MEncoderDecoder

Overview

MEncoderDecoder is a PHP class that provides simple methods for encrypting and decrypting strings. It relies on PHP's OpenSSL extension to provide secure encryption features, both symmetric and asymmetric.

Features

• Symmetric encryption with AES-256-CBC
• Asymmetric encryption with RSA key pairs
• Simplified management of encryption/decryption operations
• Secure initialization vector (IV) generation
• Custom exception handling for errors

Prerequisites

• OpenSSL extension enabled
• For asymmetric encryption: valid RSA key pairs

Make sure the OpenSSL extension is installed and enabled in your PHP configuration. You can check this with the following command:

php -m | grep openssl

If the extension is not enabled, modify your php.ini file to uncomment or add the line:

extension=openssl

Usage

Symmetric Encryption (AES-256-CBC)

Symmetric encryption uses the same key for both encryption and decryption.

use mlib\utils\crypto\MEncoderDecoder;
use mlib\utils\crypto\MEncoderDecoderException;

try {
    // Create an instance with a secret key
    $key = 'MyVeryLongAndSecureSecretKey123!';
    $encoder = new MEncoderDecoder($key);

    // Encrypt a message
    $message = 'This is a confidential message';
    $encrypted = $encoder->encode($message);
    echo "Encrypted message: " . $encrypted . "\n";

    // Decrypt the message
    $decrypted = $encoder->decode($encrypted);
    echo "Decrypted message: " . $decrypted . "\n";

} catch (MEncoderDecoderException $e) {
    echo "Encryption error: " . $e->getMessage() . "\n";
}

Asymmetric Encryption (RSA)

Asymmetric encryption uses a key pair: a public key for encryption and a private key for decryption.

Key Generation

First generate a key pair with OpenSSL:

# Generate a private key
openssl genrsa -out private_key.pem 2048

# Extract the public key
openssl rsa -in private_key.pem -pubout -out public_key.pem

Usage with MEncoderDecoder

use mlib\utils\crypto\MEncoderDecoder;
use mlib\utils\crypto\MEncoderDecoderException;

try {
    // Read keys from files
    $publicKey = file_get_contents('path/to/public_key.pem');
    $privateKey = file_get_contents('path/to/private_key.pem');

    // Create an instance for encryption (with public key)
    $encoder = new MEncoderDecoder($publicKey, false);

    // Encrypt a message (with public key)
    $message = 'This is a confidential message';
    $encrypted = $encoder->encode($message);
    echo "Encrypted message: " . base64_encode($encrypted) . "\n";

    // Create an instance for decryption (with private key)
    $decoder = new MEncoderDecoder(null, false, $privateKey);

    // Decrypt the message (with private key)
    $decrypted = $decoder->decode($encrypted);
    echo "Decrypted message: " . $decrypted . "\n";

} catch (MEncoderDecoderException $e) {
    echo "Encryption error: " . $e->getMessage() . "\n";
}

Method Reference

__construct($key = null, $symetricEncoding = true, $privateKey = null)

Constructor of the MEncoderDecoder class.

• $key: Key for symmetric encryption or public key for asymmetric encryption
• $symetricEncoding: true for symmetric encryption (default), false for asymmetric encryption
• $privateKey: Private key for asymmetric decryption

Throws an MEncoderDecoderException if OpenSSL extension is not available or if parameters are invalid.

encode($string)

Encrypts a string.

• $string: The string to encrypt
• Returns: The encrypted string

Throws an MEncoderDecoderException in case of encryption error.

decode($string)

Decrypts a previously encrypted string.

• $string: The string to decrypt
• Returns: The decrypted string

Throws an MEncoderDecoderException in case of decryption error or if private key is missing for asymmetric decryption.

Error Handling

All errors are signaled by throwing exceptions of type MEncoderDecoderException which extends PHP's standard \Exception class. You can catch these exceptions to handle errors appropriately.

try {
    $encoder = new MEncoderDecoder('my_key');
    $encrypted = $encoder->encode('message');
    // ...
} catch (\mlib\utils\crypto\MEncoderDecoderException $e) {
    // Log the error
    error_log('Encryption error: ' . $e->getMessage());

    // Display a generic message to the user
    echo 'An error occurred. Please try again later.';
}