPairGenerator ecc_key_pair_generator;
        public final ECFieldElement ecc_gx_fieldelement;
        public final ECFieldElement ecc_gy_fieldelement;
    
        public SM2()
        {
            this.ecc_p = new BigInteger(ecc_param[0], 16);
            this.ecc_a = new BigInteger(ecc_param[1], 16);
            this.ecc_b = new BigInteger(ecc_param[2], 16);
            this.ecc_n = new BigInteger(ecc_param[3], 16);
            this.ecc_gx = new BigInteger(ecc_param[4], 16);
            this.ecc_gy = new BigInteger(ecc_param[5], 16);
    
            this.ecc_gx_fieldelement = new Fp(this.ecc_p, this.ecc_gx);
            this.ecc_gy_fieldelement = new Fp(this.ecc_p, this.ecc_gy);
    
            this.ecc_curve = new ECCurve.Fp(this.ecc_p, this.ecc_a, this.ecc_b);
            this.ecc_point_g = new ECPoint.Fp(this.ecc_curve, this.ecc_gx_fieldelement, this.ecc_gy_fieldelement);
    
            this.ecc_bc_spec = new ECDomainParameters(this.ecc_curve, this.ecc_point_g, this.ecc_n);
    
            ECKeyGenerationParameters ecc_ecgenparam;
            ecc_ecgenparam = new ECKeyGenerationParameters(this.ecc_bc_spec, new SecureRandom());
    
            this.ecc_key_pair_generator = new ECKeyPairGenerator();
            this.ecc_key_pair_generator.init(ecc_ecgenparam);
        }
    }

生成随机秘钥工具类

package cn.test.encrypt.utils.sm2;
    
    
    import cn.test.encrypt.utils.Util;
    import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
    import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
    import org.bouncycastle.crypto.params.ECPublicKeyParameters;
    import org.bouncycastle.math.ec.ECPoint;
    
    import java.io.IOException;
    import java.math.BigInteger;
    
    public class SM2EncDecUtils {
        //生成随机秘钥对
        public static SM2KeyVO generateKeyPair(){
            SM2 sm2 = SM2.Instance();
            AsymmetricCipherKeyPair key = null;
            while (true){
                key=sm2.ecc_key_pair_generator.generateKeyPair();
                if(((ECPrivateKeyParameters) key.getPrivate()).getD().toByteArray().length==32){
                    break;
                }
            }
            ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters) key.getPrivate();
            ECPublicKeyParameters ecpub = (ECPublicKeyParameters) key.getPublic();
            BigInteger privateKey = ecpriv.getD();
            ECPoint publicKey = ecpub.getQ();
            SM2KeyVO sm2KeyVO = new SM2KeyVO();
            sm2KeyVO.setPublicKey(publicKey);
            sm2KeyVO.setPrivateKey(privateKey);
            //System.out.println("公钥: " + Util.byteToHex(publicKey.getEncoded()));
            //System.out.println("私钥: " + Util.byteToHex(privateKey.toByteArray()));
            return sm2KeyVO;
        }
    
        //数据加密
        public static String encrypt(byte[] publicKey, byte[] data) throws IOException
        {
            if (publicKey == null || publicKey.length == 0)
            {
                return null;
            }
    
            if (data == null || data.length == 0)
            {
                return null;
            }
    
            byte[] source = new byte[data.length];
            //将数组data复制到source
            System.arraycopy(data, 0, source, 0, data.length);
    
            Cipher cipher = new Cipher();
            SM2 sm2 = SM2.Instance();//new自建类,， SM2 sm2 = new SM2();
            ECPoint userKey = sm2.ecc_curve.decodePoint(publicKey);
    
            ECPoint c1 = cipher.Init_enc(sm2, userKey);
            cipher.Encrypt(source);
            byte[] c3 = new byte[32];
            cipher.Dofinal(c3);
    
         // System.out.println("C1 " + Util.byteToHex(c1.getEncoded()));
         // System.out.println("C2 " + Util.byteToHex(source));
         //System.out.println("C3 " + Util.byteToHex(c3));
            //C1 C2 C3拼装成加密字串
            // C1 | C2 | C3
            //return Util.byteToHex(c1.getEncoded()) + Util.byteToHex(source) + Util.byteToHex(c3);
            // C1 | C3 | C2
            return Util.byteToHex(c1.getEncoded()) + Util.byteToHex(c3) + Util.byteToHex(source);
        }
    
        //数据解密
        public static byte[] decrypt(byte[] privateKey, byte[] encryptedData) throws IOException
        {
            if (privateKey == null || privateKey.length == 0)
            {
                return null;
            }
    
            if (encryptedData == null || encryptedData.length == 0)
            {
                return null;
            }
            //加密字节数组转换为十六进制的字符串 长度变为encryptedData.length * 2
            String data = Util.byteToHex(encryptedData);
            /***分解加密字串 C1 | C2 | C3
             * （C1 = C1标志位2位 + C1实体部分128位 = 130）
             * （C3 = C3实体部分64位  = 64）
             * （C2 = encryptedData.length * 2 - C1长度  - C2长度）
    
            byte[] c1Bytes = Util.hexToByte(data.substring(0,130));
            int c2Len = encryptedData.length - 97;
            byte[] c2 = Util.hexToByte(data.substring(130,130 + 2 * c2Len));
            byte[] c3 = Util.hexToByte(data.substring(130 + 2 * c2Len,194 + 2 * c2Len));
            */
            /***分解加密字串 C1 | C3 | C2
             * （C1 = C1标志位2位 + C1实体部分128位 = 130）
             * （C3 = C3实体部分64位  = 64）
             * （C2 = encryptedData.length * 2 - C1长度  - C2长度）
             */
            byte[] c1Bytes = Util.hexToByte(data.substring(0,130));
            int c2Len = encryptedData.length - 97;
            byte[] c3 = Util.hexToByte(data.substring(130,130 + 64));
            byte[] c2 = Util.hexToByte(data.substring(194,194 + 2 * c2Len));
    
            SM2 sm2 = SM2.Instance();
            BigInteger userD = new BigInteger(1, privateKey);
    
            //通过C1实体字节来生成ECPoint
            ECPoint c1 = sm2.ecc_curve.decodePoint(c1Bytes);
            Cipher cipher = new Cipher();
            cipher.Init_dec(userD, c1);
            cipher.Decrypt(c2);
            cipher.Dofinal(c3);
    
            //返回解密结果
            return c2;
        }
    
    }

SM2曲线算法工具类

package cn.test.encrypt.utils.sm2;
    
    import cn.test.encrypt.utils.Util;
    import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
    import org.bouncycastle.crypto.digests.SM3Digest;
    import org.bouncycastle.crypto.generators.ECKeyPairGenerator;
    import org.bouncycastle.crypto.params.ECDomainParameters;
    import org.bouncycastle.crypto.params.ECKeyGenerationParameters;
    import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
    import org.bouncycastle.crypto.params.ECPublicKeyParameters;
    import org.bouncycastle.math.ec.ECCurve;
    import org.bouncycastle.math.ec.ECFieldElement;
    import org.bouncycastle.math.ec.ECFieldElement.Fp;
    import org.bouncycastle.math.ec.ECPoint;
    
    import java.math.BigInteger;
    import java.security.SecureRandom;
    
    
    public class SM2Factory {
    	/*-----------------------国密算法相关参数begin-----------
    	 * ------------------*/
    	//A 第一系数
    	private static final BigInteger a  = new BigInteger("fffffffeffffffffffffffffffffffffffffffff00000000fffffffffffffffc",16);
    	//B 第二系数
    	private static final BigInteger b  = new BigInteger("28e9fa9e9d9f5e344d5a9e4bcf6509a7f39789f515ab8f92ddbcbd414d940e93",16);
    	//曲线X系数
    	private static final BigInteger gx = new BigInteger("32c4ae2c1f1981195f9904466a39c9948fe30bbff2660be1715a4589334c74c7",16);
    	//曲线Y系数
    	private static final BigInteger gy = new BigInteger("bc3736a2f4f6779c59bdcee36b692153d0a9877cc62a474002df32e52139f0a0",16);
    	//生产者顺序系数
    	private static final BigInteger n  = new BigInteger("fffffffeffffffffffffffffffffffff7203df6b21c6052b53bbf40939d54123",16);
    	//素数
    	private static final BigInteger p  = new BigInteger("fffffffeffffffffffffffffffffffffffffffff00000000ffffffffffffffff",16);
    	//因子系数 1
    	private static final int h  = 1;
    	/*-----------------------国密算法相关参数end-----------------------------*/
    	//一些必要类
    	public final ECFieldElement ecc_gx_fieldelement;
    	public final ECFieldElement ecc_gy_fieldelement;
    	public final ECCurve ecc_curve;
    	public final ECPoint ecc_point_g;
    	public final ECDomainParameters ecc_bc_spec;
    	public final ECKeyPairGenerator ecc_key_pair_generator;
    	/**
    	 * 初始化方法
    	 * @return
    	 */
    	public static SM2Factory getInstance(){
    		return new SM2Factory();
    	}
    	public SM2Factory() {
    
    		this.ecc_gx_fieldelement = new Fp(this.p,this.gx);
    		this.ecc_gy_fieldelement = new Fp(this.p, this.gy);
    
    		this.ecc_curve = new ECCurve.Fp(this.p, this.a, this.b);
    
    		this.ecc_point_g = new ECPoint.Fp(this.ecc_curve, this.ecc_gx_fieldelement,this.ecc_gy_fieldelement);
    		this.ecc_bc_spec = new ECDomainParameters(this.ecc_curve, this.ecc_point_g, this.n);
    
    		ECKeyGenerationParameters ecc_ecgenparam;
    		ecc_ecgenparam = new ECKeyGenerationParameters(this.ecc_bc_spec, new SecureRandom());
    
    		this.ecc_key_pair_generator = new ECKeyPairGenerator();
    		this.ecc_key_pair_generator.init(ecc_ecgenparam);
    	}
    	/**
    	 * 根据私钥、曲线参数计算Z
    	 * @param userId
    	 * @param userKey
    	 * @return
    	 */
    	public  byte[] sm2GetZ(byte[] userId, ECPoint userKey){
    		SM3Digest sm3 = new SM3Digest();
    
    		int len = userId.length * 8;
    		sm3.update((byte) (len >> 8 & 0xFF));
    		sm3.update((byte) (len & 0xFF));
    		sm3.update(userId, 0, userId.length);
    
    		byte[] p = Util.byteConvert32Bytes(this.a);
    		sm3.update(p, 0, p.length);
    
    		p = Util.byteConvert32Bytes(this.b);
    		sm3.update(p, 0, p.length);
    
    		p = Util.byteConvert32Bytes(this.gx);
    		sm3.update(p, 0, p.length);
    
    		p = Util.byteConvert32Bytes(this.gy);
    		sm3.update(p, 0, p.length);
    
    		p = Util.byteConvert32Bytes(userKey.normalize().getXCoord().toBigInteger());
    		sm3.update(p, 0, p.length);
    
    		p = Util.byteConvert32Bytes(userKey.normalize().getYCoord().toBigInteger());
    		sm3.update(p, 0, p.length);
    
    		byte[] md = new byte[sm3.getDigestSize()];
    		sm3.doFinal(md, 0);
    		return md;
    	}
    	/**
    	 * 签名相关值计算
    	 * @param md
    	 * @param userD
    	 * @param userKey
    	 * @param sm2Result
    	 */
    	public void sm2Sign(byte[] md, BigInteger userD, ECPoint userKey, SM2Result sm2Result) {
    		BigInteger e = new BigInteger(1, md);
    		BigInteger k = null;
    		ECPoint kp = null;
    		BigInteger r = null;
    		BigInteger s = null;
    		do {
    			do {
    				// 正式环境
    				AsymmetricCipherKeyPair keypair = ecc_key_pair_generator.generateKeyPair();
    				ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters) keypair.getPrivate();
    				ECPublicKeyParameters ecpub = (ECPublicKeyParameters) keypair.getPublic();
    				k = ecpriv.getD();
    				kp = ecpub.getQ();
    				//System.out.println("BigInteger:" + k + "\nECPoint:" + kp);
    
    				//System.out.println("计算曲线点X1: "+ kp.getXCoord().toBigInteger().toString(16));
    				//System.out.println("计算曲线点Y1: "+ kp.getYCoord().toBigInteger().toString(16));
    				//System.out.println("");
    				// r
    				r = e.add(kp.getXCoord().toBigInteger());
    				r = r.mod(this.n);
    			} while (r.equals(BigInteger.ZERO) || r.add(k).equals(this.n)||r.toString(16).length()!=64);
    
    			// (1 + dA)~-1
    			BigInteger da_1 = userD.add(BigInteger.ONE);
    			da_1 = da_1.modInverse(this.n);
    			// s
    			s = r.multiply(userD);
    			s = k.subtract(s).mod(this.n);
    			s = da_1.multiply(s).mod(this.n);
    		} while (s.equals(BigInteger.ZERO)||(s.toString(16).length()!=64));
    
    		sm2Result.r = r;
    		sm2Result.s = s;
    	}
    	/**
    	 * 验签
    	 * @param md sm3摘要
    	 * @param userKey 根据公钥decode一个ecpoint对象
    	 * @param r 没有特殊含义
    	 * @param s 没有特殊含义
    	 * @param sm2Result 接收参数的对象
    	 */
    	public void sm2Verify(byte md[], ECPoint userKey, BigInteger r,
                              BigInteger s, SM2Result sm2Result) {
    		sm2Result.R = null;
    		BigInteger e = new BigInteger(1, md);
    		BigInteger t = r.add(s).mod(this.n);
    		if (t.equals(BigInteger.ZERO)) {
    			return;
    		} else {
    			ECPoint x1y1 = ecc_point_g.multiply(sm2Result.s);
    			//System.out.println("计算曲线点X0: "+ x1y1.normalize().getXCoord().toBigInteger().toString(16));
    			//System.out.println("计算曲线点Y0: "+ x1y1.normalize().getYCoord().toBigInteger().toString(16));
    			//System.out.println("");
    
    			x1y1 = x1y1.add(userKey.multiply(t));
    			//System.out.println("计算曲线点X1: "+ x1y1.normalize().getXCoord().toBigInteger().toString(16));
    			//System.out.println("计算曲线点Y1: "+ x1y1.normalize().getYCoord().toBigInteger().toString(16));
    			//System.out.println("");
    			sm2Result.R = e.add(x1y1.normalize().getXCoord().toBigInteger()).mod(this.n);
    			//System.out.println("R: " + sm2Result.R.toString(16));
    			return;
    		}
    	}
    
    }

工具类

package cn.test.encrypt.utils;
    
    import java.math.BigInteger;
    
    public class Util {
        /**
         * 整形转换成网络传输的字节流（字节数组）型数据
         *
         * @param num 一个整型数据
         * @return 4个字节的自己数组
         */
        public static byte[] intToBytes(int num) {
            byte[] bytes = new byte[4];
            bytes[0] = (byte) (0xff & (num >> 0));
            bytes[1] = (byte) (0xff & (num >> 8));
            bytes[2] = (byte) (0xff & (num >> 16));
            bytes[3] = (byte) (0xff & (num >> 24));
            return bytes;
        }
    
        /**
         * 四个字节的字节数据转换成一个整形数据
         *
         * @param bytes 4个字节的字节数组
         * @return 一个整型数据
         */
        public static int byteToInt(byte[] bytes) {
            int num = 0;
            int temp;
            temp = (0x000000ff & (bytes[0])) << 0;
            num = num | temp;
            temp = (0x000000ff & (bytes[1])) << 8;
            num = num | temp;
            temp = (0x000000ff & (bytes[2])) << 16;
            num = num | temp;
            temp = (0x000000ff & (bytes[3])) << 24;
            num = num | temp;
            return num;
        }
    
        /**
         * 长整形转换成网络传输的字节流（字节数组）型数据
         *
         * @param num 一个长整型数据
         * @return 4个字节的自己数组
         */
        public static byte[] longToBytes(long num) {
            byte[] bytes = new byte[8];
            for (int i = 0; i < 8; i++) {
                bytes[i] = (byte) (0xff & (num >> (i * 8)));
            }
    
            return bytes;
        }
    
        /**
         * 大数字转换字节流（字节数组）型数据
         *
         * @param n
         * @return
         */
        public static byte[] byteConvert32Bytes(BigInteger n) {
            byte tmpd[] = (byte[]) null;
            if (n == null) {
                return null;
            }
    
            if (n.toByteArray().length == 33) {
                tmpd = new byte[32];
                System.arraycopy(n.toByteArray(), 1, tmpd, 0, 32);
            } else if (n.toByteArray().length == 32) {
                tmpd = n.toByteArray();
            } else {
                tmpd = new byte[32];
                for (int i = 0; i < 32 - n.toByteArray().length; i++) {
                    tmpd[i] = 0;
                }
                System.arraycopy(n.toByteArray(), 0, tmpd, 32 - n.toByteArray().length, n.toByteArray().length);
            }
            return tmpd;
        }
    
        /**
         * 换字节流（字节数组）型数据转大数字
         *
         * @param b
         * @return
         */
        public static BigInteger byteConvertInteger(byte[] b) {
            if (b[0] < 0) {
                byte[] temp = new byte[b.length + 1];
                temp[0] = 0;
                System.arraycopy(b, 0, temp, 1, b.length);
                return new BigInteger(temp);
            }
            return new BigInteger(b);
        }
    
        /**
         * 根据字节数组获得值(十六进制数字)
         *
         * @param bytes
         * @return
         */
        public static String getHexString(byte[] bytes) {
            return getHexString(bytes, true);
        }
    
        /**
         * 根据字节数组获得值(十六进制数字)
         *
         * @param bytes
         * @param upperCase
         * @return
         */
        public static String getHexString(byte[] bytes, boolean upperCase) {
            String ret = "";
            for (int i = 0; i < bytes.length; i++) {
                ret += Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1);
            }
            return upperCase ? ret.toUpperCase() : ret;
        }
    
        /**
         * 打印十六进制字符串
         *
         * @param bytes
         */
        public static void printHexString(byte[] bytes) {
            for (int i = 0; i < bytes.length; i++) {
                String hex = Integer.toHexString(bytes[i] & 0xFF);
                if (hex.length() == 1) {
                    hex = '0' + hex;
                }
                System.out.print("0x" + hex.toUpperCase() + ",");
            }
            System.out.println("");
        }
    
        /**
         * Convert hex string to byte[]
         *
         * @param hexString the hex string
         * @return byte[]
         */
        public static byte[] hexStringToBytes(String hexString) {
            if (hexString == null || hexString.equals("")) {
                return null;
            }
    
            hexString = hexString.toUpperCase();
            int length = hexString.length() / 2;
            char[] hexChars = hexString.toCharArray();
            byte[] d = new byte[length];
            for (int i = 0; i < length; i++) {
                int pos = i * 2;
                d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));
            }
            return d;
        }
    
        /**
         * Convert char to byte
         *
         * @param c char
         * @return byte
         */
        public static byte charToByte(char c) {
            return (byte) "0123456789ABCDEF".indexOf(c);
        }
    
        /**
         * 用于建立十六进制字符的输出的小写字符数组
         */
        private static final char[] DIGITS_LOWER = {'0', '1', '2', '3', '4', '5',
                '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
    
        /**
         * 用于建立十六进制字符的输出的大写字符数组
         */
        private static final char[] DIGITS_UPPER = {'0', '1', '2', '3', '4', '5',
                '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
    
        /**
         * 将字节数组转换为十六进制字符数组
         *
         * @param data byte[]
         * @return 十六进制char[]
         */
        public static char[] encodeHex(byte[] data) {
            return encodeHex(data, true);
        }
    
        /**
         * 将字节数组转换为十六进制字符数组
         *
         * @param data        byte[]
         * @param toLowerCase <code>true</code> 传换成小写格式 ， <code>false</code> 传换成大写格式
         * @return 十六进制char[]
         */
        public static char[] encodeHex(byte[] data, boolean toLowerCase) {
            return encodeHex(data, toLowerCase ? DIGITS_LOWER : DIGITS_UPPER);
        }
    
        /**
         * 将字节数组转换为十六进制字符数组
         *
         * @param data     byte[]
         * @param toDigits 用于控制输出的char[]
         * @return 十六进制char[]
         */
        protected static char[] encodeHex(byte[] data, char[] toDigits) {
            int l = data.length;
            char[] out = new char[l << 1];
            // two characters form the hex value.
            for (int i = 0, j = 0; i < l; i++) {
                out[j++] = toDigits[(0xF0 & data[i]) >>> 4];
                out[j++] = toDigits[0x0F & data[i]];
            }
            return out;
        }
    
        /**
         * 将字节数组转换为十六进制字符串
         *
         * @param data byte[]
         * @return 十六进制String
         */
        public static String encodeHexString(byte[] data) {
            return encodeHexString(data, true);
        }
    
        /**
         * 将字节数组转换为十六进制字符串
         *
         * @param data        byte[]
         * @param toLowerCase <code>true</code> 传换成小写格式 ， <code>false</code> 传换成大写格式
         * @return 十六进制String
         */
        public static String encodeHexString(byte[] data, boolean toLowerCase) {
            return encodeHexString(data, toLowerCase ? DIGITS_LOWER : DIGITS_UPPER);
        }
    
        /**
         * 将字节数组转换为十六进制字符串
         *
         * @param data     byte[]
         * @param toDigits 用于控制输出的char[]
         * @return 十六进制String
         */
        protected static String encodeHexString(byte[] data, char[] toDigits) {
            return new String(encodeHex(data, toDigits));
        }
    
        /**
         * 将十六进制字符数组转换为字节数组
         *
         * @param data 十六进制char[]
         * @return byte[]
         * @throws RuntimeException 如果源十六进制字符数组是一个奇怪的长度，将抛出运行时异常
         */
        public static byte[] decodeHex(char[] data) {
            int len = data.length;
    
            if ((len & 0x01) != 0) {
                throw new RuntimeException("Odd number of characters.");
            }
    
            byte[] out = new byte[len >> 1];
    
            // two characters form the hex value.
            for (int i = 0, j = 0; j < len; i++) {
                int f = toDigit(data[j], j) << 4;
                j++;
                f = f | toDigit(data[j], j);
                j++;
                out[i] = (byte) (f & 0xFF);
            }
    
            return out;
        }
    
        /**
         * 将十六进制字符转换成一个整数
         *
         * @param ch    十六进制char
         * @param index 十六进制字符在字符数组中的位置
         * @return 一个整数
         * @throws RuntimeException 当ch不是一个合法的十六进制字符时，抛出运行时异常
         */
        protected static int toDigit(char ch, int index) {
            int digit = Character.digit(ch, 16);
            if (digit == -1) {
                throw new RuntimeException("Illegal hexadecimal character " + ch
                        + " at index " + index);
            }
            return digit;
        }
    
        /**
         * 数字字符串转ASCII码字符串
         *
         * @param String 字符串
         * @return ASCII字符串
         */
        public static String StringToAsciiString(String content) {
            String result = "";
            int max = content.length();
            for (int i = 0; i < max; i++) {
                char c = content.charAt(i);
                String b = Integer.toHexString(c);
                result = result + b;
            }
            return result;
        }
    
        /**
         * 十六进制转字符串
         *
         * @param hexString  十六进制字符串
         * @param encodeType 编码类型4：Unicode，2：普通编码
         * @return 字符串
         */
        public static String hexStringToString(String hexString, int encodeType) {
            String result = "";
            int max = hexString.length() / encodeType;
            for (int i = 0; i < max; i++) {
                char c = (char) hexStringToAlgorism(hexString
                        .substring(i * encodeType, (i + 1) * encodeType));
                result += c;
            }
            return result;
        }
    
        /**
         * 十六进制字符串装十进制
         *
         * @param hex 十六进制字符串
         * @return 十进制数值
         */
        public static int hexStringToAlgorism(String hex) {
            hex = hex.toUpperCase();
            int max = hex.length();
            int result = 0;
            for (int i = max; i > 0; i--) {
                char c = hex.charAt(i - 1);
                int algorism = 0;
                if (c >= '0' && c <= '9') {
                    algorism = c - '0';
                } else {
                    algorism = c - 55;
                }
                result += Math.pow(16, max - i) * algorism;
            }
            return result;
        }
    
        /**
         * 十六转二进制
         *
         * @param hex 十六进制字符串
         * @return 二进制字符串
         */
        public static String hexStringToBinary(String hex) {
            hex = hex.toUpperCase();
            String result = "";
            int max = hex.length();
            for (int i = 0; i < max; i++) {
                char c = hex.charAt(i);
                switch (c) {
                    case '0':
                        result += "0000";
                        break;
                    case '1':
                        result += "0001";
                        break;
                    case '2':
                        result += "0010";
                        break;
                    case '3':
                        result += "0011";
                        break;
                    case '4':
                        result += "0100";
                        break;
                    case '5':
                        result += "0101";
                        break;
                    case '6':
                        result += "0110";
                        break;
                    case '7':
                        result += "0111";
                        break;
                    case '8':
                        result += "1000";
                        break;
                    case '9':
                        result += "1001";
                        break;
                    case 'A':
                        result += "1010";
                        break;
                    case 'B':
                        result += "1011";
                        break;
                    case 'C':
                        result += "1100";
                        break;
                    case 'D':
                        result += "1101";
                        break;
                    case 'E':
                        result += "1110";
                        break;
                    case 'F':
                        result += "1111";
                        break;
                }
            }
            return result;
        }
    
        /**
         * ASCII码字符串转数字字符串
         *
         * @param String ASCII字符串
         * @return 字符串
         */
        public static String AsciiStringToString(String content) {
            String result = "";
            int length = content.length() / 2;
            for (int i = 0; i < length; i++) {
                String c = content.substring(i * 2, i * 2 + 2);
                int a = hexStringToAlgorism(c);
                char b = (char) a;
                String d = String.valueOf(b);
                result += d;
            }
            return result;
        }
    
        /**
         * 将十进制转换为指定长度的十六进制字符串
         *
         * @param algorism  int 十进制数字
         * @param maxLength int 转换后的十六进制字符串长度
         * @return String 转换后的十六进制字符串
         */
        public static String algorismToHexString(int algorism, int maxLength) {
            String result = "";
            result = Integer.toHexString(algorism);
    
            if (result.length() % 2 == 1) {
                result = "0" + result;
            }
            return patchHexString(result.toUpperCase(), maxLength);
        }
    
        /**
         * 字节数组转为普通字符串（ASCII对应的字符）
         *
         * @param bytearray byte[]
         * @return String
         */
        public static String byteToString(byte[] bytearray) {
            String result = "";
            char temp;
    
            int length = bytearray.length;
            for (int i = 0; i < length; i++) {
                temp = (char) bytearray[i];
                result += temp;
            }
            return result;
        }
    
        /**
         * 二进制字符串转十进制
         *
         * @param binary 二进制字符串
         * @return 十进制数值
         */
        public static int binaryToAlgorism(String binary) {
            int max = binary.length();
            int result = 0;
            for (int i = max; i > 0; i--) {
                char c = binary.charAt(i - 1);
                int algorism = c - '0';
                result += Math.pow(2, max - i) * algorism;
            }
            return result;
        }
    
        /**
         * 十进制转换为十六进制字符串
         *
         * @param algorism int 十进制的数字
         * @return String 对应的十六进制字符串
         */
        public static String algorismToHEXString(int algorism) {
            String result = "";
            result = Integer.toHexString(algorism);
    
            if (result.length() % 2 == 1) {
                result = "0" + result;
    
            }
            result = result.toUpperCase();
    
            return result;
        }
    
        /**
         * HEX字符串前补0，主要用于长度位数不足。
         *
         * @param str       String 需要补充长度的十六进制字符串
         * @param maxLength int 补充后十六进制字符串的长度
         * @return 补充结果
         */
        static public String patchHexString(String str, int maxLength) {
            String temp = "";
            for (int i = 0; i < maxLength - str.length(); i++) {
                temp = "0" + temp;
            }
            str = (temp + str).substring(0, maxLength);
            return str;
        }
    
        /**
         * 将一个字符串转换为int
         *
         * @param s          String 要转换的字符串
         * @param defaultInt int 如果出现异常,默认返回的数字
         * @param radix      int 要转换的字符串是什么进制的,如16 8 10.
         * @return int 转换后的数字
         */
        public static int parseToInt(String s, int defaultInt, int radix) {
            int i = 0;
            try {
                i = Integer.parseInt(s, radix);
            } catch (NumberFormatException ex) {
                i = defaultInt;
            }
            return i;
        }
    
        /**
         * 将一个十进制形式的数字字符串转换为int
         *
         * @param s          String 要转换的字符串
         * @param defaultInt int 如果出现异常,默认返回的数字
         * @return int 转换后的数字
         */
        public static int parseToInt(String s, int defaultInt) {
            int i = 0;
            try {
                i = Integer.parseInt(s);
            } catch (NumberFormatException ex) {
                i = defaultInt;
            }
            return i;
        }
    
        /**
         * 十六进制串转化为byte数组
         *
         * @return the array of byte
         */
        public static byte[] hexToByte(String hex)
                throws IllegalArgumentException {
            if (hex.length() % 2 != 0) {
                throw new IllegalArgumentException();
            }
            char[] arr = hex.toCharArray();
            byte[] b = new byte[hex.length() / 2];
            for (int i = 0, j = 0, l = hex.length(); i < l; i++, j++) {
                String swap = "" + arr[i++] + arr[i];
                int byteint = Integer.parseInt(swap, 16) & 0xFF;
                b[j] = new Integer(byteint).byteValue();
            }
            return b;
        }
    
        /**
         * 字节数组转换为十六进制字符串
         *
         * @param b byte[] 需要转换的字节数组
         * @return String 十六进制字符串
         */
        public static String byteToHex(byte b[]) {
            if (b == null) {
                throw new IllegalArgumentException(
                        "Argument b ( byte array ) is null! ");
            }
            String hs = "";
            String stmp = "";
            for (int n = 0; n < b.length; n++) {
                stmp = Integer.toHexString(b[n] & 0xff);
                if (stmp.length() == 1) {
                    hs = hs + "0" + stmp;
                } else {
                    hs = hs + stmp;
                }
            }
            return hs.toLowerCase();
            //return hs.toUpperCase();
        }
    
        public static byte[] subByte(byte[] input, int startIndex, int length) {
            byte[] bt = new byte[length];
            for (int i = 0; i < length; i++) {
                bt[i] = input[i + startIndex];
            }
            return bt;
        }
    }

SM2对象

package cn.test.encrypt.utils.sm2;
    
    import cn.test.encrypt.utils.Util;
    import cn.test.encrypt.test.SecurityTestAll;
    import org.bouncycastle.math.ec.ECPoint;
    
    import java.math.BigInteger;
    
    public class SM2KeyVO {
        BigInteger privateKey ;
        ECPoint publicKey ;
    
        public BigInteger getPrivateKey() {
            return privateKey;
        }
    
        public void setPrivateKey(BigInteger privateKey) {
            this.privateKey = privateKey;
        }
    
        public ECPoint getPublicKey() {
            return publicKey;
        }
    
        public void setPublicKey(ECPoint publicKey) {
            this.publicKey = publicKey;
        }
    
        //HardPubKey:3059301306072A8648CE3D020106082A811CCF5501822D03420004+X+Y
        //SoftPubKey:04+X+Y
        public String getPubHexInSoft(){
            return Util.byteToHex(publicKey.getEncoded(true));
            //System.out.println("公钥: " + );
        }
        public String getPubHexInHard(){
            return SecurityTestAll.SM2PubHardKeyHead +Util.byteToHex(publicKey.getEncoded(true));
        }
        public String getPriHexInSoft(){
            return Util.byteToHex(privateKey.toByteArray());
        }
    }

#### 测试Demo ####

public static void main(String[] args) {
            SM2KeyVO initKeyVO = SM2EncDecUtils.generateKeyPair();
            System.out.println("初始公钥为: "+initKeyVO.getPubHexInSoft());
            System.out.println("初始私钥为: "+initKeyVO.getPriHexInSoft());
        }

输出结果：

![8ac50b098e6247f398c2b28efb0a824b.png][]

### 2、数据加解密 ###

简单业务描述：使用初始公钥加密工作公钥，使用初始私钥解密加密后公钥；

Demo

public static void main(String[] args) throws IOException {
            //生成初始秘钥
            SM2KeyVO initKeyVO = SM2EncDecUtils.generateKeyPair();
            String initPubKey = initKeyVO.getPubHexInSoft();
            String initPriKey = initKeyVO.getPriHexInSoft();
            System.out.println("初始公钥为: " + initPubKey);
            System.out.println("初始私钥为: " + initPriKey);
            //生成工作秘钥
            SM2KeyVO serverKey = SM2EncDecUtils.generateKeyPair();
            String serverPubKey = serverKey.getPubHexInSoft();
            String serverPriKey = serverKey.getPriHexInSoft();
            System.out.println("服务端公钥为: " + serverPubKey);
            System.out.println("服务端私钥为: " + serverPriKey);
            //使用初始公钥加密服务端公钥 注意格式字节数组
            String encryptServerPubKey = SM2EncDecUtils.encrypt(Convert.hexToBytes(initPubKey), serverPubKey.getBytes());
            System.out.println("加密后公钥："+encryptServerPubKey);
            //使用初始私钥解密服务端公钥 注意格式
            byte[] decrypt = SM2EncDecUtils.decrypt(Convert.hexToBytes(initPriKey), Convert.hexToBytes(encryptServerPubKey));
            System.out.println("解密后服务端公钥："+new String(decrypt));
            if (serverPubKey.equals(new String(decrypt)))
                System.out.println("——————————解密成功——————————");
    
        }

结果：

![f21ea87556694647ab1160304a12957a.png][]

至此，SM2的公私钥生成以及加解密就完成了，下一期内容为生成Sign以及验证。

[8ac50b098e6247f398c2b28efb0a824b.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/121a455824a24a2e90e2295924465d2b.png
[f21ea87556694647ab1160304a12957a.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/0b438ba6165946269d8975e921f23ad5.png