PHP对字符串的六种加密解密方法

方法一、

function encryptDecrypt($key, $string, $decrypt)
{
    if ($decrypt) {
        $decrypted = rtrim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, md5($key), base64_decode($string), MCRYPT_MODE_CBC, md5(md5($key))), "12");
        return $decrypted;
    } else {
        $encrypted = base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, md5($key), $string, MCRYPT_MODE_CBC, md5(md5($key))));
        return $encrypted;
    }
}

//加密:"z0JAx4qMwcF+db5TNbp/xwdUM84snRsXvvpXuaCa4Bk=" 
echo encryptDecrypt('password', 'Helloweba欢迎您', 0);
//解密:"Helloweba欢迎您" 
echo encryptDecrypt('password', 'z0JAx4qMwcF+db5TNbp/xwdUM84snRsXvvpXuaCa4Bk=', 1);

方法二、

//加密函数 
function lock_url($txt, $key = 'liiu')
{
    $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=+";
    $nh = rand(0, 64);
    $ch = $chars[$nh];
    $mdKey = md5($key . $ch);
    $mdKey = substr($mdKey, $nh % 8, $nh % 8 + 7);
    $txt = base64_encode($txt);
    $tmp = '';
    $i = 0;
    $j = 0;
    $k = 0;
    for ($i = 0; $i < strlen($txt); $i++) {
        $k = $k == strlen($mdKey) ? 0 : $k;
        $j = ($nh + strpos($chars, $txt[$i]) + ord($mdKey[$k++])) % 64;
        $tmp .= $chars[$j];
    }
    return urlencode($ch . $tmp);
}
//解密函数 

function unlock_url($txt, $key = 'liiu')
{
    $txt = urldecode($txt);
    $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=+";
    $ch = $txt[0];
    $nh = strpos($chars, $ch);
    $mdKey = md5($key . $ch);
    $mdKey = substr($mdKey, $nh % 8, $nh % 8 + 7);
    $txt = substr($txt, 1);
    $tmp = '';
    $i = 0;
    $j = 0;
    $k = 0;
    for ($i = 0; $i < strlen($txt); $i++) {
        $k = $k == strlen($mdKey) ? 0 : $k;
        $j = strpos($chars, $txt[$i]) - $nh - ord($mdKey[$k++]);
        while ($j < 0) $j += 64;
        $tmp .= $chars[$j];
    }
    return base64_decode($tmp);
}

方法三、改进后的算法

//加密函数 
function lock_url($txt, $key = 'str')
{
    $txt = $txt . $key;
    $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=+";
    $nh = rand(0, 64);
    $ch = $chars[$nh];
    $mdKey = md5($key . $ch);
    $mdKey = substr($mdKey, $nh % 8, $nh % 8 + 7);
    $txt = base64_encode($txt);
    $tmp = '';
    $i = 0;
    $j = 0;
    $k = 0;
    for ($i = 0; $i < strlen($txt); $i++) {
        $k = $k == strlen($mdKey) ? 0 : $k;
        $j = ($nh + strpos($chars, $txt[$i]) + ord($mdKey[$k++])) % 64;
        $tmp .= $chars[$j];
    }
    return urlencode(base64_encode($ch . $tmp));
}
//解密函数 
function unlock_url($txt, $key = 'str')
{
    $txt = base64_decode(urldecode($txt));
    $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=+";
    $ch = $txt[0];
    $nh = strpos($chars, $ch);
    $mdKey = md5($key . $ch);
    $mdKey = substr($mdKey, $nh % 8, $nh % 8 + 7);
    $txt = substr($txt, 1);
    $tmp = '';
    $i = 0;
    $j = 0;
    $k = 0;
    for ($i = 0; $i < strlen($txt); $i++) {
        $k = $k == strlen($mdKey) ? 0 : $k;
        $j = strpos($chars, $txt[$i]) - $nh - ord($mdKey[$k++]);
        while ($j < 0) $j += 64;
        $tmp .= $chars[$j];
    }
    return trim(base64_decode($tmp), $key);
}

方法四、

function passport_encrypt($txt, $key = 'liiu')
{
    srand((float)microtime() * 1000000);
    $encrypt_key = md5(rand(0, 32000));
    $ctr = 0;
    $tmp = '';
    for ($i = 0; $i < strlen($txt); $i++) {
        $ctr = $ctr == strlen($encrypt_key) ? 0 : $ctr;
        $tmp .= $encrypt_key[$ctr] . ($txt[$i] ^ $encrypt_key[$ctr++]);
    }
    return urlencode(base64_encode(passport_key($tmp, $key)));
}

function passport_decrypt($txt, $key = 'liiu')
{
    $txt = passport_key(base64_decode(urldecode($txt)), $key);
    $tmp = '';
    for ($i = 0; $i < strlen($txt); $i++) {
        $md5 = $txt[$i];
        $tmp .= $txt[++$i] ^ $md5;
    }
    return $tmp;
}

function passport_key($txt, $encrypt_key)
{
    $encrypt_key = md5($encrypt_key);
    $ctr = 0;
    $tmp = '';
    for ($i = 0; $i < strlen($txt); $i++) {
        $ctr = $ctr == strlen($encrypt_key) ? 0 : $ctr;
        $tmp .= $txt[$i] ^ $encrypt_key[$ctr++];
    }
    return $tmp;
}

$txt = "1";
$key = "testkey";
$encrypt = passport_encrypt($txt, $key);
$decrypt = passport_decrypt($encrypt, $key);

echo $encrypt . "<br>";
echo $decrypt . "<br>";

方法五、非常给力的authcode加密函数，Discuz!经典代码（带详解）

//函数authcode($string, $operation, $key, $expiry)中的$string：字符串，明文或密文；$operation：DECODE表示解密，其它表示加密；$key：密匙；$expiry：密文有效期。 
function authcode($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 = 'abcdef';
$key = 'www.helloweba.com';
echo authcode($str, 'ENCODE', $key, 0); //加密  
$str = '56f4yER1DI2WTzWMqsfPpS9hwyoJnFP2MpC8SOhRrxO7BOk';
echo authcode($str, 'DECODE', $key, 0); //解密  

方法六、

/**
 * $string：需要加解密的字符串；
 * $operation：E表示加密，D表示解密；
 * $key：自定义密匙
 */
function string($string, $operation, $key = '')
{
    $key = md5($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));
    }
}