cryptotokenkitlisted

# CryptoTokenKit Use CryptoTokenKit for token driver extensions, smart-card communication, token sessions, token-backed keychain integration, and certificate-based authentication in Swift 6.3 apps. **Platform availability:** CryptoTokenKit classes are available across Apple platforms, but capability depends on extension point, entitlement, hardware, and OS version. The smart-card app extension flow for login/keychain unlock is macOS. `TKSmartCardSlotManager.default` is optional and returns `nil` unless smart-card access is enabled. iOS/iPadOS 26+ add NFC smart-card slots and registration. ## Contents - [Architecture Overview](#architecture-overview) - [Token Extensions](#token-extensions) - [Token Sessions](#token-sessions) - [Smart Card Communication](#smart-card-communication) - [Keychain Integration](#keychain-integration) - [Certificate Authentication](#certificate-authentication) - [Token Watching](#token-watching) - [Error Handling](#error-handling) - [Common Mistakes](#common-mistakes) - [Review Checklist](#review-checklist) - [References](#references) ## Architecture Overview CryptoTokenKit bridges hardware security tokens (smart cards, USB tokens) with authentication and keychain services. The framework has three main usage modes: **Smart-card token extensions** -- macOS app extensions that make a hardware token's cryptographic items available to system login and keychain unlock. The driver handles token lifecycle, session management, and cryptographic operati