README

AesBridge is a modern, secure, and cross-language AES encryption library. It offers a unified interface for encrypting and decrypting data across multiple programming languages. Supports GCM, CBC, and legacy AES Everywhere modes.

This is the PHP implementation of the core project.
👉 Main repository: https://github.com/mervick/aes-bridge

Features

• 🔐 AES-256 encryption in GCM (recommended) and CBC modes
• 🌍 Cross-Platform: Consistent behavior across different languages
• 📦 Compact binary format or base64 output
• ✅ HMAC Integrity: CBC mode includes HMAC verification
• 🔄 Backward Compatible: Supports legacy AES Everywhere format

Requirements

• PHP 7.4 or higher
• OpenSSL extension

Installation

composer require mervick/aes-bridge:"^2.0"

Basic Usage

use AesBridge\Gcm;
use AesBridge\Cbc;

// encrypt/decrypt using GCM mode (recommended)
$ciphertext = Gcm::encrypt("My secret message", "MyStrongPass")
$plaintext = Gcm::decrypt($ciphertext, "MyStrongPass")

// encrypt/decrypt using CBC mode
$ciphertext = Cbc::encrypt("My secret message", "MyStrongPass")
$plaintext = Cbc::decrypt($ciphertext, "MyStrongPass")

API Reference

GCM Mode (recommended)

• Gcm::encrypt(data, passphrase)
  Encrypts a string using AES-GCM. Returns: base64-encoded string.

• Gcm::decrypt(ciphertext, passphrase)
  Decrypts a base64-encoded string encrypted with Gcm::encrypt.

• Gcm::encryptBin(data, passphrase)
  Returns encrypted binary data using AES-GCM.

• Gcm::decryptBin(ciphertext, passphrase)
  Decrypts binary data encrypted with Gcm::encryptBin.

CBC Mode

• Cbc::encrypt(data, passphrase)
  Encrypts a string using AES-CBC. HMAC is used for integrity verification.
  Returns: base64-encoded string.

• Cbc::decrypt(ciphertext, passphrase)
  Decrypts a base64-encoded string encrypted with Cbc::encrypt and verifies HMAC.

• Cbc::encryptBin(data, passphrase)
  Returns encrypted binary data using AES-CBC with HMAC.

• Cbc::decryptBin(ciphertext, passphrase)
  Decrypts binary data encrypted with Cbc::encryptBin and verifies HMAC.

Legacy Compatibility

⚠️ These functions are kept for backward compatibility only. Their usage is strongly discouraged in new applications.

• Legacy::encrypt(data, passphrase)
  Encrypts a string in the legacy AES Everywhere format.

• Legacy::decrypt(ciphertext, passphrase)
  Decrypts a string encrypted in the legacy AES Everywhere format.

Error Handling

All methods throw exceptions for:

• Invalid input data
• Incorrect passwords
• Corrupted ciphertext
• HMAC verification failures (CBC mode)