ios/docs/CRYPTO_GUIDELINES.md

Crypto Wallet Review Guidelines

Consumed by automated code review (CodeRabbit) and by human reviewers.

1. Secret material

Secret material = mnemonic phrases, BIP-39 seeds, private keys, extended private keys, signing keys, passphrases, PINs.

• MUST NOT appear in logs, analytics, crash reports, telemetry.
• MUST NOT be written to clipboard automatically or from background business logic.
• Clipboard copy is allowed only as an explicit user action from a sensitive-data screen, ideally with a confirmation step and routed through the app's centralized clipboard helper.
• MUST NOT be persisted in UserDefaults, plist, or plain files.
• Acceptable storage only: Keychain (SecItemAdd) with kSecAttrAccessibleWhenUnlockedThisDeviceOnly or stricter.

2. Randomness

Cryptographic randomness MUST use:

• SecRandomCopyBytes or CryptoKit.

arc4random, Int.random, and Double.random are prohibited in any code path deriving nonces, salts, IVs, or private keys.

3. iOS architecture (project conventions)

• Modal presentation through Coordinator.shared only. No direct .sheet / .fullScreenCover / UIKit present in SwiftUI views.
• Mutations of @Published from Task { ... } go through @MainActor methods.
• Push navigation via NavigationPath + navigationDestination(for:).
• .xcodeproj/project.pbxproj, .xcconfig, .entitlements, Info.plist — edited only through Xcode, not by hand.