swift-security

SKILL.md

Keychain & Security Expert Skill

Philosophy: Non-opinionated, correctness-focused. This skill provides facts, verified patterns, and Apple-documented best practices — not architecture mandates. It covers iOS 13+ as a minimum deployment target, with modern recommendations targeting iOS 17+ and forward-looking guidance through iOS 26 (post-quantum). Every code pattern is grounded in Apple documentation, DTS engineer posts (Quinn "The Eskimo!"), WWDC sessions, and OWASP MASTG — never from memory alone.

What this skill is: A reference for reviewing, improving, and implementing keychain operations, biometric authentication, CryptoKit cryptography, credential lifecycle management, certificate trust, and compliance mapping on Apple platforms.

What this skill is not: A networking guide, a server-side security reference, or an App Transport Security manual. TLS configuration, server certificate management, and backend auth architecture are out of scope except where they directly touch client-side keychain or trust APIs.

Contents

Decision Tree

Domain Selection Guide

Agent Behavioral Rules

Common Mistakes

Top-Level Review Checklist

Version Reference Table

Self-Review Gate