SM2加密

àì夳堔傛蜴生んèń 2022-04-25 06:00 193阅读 0赞

1、引入依赖

<dependency>
         <groupId>org.bouncycastle</groupId>
         <artifactId>bcprov-jdk15on</artifactId>
         <version>1.54</version>
     </dependency>

2、Util

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.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;
        }
    }

3、Cipher

public class Cipher {
    	private int ct;
        private ECPoint p2;
        private SM3Digest sm3keybase;
        private SM3Digest sm3c3;
        private byte key[];
        private byte keyOff;
     
        public Cipher() {
            this.ct = 1;
            this.key = new byte[32];
            this.keyOff = 0;
        }
     
        private void Reset() {
            this.sm3keybase = new SM3Digest();
            this.sm3c3 = new SM3Digest();
            
            byte p[] = Util.byteConvert32Bytes(p2.getX().toBigInteger());
            this.sm3keybase.update(p, 0, p.length);
            this.sm3c3.update(p, 0, p.length);
            
            p = Util.byteConvert32Bytes(p2.getY().toBigInteger());
            this.sm3keybase.update(p, 0, p.length);
            this.ct = 1;
            NextKey();
        }
     
        private void NextKey() {
            SM3Digest sm3keycur = new SM3Digest(this.sm3keybase);
            sm3keycur.update((byte) (ct >> 24 & 0xff));
            sm3keycur.update((byte) (ct >> 16 & 0xff));
            sm3keycur.update((byte) (ct >> 8 & 0xff));
            sm3keycur.update((byte) (ct & 0xff));
            sm3keycur.doFinal(key, 0);
            this.keyOff = 0;
            this.ct++;
        }
     
        public ECPoint Init_enc(SM2 sm2, ECPoint userKey) {
            AsymmetricCipherKeyPair key = sm2.ecc_key_pair_generator.generateKeyPair();
            ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters) key.getPrivate();
            ECPublicKeyParameters ecpub = (ECPublicKeyParameters) key.getPublic();
            BigInteger k = ecpriv.getD();
            ECPoint c1 = ecpub.getQ();
            this.p2 = userKey.multiply(k);
            Reset();
            return c1;
        }
     
        public void Encrypt(byte data[]) {
            this.sm3c3.update(data, 0, data.length);
            for (int i = 0; i < data.length; i++) {
                if (keyOff == key.length) {
                    NextKey();
                }
                data[i] ^= key[keyOff++];
            }
        }
     
        public void Init_dec(BigInteger userD, ECPoint c1) {
            this.p2 = c1.multiply(userD);
            Reset();
        }
     
        public void Decrypt(byte data[]) {
            for (int i = 0; i < data.length; i++) {
                if (keyOff == key.length) {
                    NextKey();
                }
                data[i] ^= key[keyOff++];
            }
            this.sm3c3.update(data, 0, data.length);
        }
     
        public void Dofinal(byte c3[]) {
            byte p[] = Util.byteConvert32Bytes(p2.getY().toBigInteger());
            this.sm3c3.update(p, 0, p.length);
            this.sm3c3.doFinal(c3, 0);
            Reset();
        }
    }

4、SM2

public class SM2 {
    	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);
        }
    }

5、SM2Utils

public class SM2Utils {
    	//生成随机秘钥对
    	public static String prik = "";
        // 国密规范正式公钥
    	public static String pubk = "";
    
        public static void generateKeyPair(){
            SM2 sm2 = SM2.Instance();
            AsymmetricCipherKeyPair key = sm2.ecc_key_pair_generator.generateKeyPair();
            ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters) key.getPrivate();
            ECPublicKeyParameters ecpub = (ECPublicKeyParameters) key.getPublic();
            BigInteger privateKey = ecpriv.getD();
            ECPoint publicKey = ecpub.getQ();
            
            prik=Util.byteToHex(privateKey.toByteArray());
            pubk=Util.byteToHex(publicKey.getEncoded());
            System.out.println("公钥: " + pubk);
            System.out.println("私钥: " + prik);
        }
        
        //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];
            System.arraycopy(data, 0, source, 0, data.length);
            
            Cipher cipher = new Cipher();
            SM2 sm2 = SM2.Instance();
            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);
    
            //C1 C2 C3拼装成加密字串
            return Util.byteToHex(c1.getEncoded()) + Util.byteToHex(source) + Util.byteToHex(c3);
        }
        
        //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 = 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));
            
            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;
        }
        
        public static void main(String[] args) throws Exception {
            generateKeyPair();
            String plainText = "测试一下";
            byte[] sourceData = plainText.getBytes();
            System.out.println("加密姓名: ");
            String cipherText = SM2Utils.encrypt(Util.hexToByte(pubk), sourceData);
            System.out.println(cipherText);
            System.out.println("解密姓名: ");
            plainText = new String(SM2Utils.decrypt(Util.hexToByte(prik), Util.hexToByte(cipherText)));
            System.out.println(plainText);
        }
    }