Encrypt in PHP and decrypt in JS - AES256

Question

The function will receive a file uploaded, and will encrypt this one to save in the server, i'm think about using openssl_encrypt.

The encryption type will be AES256.

After when a web-service is requested will return a base 64 encrypted document to be decrypted in the JS side using the crypto-js.

For know, my question is how can i do the encryption process using openssl_encrypt php function?

Encrypt process:

1. fopen
2. encrypt
3. encode base64
4. fwrite
5. fclose

Decrypt process:

1. Decode base 64
2. Decrypt
3. Open the pdf document

The processes above, is the idea i have in mind, please correct me if i'm wrong or there is a mistake.

Phase 1:

PHP Code:

After handling the file:

$encryptionMethod = "AES-256-CBC";
$secret = "1234567890@@@@@@@@@@123456789012";  //must be 32 char length
$iv = substr($secret, 0, 16);
$encryptedMessage = openssl_encrypt($textToEncrypt, $encryptionMethod, $secret,0,$iv);

On jquery to decrypt doesn't work:

var ckey = "1234567890@@@@@@@@@@123456789012";
var decrypted = CryptoJS.AES.decrypt(data.content, ckey, { iv: "1234567890@@@@@@" });  

The pdf is generated again but i'm not able to open, shows an error message "Acrobat cannot open the file"..

Why am i getting this?

Answer 1

Encrypt/Decrypt working!

PHP SIDE TO ENCRYPT

$encryptionMethod = "AES-256-CBC";
$secret = "1234567890@@@@@@@@@@123456789012";  //must be 32 char length
$iv = substr($secret, 0, 16);
$encryptedMessage = openssl_encrypt($textToEncrypt, $encryptionMethod, $secret,0,$iv);`

CRYPTOJS TO DECRYPT

var cipherParams = CryptoJS.lib.CipherParams.create({ciphertext: CryptoJS.enc.Hex.parse(data.toString())});
var decrypted = CryptoJS.AES.decrypt(cipherParams, CryptoJS.enc.Hex.parse(key), { iv: CryptoJS.enc.Hex.parse(iv) });
window.open("data:application/pdf;base64, " + btoa(decrypted.toString(CryptoJS.enc.Utf8)));