Java DES 加密

最新推荐文章于 2024-04-23 15:13:36 发布
不让我跟傻子玩
最新推荐文章于 2024-04-23 15:13:36 发布
阅读量216
点赞数
分类专栏： Java android
本文链接：https://blog.youkuaiyun.com/xj531/article/details/115737991
版权
加密解密 java
android 同时被 2 个专栏收录
16 篇文章
订阅专栏
Java
1 篇文章
订阅专栏
优化后的des加密工具类


/**
 *  参照 Android 4.4.2的源码DES.java 主要解决的问题：以前的DesUtisl巨耗内存 加密360字节，需要耗内存1.7M
 * 新算法内存消耗：需要加密长度一样的result串.
 */
public class DesUtil {

    public static final int FLAG_ENCRYPT = 1;

    public static final int FLAG_DECRYPT = 0;

    /**
     * what follows is mainly taken from "Applied Cryptography", by Bruce Schneier, however it also
     * bears great resemblance to Richard Outerbridge's D3DES...
     */

    static short[] Df_Key = {0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba, 0x98,
            0x76, 0x54, 0x32, 0x10,
            0x89, 0xab, 0xcd, 0xef, 0x01, 0x23, 0x45, 0x67};

    static short[] bytebit = {0200, 0100, 040, 020, 010, 04, 02, 01};

    static int[] bigbyte = {0x800000, 0x400000, 0x200000, 0x100000, 0x80000, 0x40000, 0x20000,
            0x10000, 0x8000, 0x4000, 0x2000,
            0x1000, 0x800, 0x400, 0x200, 0x100, 0x80, 0x40, 0x20, 0x10, 0x8, 0x4, 0x2, 0x1};

    /*
     * Use the key schedule specified in the Standard (ANSI X3.92-1981).
     */

    static byte[] pc1 = {56, 48, 40, 32, 24, 16, 8, 0, 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34,
            26, 18, 10, 2, 59, 51,
            43, 35, 62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 60, 52, 44, 36,
            28, 20, 12, 4, 27, 19, 11, 3};

    static byte[] totrot = {1, 2, 4, 6, 8, 10, 12, 14, 15, 17, 19, 21, 23, 25, 27, 28};

    static byte[] pc2 = {13, 16, 10, 23, 0, 4, 2, 27, 14, 5, 20, 9, 22, 18, 11, 3, 25, 7, 15, 6, 26,
            19, 12, 1, 40, 51, 30,
            36, 46, 54, 29, 39, 50, 44, 32, 47, 43, 48, 38, 55, 33, 52, 45, 41, 49, 35, 28, 31};

    static int[] SP1 = {0x01010400, 0x00000000, 0x00010000, 0x01010404, 0x01010004, 0x00010404,
            0x00000004, 0x00010000,
            0x00000400, 0x01010400, 0x01010404, 0x00000400, 0x01000404, 0x01010004, 0x01000000,
            0x00000004, 0x00000404, 0x01000400, 0x01000400,
            0x00010400, 0x00010400, 0x01010000, 0x01010000, 0x01000404, 0x00010004, 0x01000004,
            0x01000004, 0x00010004, 0x00000000, 0x00000404,
            0x00010404, 0x01000000, 0x00010000, 0x01010404, 0x00000004, 0x01010000, 0x01010400,
            0x01000000, 0x01000000, 0x00000400, 0x01010004,
            0x00010000, 0x00010400, 0x01000004, 0x00000400, 0x00000004, 0x01000404, 0x00010404,
            0x01010404, 0x00010004, 0x01010000, 0x01000404,
            0x01000004, 0x00000404, 0x00010404, 0x01010400, 0x00000404, 0x01000400, 0x01000400,
            0x00000000, 0x00010004, 0x00010400, 0x00000000,
            0x01010004};

    static int[] SP2 = {0x80108020, 0x80008000, 0x00008000, 0x00108020, 0x00100000, 0x00000020,
            0x80100020, 0x80008020,
            0x80000020, 0x80108020, 0x80108000, 0x80000000, 0x80008000, 0x00100000, 0x00000020,
            0x80100020, 0x00108000, 0x00100020, 0x80008020,
            0x00000000, 0x80000000, 0x00008000, 0x00108020, 0x80100000, 0x00100020, 0x80000020,
            0x00000000, 0x00108000, 0x00008020, 0x80108000,
            0x80100000, 0x00008020, 0x00000000, 0x00108020, 0x80100020, 0x00100000, 0x80008020,
            0x80100000, 0x80108000, 0x00008000, 0x80100000,
            0x80008000, 0x00000020, 0x80108020, 0x00108020, 0x00000020, 0x00008000, 0x80000000,
            0x00008020, 0x80108000, 0x00100000, 0x80000020,
            0x00100020, 0x80008020, 0x80000020, 0x00100020, 0x00108000, 0x00000000, 0x80008000,
            0x00008020, 0x80000000, 0x80100020, 0x80108020,
            0x00108000};

    static int[] SP3 = {0x00000208, 0x08020200, 0x00000000, 0x08020008, 0x08000200, 0x00000000,
            0x00020208, 0x08000200,
            0x00020008, 0x08000008, 0x08000008, 0x00020000, 0x08020208, 0x00020008, 0x08020000,
            0x00000208, 0x08000000, 0x00000008, 0x08020200,
            0x00000200, 0x00020200, 0x08020000, 0x08020008, 0x00020208, 0x08000208, 0x00020200,
            0x00020000, 0x08000208, 0x00000008, 0x08020208,
            0x00000200, 0x08000000, 0x08020200, 0x08000000, 0x00020008, 0x00000208, 0x00020000,
            0x08020200, 0x08000200, 0x00000000, 0x00000200,
            0x00020008, 0x08020208, 0x08000200, 0x08000008, 0x00000200, 0x00000000, 0x08020008,
            0x08000208, 0x00020000, 0x08000000, 0x08020208,
            0x00000008, 0x00020208, 0x00020200, 0x08000008, 0x08020000, 0x08000208, 0x00000208,
            0x08020000, 0x00020208, 0x00000008, 0x08020008,
            0x00020200};

    static int[] SP4 = {0x00802001, 0x00002081, 0x00002081, 0x00000080, 0x00802080, 0x00800081,
            0x00800001, 0x00002001,
            0x00000000, 0x00802000, 0x00802000, 0x00802081, 0x00000081, 0x00000000, 0x00800080,
            0x00800001, 0x00000001, 0x00002000, 0x00800000,
            0x00802001, 0x00000080, 0x00800000, 0x00002001, 0x00002080, 0x00800081, 0x00000001,
            0x00002080, 0x00800080, 0x00002000, 0x00802080,
            0x00802081, 0x00000081, 0x00800080, 0x00800001, 0x00802000, 0x00802081, 0x00000081,
            0x00000000, 0x00000000, 0x00802000, 0x00002080,
            0x00800080, 0x00800081, 0x00000001, 0x00802001, 0x00002081, 0x00002081, 0x00000080,
            0x00802081, 0x00000081, 0x00000001, 0x00002000,
            0x00800001, 0x00002001, 0x00802080, 0x00800081, 0x00002001, 0x00002080, 0x00800000,
            0x00802001, 0x00000080, 0x00800000, 0x00002000,
            0x00802080};

    static int[] SP5 = {0x00000100, 0x02080100, 0x02080000, 0x42000100, 0x00080000, 0x00000100,
            0x40000000, 0x02080000,
            0x40080100, 0x00080000, 0x02000100, 0x40080100, 0x42000100, 0x42080000, 0x00080100,
            0x40000000, 0x02000000, 0x40080000, 0x40080000,
            0x00000000, 0x40000100, 0x42080100, 0x42080100, 0x02000100, 0x42080000, 0x40000100,
            0x00000000, 0x42000000, 0x02080100, 0x02000000,
            0x42000000, 0x00080100, 0x00080000, 0x42000100, 0x00000100, 0x02000000, 0x40000000,
            0x02080000, 0x42000100, 0x40080100, 0x02000100,
            0x40000000, 0x42080000, 0x02080100, 0x40080100, 0x00000100, 0x02000000, 0x42080000,
            0x42080100, 0x00080100, 0x42000000, 0x42080100,
            0x02080000, 0x00000000, 0x40080000, 0x42000000, 0x00080100, 0x02000100, 0x40000100,
            0x00080000, 0x00000000, 0x40080000, 0x02080100,
            0x40000100};

    static int[] SP6 = {0x20000010, 0x20400000, 0x00004000, 0x20404010, 0x20400000, 0x00000010,
            0x20404010, 0x00400000,
            0x20004000, 0x00404010, 0x00400000, 0x20000010, 0x00400010, 0x20004000, 0x20000000,
            0x00004010, 0x00000000, 0x00400010, 0x20004010,
            0x00004000, 0x00404000, 0x20004010, 0x00000010, 0x20400010, 0x20400010, 0x00000000,
            0x00404010, 0x20404000, 0x00004010, 0x00404000,
            0x20404000, 0x20000000, 0x20004000, 0x00000010, 0x20400010, 0x00404000, 0x20404010,
            0x00400000, 0x00004010, 0x20000010, 0x00400000,
            0x20004000, 0x20000000, 0x00004010, 0x20000010, 0x20404010, 0x00404000, 0x20400000,
            0x00404010, 0x20404000, 0x00000000, 0x20400010,
            0x00000010, 0x00004000, 0x20400000, 0x00404010, 0x00004000, 0x00400010, 0x20004010,
            0x00000000, 0x20404000, 0x20000000, 0x00400010,
            0x20004010};

    static int[] SP7 = {0x00200000, 0x04200002, 0x04000802, 0x00000000, 0x00000800, 0x04000802,
            0x00200802, 0x04200800,
            0x04200802, 0x00200000, 0x00000000, 0x04000002, 0x00000002, 0x04000000, 0x04200002,
            0x00000802, 0x04000800, 0x00200802, 0x00200002,
            0x04000800, 0x04000002, 0x04200000, 0x04200800, 0x00200002, 0x04200000, 0x00000800,
            0x00000802, 0x04200802, 0x00200800, 0x00000002,
            0x04000000, 0x00200800, 0x04000000, 0x00200800, 0x00200000, 0x04000802, 0x04000802,
            0x04200002, 0x04200002, 0x00000002, 0x00200002,
            0x04000000, 0x04000800, 0x00200000, 0x04200800, 0x00000802, 0x00200802, 0x04200800,
            0x00000802, 0x04000002, 0x04200802, 0x04200000,
            0x00200800, 0x00000000, 0x00000002, 0x04200802, 0x00000000, 0x00200802, 0x04200000,
            0x00000800, 0x04000002, 0x04000800, 0x00000800,
            0x00200002};

    static int[] SP8 = {0x10001040, 0x00001000, 0x00040000, 0x10041040, 0x10000000, 0x10001040,
            0x00000040, 0x10000000,
            0x00040040, 0x10040000, 0x10041040, 0x00041000, 0x10041000, 0x00041040, 0x00001000,
            0x00000040, 0x10040000, 0x10000040, 0x10001000,
            0x00001040, 0x00041000, 0x00040040, 0x10040040, 0x10041000, 0x00001040, 0x00000000,
            0x00000000, 0x10040040, 0x10000040, 0x10001000,
            0x00041040, 0x00040000, 0x00041040, 0x00040000, 0x10041000, 0x00001000, 0x00000040,
            0x10040040, 0x00001000, 0x00041040, 0x10001000,
            0x00000040, 0x10000040, 0x10040000, 0x10040040, 0x10000000, 0x00040000, 0x10001040,
            0x00000000, 0x10041040, 0x00040040, 0x10000040,
            0x10040000, 0x10001000, 0x10001040, 0x00000000, 0x10041040, 0x00041000, 0x00041000,
            0x00001040, 0x00001040, 0x00040040, 0x10000000,
            0x10041000};

    /**
     *  为了优化之前DesUtils.DesEncrypt效率比较低的方式。 以前的DesUtils.DesEncrypt
     * 加密360个字节数据，会使用零时内存1.7M，巨不环保.
     */
    public static byte[] desEncrypt(byte[] desKey, byte[] desData, int flag) {
        boolean encrypting = flag == FLAG_ENCRYPT ? true : false;
        int[] workingKey = generateWorkingKey(encrypting, desKey, 0);

        int totalLen = desData.length;
        // 这里与老版本的加解密方法对齐，刚好8字节整数倍时再填充8个字节
        int padlen = 8 - (totalLen % 8);
        int newlen = totalLen + padlen;
        byte[] resultData = new byte[newlen];
        int unitcount = newlen / 8;

        int count = 0;
        // 前面来unitcount -1轮整的.
        for (count = 0; count < unitcount - 1; count++) {
            transformBlock(workingKey, desData, count * 8, resultData, count * 8);
        }

        // 对齐最后的8个字节，这样处理时为了减少内存拷贝，最多只拷贝8字节内存.
        byte[] last8byte = new byte[8];
        int last8Index = count * 8;
        for (int i = 0; i < 8; i++) {
            if (last8Index < totalLen) {
                last8byte[i] = desData[last8Index];
                last8Index++;
            } else {
                last8byte[i] = (byte) padlen;
            }
        }
        transformBlock(workingKey, last8byte, 0, resultData, count * 8);

        if (flag == FLAG_DECRYPT) {
            // 处理解密时候对齐的问题
            byte[] tempResData = new byte[desData.length];
            System.arraycopy(resultData, 0, tempResData, 0, tempResData.length);
            int padlentmp = tempResData[tempResData.length - 1];
            if (padlentmp > 0 && padlentmp <= 8) {
                boolean bDesCheckResult = true;
                for (int i = 0; i < padlentmp; i++) {
                    if (padlentmp != tempResData[tempResData.length - 1 - i]) {
                        bDesCheckResult = false;
                        break;
                    }

                }
                if (bDesCheckResult) {
                    resultData = new byte[tempResData.length - padlentmp];
                    System.arraycopy(tempResData, 0, resultData, 0, resultData.length);
                }
            }
        }
        return resultData;
    }

    private static void transformBlock(int[] workingKey, byte[] in, int inOff, byte[] out,
                                       int outOff) {
        if (workingKey == null) {
            throw new IllegalStateException("DES engine not initialised!");
        }

        desFunc(workingKey, in, inOff, out, outOff);
    }

    /**
     * the DES engine.
     */
    protected static void desFunc(int[] wKey, byte[] in, int inOff, byte[] out, int outOff) {
        int left;
        left = (in[inOff + 0] & 0xff) << 24;
        left |= (in[inOff + 1] & 0xff) << 16;
        left |= (in[inOff + 2] & 0xff) << 8;
        left |= (in[inOff + 3] & 0xff);

        int right;
        right = (in[inOff + 4] & 0xff) << 24;
        right |= (in[inOff + 5] & 0xff) << 16;
        right |= (in[inOff + 6] & 0xff) << 8;
        right |= (in[inOff + 7] & 0xff);

        int work;
        work = ((left >>> 4) ^ right) & 0x0f0f0f0f;
        right ^= work;
        left ^= (work << 4);
        work = ((left >>> 16) ^ right) & 0x0000ffff;
        right ^= work;
        left ^= (work << 16);
        work = ((right >>> 2) ^ left) & 0x33333333;
        left ^= work;
        right ^= (work << 2);
        work = ((right >>> 8) ^ left) & 0x00ff00ff;
        left ^= work;
        right ^= (work << 8);
        right = ((right << 1) | ((right >>> 31) & 1)) & 0xffffffff;
        work = (left ^ right) & 0xaaaaaaaa;
        left ^= work;
        right ^= work;
        left = ((left << 1) | ((left >>> 31) & 1)) & 0xffffffff;

        for (int round = 0; round < 8; round++) {
            int fval;

            work = (right << 28) | (right >>> 4);
            work ^= wKey[round * 4 + 0];
            fval = SP7[work & 0x3f];
            fval |= SP5[(work >>> 8) & 0x3f];
            fval |= SP3[(work >>> 16) & 0x3f];
            fval |= SP1[(work >>> 24) & 0x3f];
            work = right ^ wKey[round * 4 + 1];
            fval |= SP8[work & 0x3f];
            fval |= SP6[(work >>> 8) & 0x3f];
            fval |= SP4[(work >>> 16) & 0x3f];
            fval |= SP2[(work >>> 24) & 0x3f];
            left ^= fval;
            work = (left << 28) | (left >>> 4);
            work ^= wKey[round * 4 + 2];
            fval = SP7[work & 0x3f];
            fval |= SP5[(work >>> 8) & 0x3f];
            fval |= SP3[(work >>> 16) & 0x3f];
            fval |= SP1[(work >>> 24) & 0x3f];
            work = left ^ wKey[round * 4 + 3];
            fval |= SP8[work & 0x3f];
            fval |= SP6[(work >>> 8) & 0x3f];
            fval |= SP4[(work >>> 16) & 0x3f];
            fval |= SP2[(work >>> 24) & 0x3f];
            right ^= fval;
        }

        right = (right << 31) | (right >>> 1);
        work = (left ^ right) & 0xaaaaaaaa;
        left ^= work;
        right ^= work;
        left = (left << 31) | (left >>> 1);
        work = ((left >>> 8) ^ right) & 0x00ff00ff;
        right ^= work;
        left ^= (work << 8);
        work = ((left >>> 2) ^ right) & 0x33333333;
        right ^= work;
        left ^= (work << 2);
        work = ((right >>> 16) ^ left) & 0x0000ffff;
        left ^= work;
        right ^= (work << 16);
        work = ((right >>> 4) ^ left) & 0x0f0f0f0f;
        left ^= work;
        right ^= (work << 4);

        out[outOff + 0] = (byte) ((right >>> 24) & 0xff);
        out[outOff + 1] = (byte) ((right >>> 16) & 0xff);
        out[outOff + 2] = (byte) ((right >>> 8) & 0xff);
        out[outOff + 3] = (byte) (right & 0xff);
        out[outOff + 4] = (byte) ((left >>> 24) & 0xff);
        out[outOff + 5] = (byte) ((left >>> 16) & 0xff);
        out[outOff + 6] = (byte) ((left >>> 8) & 0xff);
        out[outOff + 7] = (byte) (left & 0xff);
    }

    /**
     * generate an integer based working key based on our secret key and what we processing we are
     * planning to do.
     * <p>
     * Acknowledgements for this routine go to James Gillogly & Phil Karn. (whoever, and wherever
     * they are!).
     */
    protected static int[] generateWorkingKey(boolean encrypting, byte[] key, int off) {
        int[] newKey = new int[32];
        boolean[] pc1m = new boolean[56], pcr = new boolean[56];

        for (int j = 0; j < 56; j++) {
            int l = pc1[j];

            pc1m[j] = ((key[off + (l >>> 3)] & bytebit[l & 07]) != 0);
        }

        for (int i = 0; i < 16; i++) {
            int l;
            int m;
            int n;

            if (encrypting) {
                m = i << 1;
            } else {
                m = (15 - i) << 1;
            }

            n = m + 1;
            newKey[m] = newKey[n] = 0;

            for (int j = 0; j < 28; j++) {
                l = j + totrot[i];
                if (l < 28) {
                    pcr[j] = pc1m[l];
                } else {
                    pcr[j] = pc1m[l - 28];
                }
            }

            for (int j = 28; j < 56; j++) {
                l = j + totrot[i];
                if (l < 56) {
                    pcr[j] = pc1m[l];
                } else {
                    pcr[j] = pc1m[l - 28];
                }
            }

            for (int j = 0; j < 24; j++) {
                if (pcr[pc2[j]]) {
                    newKey[m] |= bigbyte[j];
                }

                if (pcr[pc2[j + 24]]) {
                    newKey[n] |= bigbyte[j];
                }
            }
        }

        //
        // store the processed key
        //
        for (int i = 0; i != 32; i += 2) {
            int i1;
            int i2;

            i1 = newKey[i];
            i2 = newKey[i + 1];

            newKey[i] = ((i1 & 0x00fc0000) << 6) | ((i1 & 0x00000fc0) << 10) | ((i2 & 0x00fc0000)
                    >>> 10) | ((i2 & 0x00000fc0) >>> 6);

            newKey[i + 1] =
                    ((i1 & 0x0003f000) << 12) | ((i1 & 0x0000003f) << 16) | ((i2 & 0x0003f000)
                            >>> 4) | (i2 & 0x0000003f);
        }

        return newKey;
    }
}