I have an API that requires me to encode data that I send to it through an AES-cipher.
However, the only example code I have been given is Node.js code.
I thought, how hard can it be to reimplement it in PHP as well ?
Pretty hard apparently.
Below you can see both approaches, yet you can also see different results.
Anyone an idea what might be going wrong ?
var crypto = require('crypto');
var algorithm = 'aes-128-ctr';
function encrypt(text, password) {
const key = Buffer.from(password, "hex").slice(0, 16);
const ivBuffer = Buffer.alloc(16);
const cipher = crypto.createCipheriv(algorithm, key, ivBuffer);
let crypted = cipher.update(text, "utf8", 'hex');
crypted += cipher.final('hex');
console.log(crypted);
}
encrypt('test','ed8f68b144f94c30b8add43276f0fa14');
RESULT : 3522ca23
function encrypt($text, $password) {
$iv = "0000000000000000";
$encrypted = openssl_encrypt($text, 'aes-128-ctr', $password, OPENSSL_RAW_DATA, $iv);
return bin2hex($encrypted);
}
echo encrypt('test', 'ed8f68b144f94c30b8add43276f0fa14');
RESULT: 8faa39d2
While browsing the related section (after my post) I came across this one: C# and PHP have different AES encryption results
As mentioned by t-m-adam above as well, apparently I need to align the iv and password in both examples. In PHP my iv and password were 'regular' strings, where they should have been binary strings of the same length as the cipher’s block size. My iv should (in my case) be 16 zero bytes instead of 16x the 0 character. You can see the difference by doing an echo of the code below:
$iv = "00000000000000000000000000000000";
echo $iv;
echo strlen($iv);
$iv = pack("H*", "00000000000000000000000000000000");
echo $iv;
echo strlen($iv);
Both $iv variables are of length 16 (as requested by AES) , yet the second version is composed of 0-bytes, effectively unprintable.
Without further ado, the end result, working in PHP:
function encrypt($text, $password) {
$iv = pack("H*", "00000000000000000000000000000000");
$password = pack("H*", $password);
$encrypted = openssl_encrypt($text, 'aes-128-ctr', $inputKey, OPENSSL_RAW_DATA, $iv);
return bin2hex($encrypted);
}
echo encrypt('test', 'ed8f68b144f94c30b8add43276f0fa14');
RESULT: 3522ca23
Success !!