$ show antonioribeiro/google2fa
Google2FA is a standalone PHP library implementing the Time-based One-Time Password (TOTP) algorithm as specified in RFC 6238, fully compatible with Google Authenticator and similar authenticator apps. It provides secure secret key generation (base32-encoded), HMAC-based OTP computation with configurable algorithms (SHA1, SHA256, SHA512), and OTP verification with a sliding window to accommodate clock drift. The library also includes a helper for generating otpauth:// URLs for QR code integration. It has zero external runtime dependencies beyond a constant-time base32 encoder and is designed as a single-class library with traits for modularity. The codebase is well-tested across PHP 7.4 to 8.6 (beta), employs static analysis (PHPStan, Psalm), and follows a clean, maintainable architecture with clear exception hierarchies. It is not a framework but can be used in any PHP project.
The LLM identified 1 files worth highlighting for reuse:
A trait providing constant-time base32 encoding/decoding, secure random key generation, and validation logic (Google Authenticator compatibility, character set validation, minimum length checks). It leverages the Paragonie ConstantTime library for timing-safe operations and includes power-of-two length enforcement. This component is isolated (only depends on internal Constants and ParagonieBase32) and could be extracted for any project needing secure base32 handling, demonstrating strong cryptographic hygiene and defensive programming.