AesGcm

AES-GCM authenticated encryption/decryption module

This module provides support for AES-256-GCM (Galois/Counter Mode) encryption, which provides both confidentiality and authenticity. Crystal's standard library doesn't expose GCM authentication tag methods, so this module uses direct bindings to OpenSSL's C library.

Example:

cipher = AesGcm::Cipher.new

# Encryption
encrypted = cipher.encrypt(
  key: "32_byte_key_here_____________",
  plaintext: "secret message"
)

# Decryption
decrypted = cipher.decrypt(encrypted, key: "32_byte_key_here_____________")