记录下几种php加密算法

<?php

/**
 * rc4,解密方法直接再一次加密就是解密
 * @param  [type] $data 要加密的数据
 * @param  [type] $pwd  加密使用的 key
 * @return [type]       [description]
 */
function rc4($data, $pwd) {
    $key[] = "";
    $box[] = "";
    $pwd_length = strlen($pwd);
    $data_length = strlen($data);
    $cipher = '';
    for ($i = 0; $i < 256; $i++) {
        $key[$i] = ord($pwd[$i % $pwd_length]);
        $box[$i] = $i;
    }
    for ($j = $i = 0; $i < 256; $i++) {
        $j = ($j + $box[$i] + $key[$i]) % 256;
        $tmp = $box[$i];
        $box[$i] = $box[$j];
        $box[$j] = $tmp;
    }
    for ($a = $j = $i = 0; $i < $data_length; $i++) {
        $a = ($a + 1) % 256;
        $j = ($j + $box[$a]) % 256;
        $tmp = $box[$a];
        $box[$a] = $box[$j];
        $box[$j] = $tmp;
        $k = $box[(($box[$a] + $box[$j]) % 256)];
        $cipher .= chr(ord($data[$i]) ^ $k);
    }
    return $cipher;
}

$msgkey = 'blog.kieng.cn';
$enstr = base64_encode(rc4('blog.kieng.cn', $msgkey));
echo "RC4 加密:";
echo "<br>";
echo $enstr;
echo "<br>";
$destr = rc4(base64_decode($enstr), $msgkey);
echo $destr;
echo "<hr>";

/**
 * @FunctionName   authcode
 * @param          [string]                   $string    [加(解)密文本]
 * @param          string                   $operation [加/解密]
 * @param          string                   $key       [密匙]
 * @param          int                  $expiry    [密匙有效期]
 * @return         [type]                              [加密后的文本]
 */
function authcode($string, $operation = 'DECODE', $key = '', $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));
    }
}

$str = 'blog.kieng.cn';
$key = '123465';
$authcode = authcode($str, 'ENCODE', $key, 0); //加密
echo "authcode 加密:";
echo "<br>";
echo $authcode;
echo "<br>";
echo authcode($authcode, 'DECODE', $key); //解密
echo "<hr>";

/**
 * @FunctionName   自定义加密
 * @Author         KIENG
 * @CompletionDate 2019-08-16T14:19:33+0800
 * @Copyright      [blog.kieng.cn]
 * @License        [BY-NC-SA/4.0/CN]
 * @param          string                   $tex  [等待加密的文本]
 * @param          string                   $key  [密匙]
 * @param          string                   $type [解密/加密]
 * @return         string                         [description]
 */
function encode_pass($tex, $key = '123456', $type = "encode") {
    $chrArr = array('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
        'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
        '0', '1', '2', '3', '4', '5', '6', '7', '8', '9');
    if ($type == "decode") {
        if (strlen($tex) < 14) {
            return false;
        }

        $verity_str = substr($tex, 0, 8);
        $tex = substr($tex, 8);
        if ($verity_str != substr(md5($tex), 0, 8)) {
            //完整性验证失败
            return false;
        }
    }
    $key_b = $type == "decode" ? substr($tex, 0, 6) : $chrArr[rand() % 62] . $chrArr[rand() % 62] . $chrArr[rand() % 62] . $chrArr[rand() % 62] . $chrArr[rand() % 62] . $chrArr[rand() % 62];
    $rand_key = $key_b . $key;
    $rand_key = md5($rand_key);
    $tex = $type == "decode" ? base64_decode(substr($tex, 6)) : $tex;
    $texlen = strlen($tex);
    $reslutstr = "";
    for ($i = 0; $i < $texlen; $i++) {
        $reslutstr .= $tex{$i} ^ $rand_key{$i % 32};
    }
    if ($type != "decode") {
        $reslutstr = trim($key_b . base64_encode($reslutstr), "==");
        $reslutstr = substr(md5($reslutstr), 0, 8) . $reslutstr;
    }
    return $reslutstr;
}

$str = 'blog.kieng.cn';
$key = '123465';
$enpass = encode_pass($str, $key); //加密
echo "自定义加密:";
echo "<br>";
echo $enpass;
echo "<br>";
echo encode_pass($enpass, $key, 'decode'); //解密
echo "<hr>";

/*************自定义加密二***************/

/**
 * @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;
}
$str = 'blog.kieng.cn';
$key = '123465';
$encode = encrypt($str);
echo "自定义加密二:";
echo "<br>";
echo $encode;
echo "<br>";
$decode = decrypt($encode);
echo $decode; // 加密字符串
echo "<hr>";

/*************自定义加密 4****************/

/**
 * @param $string    要加密/解密的字符串
 * @param $operation    类型，E 加密；D 解密
 * @param string $key   密钥
 * @return mixed|string
 */
function encrypts($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));
    }
}

$str = 'blog.kieng.cn';
$key = '123465';
$encode = encrypts($str, 'E');
echo "自定义加密三:";
echo "<br>";
echo $encode;
echo "<br>";
$decode = encrypts($encode, 'D');
echo $decode; // 加密字符串
echo "<hr>";