PHP初記｜xxtea類

PHP小記｜xxtea類

xxtea可逆密碼編譯演算法PHP實現：

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Class Xxtea {public function encrypt($s, $key) {return base64_encode(self :: xxtea_encrypt($s, $key));}public function decrypt($e, $key) {return self :: xxtea_decrypt(base64_decode($e), $key);}private function long2str($v, $w) {$len = count($v);$n = ($len -1) << 2;if ($w) {$m = $v[$len -1];if (($m < $n -3) || ($m > $n))return false;$n = $m;}$s = array ();for ($i = 0; $i < $len; $i++) {$s[$i] = pack("V", $v[$i]);}if ($w) {return substr(join('', $s), 0, $n);} else {return join('', $s);}}private function str2long($s, $w) {$v = unpack("V*", $s . str_repeat("\0", (4 - strlen($s) % 4) & 3));$v = array_values($v);if ($w) {$v[count($v)] = strlen($s);}return $v;}private function int32($n) {while ($n >= 2147483648)$n -= 4294967296;while ($n <= -2147483649)$n += 4294967296;return (int) $n;}private function xxtea_encrypt($str, $key) {if ($str == "") {return "";}$v = self :: str2long($str, true);$k = self :: str2long($key, false);if (count($k) < 4) {for ($i = count($k); $i < 4; $i++) {$k[$i] = 0;}}$n = count($v) - 1;$z = $v[$n];$y = $v[0];$delta = 0x9E3779B9;$q = floor(6 + 52 / ($n +1));$sum = 0;while (0 < $q--) {$sum = self :: int32($sum + $delta);$e = $sum >> 2 & 3;for ($p = 0; $p < $n; $p++) {$y = $v[$p +1];$mx = self :: int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4)) ^ self :: int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));$z = $v[$p] = self :: int32($v[$p] + $mx);}$y = $v[0];$mx = self :: int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4)) ^ self :: int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));$z = $v[$n] = self :: int32($v[$n] + $mx);}return self :: long2str($v, false);}private function xxtea_decrypt($str, $key) {if ($str == "") {return "";}$v = self :: str2long($str, false);$k = self :: str2long($key, false);if (count($k) < 4) {for ($i = count($k); $i < 4; $i++) {$k[$i] = 0;}}$n = count($v) - 1;$z = $v[$n];$y = $v[0];$delta = 0x9E3779B9;$q = floor(6 + 52 / ($n +1));$sum = self :: int32($q * $delta);while ($sum != 0) {$e = $sum >> 2 & 3;for ($p = $n; $p > 0; $p--) {$z = $v[$p -1];$mx = self :: int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4)) ^ self :: int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));$y = $v[$p] = self :: int32($v[$p] - $mx);}$z = $v[$n];$mx = self :: int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4)) ^ self :: int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));$y = $v[0] = self :: int32($v[0] - $mx);$sum = self :: int32($sum - $delta);}return self :: long2str($v, true);}}

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使用方法：

加密：

Xxtea::encrypt(明文字串, 密鑰字串);

解密：

Xxtea::decrypt(密文字串, 密鑰字串);

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