求个 转 python 的算法，原 java tea 加密算法

[copyangle]

java算法如下，可独立运行。怎奈小弟才疏学浅，有一段转换byte数组没看懂，哪位大侠能帮忙写个python版本，感激不尽～

package com.bmcc.service.pub.util;


/** 
* Tea算法
* KEY为16字节,应为包含4个int型数的int[]，一个int为4个字节
* 加密解密轮数应为8的倍数，推荐加密轮数为64轮
**/
public class Tea {
    private int[] KEY = new int[] { //加密解密所用的KEY
        1, 2, 3, 4 };
    private String separatoradd = "0"; //加密字符串分隔符"+"

    private String separatordel = "1"; //加密字符串分隔符"-"
    //加密
    private byte[] encrypt(
        byte[] content,
        int offset,
        int[] key,
        int times) { //times为加密轮数
        int[] tempInt = byteToInt(content, offset);
        int y = tempInt[0], z = tempInt[1], sum = 0, i;
        int delta = 0x9e3779b9; //这是算法标准给的值
        int a = key[0], b = key[1], c = key[2], d = key[3];

        for (i = 0; i < times; i++) {
            sum += delta;
            y += ((z << 4) + a) ^ (z + sum) ^ ((z >> 5) + b);
            z += ((y << 4) + c) ^ (y + sum) ^ ((y >> 5) + d);
        }
        tempInt[0] = y;
        tempInt[1] = z;
        return intToByte(tempInt, 0);
    }
    //解密
    private byte[] decrypt(
        byte[] encryptContent,
        int offset,
        int[] key,
        int times) {
        int[] tempInt = byteToInt(encryptContent, offset);
        int y = tempInt[0], z = tempInt[1], sum = 0xC6EF3720, i;
        int delta = 0x9e3779b9; //这是算法标准给的值
        int a = key[0], b = key[1], c = key[2], d = key[3];

        for (i = 0; i < times; i++) {
            z -= ((y << 4) + c) ^ (y + sum) ^ ((y >> 5) + d);
            y -= ((z << 4) + a) ^ (z + sum) ^ ((z >> 5) + b);
            sum -= delta;
        }
        tempInt[0] = y;
        tempInt[1] = z;

        return intToByte(tempInt, 0);
    }
    //byte[]型数据转成int[]型数据
    private int[] byteToInt(byte[] content, int offset) {

        int[] result = new int[content.length >> 2];
        for (int i = 0, j = offset; j < content.length; i++, j += 4) {
            result[i] =
                transform(content[j + 3]) | transform(content[j + 2])
                    << 8 | transform(content[j + 1])
                    << 16 | (int) content[j]
                    << 24;
        }
        return result;

    }
    //int[]型数据转成byte[]型数据
    private byte[] intToByte(int[] content, int offset) {
        byte[] result = new byte[content.length << 2];
        for (int i = 0, j = offset; j < result.length; i++, j += 4) {
            result[j + 3] = (byte) (content[i] & 0xff);
            result[j + 2] = (byte) ((content[i] >> 8) & 0xff);
            result[j + 1] = (byte) ((content[i] >> 16) & 0xff);
            result[j] = (byte) ((content[i] >> 24) & 0xff);
        }
        return result;
    }
    //若某字节被解释成负的则需将其转成无符号正数
    private int transform(byte temp) {
        int tempInt = (int) temp;
        if (tempInt < 0) {
            tempInt += 256;
        }
        return tempInt;
    }
    //  通过TEA算法加密信息
    public String encryptByTea(String info) {
        byte[] temp = info.getBytes();
        int n = 8 - temp.length % 8; //若temp的位数不足8的倍数,需要填充的位数
        byte[] encryptStr = new byte[temp.length + n];
        encryptStr[0] = (byte) n;
        System.arraycopy(temp, 0, encryptStr, n, temp.length);
        byte[] result = new byte[encryptStr.length];
        for (int offset = 0; offset < result.length; offset += 8) {
            byte[] tempEncrpt = encrypt(encryptStr, offset, KEY, 32);
            System.arraycopy(tempEncrpt, 0, result, offset, 8);
        }
        String tmp = encryptTwo(result);
        //      for (int i = 0; i < result.length; i++) {
        //          tmp = tmp + result[i] + this.separator;
        //      }
        return tmp;
    }

    private String encryptTwo(byte[] source) {
        String all = "";
        for (int i = 0; i < source.length; i++) {
            String tmp = this.separatoradd;
            int s = source[i];
            if (s < 0) {
                s = ~s + 1;
                tmp = this.separatordel;
            }
            String res = Integer.toHexString(s);
            if (res.length() == 1)
                res = "0" + res;
            all = all + res + tmp;
        }
        return all;
    }

    public byte[] decryptTwo(String res) {
        int k = 0;
        byte[] result = new byte[res.length() / 3];
        for (int i = 0, j = 3; i < res.length(); i = i + 3, j = i + 3) {
            String tmp = res.substring(i, j);
            if (this.separatoradd.charAt(0) == tmp.charAt(2))
                result[k++] = Byte.parseByte(tmp.substring(0, 2),16);
            else if (this.separatordel.charAt(0) == tmp.charAt(2))
                result[k++] = Byte.parseByte("-" + tmp.substring(0, 2),16);
        }
        return result;
    }
    //    通过TEA算法解密信息
    public String decryptByTea(String info) {
        byte[] secretInfo = this.decryptTwo(info);
        byte[] decryptStr = null;
        byte[] tempDecrypt = new byte[secretInfo.length];
        for (int offset = 0; offset < secretInfo.length; offset += 8) {
            decryptStr = decrypt(secretInfo, offset, KEY, 32);
            System.arraycopy(decryptStr, 0, tempDecrypt, offset, 8);
        }
        int n = tempDecrypt[0];
        return new String(tempDecrypt, n, decryptStr.length - n);

    }

    public static void main(String[] args) {
        Tea tea = new Tea();
        String src ="abcd1234";
        String tmp = tea.encryptByTea(src);
        String result = tea.decryptByTea("2700304515a02c16411f06e14f17b14e16401c01c0591390");
        System.out.print("原数据：");
        System.out.println(src);
        System.out.print("加密后的数据：");
        System.out.println(tmp);
        System.out.print("解密后的数据：");
        System.out.println(result);
    }
}

[copyangle]

主要是这一段不明白，求解

// 通过TEA算法加密信息
public String encryptByTea(String info) {
byte[] temp = info.getBytes();
int n = 8 - temp.length % 8; //若temp的位数不足8的倍数,需要填充的位数
byte[] encryptStr = new byte[temp.length + n];
encryptStr[0] = (byte) n;
System.arraycopy(temp, 0, encryptStr, n, temp.length);
byte[] result = new byte[encryptStr.length];
for (int offset = 0; offset < result.length; offset += 8) {
byte[] tempEncrpt = encrypt(encryptStr, offset, KEY, 32);
System.arraycopy(tempEncrpt, 0, result, offset, 8);
}
String tmp = encryptTwo(result);
// for (int i = 0; i < result.length; i++) {
// tmp = tmp + result[i] + this.separator;
// }
return tmp;
}

[zhantss]

for循环前的转换？
获取输入字符的byte数组
获取填充位数n(<8)
新的byte数组第一个位置 放填充数n（<8所以byte足够表示）
然后从第n（填充位）开始放原有temp的内容（长度正好）

for开始就是加密的过程了

[copyangle]

@zhantss python里面怎么把string转换成byte数组？

[zhantss]

@copyangle 有点复杂 建议你看一下资料

python 是动态类型 一般情况下type(target) 可以看target的类型
python2 中用encode之后type()还是得到str类型 （你可以试一下help(bytes)出来的还是str）

python3 中这样写就好了

s = 'test'
bs = bytes(s, encoding='[你的字符串编码类型/文件标注编码类型]')
或者bs = s.encode('[你的字符串编码类型/文件标注编码类型]')
这时候type(bs)得到的是bytes类型

python2 中用第二种写法就好了, 第一种一般需要判断一下,但是你看到的类型还是str,有点难理解就是了,用还是可以用,稍稍有些不同

[copyangle]

@zhantss 多谢，看来还是我基础不牢靠

[zhantss]

@copyangle 相互学习啦 python我一般经常拿来干一些日常的事情 还没写过大型的python项目呢