使用加密数据php后mcrypt_decrypt错误输出

Question

I have a small problem with php mcrypt_decrypt function. Firstly, I use a 16-byte string, and encrypt it using mcrypt_encrypt ; then, I use base64_encode , and put the output to mcrypt_decrypt , in order to get the initial string.

But the output is not what's expected. I checked that my base64 decoded string input for decoding is the exact output produced by mcrypt_decrypt . Here is my code:

//encrypt
$str="KKQT9W4st7vmdkps";
$key="43625A8C1E4330BDF84DDEE3DD105037";
$block = mcrypt_get_block_size('rijndael_128', 'ecb');
$passcrypt=mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $str, MCRYPT_MODE_ECB);
echo $passcrypt;

That outputs PTfZ6Ephh8LTxXL4In33Og== . The decryption script is the following:

//decrypt
$str='PTfZ6Ephh8LTxXL4In33Og==';
$key='43625A8C1E4330BDF84DDEE3DD105037';
$str = base64_decode($str);
$str = rtrim(mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key,
    $str, MCRYPT_MODE_ECB,''),"\0");
$block = mcrypt_get_block_size('rijndael_128', 'ecb');
echo $str;  

And the output is not KKQT9W4st7vmdkps , but -nγ kk7Ζn'T instead. Any ideas? I'm using XAMPP and Apache server.

Answer 1

谢谢反馈，这是我犯的一个愚蠢的错误……实际上，解密函数中的'PTfZ6Ephh8LTxXL4In33Og =='是错误的，因为最后“ I”为“ l” ...所以解密是不正确的。 。但这也不是我的错，因为我是从QR CODE扫描仪获取此字符串并且“ I”和“ l”显示相同的...

Answer 2

For encryption, you need to:

1) Create an encryption resource

$str = "KKQT9W4st7vmdkps";
$key = "43625A8C1E4330BDF84DDEE3DD105037";
$r = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '',MCRYPT_MODE_ECB, '');

2) Randomly create encryption vector based on the size of $r

$iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($r),MCRYPT_RAND);

3) Initiliazing module using the resource,key and string vector

mcrypt_generic_init($r,$key,$iv);

4) Encrypt data/string using resource $r

$encrypted = mcrypt_generic($r,$str);

5) Encode it using base64_encode

  $encoded = base64_encode($encrypted);
        if(!mcrypt_generic_deinit($r) || !mcrypt_module_close($r))
            $encoded = false;

6) Echoing it

echo 'Encrypted: '.$encoded;

For decryption, it's like a reverse process of encrypt

        //Using the same enrypted string       
        $decoded = (string) base64_decode(trim($encoded));
        $td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '',MCRYPT_MODE_ECB, '');
        $ivs = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        mcrypt_generic_init($td,$key, $ivs);

        $decoded = (string) trim(mdecrypt_generic($td, $decoded));

        if(!mcrypt_generic_deinit($td) || !mcrypt_module_close($td))
            $decoded = false;

Echoing it

echo 'Decrypted: '. $decoded;

Hope this helps. More info here .