SM4算法加解密及实现

你的名字 2023-09-25 22:07 134阅读 0赞

## 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][Link 1]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][Link 2]体系中，SM4主要用于[数据加密][Link 3]，其算法公开，分组长度与密钥长度均为128bit，[加密算法][Link 4]与密钥扩展算法都采用32轮非线性迭代结构，[S盒][S]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);
    
        }
    }

结束！

[Link 1]: https://baike.baidu.com/item/%E5%88%86%E7%BB%84%E5%AF%86%E7%A0%81/1436163?fromModule=lemma_inlink
[Link 2]: https://baike.baidu.com/item/%E5%95%86%E7%94%A8%E5%AF%86%E7%A0%81/10636778?fromModule=lemma_inlink
[Link 3]: https://baike.baidu.com/item/%E6%95%B0%E6%8D%AE%E5%8A%A0%E5%AF%86/11048982?fromModule=lemma_inlink
[Link 4]: https://baike.baidu.com/item/%E5%8A%A0%E5%AF%86%E7%AE%97%E6%B3%95/2816213?fromModule=lemma_inlink
[S]: https://baike.baidu.com/item/S%E7%9B%92?fromModule=lemma_inlink
[DES]: https://baike.baidu.com/item/DES/210508?fromModule=lemma_inlink
[AES]: https://baike.baidu.com/item/%E9%AB%98%E7%BA%A7%E5%8A%A0%E5%AF%86%E6%A0%87%E5%87%86/468774?fromModule=lemma_inlink&fromtitle=aes&fromid=5903