Crypt

Lithe provides a security module called Crypt that offers methods for encrypting and decrypting data using the AES-256-CBC algorithm. AES (Advanced Encryption Standard) is widely recognized for its security and efficiency in protecting sensitive data.

Installation

To install the lithemod/crypt package, run:

composer require lithemod/crypt

The source code for the Crypt module is available at github.com/lithemod/crypt.

Configuration

To use the Crypt encryption module in Lithe, you must first set the APP_KEY environment variable in your .env file. The value of this variable should be a cryptographically secure key. You can generate this key using the command php line key:generate, which will create a secure key for your application. The APP_KEY variable is essential for encryption and should be set during Lithe installation or configured manually.

Warning: Changing the encryption key (APP_KEY) invalidates all previous encryptions. Data encrypted with one key cannot be decrypted if the key is changed.

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Using Crypt

The Crypt module in Lithe provides methods for encrypting and decrypting data. Both methods use the AES-256-CBC encryption algorithm.

Encrypting a Value

To encrypt data, use the encrypt method from the Crypt module. The encrypted value is returned in base64 format.

use Lithe\Support\Security\Crypt;

$app->post('/account/create', function ($req, $res) {
    // Encrypting the 'name' field from the request body
    $encryptedName = Crypt::encrypt($req->input('name'));

    // ...

    // Returning the response
    return $res->send("Data encrypted successfully!");
});

Decrypting a Value

To decrypt data, use the decrypt method from the Crypt module. The decrypted value is returned as a string.

use Lithe\Support\Security\Crypt;

$decrypted = Crypt::decrypt($encryptedValue);

Possible Returns:

1. Successful Decryption: If decryption is successful, the decrypt method returns the decrypted data as a string.
2. Decryption Failure: If decryption fails, the method will throw a CryptException. This may occur due to an incorrect key, invalid IV, corrupted data, or other encryption-related issues.

To handle decryption failures, wrap the call to the decrypt method in a try-catch block to capture and handle exceptions.

use Lithe\Support\Security\Crypt;
use Lithe\Exceptions\Encryption\CryptException;

try {
    $decrypted = Crypt::decrypt($encryptedValue);
} catch (CryptException $e) {
    // Handle the exception here
    echo 'Error decrypting data: ' . $e->getMessage();
}

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Additional Notes

• Key Validation: Ensure that the APP_KEY variable is a valid base64 string with 32 bytes after decoding.
• Key Maintenance: Keep the APP_KEY secure and avoid frequent changes to ensure that encrypted data can be correctly decrypted.