加密 - 解密AES PHP

Question

I would like to encrypt and decrypt somes data with AES CCM!

I managed to do this operation in the same php file. But I would like to be able to send the encrypted data to another page to decrypt it with. But impossible ... Yet I send the iv, the tag and the encrypted data. Do you have a solution?

I have these errors:

Warning: openssl_decrypt(): Setting tag for AEAD cipher decryption failed in adddata1.php on line 18

Fatal error: Uncaught Exception: OpenSSL error: error:0607A082:digital envelope routines:EVP_CIPHER_CTX_set_key_length:invalid key length in adddata1.php:21 Stack trace: #0 {main} thrown in dddata1.php on line 21

First file :

$algo  = 'aes-128-ccm';
$iv    = random_bytes(openssl_cipher_iv_length($algo));
$key   = "cd9344040aa9f9217871d46ee871c59c"; 
$data = '00000000010-3b57af';
$ciphertext = openssl_encrypt(
    $data,
    $algo,
    $key,
    OPENSSL_RAW_DATA,
    $iv,
    $tag
);

echo'<a href="adddata1?data='.$ciphertext.'&tag='.$tag.'&iv='.$iv.'">"decrypte"</a>';
?>

Second file :

$algo  = 'aes-128-ccm';
$key   = "cd9344040aa9f9217871d46ee871c59c"; 

$ciphertext = $_GET['data'];
$iv = $_GET['iv'];
$tag = $_GET['tag'];
// Change 1 bit in additional authenticated data
// $i = rand(0, mb_strlen($aad, '8bit') - 1);
// $aad[$i] = $aad[$i] ^ chr(1);
$decrypt = openssl_decrypt(
    $ciphertext,
    $algo,
    $key,
    OPENSSL_RAW_DATA,
    $iv,
    $tag
);
if (false === $decrypt) {
    throw new Exception(sprintf(
        "OpenSSL error: %s", openssl_error_string()
    ));
}


printf ("Decryption %s\n", $data === $decrypt ? 'Ok' : 'Failed');
printf("<br/>");
printf(base64_encode($tag));
printf("<br/>");
printf(base64_encode($iv));
printf("<br/>");
printf(base64_encode($ciphertext));
printf("<br/>");
printf($data);
?>

In one file :

<?php

$algo  = 'aes-128-ccm';
$iv    = random_bytes(openssl_cipher_iv_length($algo));
$key   = "cd9344040aa9f9217871d46ee871c59c"; 
$data = '00000000010-3b57af';
$ciphertext = openssl_encrypt(
    $data,
    $algo,
    $key,
    OPENSSL_RAW_DATA,
    $iv,
    $tag
);

// Change 1 bit in additional authenticated data
// $i = rand(0, mb_strlen($aad, '8bit') - 1);
// $aad[$i] = $aad[$i] ^ chr(1);
$decrypt = openssl_decrypt(
    $ciphertext,
    $algo,
    $key,
    OPENSSL_RAW_DATA,
    $iv,
    $tag
);
if (false === $decrypt) {
    throw new Exception(sprintf(
        "OpenSSL error: %s", openssl_error_string()
    ));
}


printf ("Decryption %s\n", $data === $decrypt ? 'Ok' : 'Failed');
printf("<br/>");
printf(base64_encode($tag));
printf("<br/>");
printf(base64_encode($iv));
printf("<br/>");
printf(base64_encode($ciphertext));
printf("<br/>");
printf($data);
?>

Thanks

Answer 1

The issue is likely the iv. You are generating random bytes and adding them as a request parameter in a URL, where string encodings matter. Convert the bytes to characters which are valid in a URL. bin2hex is one simple method:

echo '<a href="adddata1?data='.$ciphertext.'&iv='.bin2hex($iv)...

And on the receiving end convert it back:

$iv = hex2bin($_GET['iv']);