[移动开发]国密SM4对称加密算法（对本地文件的加解密）代码展示

代码

package com.example.demo.MIMAXUE.SM;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

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

public class SM4Utils {
//	private String secretKey = "";
//    private String iv = "";
//    private boolean hexString = false;

    public String secretKey = "";
    private String iv = "";
    public boolean hexString = false;

    public SM4Utils()
    {
    }
    public String encryptData_ECB(String plainText)
    {
        try
        {
            SM4_Context ctx = new SM4_Context();
            ctx.isPadding = true;
            ctx.mode = SM4.SM4_ENCRYPT;

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

            SM4 sm4 = new SM4();
            sm4.sm4_setkey_enc(ctx, keyBytes);
            byte[] encrypted = sm4.sm4_crypt_ecb(ctx, plainText.getBytes("GBK"));
            String 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("");
            }
            return cipherText;
        }
        catch (Exception e)
        {
            e.printStackTrace();
            return null;
        }
    }

    public String decryptData_ECB(String cipherText)
    {
        try
        {
            SM4_Context ctx = new SM4_Context();
            ctx.isPadding = true;
            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, new BASE64Decoder().decodeBuffer(cipherText));
            return new String(decrypted, "GBK");
        }
        catch (Exception e)
        {
            e.printStackTrace();
            return null;
        }
    }

    public String encryptData_CBC(String plainText)
    {
        try
        {
            SM4_Context ctx = new SM4_Context();
            ctx.isPadding = true;
            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("GBK"));
            String 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("");
            }
            return cipherText;
        }
        catch (Exception e)
        {
            e.printStackTrace();
            return null;
        }
    }

    public String decryptData_CBC(String cipherText)
    {
        try
        {
            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));
            return new String(decrypted, "GBK");
        }
        catch (Exception e)
        {
            e.printStackTrace();
            return null;
        }
    }

    public static String encryAndDesFile() throws IOException {
        StringBuffer fileData = new StringBuffer();
        //"G:\\jjDown\\shengyue.mp4"
        BufferedReader reader = new BufferedReader(new FileReader("G:\\jjDown\\538.mp4"));
        char[] buf = new char[1024];
        int numRead=0;
        while((numRead=reader.read(buf)) != -1){
            String readData = String.valueOf(buf, 0, numRead);
            fileData.append(readData);
        }
        //缓冲区使用完必须关掉
        reader.close();
        return fileData.toString();
    }

    public static void main(String[] args) throws IOException
    {
        Long avgENCTime = 0L;
        Long avgDecTime = 0L;
        for(int i=0;i<1;i++) {
            String plainText = encryAndDesFile();

            SM4Utils sm4 = new SM4Utils();
            sm4.secretKey = "JeF8U9wHFOMfs2Y8";
            sm4.hexString = false;
            String cipherText;

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

            //System.out.println("CBC模式加密");
            sm4.iv = "UISwD9fW6cFh9SNS";
            Long startTime = System.currentTimeMillis();
            cipherText = sm4.encryptData_CBC(plainText);
            Long endTime = System.currentTimeMillis();
            avgENCTime+=(endTime-startTime);
            System.out.println("sm4加密花费时间" + (endTime - startTime) + "ms");

            System.out.println("密文: " + cipherText);
            System.out.println("");

            Long startTime1 = System.currentTimeMillis();
            plainText = sm4.decryptData_CBC(cipherText);
            Long endTime1 = System.currentTimeMillis();
            avgDecTime+=(endTime1-startTime1);
            System.out.println("sm4加密花费时间" + (endTime - startTime) + "ms");
            System.out.println("sm4解密花费时间" + (endTime1 - startTime1) + "ms");
        }
        System.out.println("********************************************************************************");

    }
}

package com.example.demo.MIMAXUE.SM;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;

public class SM4 {
    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);
    }

    private byte[] padding(byte[] input, int mode)
    {
        if (input == null)
        {
            return null;
        }

        byte[] ret = (byte[]) null;
        if (mode == SM4_ENCRYPT)
        {
            int p = 16 - input.length % 16;
            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) p;
            }
        }
        else
        {
            int p = input[input.length - 1];
            ret = new byte[input.length - p];
            System.arraycopy(input, 0, ret, 0, input.length - p);
        }
        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;
    }
}

package com.example.demo.MIMAXUE.SM;

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];
    }
}

package com.example.demo.MIMAXUE.SM;

import java.math.BigInteger;

public class Util {
    /**
     * 整形转换成网络传输的字节流（字节数组）型数据
     *
     * @param num 一个整型数据
     * @return 4个字节的自己数组
     */
    public static byte[] intToBytes(int num)
    {
        byte[] bytes = new byte[4];
        bytes[0] = (byte) (0xff & (num >> 0));
        bytes[1] = (byte) (0xff & (num >> 8));
        bytes[2] = (byte) (0xff & (num >> 16));
        bytes[3] = (byte) (0xff & (num >> 24));
        return bytes;
    }

    /**
     * 四个字节的字节数据转换成一个整形数据
     *
     * @param bytes 4个字节的字节数组
     * @return 一个整型数据
     */
    public static int byteToInt(byte[] bytes)
    {
        int num = 0;
        int temp;
        temp = (0x000000ff & (bytes[0])) << 0;
        num = num | temp;
        temp = (0x000000ff & (bytes[1])) << 8;
        num = num | temp;
        temp = (0x000000ff & (bytes[2])) << 16;
        num = num | temp;
        temp = (0x000000ff & (bytes[3])) << 24;
        num = num | temp;
        return num;
    }

    /**
     * 长整形转换成网络传输的字节流（字节数组）型数据
     *
     * @param num 一个长整型数据
     * @return 4个字节的自己数组
     */
    public static byte[] longToBytes(long num)
    {
        byte[] bytes = new byte[8];
        for (int i = 0; i < 8; i++)
        {
            bytes[i] = (byte) (0xff & (num >> (i * 8)));
        }

        return bytes;
    }

    /**
     * 大数字转换字节流（字节数组）型数据
     *
     * @param n
     * @return
     */
    public static byte[] byteConvert32Bytes(BigInteger n)
    {
        byte tmpd[] = (byte[])null;
        if(n == null)
        {
            return null;
        }

        if(n.toByteArray().length == 33)
        {
            tmpd = new byte[32];
            System.arraycopy(n.toByteArray(), 1, tmpd, 0, 32);
        }
        else if(n.toByteArray().length == 32)
        {
            tmpd = n.toByteArray();
        }
        else
        {
            tmpd = new byte[32];
            for(int i = 0; i < 32 - n.toByteArray().length; i++)
            {
                tmpd[i] = 0;
            }
            System.arraycopy(n.toByteArray(), 0, tmpd, 32 - n.toByteArray().length, n.toByteArray().length);
        }
        return tmpd;
    }

    /**
     * 换字节流（字节数组）型数据转大数字
     *
     * @param b
     * @return
     */
    public static BigInteger byteConvertInteger(byte[] b)
    {
        if (b[0] < 0)
        {
            byte[] temp = new byte[b.length + 1];
            temp[0] = 0;
            System.arraycopy(b, 0, temp, 1, b.length);
            return new BigInteger(temp);
        }
        return new BigInteger(b);
    }

    /**
     * 根据字节数组获得值(十六进制数字)
     *
     * @param bytes
     * @return
     */
    public static String getHexString(byte[] bytes)
    {
        return getHexString(bytes, true);
    }

    /**
     * 根据字节数组获得值(十六进制数字)
     *
     * @param bytes
     * @param upperCase
     * @return
     */
    public static String getHexString(byte[] bytes, boolean upperCase)
    {
        String ret = "";
        for (int i = 0; i < bytes.length; i++)
        {
            ret += Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1);
        }
        return upperCase ? ret.toUpperCase() : ret;
    }

    /**
     * 打印十六进制字符串
     *
     * @param bytes
     */
    public static void printHexString(byte[] bytes)
    {
        for (int i = 0; i < bytes.length; i++)
        {
            String hex = Integer.toHexString(bytes[i] & 0xFF);
            if (hex.length() == 1)
            {
                hex = '0' + hex;
            }
            System.out.print("0x" + hex.toUpperCase() + ",");
        }
        System.out.println("");
    }

    /**
     * Convert hex string to byte[]
     *
     * @param hexString
     *            the hex string
     * @return byte[]
     */
    public static byte[] hexStringToBytes(String hexString)
    {
        if (hexString == null || hexString.equals(""))
        {
            return null;
        }

        hexString = hexString.toUpperCase();
        int length = hexString.length() / 2;
        char[] hexChars = hexString.toCharArray();
        byte[] d = new byte[length];
        for (int i = 0; i < length; i++)
        {
            int pos = i * 2;
            d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));
        }
        return d;
    }

    /**
     * Convert char to byte
     *
     * @param c
     *            char
     * @return byte
     */
    public static byte charToByte(char c)
    {
        return (byte) "0123456789ABCDEF".indexOf(c);
    }

    /**
     * 用于建立十六进制字符的输出的小写字符数组
     */
    private static final char[] DIGITS_LOWER = {'0', '1', '2', '3', '4', '5',
            '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};

    /**
     * 用于建立十六进制字符的输出的大写字符数组
     */
    private static final char[] DIGITS_UPPER = {'0', '1', '2', '3', '4', '5',
            '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};

    /**
     * 将字节数组转换为十六进制字符数组
     *
     * @param data byte[]
     * @return 十六进制char[]
     */
    public static char[] encodeHex(byte[] data) {
        return encodeHex(data, true);
    }

    /**
     * 将字节数组转换为十六进制字符数组
     *
     * @param data        byte[]
     * @param toLowerCase <code>true</code> 传换成小写格式 ， <code>false</code> 传换成大写格式
     * @return 十六进制char[]
     */
    public static char[] encodeHex(byte[] data, boolean toLowerCase) {
        return encodeHex(data, toLowerCase ? DIGITS_LOWER : DIGITS_UPPER);
    }

    /**
     * 将字节数组转换为十六进制字符数组
     *
     * @param data     byte[]
     * @param toDigits 用于控制输出的char[]
     * @return 十六进制char[]
     */
    protected static char[] encodeHex(byte[] data, char[] toDigits) {
        int l = data.length;
        char[] out = new char[l << 1];
        // two characters form the hex value.
        for (int i = 0, j = 0; i < l; i++) {
            out[j++] = toDigits[(0xF0 & data[i]) >>> 4];
            out[j++] = toDigits[0x0F & data[i]];
        }
        return out;
    }

    /**
     * 将字节数组转换为十六进制字符串
     *
     * @param data byte[]
     * @return 十六进制String
     */
    public static String encodeHexString(byte[] data) {
        return encodeHexString(data, true);
    }

    /**
     * 将字节数组转换为十六进制字符串
     *
     * @param data        byte[]
     * @param toLowerCase <code>true</code> 传换成小写格式 ， <code>false</code> 传换成大写格式
     * @return 十六进制String
     */
    public static String encodeHexString(byte[] data, boolean toLowerCase) {
        return encodeHexString(data, toLowerCase ? DIGITS_LOWER : DIGITS_UPPER);
    }

    /**
     * 将字节数组转换为十六进制字符串
     *
     * @param data     byte[]
     * @param toDigits 用于控制输出的char[]
     * @return 十六进制String
     */
    protected static String encodeHexString(byte[] data, char[] toDigits) {
        return new String(encodeHex(data, toDigits));
    }

    /**
     * 将十六进制字符数组转换为字节数组
     *
     * @param data 十六进制char[]
     * @return byte[]
     * @throws RuntimeException 如果源十六进制字符数组是一个奇怪的长度，将抛出运行时异常
     */
    public static byte[] decodeHex(char[] data) {
        int len = data.length;

        if ((len & 0x01) != 0) {
            throw new RuntimeException("Odd number of characters.");
        }

        byte[] out = new byte[len >> 1];

        // two characters form the hex value.
        for (int i = 0, j = 0; j < len; i++) {
            int f = toDigit(data[j], j) << 4;
            j++;
            f = f | toDigit(data[j], j);
            j++;
            out[i] = (byte) (f & 0xFF);
        }

        return out;
    }

    /**
     * 将十六进制字符转换成一个整数
     *
     * @param ch    十六进制char
     * @param index 十六进制字符在字符数组中的位置
     * @return 一个整数
     * @throws RuntimeException 当ch不是一个合法的十六进制字符时，抛出运行时异常
     */
    protected static int toDigit(char ch, int index) {
        int digit = Character.digit(ch, 16);
        if (digit == -1) {
            throw new RuntimeException("Illegal hexadecimal character " + ch
                    + " at index " + index);
        }
        return digit;
    }

    /**
     * 数字字符串转ASCII码字符串
     *
     * @param
     *
     * @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
     *
     * @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;
    }
}

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