SM4算法加解密及实现

SM4 是什么？

SM4.0（原名SMS4.0）是中华人民共和国政府采用的一种分组密码标准，由国家密码管理局于2012年3月21日发布。相关标准为“GM/T 0002-2012《SM4分组密码算法》（原SMS4分组密码算法）”。

在商用密码体系中，SM4主要用于数据加密，其算法公开，分组长度与密钥长度均为128bit，加密算法与密钥扩展算法都采用32轮非线性迭代结构，S盒为固定的8比特输入8比特输出。

相关概念

在密码学中，分组加密（英语：Block cipher），又称分块加密或块密码，是一种对称密钥算法。
它将明文分成多个等长的模块（block），使用确定的算法和对称密钥对每组分别加密解密。分组加密是极其重要的加密协议组成，其中典型的如DES和AES作为美国政府核定的标准加密算法，应用领域从电子邮件加密到银行交易转帐，非常广泛。

国密即国家密码局认定的国产密码算法。主要有SM1，SM2，SM3，SM4。密钥长度和分组长度均为128位。

• SM1为对称加密。其加密强度与AES相当。该算法不公开，调用该算法时，需要通过加密芯片的接口进行调用。

• SM2为非对称加密，基于ECC。该算法已公开。由于该算法基于ECC，故其签名速度与秘钥生成速度都快于RSA。ECC 256位（SM2采用的就是ECC 256位的一种）安全强度比RSA 2048位高，但运算速度快于RSA。

• SM3消息摘要。可以用MD5作为对比理解。该算法已公开。校验结果为256位。

• 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。

SM4基本算法

SM4密码算法使用的基本运算为异或和循环移位。

• 异或：⊕，32位异或运算;

• 循环移位：<<<i，把32位字循环左移i位;

• 字：(32位)

加解密模式

• ECB模式

  • 电子密码本模式，最古老，最简单的模式，将加密的数据分成若干组，每组的大小跟加密密钥相同。不足的部分进行填充。

  • 按照顺序将计算所得的数据连在一起即可，各段数据之间互不影响。

  • 优点：简单；有利于并行计算；误差不会被传递；

  • 缺点：不能隐藏明文的模式；可能对明文进行主动攻击；

• CBC模式

  • 密文分组链接模式，也需要进行分组，不足的部分按照指定的数据进行填充。

  • 需要一个初始化向量，每个分组数据与上一个分组数据加密的结果进行异或运算，最后再进行加密。将所有分组加密的结果连接起来就形成了最终的结果。

  • 优点：不容易进行主动攻击；安全性好于ECB；

  • 缺点：不利于并行计算；误差传递；需要初始化向量；

代码实现

SM4.java

package com.qmrz.worksite.util.sm4;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Arrays;

public class SM4 {
    /**
     * ENCRYPT与DECRYPT为加解密的判断依据
     */
    public static final int SM4_ENCRYPT = 1;
    public static final int SM4_DECRYPT = 0;

    private long GET_ULONG_BE(byte[] b, int i) {
        long n = (long) (b[i] & 0xff) << 24 | (long) ((b[i + 1] & 0xff) << 16) | (long) ((b[i + 2] & 0xff) << 8) | (long) (b[i + 3] & 0xff) & 0xffffffffL;
        return n;
    }

    private void PUT_ULONG_BE(long n, byte[] b, int i) {
        b[i] = (byte) (int) (0xFF & n >> 24);
        b[i + 1] = (byte) (int) (0xFF & n >> 16);
        b[i + 2] = (byte) (int) (0xFF & n >> 8);
        b[i + 3] = (byte) (int) (0xFF & n);
    }

    private long SHL(long x, int n) {
        return (x & 0xFFFFFFFF) << n;
    }

    private long ROTL(long x, int n) {
        return SHL(x, n) | x >> (32 - n);
    }

    private void SWAP(long[] sk, int i) {
        long t = sk[i];
        sk[i] = sk[(31 - i)];
        sk[(31 - i)] = t;
    }

    public static final byte[] SboxTable = {(byte) 0xd6, (byte) 0x90, (byte) 0xe9, (byte) 0xfe,
            (byte) 0xcc, (byte) 0xe1, 0x3d, (byte) 0xb7, 0x16, (byte) 0xb6,
            0x14, (byte) 0xc2, 0x28, (byte) 0xfb, 0x2c, 0x05, 0x2b, 0x67,
            (byte) 0x9a, 0x76, 0x2a, (byte) 0xbe, 0x04, (byte) 0xc3,
            (byte) 0xaa, 0x44, 0x13, 0x26, 0x49, (byte) 0x86, 0x06,
            (byte) 0x99, (byte) 0x9c, 0x42, 0x50, (byte) 0xf4, (byte) 0x91,
            (byte) 0xef, (byte) 0x98, 0x7a, 0x33, 0x54, 0x0b, 0x43,
            (byte) 0xed, (byte) 0xcf, (byte) 0xac, 0x62, (byte) 0xe4,
            (byte) 0xb3, 0x1c, (byte) 0xa9, (byte) 0xc9, 0x08, (byte) 0xe8,
            (byte) 0x95, (byte) 0x80, (byte) 0xdf, (byte) 0x94, (byte) 0xfa,
            0x75, (byte) 0x8f, 0x3f, (byte) 0xa6, 0x47, 0x07, (byte) 0xa7,
            (byte) 0xfc, (byte) 0xf3, 0x73, 0x17, (byte) 0xba, (byte) 0x83,
            0x59, 0x3c, 0x19, (byte) 0xe6, (byte) 0x85, 0x4f, (byte) 0xa8,
            0x68, 0x6b, (byte) 0x81, (byte) 0xb2, 0x71, 0x64, (byte) 0xda,
            (byte) 0x8b, (byte) 0xf8, (byte) 0xeb, 0x0f, 0x4b, 0x70, 0x56,
            (byte) 0x9d, 0x35, 0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, (byte) 0xd1,
            (byte) 0xa2, 0x25, 0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, (byte) 0x87,
            (byte) 0xd4, 0x00, 0x46, 0x57, (byte) 0x9f, (byte) 0xd3, 0x27,
            0x52, 0x4c, 0x36, 0x02, (byte) 0xe7, (byte) 0xa0, (byte) 0xc4,
            (byte) 0xc8, (byte) 0x9e, (byte) 0xea, (byte) 0xbf, (byte) 0x8a,
            (byte) 0xd2, 0x40, (byte) 0xc7, 0x38, (byte) 0xb5, (byte) 0xa3,
            (byte) 0xf7, (byte) 0xf2, (byte) 0xce, (byte) 0xf9, 0x61, 0x15,
            (byte) 0xa1, (byte) 0xe0, (byte) 0xae, 0x5d, (byte) 0xa4,
            (byte) 0x9b, 0x34, 0x1a, 0x55, (byte) 0xad, (byte) 0x93, 0x32,
            0x30, (byte) 0xf5, (byte) 0x8c, (byte) 0xb1, (byte) 0xe3, 0x1d,
            (byte) 0xf6, (byte) 0xe2, 0x2e, (byte) 0x82, 0x66, (byte) 0xca,
            0x60, (byte) 0xc0, 0x29, 0x23, (byte) 0xab, 0x0d, 0x53, 0x4e, 0x6f,
            (byte) 0xd5, (byte) 0xdb, 0x37, 0x45, (byte) 0xde, (byte) 0xfd,
            (byte) 0x8e, 0x2f, 0x03, (byte) 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b,
            0x51, (byte) 0x8d, 0x1b, (byte) 0xaf, (byte) 0x92, (byte) 0xbb,
            (byte) 0xdd, (byte) 0xbc, 0x7f, 0x11, (byte) 0xd9, 0x5c, 0x41,
            0x1f, 0x10, 0x5a, (byte) 0xd8, 0x0a, (byte) 0xc1, 0x31,
            (byte) 0x88, (byte) 0xa5, (byte) 0xcd, 0x7b, (byte) 0xbd, 0x2d,
            0x74, (byte) 0xd0, 0x12, (byte) 0xb8, (byte) 0xe5, (byte) 0xb4,
            (byte) 0xb0, (byte) 0x89, 0x69, (byte) 0x97, 0x4a, 0x0c,
            (byte) 0x96, 0x77, 0x7e, 0x65, (byte) 0xb9, (byte) 0xf1, 0x09,
            (byte) 0xc5, 0x6e, (byte) 0xc6, (byte) 0x84, 0x18, (byte) 0xf0,
            0x7d, (byte) 0xec, 0x3a, (byte) 0xdc, 0x4d, 0x20, 0x79,
            (byte) 0xee, 0x5f, 0x3e, (byte) 0xd7, (byte) 0xcb, 0x39, 0x48};

    public static final int[] FK = {0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc};

    public static final int[] CK = {0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,
            0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9,
            0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249,
            0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,
            0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,
            0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,
            0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209,
            0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279};

    private byte sm4Sbox(byte inch) {
        int i = inch & 0xFF;
        byte retVal = SboxTable[i];
        return retVal;
    }

    private long sm4Lt(long ka) {
        long bb = 0L;
        long c = 0L;
        byte[] a = new byte[4];
        byte[] b = new byte[4];
        PUT_ULONG_BE(ka, a, 0);
        b[0] = sm4Sbox(a[0]);
        b[1] = sm4Sbox(a[1]);
        b[2] = sm4Sbox(a[2]);
        b[3] = sm4Sbox(a[3]);
        bb = GET_ULONG_BE(b, 0);
        c = bb ^ ROTL(bb, 2) ^ ROTL(bb, 10) ^ ROTL(bb, 18) ^ ROTL(bb, 24);
        return c;
    }

    private long sm4F(long x0, long x1, long x2, long x3, long rk) {
        return x0 ^ sm4Lt(x1 ^ x2 ^ x3 ^ rk);
    }

    private long sm4CalciRK(long ka) {
        long bb = 0L;
        long rk = 0L;
        byte[] a = new byte[4];
        byte[] b = new byte[4];
        PUT_ULONG_BE(ka, a, 0);
        b[0] = sm4Sbox(a[0]);
        b[1] = sm4Sbox(a[1]);
        b[2] = sm4Sbox(a[2]);
        b[3] = sm4Sbox(a[3]);
        bb = GET_ULONG_BE(b, 0);
        rk = bb ^ ROTL(bb, 13) ^ ROTL(bb, 23);
        return rk;
    }

    private void sm4_setkey(long[] SK, byte[] key) {
        long[] MK = new long[4];
        long[] k = new long[36];
        int i = 0;
        MK[0] = GET_ULONG_BE(key, 0);
        MK[1] = GET_ULONG_BE(key, 4);
        MK[2] = GET_ULONG_BE(key, 8);
        MK[3] = GET_ULONG_BE(key, 12);
        k[0] = MK[0] ^ (long) FK[0];
        k[1] = MK[1] ^ (long) FK[1];
        k[2] = MK[2] ^ (long) FK[2];
        k[3] = MK[3] ^ (long) FK[3];
        for (; i < 32; i++) {
            k[(i + 4)] = (k[i] ^ sm4CalciRK(k[(i + 1)] ^ k[(i + 2)] ^ k[(i + 3)] ^ (long) CK[i]));
            SK[i] = k[(i + 4)];
        }
    }

    private void sm4_one_round(long[] sk, byte[] input, byte[] output) {
        int i = 0;
        long[] ulbuf = new long[36];
        ulbuf[0] = GET_ULONG_BE(input, 0);
        ulbuf[1] = GET_ULONG_BE(input, 4);
        ulbuf[2] = GET_ULONG_BE(input, 8);
        ulbuf[3] = GET_ULONG_BE(input, 12);
        while (i < 32) {
            ulbuf[(i + 4)] = sm4F(ulbuf[i], ulbuf[(i + 1)], ulbuf[(i + 2)], ulbuf[(i + 3)], sk[i]);
            i++;
        }
        PUT_ULONG_BE(ulbuf[35], output, 0);
        PUT_ULONG_BE(ulbuf[34], output, 4);
        PUT_ULONG_BE(ulbuf[33], output, 8);
        PUT_ULONG_BE(ulbuf[32], output, 12);
    }

    public static byte[] PKCS5Padding(byte[] inputByte) {
        // 获取字段长度
        int length = inputByte.length;
        // 补齐位数
        int leftLength = 16 - (length % 16);
        // 定义新字节
        byte[] arrayReturn = new byte[length + leftLength];
        // 定义填充字节
        byte[] plusbyte = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e,
                0x0f,0x10 };
        // 是否满足为16字节倍数
        //if (leftLength < 16) {
        // 不满足16倍数自动填充
        for (int i = 0; i < length + leftLength; i++) {
            if (i < length) {
                // 赋值
                arrayReturn[i] = inputByte[i];
            } else {
                // 补齐位数
                arrayReturn[i] = (byte)leftLength;
            }
        }
        // System.out.println("填充的字节："+plusbyte[leftLength]);
//        } else {
//            for (int i = 0; i < length + 16; i++) {
//                if (i < length) {
//                    // 赋值ֵ
//                    arrayReturn[i] = inputByte[i];
//                } else {
//                    // 补齐位数
//                    arrayReturn[i] = (byte)16;
//                }
//            }
//        }
        return arrayReturn;
    }

    public static byte[] PKCS7PaddingRestore(byte[] paramArray) throws Exception {
        //try {
        // 定义是否需要消除填充数据
        //boolean needRestore = true;
        int length = paramArray.length;// 获取字节长度
        // 拆分并获取最后一组16倍数数值
        byte[] paramByteLast = Arrays.copyOfRange(paramArray, length - 16, length);
        // 获取最后一个字节
        byte byteLast = paramByteLast[paramByteLast.length - 1];

        return Arrays.copyOfRange(paramArray,0,length-byteLast);
//            // 开始填充字节位置
//            int paddingNum = paramByteLast.length - byteLast;
//            if (paddingNum > 0) {
//               // 判断数组字节位数的字节是否与最后字节相等
//               for (int i = paddingNum; i < paramByteLast.length; i++) {
//                  byte paramSon = paramByteLast[i];
//                  if (byteLast != paramSon) {
//                     needRestore = false;
//                  }
//               }
//            } else {
//               needRestore = false;
//            }
//            if (needRestore) {
//               // 组合新数组并返回
//               byte[] resultArray = Arrays.copyOfRange(paramArray, 0, length - byteLast);
//               return resultArray;
//            }
//            return paramArray;
//         } catch (Exception e) {
//            throw new Exception("数据异常，字节填充还原错误，异常抛出！" + e.getMessage());
//         }
    }

    //修改了填充模式,为模式
    private byte[] padding(byte[] input, int mode) {
        byte[] ret = (byte[]) null;
        if (mode == SM4_ENCRYPT) {
            //填充:hex必须是32的整数倍填充 ,填充的是80  00 00 00
//            int p = 16 - input.length % 16;
//            String inputHex = Util.byteToHex(input)+ "80";
//            StringBuffer stringBuffer =new StringBuffer(inputHex);
//            for (int i = 0; i <p-1 ; i++) {
//                stringBuffer.append("00");
//            }
//            ret= Util.hexToByte(stringBuffer.toString());

            try {
                ret = PKCS5Padding(input);
            } catch (Exception e) {
                e.printStackTrace();
            }


            //ret = new byte[input.length + p];
            /*System.arraycopy(input, 0, ret, 0, input.length);
            for (int i = 0; i < p; i++) {
                ret[input.length + i] = (byte) '?';
            }*/
        } else {
            /*int p = input[input.length - 1];
            ret = new byte[input.length - p];
            System.arraycopy(input, 0, ret, 0, input.length - p);*/


//            String inputHex =Util.byteToHex(input);
//            int i = inputHex.lastIndexOf("80");
//            String substring = inputHex.substring(0, i);
//            ret= Util.hexToByte(substring);
            try {
                ret = PKCS7PaddingRestore(input);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return ret;
    }

    public void sm4_setkey_enc(SM4_Context ctx, byte[] key) throws Exception {
        if (ctx == null) {
            throw new Exception("ctx is null!");
        }

        if (key == null || key.length != 16) {
            throw new Exception("key error!");
        }

        ctx.mode = SM4_ENCRYPT;
        sm4_setkey(ctx.sk, key);
    }

    public void sm4_setkey_dec(SM4_Context ctx, byte[] key) throws Exception {
        if (ctx == null) {
            throw new Exception("ctx is null!");
        }

        if (key == null
//                || key.length != 16
        ) {
            throw new Exception("key error!");
        }

        int i = 0;
        ctx.mode = SM4_DECRYPT;
        sm4_setkey(ctx.sk, key);
        for (i = 0; i < 16; i++) {
            SWAP(ctx.sk, i);
        }
    }

    public byte[] sm4_crypt_ecb(SM4_Context ctx, byte[] input) throws Exception {
        if (input == null) {
            throw new Exception("input is null!");
        }

        if ((ctx.isPadding) && (ctx.mode == SM4_ENCRYPT)) {
            input = padding(input, SM4_ENCRYPT);
        }

        int length = input.length;
        ByteArrayInputStream bins = new ByteArrayInputStream(input);
        ByteArrayOutputStream bous = new ByteArrayOutputStream();
        for (; length > 0; length -= 16) {
            byte[] in = new byte[16];
            byte[] out = new byte[16];
            bins.read(in);
            sm4_one_round(ctx.sk, in, out);
            bous.write(out);
        }

        byte[] output = bous.toByteArray();
        if (ctx.isPadding && ctx.mode == SM4_DECRYPT) {
            output = padding(output, SM4_DECRYPT);
        }
        bins.close();
        bous.close();
        return output;
    }

    public byte[] sm4_crypt_cbc(SM4_Context ctx, byte[] iv, byte[] input) throws Exception {
        if (iv == null || iv.length != 16) {
            throw new Exception("iv error!");
        }

        if (input == null) {
            throw new Exception("input is null!");
        }

        if (ctx.isPadding && ctx.mode == SM4_ENCRYPT) {
            input = padding(input, SM4_ENCRYPT);
        }

        int i = 0;
        int length = input.length;
        ByteArrayInputStream bins = new ByteArrayInputStream(input);
        ByteArrayOutputStream bous = new ByteArrayOutputStream();
        if (ctx.mode == SM4_ENCRYPT) {
            for (; length > 0; length -= 16) {
                byte[] in = new byte[16];
                byte[] out = new byte[16];
                byte[] out1 = new byte[16];

                bins.read(in);
                for (i = 0; i < 16; i++) {
                    out[i] = ((byte) (in[i] ^ iv[i]));
                }
                sm4_one_round(ctx.sk, out, out1);
                System.arraycopy(out1, 0, iv, 0, 16);
                bous.write(out1);
            }
        } else {
            byte[] temp = new byte[16];
            for (; length > 0; length -= 16) {
                byte[] in = new byte[16];
                byte[] out = new byte[16];
                byte[] out1 = new byte[16];

                bins.read(in);
                System.arraycopy(in, 0, temp, 0, 16);
                sm4_one_round(ctx.sk, in, out);
                for (i = 0; i < 16; i++) {
                    out1[i] = ((byte) (out[i] ^ iv[i]));
                }
                System.arraycopy(temp, 0, iv, 0, 16);
                bous.write(out1);
            }
        }

        byte[] output = bous.toByteArray();
        if (ctx.isPadding && ctx.mode == SM4_DECRYPT) {
            output = padding(output, SM4_DECRYPT);
        }
        bins.close();
        bous.close();
        return output;
    }
}

SM4_Context.java

package com.qmrz.worksite.util.sm4;

public class SM4_Context {
    public int mode;

    public long[] sk;

    public boolean isPadding;

    public SM4_Context()
    {
        this.mode = 1;
        this.isPadding = true;
        this.sk = new long[32];
    }
}

Util.java

package com.qmrz.worksite.util.sm4;

import java.math.BigInteger;

/**
 * sm4加密解密工具类
 */
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 content 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 content 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;
    }
}

SM4Utils.java

package com.qmrz.worksite.util.sm4;


import com.sun.org.apache.xerces.internal.impl.dv.util.Base64;

import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Sm4 加密解密CBC、ECB模式
 */
public class SM4Utils {
    //密钥
    public String secretKey = "";
    //向量
    public String iv = "";
    //声明密钥和向量是否是32长度的十六进制的字符串，
    //如果true则需要设置密钥向量都是十六进制的32长度字符串。
    // Util.byteToHex("b7b3gSMFWd9a67i1".getBytes())
    public boolean hexString = false;

    public SM4Utils() {
    }

    /**
     * ECB模式加密
     * @param plainText
     * @return
     */
    public String encryptData_ECB(String plainText) {
        try {
            SM4_Context ctx = new SM4_Context();
            ctx.isPadding = false;
            ctx.mode = SM4.SM4_ENCRYPT;

            byte[] keyBytes;
            if (hexString) {
                keyBytes = Util.hexStringToBytes(secretKey);
            } else {
                //keyBytes = secretKey.getBytes();
                keyBytes = Util.hexStringToBytes(secretKey);
            }

            SM4 sm4 = new SM4();
            sm4.sm4_setkey_enc(ctx, keyBytes);
            byte[] encrypted = sm4.sm4_crypt_ecb(ctx, plainText.getBytes("UTF-8"));
            return Util.byteToHex(encrypted);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * ECB模式加密
     * @param plainText
     * @return
     */
    public String encryptData_ECB(byte[] plainText) {
        try {
            SM4_Context ctx = new SM4_Context();
            ctx.isPadding = false;
            ctx.mode = SM4.SM4_ENCRYPT;

            byte[] keyBytes;
            if (hexString) {
                keyBytes = Util.hexStringToBytes(secretKey);
            } else {
                //keyBytes = secretKey.getBytes();
                keyBytes = Util.hexStringToBytes(secretKey);
            }

            SM4 sm4 = new SM4();
            sm4.sm4_setkey_enc(ctx, keyBytes);
            byte[] encrypted = sm4.sm4_crypt_ecb(ctx, plainText);
            return Util.byteToHex(encrypted);
        } catch (Exception e) {
            e.printStackTrace();
            return "";
        }
    }

    /**
     * ECB模式解密
     * @param cipherText
     * @return
     */
    public String decryptData_ECB(String cipherText) {
        try {
            byte[] encrypted = Util.hexToByte(cipherText);
//            cipherText= Base64.encode(encrypted);;
//            //cipherText = new BASE64Encoder().encode(encrypted);
//            if (cipherText != null && cipherText.trim().length() > 0) {
//                Pattern p = Pattern.compile("\\s*|\t|\r|\n");
//                Matcher m = p.matcher(cipherText);
//                cipherText = m.replaceAll("");
//            }

            SM4_Context ctx = new SM4_Context();
            ctx.isPadding = false;
            ctx.mode = SM4.SM4_DECRYPT;

            byte[] keyBytes;
            if (hexString) {
                keyBytes = Util.hexStringToBytes(secretKey);
            } else {
                keyBytes = secretKey.getBytes();
            }
            SM4 sm4 = new SM4();
            sm4.sm4_setkey_dec(ctx, keyBytes);
            byte[] decrypted = sm4.sm4_crypt_ecb(ctx, encrypted);
            // byte[] decrypted = sm4.sm4_crypt_ecb(ctx, new BASE64Decoder().decodeBuffer(cipherText));
            return new String(decrypted, "UTF-8");
        } catch (Exception e) {
            e.printStackTrace();
            return "";
        }
    }

    /**
     * CBC模式加密
     * @param plainText
     * @return
     */
    public String encryptData_CBC(String plainText) {
        try {
            SM4_Context ctx = new SM4_Context();
            ctx.isPadding = false;
            ctx.mode = SM4.SM4_ENCRYPT;

            byte[] keyBytes;
            byte[] ivBytes;
            if (hexString) {
                keyBytes = Util.hexStringToBytes(secretKey);
                ivBytes = Util.hexStringToBytes(iv);
            } else {
                keyBytes = secretKey.getBytes();
                ivBytes = iv.getBytes();
            }

            SM4 sm4 = new SM4();
            sm4.sm4_setkey_enc(ctx, keyBytes);
            byte[] encrypted = sm4.sm4_crypt_cbc(ctx, ivBytes, plainText.getBytes("UTF-8"));
            return Util.byteToHex(encrypted);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * CBC模式解密
     * @param cipherText
     * @return
     */
    public String decryptData_CBC(String cipherText) {
        try {
            byte[] encrypted = Util.hexToByte(cipherText);
            cipherText= Base64.encode(encrypted);
            //cipherText = new BASE64Encoder().encode(encrypted);
            if (cipherText != null && cipherText.trim().length() > 0) {
                Pattern p = Pattern.compile("\\s*|\t|\r|\n");
                Matcher m = p.matcher(cipherText);
                cipherText = m.replaceAll("");
            }
            SM4_Context ctx = new SM4_Context();
            ctx.isPadding = true;
            ctx.mode = SM4.SM4_DECRYPT;

            byte[] keyBytes;
            byte[] ivBytes;
            if (hexString) {
                keyBytes = Util.hexStringToBytes(secretKey);
                ivBytes = Util.hexStringToBytes(iv);
            } else {
                keyBytes = secretKey.getBytes();
                ivBytes = iv.getBytes();
            }

            SM4 sm4 = new SM4();
            sm4.sm4_setkey_dec(ctx, keyBytes);
            //byte[] decrypted = sm4.sm4_crypt_cbc(ctx, ivBytes, new BASE64Decoder().decodeBuffer(cipherText));
            byte[] decrypted = sm4.sm4_crypt_cbc(ctx, ivBytes, Base64.decode(cipherText));
            /*String text = new String(decrypted, "UTF-8");
            return text.substring(0,text.length()-1);*/
            return new String(decrypted, "UTF-8");
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public static void main(String[] args) throws IOException {
        String plainText = "{\"appType\":\"3.0.27\",\"deviceType\":\"F8282C20M\",\"osType\":\"linux\",\"privateKey\":\"C97E76AF40C82627E4BDF23B2DB9D476\",\"terminalID\":\"PF8282C20MB0DF31AB\"}";
        String s = Util.byteToHex(plainText.getBytes());
        System.out.println("原文" + s);
        SM4Utils sm4 = new SM4Utils();
        sm4.secretKey = "C97E76AF40C82627E4BDF23B2DB9D476";
        sm4.hexString = true;

        System.out.println("ECB模式加密");
        String cipherText = sm4.encryptData_ECB(plainText);
        System.out.println("密文: " + cipherText);
        System.out.println();

        System.out.println("ECB模式解密");
        String plainText1 = sm4.decryptData_ECB(cipherText);
        System.out.println("明文: " + plainText1);
        System.out.println();

//        System.out.println("CBC模式加密");
//        sm4.iv = "31313131313131313131313131313131";
//        String cipherText2 = sm4.encryptData_CBC(plainText);
//        System.out.println("加密密文: " + cipherText2);
//        System.out.println("");
//
//        String plainText3 = sm4.decryptData_CBC(cipherText2);
//        System.out.println("解密明文: " + plainText3);

    }
}

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