本文實例講述了php源碼分析之DZX1.5加密解密函數authcode用法。分享給大家供大家參考。具體分析如下：
?
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 <?php $authkey = ''; /** * @param string $string: 輸入的需要加密（或解密）的明文（或密文） * @param string $operation: 'DECODE'或其它，其中默認表示解密，輸入其它表示加密 * @param string $key: 加解密密鑰 * @param int $expiry: 有效期 */ function authcode($string, $operation = 'DECODE', $key = '', $expiry = 0) { global $authkey; $ckey_length = 4; $key = md5($key != '' ? $key : $authkey); $keya = md5(substr($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)); } } $str = '1234'; $key = '1234'; echo "明文:".$str; echo "<br />"; echo "密鑰:".$key; $encode = authcode($str,'11',$key); echo "<br />"; echo "加密後的密文:".$encode; echo "<br />"; $decode = authcode($encode,'DECODE',$key); echo "解密後的明文:".$decode; /*End of php*/運行結果如下：
明文:1234
密鑰:1234
加密後的密文:a52f67eXZGVy0HtQBo4vOREhq3WxnL6E2zlx75JGfoJW
解密後的明文:1234
希望本文所述對大家的php程序設計有所幫助。
