/*
 * Copyright 1999-2012 Alibaba Group.
 *  
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.cobar.mysql;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * 加密解密工具类
 * 
 * @author xianmao.hexm 2010-4-14 下午03:22:05
 */
public class SecurityUtil {

    public static final byte[] scramble411(byte[] pass, byte[] seed) throws NoSuchAlgorithmException {
        MessageDigest md = MessageDigest.getInstance("SHA-1");
        byte[] pass1 = md.digest(pass);
        md.reset();
        byte[] pass2 = md.digest(pass1);
        md.reset();
        md.update(seed);
        byte[] pass3 = md.digest(pass2);
        for (int i = 0; i < pass3.length; i++) {
            pass3[i] = (byte) (pass3[i] ^ pass1[i]);
        }
        return pass3;
    }

    public static final String scramble323(String pass, String seed) {
        if ((pass == null) || (pass.length() == 0)) {
            return pass;
        }
        byte b;
        double d;
        long[] pw = hash(seed);
        long[] msg = hash(pass);
        long max = 0x3fffffffL;
        long seed1 = (pw[0] ^ msg[0]) % max;
        long seed2 = (pw[1] ^ msg[1]) % max;
        char[] chars = new char[seed.length()];
        for (int i = 0; i < seed.length(); i++) {
            seed1 = ((seed1 * 3) + seed2) % max;
            seed2 = (seed1 + seed2 + 33) % max;
            d = (double) seed1 / (double) max;
            b = (byte) java.lang.Math.floor((d * 31) + 64);
            chars[i] = (char) b;
        }
        seed1 = ((seed1 * 3) + seed2) % max;
        seed2 = (seed1 + seed2 + 33) % max;
        d = (double) seed1 / (double) max;
        b = (byte) java.lang.Math.floor(d * 31);
        for (int i = 0; i < seed.length(); i++) {
            chars[i] ^= (char) b;
        }
        return new String(chars);
    }

    private static long[] hash(String src) {
        long nr = 1345345333L;
        long add = 7;
        long nr2 = 0x12345671L;
        long tmp;
        for (int i = 0; i < src.length(); ++i) {
            switch (src.charAt(i)) {
            case ' ':
            case '\t':
                continue;
            default:
                tmp = (0xff & src.charAt(i));
                nr ^= ((((nr & 63) + add) * tmp) + (nr << 8));
                nr2 += ((nr2 << 8) ^ nr);
                add += tmp;
            }
        }
        long[] result = new long[2];
        result[0] = nr & 0x7fffffffL;
        result[1] = nr2 & 0x7fffffffL;
        return result;
    }

}