CODEWITHSUNDEEP
phpopensslphp-5.6php-opensslphp-7.2
Jonatas Rodrigues
Jonatas Rodrigues

Reputation: 67

PHP Warning: openssl_decrypt(): IV passed is 32 bytes long which is longer than the 16 expected by selected cipher

I need to implement openSSL in my application, because we had to change the version from 5.6 to version 7.2

I would like to understand how to solve this problem.

Any doubts that arise about my environment, or how I am using the application, just ask that I will respond.

<?php

$dados = '#########################################################';

$key = '################################';
$iv = '################################';

/**
 * running in version 7.2
 */
$data = openssl_decrypt($dados, 'AES-128-CBC', $key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $iv);
/**
 * Erro:
 * $ clear && ./php descriptografa-senha.php
 *
 * PHP Warning:  openssl_decrypt(): IV passed is 32 bytes long which is longer than the 16 expected by selected cipher, truncating in ./descriptografa-senha.php on line 12
 * PHP Stack trace:
 * PHP   1. {main}() ./descriptografa-senha.php:0
 * PHP   2. openssl_decrypt() ./descriptografa-senha.php:12
 *
 * Warning: openssl_decrypt(): IV passed is 32 bytes long which is longer than the 16 expected by selected cipher, truncating in ./descriptografa-senha.php on line 12
 *
 * Call Stack:
 *     0.4121     125736   1. {main}() ./descriptografa-senha.php:0
 *     0.4121     126312   2. openssl_decrypt() ./descriptografa-senha.php:12
 */

/**
 * running in version 5.6
 */
$mcrypt_cipher = MCRYPT_RIJNDAEL_256;
$mcrypt_mode = MCRYPT_MODE_CBC;
$encrypted = $dados;

$iv_utf = mb_convert_encoding($iv, 'UTF-8');
$decrypted = mcrypt_decrypt($mcrypt_cipher, $key, base64_decode($encrypted), $mcrypt_mode, $iv_utf);

print_r($decrypted);
/**
 * performed normally
 */

This was the code that generated the encryption, see if you can understand something and help me in the problem, the language to use to encrypt is C # and the language to decrypt and PHP 7.2

public static string Cryptography(string text, string pass = "#############################")
{
    if (string.IsNullOrEmpty(pass))
        return string.Empty;

    var rijndaelmanaged = new RijndaelManaged();
    rijndaelmanaged.KeySize = 256;
    rijndaelmanaged.BlockSize = 256;
    rijndaelmanaged.Padding = PaddingMode.PKCS7;
    rijndaelmanaged.Key = Convert.FromBase64String(Base64Encode(pass));

    rijndaelmanaged.IV = Convert.FromBase64String(Base64Encode(vetorInicializacao));

    var encrypt = rijndaelmanaged.CreateEncryptor(rijndaelmanaged.Key, rijndaelmanaged.IV);
    byte[] xBuff = null;
    using (var ms = new MemoryStream())
    {
        using (var cs = new CryptoStream(ms, encrypt, CryptoStreamMode.Write))
        {
            byte[] xXml = Encoding.UTF8.GetBytes(text);
            cs.Write(xXml, 0, xXml.Length);
        }

        xBuff = ms.ToArray();
    }

    String out = Convert.ToBase64String(xBuff);
    return out;
}

Upvotes: 4

Views: 20640

Answers (2)

Jonatas Rodrigues
Jonatas Rodrigues

Reputation: 67

The solution to this is to use the phpseclib/mcrypt_compat library

composer require phpseclib/mcrypt_compat

Upvotes: -1

Alex Howansky
Alex Howansky

Reputation: 53626

From the manual:

$iv is as in the case of $password, a String of bytes.

It looks like you have $iv encoded as a hexadecimal string:

$iv = '################################';

You probably just need to convert it to a binary byte string:

$iv = hex2bin('################################');

Ditto for $key.

Upvotes: 5

Related Questions