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This article introduces three commonly used encryption and decryption algorithms in PHP. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.
Method one:
/** * @param $string 要加密/解密的字符串 * @param string $operation 类型,ENCODE 加密;DECODE 解密 * @param string $key 密匙 * @param int $expiry 有效期 * @return string */ function authcode($string, $operation = 'DECODE', $key = 'encrypt', $expiry = 0) { // 动态密匙长度,相同的明文会生成不同密文就是依靠动态密匙 $ckey_length = 4; // 密匙 $key = md5($key ? $key : $GLOBALS['discuz_auth_key']); // 密匙a会参与加解密 $keya = md5(substr($key, 0, 16)); // 密匙b会用来做数据完整性验证 $keyb = md5(substr($key, 16, 16)); // 密匙c用于变化生成的密文 $keyc = $ckey_length ? ($operation == 'DECODE' ? substr($string, 0, $ckey_length) : substr(md5(microtime()), -$ckey_length)) : ''; // 参与运算的密匙 $cryptkey = $keya . md5($keya . $keyc); $key_length = strlen($cryptkey); // 明文,前10位用来保存时间戳,解密时验证数据有效性,10到26位用来保存$keyb(密匙b), //解密时会通过这个密匙验证数据完整性 // 如果是解码的话,会从第$ckey_length位开始,因为密文前$ckey_length位保存 动态密匙,以保证解密正确 $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); $rndkey = array(); // 产生密匙簿 for ($i = 0; $i <= 255; $i++) { $rndkey[$i] = ord($cryptkey[$i % $key_length]); } // 用固定的算法,打乱密匙簿,增加随机性,好像很复杂,实际上对并不会增加密文的强度 for ($j = $i = 0; $i < 256; $i++) { $j = ($j + $box[$i] + $rndkey[$i]) % 256; $tmp = $box[$i]; $box[$i] = $box[$j]; $box[$j] = $tmp; } // 核心加解密部分 for ($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; // 从密匙簿得出密匙进行异或,再转成字符 $result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256])); } if ($operation == 'DECODE') { // 验证数据有效性,请看未加密明文的格式 if ((substr($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 { // 把动态密匙保存在密文里,这也是为什么同样的明文,生产不同密文后能解密的原因 // 因为加密后的密文可能是一些特殊字符,复制过程可能会丢失,所以用base64编码 return $keyc . str_replace('=', '', base64_encode($result)); } }
Use:
$string = '加密字符串'; // 加密 $encode = authcode($string, 'ENCODE'); echo $encode . '</br>'; // a2f4bSYyUrTum1nAAA9X9BrC4Z3DZazcSa4eLcvDoCnmYc1LTdvtqS4aCds // 解密 $decode = authcode($encode, 'DECODE'); echo $decode; // 加密字符串
Method two:
/** * @param $string 要加密/解密的字符串 * @param $operation 类型,E 加密;D 解密 * @param string $key 密钥 * @return mixed|string */ function encrypt($string, $operation, $key = 'encrypt') { $key = md5($key); $key_length = strlen($key); $string = $operation == 'D' ? base64_decode($string) : substr(md5($string . $key), 0, 8) . $string; $string_length = strlen($string); $rndkey = $box = array(); $result = ''; for ($i = 0; $i <= 255; $i++) { $rndkey[$i] = ord($key[$i % $key_length]); $box[$i] = $i; } for ($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 ($operation == 'D') { if (substr($result, 0, 8) == substr(md5(substr($result, 8) . $key), 0, 8)) { return substr($result, 8); } else { return ''; } } else { return str_replace('=', '', base64_encode($result)); } }
Usage:
$string = '加密字符串'; // 加密 $encode = encrypt($string, 'E'); echo $encode . '</br>'; // 0Jzym5UzkRKH726U7Pyt7ixzLz9YEEA // 解密 $decode = encrypt($encode, 'D'); echo $decode; // 加密字符串
Method 3:
/** * @param $data 要加密的字符串 * @param $key 密钥 * @return string */ function encrypt($data, $key = 'encrypt') { $key = md5($key); $x = 0; $len = strlen($data); $l = strlen($key); $char = ''; for ($i = 0; $i < $len; $i++) { if ($x == $l) { $x = 0; } $char .= $key{$x}; $x++; } $str = ''; for ($i = 0; $i < $len; $i++) { $str .= chr(ord($data{$i}) + (ord($char{$i})) % 256); } return base64_encode($str); } /** * @param $data 要解密的字符串 * @param $key 密钥 * @return string */ function decrypt($data, $key = 'encrypt') { $key = md5($key); $x = 0; $data = base64_decode($data); $len = strlen($data); $l = strlen($key); $char = ''; for ($i = 0; $i < $len; $i++) { if ($x == $l) { $x = 0; } $char .= substr($key, $x, 1); $x++; } $str = ''; for ($i = 0; $i < $len; $i++) { if (ord(substr($data, $i, 1)) < ord(substr($char, $i, 1))) { $str .= chr((ord(substr($data, $i, 1)) + 256) - ord(substr($char, $i, 1))); } else { $str .= chr(ord(substr($data, $i, 1)) - ord(substr($char, $i, 1))); } } return $str; }
Use:
$string = '加密字符串'; // 加密 $encode = encrypt($string); echo $encode . '</br>'; // Gr0DHeHrRw7KGBLcSOzj // 解密 $decode = decrypt($encode); echo $decode; // 加密字符串
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