B4J Question AES Encryption/Decryption

[ThRuST]

Hi! I'm looking for a solution to use AES algorithm in my project and decided to post a question about it.
As this concerns B4J I posted it here, but if it's compatible with B4X it would be great.

I found this page as a reference, you'll find it here

Best regards,
Roger

 

[jahswant]

Did you see this ?

[B4x] AES-256 encryption with salt and iv (works with all platforms like php, .net, etc.)

This example is based on agrahams encryption library: Encryption Lib 1. Generate a 32 byte pw (just call the sub) and store it 2. Encrypt the data by calling AES_Encrypt. Return is a byte array or a base64 encoded string 3. Salt is a random value which is added at the beginning of the encrypted...

www.b4x.com

 

[ThRuST]

@jahswant I've never seen that before, I'll check it out more closely. Thanks

Here's a solution for PHP by @QtechLab

<?PHP

$data = "JlTf/Y6JTO6dXUbYrEcCuQ==";
$key = "Salted_key_is_here";
$test = decrypt256($data, $key);

echo "Result: " . $test;


function encrypt256($data, $key)
{
    $method = 'aes-256-cbc';
    
    // Must be exact 32 chars (256 bit). Salt32 make a robust hash around the entered key
    $password = $key; //salt32($key);
    
    // IV must be exact 16 chars (128 bit) Example with zeros
    $iv = chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0);
    //
    $encrypted = base64_encode(openssl_encrypt($data, $method, $password, OPENSSL_RAW_DATA, $iv));
    
    return $encrypted;
}

function decrypt256($dataEncrypted, $key)
{
    $method = 'aes-256-cbc';
    
    // Must be exact 32 chars (256 bit). Salt32 make a robust hash around the entered key
    $password = $key; //salt32($key);
    
    // IV must be exact 16 chars (128 bit)  Example with zeros
    $iv = chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0);
    //
    $decrypted = openssl_decrypt(base64_decode($dataEncrypted), $method, $password, OPENSSL_RAW_DATA, $iv);
 
    return $decrypted;
}

?>

 

[ThRuST]

I found that there's jB4XEncryption library buildt into the IDE. It would be nice to use that since it's compatible with all B4X tools. Anyone?
The post is from 2014 but it's still in the IDE.

Here's the thread

 

[Erel]

What is the question? B4XEncryption is an excellent option.

 

[ThRuST]

@Erel I am evaluating a cross platform encryption/decryption solution for my project.
Then I noticed B4XEncryption library in the IDE. Does that handle AES for all B4X IDE's? I want to encrypt/decrypt a file and save it back.

 

[Erel]

Does that handle AES for all B4X IDE's?

Yes.

 

[ThRuST]

@Erel Should we use the example from this >post<, or is there an updated version? Perhaps it's been documented in the Libraries section.
It depends on something called BouncyCastle

 

[Erel]

Everything you need is in that post. Note that it was updated on 2021.

 

[ThRuST]

@Erel I downloaded the file BouncyCastle and noticed it already was part of B4J v9.50 which I currently use. I'll investigate this more deeply.
B4XEncryption seems the way to go. Thanks