XXTea算法Java版

第一个版本：

public class XXTEA {
   private XXTEA() {}


   /** * Encrypt data with key. * * @param data * @param key * @return */
   public static byte[] encrypt(byte[] data, byte[] key) {
       if (data.length == 0) {
           return data;
       }
       return toByteArray(
               encrypt(toIntArray(data, false), toIntArray(key, false)), false);
   }

   /** * Decrypt data with key. * * @param data * @param key * @return */
   public static byte[] decrypt(byte[] data, byte[] key) {
       if (data.length == 0) {
           return data;
       }
       return toByteArray(
               decrypt(toIntArray(data, false), toIntArray(key, false)), false);
   }

   /** * Encrypt data with key. * * @param v * @param k * @return */
   public static int[] encrypt(int[] v, int[] k) {
       int n = v.length;

       int y;
       int p;
       int rounds = 6 + 52/n;
       int sum = 0;
       int z = v[n-1];
       int delta = 0x9E3779B9;
       do {
           sum += delta;
           int e = (sum >>> 2) & 3;
           for (p=0; p<n-1; p++) {
             y = v[p+1]; 
             z = v[p] += (z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (k[p & 3 ^ e] ^ z);
           }
           y = v[0];
           z = v[n-1] += (z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (k[p & 3 ^ e] ^ z);
         } while (--rounds > 0);

       return v;
   }

   /** * Decrypt data with key. * * @param v * @param k * @return */
   public static int[] decrypt(int[] v, int[] k) {
       int n = v.length;
       int z = v[n - 1], y = v[0], delta = 0x9E3779B9, sum, e;
       int p;
       int rounds = 6 + 52/n;
       sum = rounds*delta;
       y = v[0];
       do {
         e = (sum >>> 2) & 3;
         for (p=n-1; p>0; p--) {
           z = v[p-1];
           y = v[p] -= (z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (k[p & 3 ^ e] ^ z);
         }
         z = v[n-1];
         y = v[0] -= (z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (k[p & 3 ^ e] ^ z);
       } while ((sum -= delta) != 0);
       return v;
   }

   /** * Convert byte array to int array. * * @param data * @param includeLength * @return */
   private static int[] toIntArray(byte[] data, boolean includeLength) {
       int n = (((data.length & 3) == 0)
               ? (data.length >>> 2)
               : ((data.length >>> 2) + 1));
       int[] result;

       if (includeLength) {
           result = new int[n + 1];
           result[n] = data.length;
       } else {
           result = new int[n];
       }
       n = data.length;
       for (int i = 0; i < n; i++) {
           result[i >>> 2] |= (0x000000ff & data[i]) << ((i & 3) << 3);
       }
       return result;
   }

   /** * Convert int array to byte array. * * @param data * @param includeLength * @return */
   private static byte[] toByteArray(int[] data, boolean includeLength) {
       int n = data.length << 2;

       ;
       if (includeLength) {
           int m = data[data.length - 1];

           if (m > n) {
               return null;
           } else {
               n = m;
           }
       }
       byte[] result = new byte[n];

       for (int i = 0; i < n; i++) {
           result[i] = (byte) ((data[i >>> 2] >>> ((i & 3) << 3)) & 0xff);
       }
       return result;
   }
}

其中key为数组，如下：

public final static int[] KEY = new int[]{//加密解密所用的KEY
            0x789f5645, 0xf68bd5a4,
            0x81963ffa, 0x458fac58
    };

第二个版本：

package com.cardvalue.sys.widget;

import java.nio.charset.Charset;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.ArrayList;
import java.util.List;

import android.util.Base64;

/* * XXTEA 加密算法 */
public class XXTEA {
    public static String Encrypt(String data, String key) {
        return ToHexString(TEAEncrypt(
                ToLongArray(PadRight(data, MIN_LENGTH).getBytes(
                        Charset.forName("UTF8"))),
                        ToLongArray(PadRight(key, MIN_LENGTH).getBytes(
                                Charset.forName("UTF8")))));
    }

    public static String Decrypt(String data, String key) {
        if (data == null || data.length() < MIN_LENGTH) {
            return data;
        }
        byte[] code = ToByteArray(TEADecrypt(
                ToLongArray(data),
                ToLongArray(PadRight(key, MIN_LENGTH).getBytes(
                        Charset.forName("UTF8")))));
        return new String(code, Charset.forName("UTF8"));
    }

    private static long[] TEAEncrypt(long[] data, long[] key) {
        int n = data.length;
        if (n < 1) {
            return data;
        }

        long z = data[data.length - 1], y = data[0], sum = 0, e, p, q;
        q = 6 + 52 / n;
        while (q-- > 0) {
            sum += DELTA;
            e = (sum >> 2) & 3;
            for (p = 0; p < n - 1; p++) {
                y = data[(int) (p + 1)];
                z = data[(int) p] += (z >> 5 ^ y << 2) + (y >> 3 ^ z << 4)
                        ^ (sum ^ y) + (key[(int) (p & 3 ^ e)] ^ z);
            }
            y = data[0];
            z = data[n - 1] += (z >> 5 ^ y << 2) + (y >> 3 ^ z << 4)
                    ^ (sum ^ y) + (key[(int) (p & 3 ^ e)] ^ z);
        }

        return data;
    }

    private static long[] TEADecrypt(long[] data, long[] key) {
        int n = data.length;
        if (n < 1) {
            return data;
        }

        long z = data[data.length - 1], y = data[0], sum = 0, e, p, q;
        q = 6 + 52 / n;
        sum = q * DELTA;
        while (sum != 0) {
            e = (sum >> 2) & 3;
            for (p = n - 1; p > 0; p--) {
                z = data[(int) (p - 1)];
                y = data[(int) p] -= (z >> 5 ^ y << 2) + (y >> 3 ^ z << 4)
                        ^ (sum ^ y) + (key[(int) (p & 3 ^ e)] ^ z);
            }
            z = data[n - 1];
            y = data[0] -= (z >> 5 ^ y << 2) + (y >> 3 ^ z << 4) ^ (sum ^ y)
                    + (key[(int) (p & 3 ^ e)] ^ z);
            sum -= DELTA;
        }

        return data;
    }

    private static long[] ToLongArray(byte[] data) {
        int n = (data.length % 8 == 0 ? 0 : 1) + data.length / 8;
        long[] result = new long[n];

        for (int i = 0; i < n - 1; i++) {
            result[i] = bytes2long(data, i * 8);
        }

        byte[] buffer = new byte[8];
        for (int i = 0, j = (n - 1) * 8; j < data.length; i++, j++) {
            buffer[i] = data[j];
        }
        result[n - 1] = bytes2long(buffer, 0);

        return result;
    }

    private static byte[] ToByteArray(long[] data) {
        List<Byte> result = new ArrayList<Byte>();

        for (int i = 0; i < data.length; i++) {
            byte[] bs = long2bytes(data[i]);
            for (int j = 0; j < 8; j++) {
                result.add(bs[j]);
            }
        }

        while (result.get(result.size() - 1) == SPECIAL_CHAR) {
            result.remove(result.size() - 1);
        }

        byte[] ret = new byte[result.size()];
        for (int i = 0; i < ret.length; i++) {
            ret[i] = result.get(i);
        }
        return ret;
    }

    public static byte[] long2bytes(long num) {
        ByteBuffer buffer = ByteBuffer.allocate(8).order(
                ByteOrder.LITTLE_ENDIAN);
        buffer.putLong(num);
        return buffer.array();
    }

    public static long bytes2long(byte[] b, int index) {
        ByteBuffer buffer = ByteBuffer.allocate(8).order(
                ByteOrder.LITTLE_ENDIAN);
        buffer.put(b, index, 8);
        return buffer.getLong(0);
    }

    private static String ToHexString(long[] data) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < data.length; i++) {
            sb.append(PadLeft(Long.toHexString(data[i]), 16));
        }
        return sb.toString();
    }




    private static long[] ToLongArray(String data) {
        int len = data.length() / 16;
        long[] result = new long[len];
        for (int i = 0; i < len; i++) {
            result[i] = new BigInteger(data.substring(i * 16, i * 16 + 16), 16)
            .longValue();
        }
        return result;
    }

    private static String PadRight(String source, int length) {
        while (source.length() < length) {
            source += SPECIAL_CHAR;
        }
        return source;
    }

    private static String PadLeft(String source, int length) {
        while (source.length() < length) {
            source = '0' + source;
        }
        return source;
    }

    private static long DELTA = 0x9E3779B9;
    private static int MIN_LENGTH = 32;
    private static char SPECIAL_CHAR = '\0';
}

其中key为字符串，如下：

public final static String KEY = "lizhixian";