求一个PHP函数的Python版本

[simonw]

这是discuz 中的加密解密函数, 求完全等效的python实现版本.

function _authcode($string, $operation = 'DECODE', $key = '', $expiry = 0) {
	$ckey_length = 4;

	$key = md5($key ? $key : UC_KEY);
	$keya = md5(substr($key, 0, 16));
	$keyb = md5(substr($key, 16, 16));
	$keyc = $ckey_length ? ($operation == 'DECODE' ? substr($string, 0, $ckey_length): substr(md5(microtime()), -$ckey_length)) : '';

	$cryptkey = $keya.md5($keya.$keyc);
	$key_length = strlen($cryptkey);

	$string = $operation == 'DECODE' ? base64_decode(substr($string, $ckey_length)) : sprintf('%010d', $expiry ? $expiry + time() : 0).substr(md5($string.$keyb), 0, 16).$string;
	$string_length = strlen($string);

	$result = '';
	$box = range(0, 255);

	$rndkey = array();
	for($i = 0; $i <= 255; $i++) {
		$rndkey[$i] = ord($cryptkey[$i % $key_length]);
	}

	for($j = $i = 0; $i < 256; $i++) {
		$j = ($j + $box[$i] + $rndkey[$i]) % 256;
		$tmp = $box[$i];
		$box[$i] = $box[$j];
		$box[$j] = $tmp;
	}

	for($a = $j = $i = 0; $i < $string_length; $i++) {
		$a = ($a + 1) % 256;
		$j = ($j + $box[$a]) % 256;
		$tmp = $box[$a];
		$box[$a] = $box[$j];
		$box[$j] = $tmp;
		$result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256]));
	}

	if($operation == 'DECODE') {
		if((substr($result, 0, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result, 26).$keyb), 0, 16)) {
			return substr($result, 26);
		} else {
				return '';
			}
	} else {
		return $keyc.str_replace('=', '', base64_encode($result));
	}

}

[thy38]

代码写好了，但我的PHP不行，有几样东西我吃得不太准。请LZ多做测试：

1.php的microtime()是否等于Python的str(time.time())，即时间戳？
2.php的base64_decode是否等于Python的base64.decodestring()？
3.substr($result, 0, 10) == 0不知道是个什么意思？
4.substr($result, 0, 10) - time()是否是转化为数字相减？

其它没问题：

import hashlib.md5 as md5
import base64
import time

UC_KEY = '123456'

def _authcode(string, operation='DECODE', key='', expiry = 0):
    ckey_length = 4;

    key = md5(UC_KEY if key=='' else key).digest()
    keya = md5(key[:16]).digest()
    keyb = md5(key[16:32]).digest()

    if ckey_length == 0 :
        keyc = ''
    else:
        keyc = string[:ckey_length] if operation == 'DECODE'\
                else md5(str(time.time())).digest()[-ckey_length:]

    cryptkey = keya + md5(keya+keyc)
    key_length = len(cryptkey)

    strExpiry = '%010d' % (0 if expiry==0 else expiry + time.time())
    string = base64.decodestring(string[ckey_length:]) if operation == 'DECODE'\
                else strExpiry+md5(string+keyb)[:16]+string
    string_length = len(string)

    result = ''
    box = range(256)

    rndkey = []
    for i in range(256):
        rndkey.append(ord(cryptkey[i % key_length]))

    for i in range(256):
        j = (j + box[i] + rndkey[i]) % 256
        box[i],box[j] = box[j],box[i]

    for i in range(string_length):
        a = (a+1) % 256
        j = (j+box[a]) % 256
        box[a],box[j] = box[j],box[a]
        result += chr(ord(string[i]) ^ (box[(box[a] + box[j]) % 256]))

    if operation == 'DECODE':
        if  int(result[:10]) == 0 or\
            int(result[:10]) - time() > 0 and\
            result[10:26] == md5(result[26:]+keyb)[:16]:
            return result[26:]
        else: return ''
    else:
        return keyc.replace('=', '', base64.encodestring(result))

[thy38]

忘了说，环境是Python 2.6.4

[thy38]

Python中也有md5模块（当然现在推荐用hashlib），改写倒不难，但你的UC_KEY我怎么办呢？

[miaomiao83]

顶

[simonw]

帮改个, 多谢啊, UC_KEY就当个全局变量就行了

[simonw]

需要的是python 2.4-2.6的 不要3.x的