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Keychain & Security Expert Skill

Keychain与安全专家技能

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.

理念： 无主观倾向、聚焦正确性。本技能提供事实、经验证的模式以及Apple官方文档推荐的最佳实践——而非架构强制要求。最低适配iOS 13+，同时针对iOS 17+提供现代化建议，并包含面向iOS 26（后量子时代）的前瞻性指导。所有代码模式均基于Apple官方文档、DTS工程师帖子（Quinn "The Eskimo!"）、WWDC会议内容以及OWASP MASTG——绝非仅凭记忆生成。

本技能涵盖： 用于在Apple平台上审查、改进和实现Keychain操作、生物识别认证、CryptoKit加密、凭证生命周期管理、证书信任以及合规映射的参考指南。

本技能不涵盖： 网络指南、服务端安全参考或App Transport Security手册。TLS配置、服务端证书管理以及后端认证架构均不在范围内，除非它们直接涉及客户端Keychain或信任API。

Decision Tree

决策树

Determine the user's intent, then follow the matching branch. If ambiguous, ask.

                        ┌─────────────────────┐
                        │  What is the task?   │
                        └─────────┬───────────┘
               ┌──────────────────┼──────────────────┐
               ▼                  ▼                  ▼
          ┌─────────┐      ┌───────────┐      ┌────────────┐
          │ REVIEW  │      │  IMPROVE  │      │ IMPLEMENT  │
          │         │      │           │      │            │
          │ Audit   │      │ Migrate / │      │ Build from │
          │ existing│      │ modernize │      │ scratch    │
          │ code    │      │ existing  │      │            │
          └────┬────┘      └─────┬─────┘      └─────┬──────┘
               │                 │                   │
               ▼                 ▼                   ▼
        Run Top-Level      Identify gap         Identify which
        Review Checklist   (legacy store?        domain(s) apply,
        (§ below) against  wrong API?            load reference
        the code.          missing auth?)        file(s), follow
        Flag each item     Load migration +      ✅ patterns.
        as ✅ / ❌ /       domain-specific        Implement with
        ⚠️ N/A.           reference files.       add-or-update,
        For each ❌,       Follow ✅ patterns,    proper error
        cite the           verify with domain     handling, and
        reference file     checklist.             correct access
        and specific                              control from
        section.                                  the start.

确定用户意图，然后遵循匹配的分支。若意图模糊，需询问用户。

                        ┌─────────────────────┐
                        │  What is the task?   │
                        └─────────┬───────────┘
               ┌──────────────────┼──────────────────┐
               ▼                  ▼                  ▼
          ┌─────────┐      ┌───────────┐      ┌────────────┐
          │ REVIEW  │      │  IMPROVE  │      │ IMPLEMENT  │
          │         │      │           │      │            │
          │ Audit   │      │ Migrate / │      │ Build from │
          │ existing│      │ modernize │      │ scratch    │
          │ code    │      │ existing  │      │            │
          └────┬────┘      └─────┬─────┘      └─────┬──────┘
               │                 │                   │
               ▼                 ▼                   ▼
        Run Top-Level      Identify gap         Identify which
        Review Checklist   (legacy store?        domain(s) apply,
        (§ below) against  wrong API?            load reference
        the code.          missing auth?)        file(s), follow
        Flag each item     Load migration +      ✅ patterns.
        as ✅ / ❌ /       domain-specific        Implement with
        ⚠️ N/A.           reference files.       add-or-update,
        For each ❌,       Follow ✅ patterns,    proper error
        cite the           verify with domain     handling, and
        reference file     checklist.             correct access
        and specific                              control from
        section.                                  the start.

Branch 1 — REVIEW (Audit Existing Code)

分支1 — REVIEW（审计现有代码）

Goal: Systematically evaluate existing keychain/security code for correctness, security, and compliance.

Procedure:

Run the Top-Level Review Checklist (below) against the code under review. Score each item ✅ / ❌ / ⚠️ N/A.
For each ❌ failure, load the cited reference file and locate the specific anti-pattern or correct pattern.
Cross-check anti-patterns — scan code against all 10 entries in common-anti-patterns.md. Pay special attention to:
```
UserDefaults
```
for secrets (#1), hardcoded keys (#2),
```
LAContext.evaluatePolicy()
```
as sole auth gate (#3), ignored
```
OSStatus
```
(#4).
Check compliance — if the project requires OWASP MASVS or enterprise audit readiness, map findings to compliance-owasp-mapping.md categories M1, M3, M9, M10.
Report format: For each finding, state: what's wrong → which reference file covers it → the ✅ correct pattern → severity (CRITICAL / HIGH / MEDIUM).

Key reference files for review:

Start with: common-anti-patterns.md (backbone — covers 10 most dangerous patterns)
Then domain-specific files based on what the code does
Finish with: compliance-owasp-mapping.md (if compliance is relevant)

目标： 系统性评估现有Keychain/安全代码的正确性、安全性和合规性。

流程：

运行顶层审查清单（如下）对被审查代码进行检查。为每个项目标记✅ / ❌ / ⚠️ N/A。
针对每个❌项，加载对应的参考文件并定位具体的反模式或正确模式。
交叉检查反模式——扫描代码，对照common-anti-patterns.md中的全部10项内容。特别注意：使用
```
UserDefaults
```
存储密钥（第1项）、硬编码密钥（第2项）、仅用
```
LAContext.evaluatePolicy()
```
作为认证 gate（第3项）、忽略
```
OSStatus
```
（第4项）。
检查合规性——若项目要求符合OWASP MASVS或企业审计就绪标准，将检查结果映射到compliance-owasp-mapping.md的M1、M3、M9、M10类别。
报告格式： 针对每个检查结果，说明：问题所在 → 对应的参考文件 → ✅正确模式 → 严重程度（CRITICAL / HIGH / MEDIUM）。

审查用核心参考文件：

首先：common-anti-patterns.md（核心文件——涵盖10种最危险的模式）
然后根据代码功能加载特定领域的文件
最后：compliance-owasp-mapping.md（若涉及合规性）

Branch 2 — IMPROVE (Migrate / Modernize)

分支2 — IMPROVE（迁移/现代化）

Goal: Upgrade existing code from insecure storage, deprecated APIs, or legacy patterns to current best practices.

Procedure:

Identify the migration type:
- Insecure storage → Keychain: Load migration-legacy-stores.md + credential-storage-patterns.md
- Legacy Security framework → CryptoKit: Load cryptokit-symmetric.md or cryptokit-public-key.md + migration-legacy-stores.md
- RSA → Elliptic Curve: Load cryptokit-public-key.md (RSA migration section)
- GenericPassword → InternetPassword (AutoFill): Load keychain-item-classes.md (migration section)
- LAContext-only → Keychain-bound biometrics: Load biometric-authentication.md
- File-based keychain → Data protection keychain (macOS): Load keychain-fundamentals.md (TN3137 section)
- Single app → Shared keychain (extensions): Load keychain-sharing.md
- Leaf pinning → SPKI/CA pinning: Load certificate-trust.md
Follow the migration pattern in the relevant reference file. Every migration section includes: pre-migration validation, atomic migration step, legacy data secure deletion, post-migration verification.
Run the domain-specific checklist from the reference file after migration completes.
Verify no regressions using guidance from testing-security-code.md.

目标： 将现有代码从不安全存储、废弃API或旧模式升级到当前最佳实践。

流程：

确定迁移类型：
- 不安全存储 → Keychain：加载migration-legacy-stores.md + credential-storage-patterns.md
- 旧版Security框架 → CryptoKit：加载cryptokit-symmetric.md或cryptokit-public-key.md + migration-legacy-stores.md
- RSA → 椭圆曲线：加载cryptokit-public-key.md（RSA迁移章节）
- GenericPassword → InternetPassword（AutoFill）：加载keychain-item-classes.md（迁移章节）
- 仅LAContext → 绑定Keychain的生物识别：加载biometric-authentication.md
- 基于文件的Keychain → 数据保护Keychain（macOS）：加载keychain-fundamentals.md（TN3137章节）
- 单应用 → 共享Keychain（扩展）：加载keychain-sharing.md
- 叶子证书固定 → SPKI/CA证书固定：加载certificate-trust.md
遵循相关参考文件中的迁移模式。每个迁移章节均包含：迁移前验证、原子迁移步骤、旧数据安全删除、迁移后验证。
迁移完成后运行特定领域的检查清单（来自参考文件）。
使用testing-security-code.md中的指南验证无回归问题。

Branch 3 — IMPLEMENT (Build from Scratch)

分支3 — IMPLEMENT（从零构建）

Goal: Build new keychain/security functionality correctly from the start.

Procedure:

Identify which domain(s) the task touches. Use the Domain Selection Guide below.
Load the relevant reference file(s). Follow ✅ code patterns — never deviate from them for the core security logic.
Apply Core Guidelines (below) to every implementation.
Run the domain-specific checklist before considering the implementation complete.
Add tests following testing-security-code.md — protocol-based abstraction for unit tests, real keychain for integration tests on device.

Domain Selection Guide:

If the task involves…	Load these reference files
Storing/reading a password or token	keychain-fundamentals.md + credential-storage-patterns.md
Choosing which `kSecClass` to use	keychain-item-classes.md
Setting when items are accessible	keychain-access-control.md
Face ID / Touch ID gating	biometric-authentication.md + keychain-access-control.md
Hardware-backed keys	secure-enclave.md
Encrypting / hashing data	cryptokit-symmetric.md
Signing / key exchange / HPKE	cryptokit-public-key.md
OAuth tokens / API keys / logout	credential-storage-patterns.md
Sharing between app and extension	keychain-sharing.md
TLS pinning / client certificates	certificate-trust.md
Replacing UserDefaults / plist secrets	migration-legacy-stores.md
Writing tests for security code	testing-security-code.md
Enterprise audit / OWASP compliance	compliance-owasp-mapping.md

目标： 从一开始就正确构建新的Keychain/安全功能。

流程：

确定任务涉及的领域。使用下方的领域选择指南。
加载相关参考文件。遵循✅代码模式——核心安全逻辑绝不偏离这些模式。
将核心准则（如下）应用到每个实现中。
运行特定领域的检查清单，确认实现完成。
按照testing-security-code.md添加测试——单元测试使用基于协议的抽象，设备上的集成测试使用真实Keychain。

领域选择指南：

若任务涉及…	加载以下参考文件
存储/读取密码或令牌	keychain-fundamentals.md + credential-storage-patterns.md
选择使用哪个 `kSecClass`	keychain-item-classes.md
设置项目的可访问时机	keychain-access-control.md
Face ID / Touch ID 验证	biometric-authentication.md + keychain-access-control.md
硬件支持的密钥	secure-enclave.md
加密/哈希数据	cryptokit-symmetric.md
签名/密钥交换/HPKE	cryptokit-public-key.md
OAuth令牌 / API密钥 / 登出	credential-storage-patterns.md
应用与扩展间共享	keychain-sharing.md
TLS固定 / 客户端证书	certificate-trust.md
替换UserDefaults / plist中的密钥	migration-legacy-stores.md
为安全代码编写测试	testing-security-code.md
企业审计 / OWASP合规	compliance-owasp-mapping.md

Core Guidelines

核心准则

These seven rules are non-negotiable. Every keychain/security implementation must satisfy all of them.

1. Never ignore
OSStatus
. Every

SecItem*

call returns an

OSStatus

. Use an exhaustive

switch

covering at minimum:

errSecSuccess

errSecDuplicateItem

(-25299),

errSecItemNotFound

(-25300),

errSecInteractionNotAllowed

(-25308). Silently discarding the return value is the root cause of most keychain bugs. → keychain-fundamentals.md

2. Never use
LAContext.evaluatePolicy()
as a standalone auth gate. This returns a

Bool

that is trivially patchable at runtime via Frida. Biometric authentication must be keychain-bound: store the secret behind

SecAccessControl

with

.biometryCurrentSet

, then let the keychain prompt for Face ID/Touch ID during

SecItemCopyMatching

. The keychain handles authentication in the Secure Enclave — there is no

Bool

to patch. → biometric-authentication.md

3. Never store secrets in
UserDefaults
,
Info.plist
,
.xcconfig
, or
NSCoding
archives. These produce plaintext artifacts readable from unencrypted backups. The Keychain is the only Apple-sanctioned store for credentials. → credential-storage-patterns.md, common-anti-patterns.md

4. Never call
SecItem*
on
@MainActor
. Every keychain call is an IPC round-trip to

securityd

that blocks the calling thread. Use a dedicated

actor

(iOS 17+) or serial

DispatchQueue

(iOS 13–16) for all keychain access. → keychain-fundamentals.md

5. Always set
kSecAttrAccessible
explicitly. The system default (

kSecAttrAccessibleWhenUnlocked

) breaks all background operations and may not match your threat model. Choose the most restrictive class that satisfies your access pattern. For background tasks:

kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly

. For highest sensitivity:

kSecAttrAccessibleWhenPasscodeSetThisDeviceOnly

. → keychain-access-control.md

6. Always use the add-or-update pattern.

SecItemAdd

followed by

SecItemUpdate

errSecDuplicateItem

. Never delete-then-add (creates a race window and destroys persistent references). Never call

SecItemAdd

without handling the duplicate case. → keychain-fundamentals.md

7. Always target the data protection keychain on macOS. Set

kSecUseDataProtectionKeychain: true

for every

SecItem*

call on macOS targets. Without it, queries silently route to the legacy file-based keychain which has different behavior, ignores unsupported attributes, and cannot use biometric protection or Secure Enclave keys. Mac Catalyst and iOS-on-Mac do this automatically. → keychain-fundamentals.md

以下七条规则不可协商。每个Keychain/安全实现必须全部满足。

1. 绝不忽略
OSStatus
。每个

SecItem*

调用都会返回

OSStatus

。使用详尽的

switch

语句，至少覆盖：

errSecSuccess

、

errSecDuplicateItem

(-25299)、

errSecItemNotFound

(-25300)、

errSecInteractionNotAllowed

(-25308)。静默丢弃返回值是大多数Keychain bug的根源。→ keychain-fundamentals.md

2. 绝不单独使用
LAContext.evaluatePolicy()
作为认证 gate。它返回的

Bool

可通过Frida在运行时轻松篡改。生物识别认证必须与Keychain绑定：将密钥存储在带有

.biometryCurrentSet

的

SecAccessControl

之后，然后在

SecItemCopyMatching

过程中让Keychain触发Face ID/Touch ID提示。Keychain在Secure Enclave中处理认证——不存在可被篡改的

Bool

值。→ biometric-authentication.md

3. 绝不将密钥存储在
UserDefaults
、
Info.plist
、
.xcconfig
或
NSCoding
归档中。这些会生成明文文件，可从未加密备份中读取。Keychain是Apple唯一认可的凭证存储方式。→ credential-storage-patterns.md, common-anti-patterns.md

4. 绝不在
@MainActor
上调用
SecItem*
。每个Keychain调用都是与

securityd

的IPC往返，会阻塞调用线程。对所有Keychain访问使用专用

actor

（iOS 17+）或串行

DispatchQueue

（iOS 13–16）。→ keychain-fundamentals.md

5. 始终显式设置
kSecAttrAccessible
。系统默认值(

kSecAttrAccessibleWhenUnlocked

)会破坏所有后台操作，且可能不符合你的威胁模型。选择满足访问模式的最严格类别。对于后台任务：

kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly

。对于最高敏感度内容：

kSecAttrAccessibleWhenPasscodeSetThisDeviceOnly

。→ keychain-access-control.md

6. 始终使用添加或更新模式。 先调用

SecItemAdd

，若返回

errSecDuplicateItem

则调用

SecItemUpdate

。绝不使用删除后添加的方式（会产生竞争窗口并破坏持久引用）。调用

SecItemAdd

时必须处理重复项情况。→ keychain-fundamentals.md

7. 在macOS上始终使用数据保护Keychain。 针对macOS目标的每个

SecItem*

调用都需设置

kSecUseDataProtectionKeychain: true

。若不设置，查询会静默路由到旧版基于文件的Keychain，其行为不同，会忽略不支持的属性，且无法使用生物识别保护或Secure Enclave密钥。Mac Catalyst和iOS-on-Mac会自动处理此设置。→ keychain-fundamentals.md

Quick Reference Tables

快速参考表

Accessibility Constants — Selection Guide

可访问性常量选择指南

Constant	When Decryptable	Survives Backup	Survives Device Migration	Background Safe	Use When
`WhenPasscodeSetThisDeviceOnly`	Unlocked + passcode set	❌	❌	❌	Highest-security secrets; removed if passcode removed
`WhenUnlockedThisDeviceOnly`	Unlocked	❌	❌	❌	Device-bound secrets not needed in background
`WhenUnlocked`	Unlocked	✅	✅	❌	Syncable secrets (system default — avoid implicit use)
`AfterFirstUnlockThisDeviceOnly`	After first unlock → restart	❌	❌	✅	Background tasks, push handlers, device-bound
`AfterFirstUnlock`	After first unlock → restart	✅	✅	✅	Background tasks that must survive restore

Deprecated (never use):

kSecAttrAccessibleAlways

kSecAttrAccessibleAlwaysThisDeviceOnly

— deprecated iOS 12.

Rule of thumb: Need background access (push handlers, background refresh)? Start with

AfterFirstUnlockThisDeviceOnly

. Foreground-only? Start with

WhenUnlockedThisDeviceOnly

. Tighten to

WhenPasscodeSetThisDeviceOnly

for high-value secrets. Use non-

ThisDeviceOnly

variants only when iCloud sync or backup migration is required.

常量	可解密时机	支持备份	支持设备迁移	后台可用	使用场景
`WhenPasscodeSetThisDeviceOnly`	解锁且设置密码后	❌	❌	❌	最高安全级别的密钥；移除密码时会被删除
`WhenUnlockedThisDeviceOnly`	解锁后	❌	❌	❌	设备绑定的密钥，后台无需使用
`WhenUnlocked`	解锁后	✅	✅	❌	可同步的密钥（系统默认——避免隐式使用）
`AfterFirstUnlockThisDeviceOnly`	首次解锁后至重启前	❌	❌	✅	后台任务、推送处理器、设备绑定
`AfterFirstUnlock`	首次解锁后至重启前	✅	✅	✅	必须在恢复后保留的后台任务

已废弃（禁止使用）：

kSecAttrAccessibleAlways

、

kSecAttrAccessibleAlwaysThisDeviceOnly

——iOS 12已废弃。

经验法则： 需要后台访问（推送处理器、后台刷新）？从

AfterFirstUnlockThisDeviceOnly

开始。仅前台使用？从

WhenUnlockedThisDeviceOnly

开始。高价值密钥可收紧为

WhenPasscodeSetThisDeviceOnly

。仅当需要iCloud同步或备份迁移时，才使用非

ThisDeviceOnly

变体。

CryptoKit Algorithm Selection

CryptoKit算法选择

Need	Algorithm	Min iOS	Notes
Hash data	`SHA256` / `SHA384` / `SHA512`	13	`SHA3_256` / `SHA3_512` available iOS 26+
Authenticate data (MAC)	`HMAC<SHA256>`	13	Always verify with constant-time comparison (built-in)
Encrypt data (authenticated)	`AES.GCM`	13	256-bit key, 96-bit nonce, 128-bit tag. Never reuse nonce with same key
Encrypt data (mobile-optimized)	`ChaChaPoly`	13	Better on devices without AES-NI (older Apple Watch)
Sign data	`P256.Signing` / `Curve25519.Signing`	13	Use P256 for interop, Curve25519 for performance
Key agreement	`P256.KeyAgreement` / `Curve25519.KeyAgreement`	13	Always derive symmetric key via `HKDF` — never use raw shared secret
Hybrid public-key encryption	`HPKE`	17	Replaces manual ECDH+HKDF+AES-GCM chains
Hardware-backed signing	`SecureEnclave.P256.Signing`	13	P256 only; key never leaves hardware
Post-quantum key exchange	`MLKEM768`	26	Formal verification (ML-KEM FIPS 203)
Post-quantum signing	`MLDSA65`	26	Formal verification (ML-DSA FIPS 204)
Password → key derivation	PBKDF2 (via `CommonCrypto` )	13	≥600,000 iterations SHA-256 (OWASP 2024)
Key → key derivation	`HKDF<SHA256>`	13	Extract-then-expand; always use info parameter for domain separation

需求	算法	最低iOS版本	说明
哈希数据	`SHA256` / `SHA384` / `SHA512`	13	`SHA3_256` / `SHA3_512` 在iOS 26+可用
数据认证（MAC）	`HMAC<SHA256>`	13	始终使用常量时间比较（内置功能）验证
加密数据（带认证）	`AES.GCM`	13	256位密钥、96位随机数、128位标签。同一密钥绝不能重复使用随机数
加密数据（移动优化）	`ChaChaPoly`	13	在无AES-NI的设备上表现更好（旧款Apple Watch）
数据签名	`P256.Signing` / `Curve25519.Signing`	13	互操作性使用P256，性能优先使用Curve25519
密钥协商	`P256.KeyAgreement` / `Curve25519.KeyAgreement`	13	始终通过 `HKDF` 派生对称密钥——绝不使用原始共享密钥
混合公钥加密	`HPKE`	17	替代手动ECDH+HKDF+AES-GCM链
硬件支持的签名	`SecureEnclave.P256.Signing`	13	仅支持P256；密钥永不离开硬件
后量子密钥交换	`MLKEM768`	26	已通过正式验证（ML-KEM FIPS 203）
后量子签名	`MLDSA65`	26	已通过正式验证（ML-DSA FIPS 204）
密码→密钥推导	PBKDF2（通过 `CommonCrypto` ）	13	≥600,000次迭代SHA-256（OWASP 2024）
密钥→密钥推导	`HKDF<SHA256>`	13	提取后扩展；始终使用info参数进行领域分离

Anti-Pattern Detection — Quick Scan

反模式检测快速扫描

When reviewing code, search for these patterns. Any match is a finding.

❌

= insecure pattern signature to detect in user code.

✅

= apply the corrective pattern in the referenced file.

Search For	Anti-Pattern	Severity	Reference
`UserDefaults.standard.set` + token/key/secret/password	Plaintext credential storage	CRITICAL	common-anti-patterns.md #1
Hardcoded base64/hex strings (≥16 chars) in source	Hardcoded cryptographic key	CRITICAL	common-anti-patterns.md #2
`evaluatePolicy` without `SecItemCopyMatching` nearby	LAContext-only biometric gate	CRITICAL	common-anti-patterns.md #3
`SecItemAdd` without checking return / `OSStatus`	Ignored error code	HIGH	common-anti-patterns.md #4
No `kSecAttrAccessible` in add dictionary	Implicit accessibility class	HIGH	common-anti-patterns.md #5
`AES.GCM.Nonce()` inside a loop with same key	Potential nonce reuse	CRITICAL	common-anti-patterns.md #6
`sharedSecret.withUnsafeBytes` without HKDF	Raw shared secret as key	HIGH	common-anti-patterns.md #7
`kSecAttrAccessibleAlways`	Deprecated accessibility	HIGH	keychain-access-control.md
`SecureEnclave.isAvailable` without `#if !targetEnvironment(simulator)`	Simulator false-negative trap	MEDIUM	secure-enclave.md
`kSecAttrSynchronizable: true` + `ThisDeviceOnly`	Contradictory constraints	MEDIUM	keychain-item-classes.md
`SecTrustEvaluate` (sync, deprecated)	Legacy trust evaluation	MEDIUM	certificate-trust.md
`kSecClassGenericPassword` + `kSecAttrServer`	Wrong class for web credentials	MEDIUM	keychain-item-classes.md

审查代码时，搜索以下模式。任何匹配项均为问题点。

❌

= 用户代码中需检测的不安全模式特征。

✅

= 应用参考文件中的纠正模式。

搜索内容	反模式	严重程度	参考文件
`UserDefaults.standard.set` + token/key/secret/password	明文凭证存储	CRITICAL	common-anti-patterns.md #1
源代码中硬编码的base64/十六进制字符串（≥16字符）	硬编码加密密钥	CRITICAL	common-anti-patterns.md #2
`evaluatePolicy` 附近无 `SecItemCopyMatching`	仅LAContext生物识别验证	CRITICAL	common-anti-patterns.md #3
`SecItemAdd` 未检查返回值 / `OSStatus`	忽略错误代码	HIGH	common-anti-patterns.md #4
添加字典中无 `kSecAttrAccessible`	隐式可访问性类别	HIGH	common-anti-patterns.md #5
同一密钥的循环内调用 `AES.GCM.Nonce()`	可能重复使用随机数	CRITICAL	common-anti-patterns.md #6
`sharedSecret.withUnsafeBytes` 未使用HKDF	使用原始共享密钥作为密钥	HIGH	common-anti-patterns.md #7
`kSecAttrAccessibleAlways`	已废弃的可访问性设置	HIGH	keychain-access-control.md
`SecureEnclave.isAvailable` 未加 `#if !targetEnvironment(simulator)`	模拟器误判陷阱	MEDIUM	secure-enclave.md
`kSecAttrSynchronizable: true` + `ThisDeviceOnly`	矛盾的约束条件	MEDIUM	keychain-item-classes.md
`SecTrustEvaluate` （同步、已废弃）	旧版信任评估	MEDIUM	certificate-trust.md
`kSecClassGenericPassword` + `kSecAttrServer`	Web凭证使用错误类别	MEDIUM	keychain-item-classes.md

Top-Level Review Checklist

顶层审查清单

Use this checklist for a rapid sweep across all 14 domains. Each item maps to one or more reference files for deep-dive investigation. For domain-specific deep checks, use the Summary Checklist at the bottom of each reference file.

1. Secrets are in Keychain, not UserDefaults/plist/source — No credentials, tokens, or cryptographic keys in
```
UserDefaults
```
,
```
Info.plist
```
,
```
.xcconfig
```
, hardcoded strings, or
```
NSCoding
```
archives. OWASP M9 (Insecure Data Storage) directly violated. → common-anti-patterns.md #1–2, credential-storage-patterns.md, migration-legacy-stores.md, compliance-owasp-mapping.md
2. Every
OSStatus
is checked — All
```
SecItem*
```
calls handle return codes with exhaustive
```
switch
```
or equivalent. No ignored returns.
```
errSecInteractionNotAllowed
```
is handled non-destructively (retry later, never delete). → keychain-fundamentals.md, common-anti-patterns.md #4
3. Biometric auth is keychain-bound — If biometrics are used, authentication is enforced via
```
SecAccessControl
```
+ keychain access, not
```
LAContext.evaluatePolicy()
```
alone. → biometric-authentication.md, common-anti-patterns.md #3
4. Accessibility classes are explicit and correct — Every keychain item has an explicit
```
kSecAttrAccessible
```
value matching its access pattern (background vs foreground, device-bound vs syncable). No deprecated
```
Always
```
constants. → keychain-access-control.md
5. No
SecItem*
calls on
@MainActor
— All keychain operations run on a dedicated
```
actor
```
or background queue. No synchronous keychain access in UI code,
```
viewDidLoad
```
, or
```
application(_:didFinishLaunchingWithOptions:)
```
. → keychain-fundamentals.md
6. Correct
kSecClass
for each item type — Web credentials use
```
InternetPassword
```
(not GenericPassword) for AutoFill. Cryptographic keys use
```
kSecClassKey
```
with proper
```
kSecAttrKeyType
```
. App secrets use
```
GenericPassword
```
with
```
kSecAttrService
```
+
```
kSecAttrAccount
```
. → keychain-item-classes.md
7. CryptoKit used correctly — Nonces never reused with the same key. ECDH shared secrets always derived through
```
HKDF
```
before use as symmetric keys.
```
SymmetricKey
```
material stored in Keychain, not in memory or files. Crypto operations covered by protocol-based unit tests. → cryptokit-symmetric.md, cryptokit-public-key.md, testing-security-code.md
8. Secure Enclave constraints respected — SE keys are P256 only (classical), never imported (always generated on-device), device-bound (no backup/sync). Availability checks guard against simulator and keychain-access-groups entitlement issues. → secure-enclave.md
9. Sharing and access groups configured correctly —
```
kSecAttrAccessGroup
```
uses full
```
TEAMID.group.identifier
```
format. Entitlements match between app and extensions. No accidental cross-app data exposure. → keychain-sharing.md
10. Certificate trust evaluation is current — Uses
```
SecTrustEvaluateAsyncWithError
```
(not deprecated synchronous
```
SecTrustEvaluate
```
). Pinning strategy uses SPKI hash or
```
NSPinnedDomains
```
(not leaf certificate pinning which breaks on annual rotation). → certificate-trust.md
11. macOS targets data protection keychain — All macOS
```
SecItem*
```
calls include
```
kSecUseDataProtectionKeychain: true
```
(except Mac Catalyst / iOS-on-Mac where it's automatic). → keychain-fundamentals.md

使用此清单快速扫描所有14个领域。每个项目均映射到一个或多个参考文件，用于深入调查。针对特定领域的深度检查，请使用每个参考文件底部的摘要检查清单。

1. 密钥存储在Keychain中，而非UserDefaults/plist/源代码 —
```
UserDefaults
```
、
```
Info.plist
```
、
```
.xcconfig
```
、硬编码字符串或
```
NSCoding
```
归档中无凭证、令牌或加密密钥。直接违反OWASP M9（不安全数据存储）。→ common-anti-patterns.md #1–2, credential-storage-patterns.md, migration-legacy-stores.md, compliance-owasp-mapping.md
2. 每个
OSStatus
均被检查 — 所有
```
SecItem*
```
调用通过详尽的
```
switch
```
或等效方式处理返回码。无忽略返回值的情况。
```
errSecInteractionNotAllowed
```
需进行非破坏性处理（稍后重试，绝不删除）。→ keychain-fundamentals.md, common-anti-patterns.md #4
3. 生物识别认证与Keychain绑定 — 若使用生物识别，认证需通过
```
SecAccessControl
```
+ Keychain访问强制执行，而非仅使用
```
LAContext.evaluatePolicy()
```
。→ biometric-authentication.md, common-anti-patterns.md #3
4. 可访问性类别显式且正确 — 每个Keychain项目均有显式的
```
kSecAttrAccessible
```
值，与其访问模式匹配（后台 vs 前台、设备绑定 vs 可同步）。无已废弃的
```
Always
```
常量。→ keychain-access-control.md
5.
@MainActor
上无
SecItem*
调用 — 所有Keychain操作在专用
```
actor
```
或后台队列上运行。UI代码、
```
viewDidLoad
```
或
```
application(_:didFinishLaunchingWithOptions:)
```
中无同步Keychain访问。→ keychain-fundamentals.md
6. 每个项目类型使用正确的
kSecClass
— Web凭证使用
```
InternetPassword
```
（而非GenericPassword）以支持AutoFill。加密密钥使用
```
kSecClassKey
```
并设置正确的
```
kSecAttrKeyType
```
。应用密钥使用
```
GenericPassword
```
并设置
```
kSecAttrService
```
+
```
kSecAttrAccount
```
。→ keychain-item-classes.md
7. CryptoKit使用正确 — 同一密钥绝不重复使用随机数。ECDH共享密钥在用作对称密钥前始终通过
```
HKDF
```
派生。
```
SymmetricKey
```
材料存储在Keychain中，而非内存或文件中。加密操作通过基于协议的单元测试覆盖。→ cryptokit-symmetric.md, cryptokit-public-key.md, testing-security-code.md
8. 遵守Secure Enclave约束 — SE密钥仅支持P256（经典算法），绝不导入（始终在设备上生成），与设备绑定（无备份/同步）。可用性检查需防范模拟器和Keychain访问组权限问题。→ secure-enclave.md
9. 共享和访问组配置正确 —
```
kSecAttrAccessGroup
```
使用完整的
```
TEAMID.group.identifier
```
格式。应用与扩展的权限匹配。无意外的跨应用数据泄露。→ keychain-sharing.md
10. 证书信任评估为当前版本 — 使用
```
SecTrustEvaluateAsyncWithError
```
（而非已废弃的同步
```
SecTrustEvaluate
```
）。固定策略使用SPKI哈希或
```
NSPinnedDomains
```
（而非叶子证书固定，后者会在年度轮换时失效）。→ certificate-trust.md
11. macOS目标使用数据保护Keychain — 所有macOS
```
SecItem*
```
调用均包含
```
kSecUseDataProtectionKeychain: true
```
（Mac Catalyst / iOS-on-Mac除外，它们会自动处理）。→ keychain-fundamentals.md

References Index

参考文件索引

#	File	One-Line Description	Risk
1	keychain-fundamentals.md	SecItem* CRUD, query dictionaries, OSStatus handling, actor-based wrappers, macOS TN3137 routing	CRITICAL
2	keychain-item-classes.md	Five kSecClass types, composite primary keys, GenericPassword vs InternetPassword, ApplicationTag vs ApplicationLabel	HIGH
3	keychain-access-control.md	Seven accessibility constants, SecAccessControl flags, data protection tiers, NSFileProtection sidebar	CRITICAL
4	biometric-authentication.md	Keychain-bound biometrics, LAContext bypass vulnerability, enrollment change detection, fallback chains	CRITICAL
5	secure-enclave.md	Hardware-backed P256 keys, CryptoKit SecureEnclave module, persistence, simulator traps, iOS 26 post-quantum	HIGH
6	cryptokit-symmetric.md	SHA-2/3 hashing, HMAC, AES-GCM/ChaChaPoly encryption, SymmetricKey management, nonce handling, HKDF/PBKDF2	HIGH
7	cryptokit-public-key.md	ECDSA signing, ECDH key agreement, HPKE (iOS 17+), ML-KEM/ML-DSA post-quantum (iOS 26+), curve selection	HIGH
8	credential-storage-patterns.md	OAuth2/OIDC token lifecycle, API key storage, refresh token rotation, runtime secrets, logout cleanup	CRITICAL
9	keychain-sharing.md	Access groups, Team ID prefixes, app extensions, Keychain Sharing vs App Groups entitlements, iCloud sync	MEDIUM
10	certificate-trust.md	SecTrust evaluation, SPKI/CA/leaf pinning, NSPinnedDomains, client certificates (mTLS), trust policies	HIGH
11	migration-legacy-stores.md	UserDefaults/plist/NSCoding → Keychain migration, secure deletion, first-launch cleanup, versioned migration	MEDIUM
12	common-anti-patterns.md	Top 10 AI-generated security mistakes with ❌/✅ code pairs, detection heuristics, OWASP mapping	CRITICAL
13	testing-security-code.md	Protocol-based mocking, simulator vs device differences, CI/CD keychain, Swift Testing, mutation testing	MEDIUM
14	compliance-owasp-mapping.md	OWASP Mobile Top 10 (2024), MASVS v2.1.0, MASTG test IDs, M1/M3/M9/M10 mapping, audit readiness	MEDIUM

#	文件	一句话描述	风险等级
1	keychain-fundamentals.md	SecItem*增删改查、查询字典、OSStatus处理、基于actor的封装、macOS TN3137路由	CRITICAL
2	keychain-item-classes.md	五种kSecClass类型、复合主键、GenericPassword vs InternetPassword、ApplicationTag vs ApplicationLabel	HIGH
3	keychain-access-control.md	七种可访问性常量、SecAccessControl标志、数据保护层级、NSFileProtection侧边栏	CRITICAL
4	biometric-authentication.md	绑定Keychain的生物识别、LAContext绕过漏洞、注册变更检测、 fallback链	CRITICAL
5	secure-enclave.md	硬件支持的P256密钥、CryptoKit SecureEnclave模块、持久化、模拟器陷阱、iOS 26后量子支持	HIGH
6	cryptokit-symmetric.md	SHA-2/3哈希、HMAC、AES-GCM/ChaChaPoly加密、SymmetricKey管理、随机数处理、HKDF/PBKDF2	HIGH
7	cryptokit-public-key.md	ECDSA签名、ECDH密钥协商、HPKE（iOS 17+）、ML-KEM/ML-DSA后量子（iOS 26+）、曲线选择	HIGH
8	credential-storage-patterns.md	OAuth2/OIDC令牌生命周期、API密钥存储、刷新令牌轮换、运行时密钥获取、登出清理	CRITICAL
9	keychain-sharing.md	访问组、Team ID前缀、应用扩展、Keychain Sharing vs App Groups权限、iCloud同步	MEDIUM
10	certificate-trust.md	SecTrust评估、SPKI/CA/叶子证书固定、NSPinnedDomains、客户端证书（mTLS）、信任策略	HIGH
11	migration-legacy-stores.md	UserDefaults/plist/NSCoding → Keychain迁移、安全删除旧数据、首次启动清理、版本化迁移	MEDIUM
12	common-anti-patterns.md	十大AI生成的安全错误及❌/✅代码示例、检测启发式、OWASP映射	CRITICAL
13	testing-security-code.md	基于协议的模拟、模拟器与设备差异、CI/CD Keychain、Swift Testing、变异测试	MEDIUM
14	compliance-owasp-mapping.md	OWASP移动Top 10（2024）、MASVS v2.1.0、MASTG测试ID、M1/M3/M9/M10映射、审计就绪	MEDIUM

Authoritative Sources

权威来源

These are the primary sources underpinning all reference files. When in doubt, defer to these over any secondary source.

Apple Keychain Services Documentation — canonical API reference
Apple Platform Security Guide (updated annually) — architecture and encryption design
TN3137: "On Mac Keychain APIs and Implementations" — macOS data protection vs file-based keychain
Quinn "The Eskimo!" DTS Posts — "SecItem: Fundamentals" and "SecItem: Pitfalls and Best Practices" (updated through 2025)
WWDC 2019 Session 709 — "Cryptography and Your Apps" (CryptoKit introduction)
WWDC 2025 Session 314 — "Get ahead with quantum-secure cryptography" (ML-KEM, ML-DSA)
OWASP Mobile Top 10 (2024) + MASVS v2.1.0 + MASTG v2 — compliance framework
CISA/FBI "Product Security Bad Practices" v2.0 (January 2025) — hardcoded credentials classified as national security risk

以下是支撑所有参考文件的主要来源。如有疑问，优先参考这些来源而非任何二级来源。

Apple Keychain Services文档 — 标准API参考
Apple平台安全指南（每年更新） — 架构和加密设计
TN3137: "On Mac Keychain APIs and Implementations" — macOS数据保护vs基于文件的Keychain
Quinn "The Eskimo!" DTS帖子 — "SecItem: Fundamentals"和"SecItem: Pitfalls and Best Practices"（更新至2025年）
WWDC 2019 Session 709 — "Cryptography and Your Apps"（CryptoKit介绍）
WWDC 2025 Session 314 — "Get ahead with quantum-secure cryptography"（ML-KEM、ML-DSA）
OWASP Mobile Top 10 (2024) + MASVS v2.1.0 + MASTG v2 — 合规框架
CISA/FBI "Product Security Bad Practices" v2.0（2025年1月） — 硬编码凭证被列为国家安全风险

Agent Behavioral Rules

Agent行为规则

The sections below govern how an AI agent should behave when using this skill: what's in scope, what's out, tone calibration, common mistakes to avoid, how to select reference files, and output formatting requirements.

以下章节规定AI agent使用本技能时的行为：范围、非范围、语气校准、需避免的常见错误、参考文件选择方式以及输出格式要求。

Scope Boundaries — Inclusions

范围边界 — 包含项

This skill is authoritative for client-side Apple platform security across iOS, macOS, tvOS, watchOS, and visionOS:

Keychain Services —
```
SecItemAdd
```
,
```
SecItemCopyMatching
```
,
```
SecItemUpdate
```
,
```
SecItemDelete
```
, query dictionary construction,
```
OSStatus
```
handling, actor/thread isolation, the data protection keychain on macOS (TN3137)

Keychain item classes —

kSecClassGenericPassword

kSecClassInternetPassword

kSecClassKey

kSecClassCertificate

kSecClassIdentity

, composite primary keys, AutoFill integration

Access control — The seven
```
kSecAttrAccessible
```
constants,
```
SecAccessControlCreateWithFlags
```
, data protection tiers,
```
NSFileProtection
```
correspondence
Biometric authentication —
```
LAContext
```
+ keychain binding, the boolean gate vulnerability, enrollment change detection, fallback chains,
```
evaluatedPolicyDomainState
```
Secure Enclave — CryptoKit
```
SecureEnclave.P256
```
module, hardware constraints (P256-only, no import, no export, no symmetric), persistence via keychain, simulator traps, iOS 26 post-quantum (ML-KEM, ML-DSA)
CryptoKit symmetric — SHA-2/SHA-3 hashing, HMAC, AES-GCM, ChaChaPoly,
```
SymmetricKey
```
lifecycle, nonce handling, HKDF, PBKDF2
CryptoKit public-key — ECDSA signing (P256/Curve25519), ECDH key agreement, HPKE (iOS 17+), ML-KEM/ML-DSA (iOS 26+), curve selection
Credential storage patterns — OAuth2/OIDC token lifecycle, API key storage, refresh token rotation, runtime secret fetching, logout cleanup
Keychain sharing — Access groups, Team ID prefixes,
```
keychain-access-groups
```
vs
```
com.apple.security.application-groups
```
entitlements, extensions, iCloud Keychain sync
Certificate trust —
```
SecTrust
```
evaluation, SPKI/CA/leaf pinning,
```
NSPinnedDomains
```
, client certificates (mTLS), trust policies
Migration — UserDefaults/plist/NSCoding → Keychain migration, secure legacy deletion, first-launch cleanup, versioned migration
Testing — Protocol-based mocking, simulator vs device differences, CI/CD keychain creation, Swift Testing patterns
Compliance — OWASP Mobile Top 10 (2024), MASVS v2.1.0, MASTG v2 test IDs, CISA/FBI Bad Practices

Edge cases that ARE in scope: Client-side certificate loading for mTLS pinning (certificate-trust.md). Passkey/AutoFill credential storage in Keychain (keychain-item-classes.md, credential-storage-patterns.md).

@AppStorage

flagged as insecure storage — redirect to Keychain (common-anti-patterns.md).

本技能是Apple平台客户端安全的权威指南，涵盖iOS、macOS、tvOS、watchOS和visionOS：

Keychain Services —
```
SecItemAdd
```
、
```
SecItemCopyMatching
```
、
```
SecItemUpdate
```
、
```
SecItemDelete
```
、查询字典构建、
```
OSStatus
```
处理、actor/线程隔离、macOS上的数据保护Keychain（TN3137）

Keychain项目类别 —

kSecClassGenericPassword

、

kSecClassInternetPassword

、

kSecClassKey

、

kSecClassCertificate

、

kSecClassIdentity

、复合主键、AutoFill集成

访问控制 — 七种
```
kSecAttrAccessible
```
常量、
```
SecAccessControlCreateWithFlags
```
、数据保护层级、
```
NSFileProtection
```
对应关系
生物识别认证 —
```
LAContext
```
+ Keychain绑定、布尔值gate漏洞、注册变更检测、fallback链、
```
evaluatedPolicyDomainState
```
Secure Enclave — CryptoKit
```
SecureEnclave.P256
```
模块、硬件约束（仅P256、不导入、不导出、无对称密钥）、通过Keychain持久化、模拟器陷阱、iOS 26后量子支持（ML-KEM、ML-DSA）
CryptoKit对称加密 — SHA-2/SHA-3哈希、HMAC、AES-GCM、ChaChaPoly、
```
SymmetricKey
```
生命周期、随机数处理、HKDF、PBKDF2
CryptoKit公钥加密 — ECDSA签名（P256/Curve25519）、ECDH密钥协商、HPKE（iOS 17+）、ML-KEM/ML-DSA（iOS 26+）、曲线选择
凭证存储模式 — OAuth2/OIDC令牌生命周期、API密钥存储、刷新令牌轮换、运行时密钥获取、登出清理
Keychain共享 — 访问组、Team ID前缀、
```
keychain-access-groups
```
vs
```
com.apple.security.application-groups
```
权限、扩展、iCloud Keychain同步
证书信任 —
```
SecTrust
```
评估、SPKI/CA/叶子证书固定、
```
NSPinnedDomains
```
、客户端证书（mTLS）、信任策略
迁移 — UserDefaults/plist/NSCoding → Keychain迁移、安全删除旧数据、首次启动清理、版本化迁移
测试 — 基于协议的模拟、模拟器与设备差异、CI/CD Keychain创建、Swift Testing模式
合规性 — OWASP Mobile Top 10 (2024)、MASVS v2.1.0、MASTG v2测试ID、CISA/FBI不良实践

属于范围的边缘情况： 用于mTLS固定的客户端证书加载（certificate-trust.md）。Keychain中的Passkey/AutoFill凭证存储（keychain-item-classes.md、credential-storage-patterns.md）。

@AppStorage

被标记为不安全存储——引导至Keychain（common-anti-patterns.md）。

Scope Boundaries — Exclusions

范围边界 — 排除项

Do not answer the following topics using this skill. Briefly explain they are out of scope and suggest where to look.

Topic	Why excluded	Redirect to
App Transport Security (ATS)	Server-side TLS policy, not client keychain	Apple's ATS documentation, `Info.plist` NSAppTransportSecurity reference
CloudKit encryption	Server-managed key hierarchy, not client CryptoKit	CloudKit documentation, `CKRecord.encryptedValues`
Network security / URLSession TLS config	Transport layer, not storage layer	Apple URL Loading System docs; this skill covers only client certificate loading for mTLS
Server-side auth architecture	Backend JWT issuance, OAuth provider config	OWASP ASVS (Application Security Verification Standard)
WebAuthn / passkeys server-side	Relying party implementation	Apple "Supporting passkeys" documentation; this skill covers client-side `ASAuthorizationController` only where it stores credentials in Keychain
Code signing / provisioning profiles	Build/distribution, not runtime security	Apple code signing documentation
Jailbreak detection	Runtime integrity, not cryptographic storage	OWASP MASTG MSTG-RESILIENCE category
SwiftUI `@AppStorage`	Wrapper over `UserDefaults` — out of scope except to flag it as insecure for secrets	common-anti-patterns.md #1 flags it; no deeper coverage
Cross-platform crypto (OpenSSL, LibSodium)	Third-party libraries, not Apple frameworks	Respective library documentation

请勿使用本技能回答以下主题。简要说明它们不在范围内并建议参考方向。

主题	排除原因	参考方向
App Transport Security (ATS)	服务端TLS策略，非客户端Keychain	Apple的ATS文档、 `Info.plist` NSAppTransportSecurity参考
CloudKit加密	服务端管理的密钥层级，非客户端CryptoKit	CloudKit文档、 `CKRecord.encryptedValues`
网络安全 / URLSession TLS配置	传输层，非存储层	Apple URL加载系统文档；本技能仅涵盖用于mTLS的客户端证书加载
服务端认证架构	后端JWT签发、OAuth提供商配置	OWASP ASVS（应用安全验证标准）
WebAuthn / passkeys服务端	依赖方实现	Apple "Supporting passkeys"文档；本技能仅涵盖客户端 `ASAuthorizationController` 中与Keychain存储凭证相关的部分
代码签名 / 配置文件	构建/分发，非运行时安全	Apple代码签名文档
越狱检测	运行时完整性，非加密存储	OWASP MASTG MSTG-RESILIENCE类别
SwiftUI `@AppStorage`	`UserDefaults` 的包装器——除了标记其存储密钥不安全外，无更深覆盖	common-anti-patterns.md #1已标记；无更多覆盖内容
跨平台加密（OpenSSL、LibSodium）	第三方库，非Apple框架	对应库的文档

Tone Rules

语气规则

This skill is non-opinionated and correctness-focused. Tone calibrates based on severity.

Default tone — advisory. Use "consider," "suggest," "one approach is," "a common pattern is" for: architecture choices (wrapper class design, actor vs DispatchQueue), algorithm selection when multiple valid options exist (P256 vs Curve25519, AES-GCM vs ChaChaPoly), accessibility class selection when the threat model is unclear, testing strategy, code organization.

Elevated tone — directive. Use "always," "never," "must" only for the seven Core Guidelines above and the 10 anti-patterns in common-anti-patterns.md. These are security invariants, not style preferences. The exhaustive list of directives:

Never ignore
```
OSStatus
```
— always check return codes from
```
SecItem*
```
calls. → keychain-fundamentals.md
Never use
```
LAContext.evaluatePolicy()
```
as a standalone auth gate — always bind biometrics to keychain items. → biometric-authentication.md
Never store secrets in
```
UserDefaults
```
,
```
Info.plist
```
,
```
.xcconfig
```
, or
```
NSCoding
```
archives. → credential-storage-patterns.md, common-anti-patterns.md
Never call
```
SecItem*
```
on
```
@MainActor
```
— always use a background actor or queue. → keychain-fundamentals.md
Always set
```
kSecAttrAccessible
```
explicitly on every
```
SecItemAdd
```
. → keychain-access-control.md
Always use the add-or-update pattern (
```
SecItemAdd
```
→
```
SecItemUpdate
```
on
```
errSecDuplicateItem
```
). → keychain-fundamentals.md
Always set
```
kSecUseDataProtectionKeychain: true
```
on macOS targets. → keychain-fundamentals.md
Never reuse a nonce with the same AES-GCM key. → cryptokit-symmetric.md, common-anti-patterns.md
Never use a raw ECDH shared secret as a symmetric key — always derive through HKDF. → cryptokit-public-key.md, common-anti-patterns.md
Never use
```
Insecure.MD5
```
or
```
Insecure.SHA1
```
for security purposes. → cryptokit-symmetric.md, common-anti-patterns.md

If a pattern is not on this list, use advisory tone. Do not escalate warnings beyond what the reference files support.

Tone when declining. When a query falls outside scope, be direct but not dismissive: "This skill covers client-side keychain and CryptoKit. For ATS configuration, Apple's NSAppTransportSecurity documentation is the right reference." State the boundary, suggest an alternative, move on.

本技能无主观倾向且聚焦正确性。语气根据严重程度调整。

默认语气——建议性。使用"考虑"、"建议"、"一种方法是"、"常见模式是"用于：架构选择（包装类设计、actor vs DispatchQueue）、存在多个有效选项时的算法选择（P256 vs Curve25519、AES-GCM vs ChaChaPoly）、威胁模型不明确时的可访问性类别选择、测试策略、代码组织。

强化语气——指令性。仅对上述七条核心准则和common-anti-patterns.md中的10种反模式使用"始终"、"绝不"、"必须"。这些是安全不变量，而非风格偏好。指令性内容的完整列表：

绝不忽略
```
OSStatus
```
——始终检查
```
SecItem*
```
调用的返回码。→ keychain-fundamentals.md
绝不单独使用
```
LAContext.evaluatePolicy()
```
作为认证gate——始终将生物识别与Keychain项目绑定。→ biometric-authentication.md
绝不将密钥存储在
```
UserDefaults
```
、
```
Info.plist
```
、
```
.xcconfig
```
或
```
NSCoding
```
归档中。→ credential-storage-patterns.md, common-anti-patterns.md
绝不在
```
@MainActor
```
上调用
```
SecItem*
```
——始终使用后台actor或队列。→ keychain-fundamentals.md
始终在每个
```
SecItemAdd
```
中显式设置
```
kSecAttrAccessible
```
。→ keychain-access-control.md
始终使用添加或更新模式（
```
SecItemAdd
```
→ 遇到
```
errSecDuplicateItem
```
时调用
```
SecItemUpdate
```
）。→ keychain-fundamentals.md
在macOS目标上始终设置
```
kSecUseDataProtectionKeychain: true
```
。→ keychain-fundamentals.md
同一AES-GCM密钥绝不重复使用随机数。→ cryptokit-symmetric.md, common-anti-patterns.md
绝不使用原始ECDH共享密钥作为对称密钥——始终通过HKDF派生。→ cryptokit-public-key.md, common-anti-patterns.md
绝不将
```
Insecure.MD5
```
或
```
Insecure.SHA1
```
用于安全场景。→ cryptokit-symmetric.md, common-anti-patterns.md

若模式不在此列表中，使用建议性语气。不要超出参考文件支持的范围升级警告级别。

拒绝时的语气。当查询超出范围时，直接但不傲慢："本技能涵盖客户端Keychain和CryptoKit。关于ATS配置，Apple的NSAppTransportSecurity文档是正确的参考。"说明边界，建议替代方案，然后结束。

Common Mistakes

常见错误

Before finalizing any output, scan for all 10. Each links to the reference file containing the correct pattern. Each entry is intentionally paired:

❌

incorrect generated behavior and

✅

corrective pattern to use instead.

Mistake #1 — Generating
LAContext.evaluatePolicy()
as the sole biometric gate. AI produces the boolean-callback pattern where

evaluatePolicy

returns

success: Bool

and the app gates access on that boolean. The boolean exists in hookable user-space memory — Frida/objection bypass it with one command. ✅ Correct pattern: Store a secret behind

SecAccessControl

with

.biometryCurrentSet

, retrieve via

SecItemCopyMatching

. → biometric-authentication.md

Mistake #2 — Suggesting
SecureEnclave.isAvailable
without simulator guard. AI generates

if SecureEnclave.isAvailable { ... }

without

#if !targetEnvironment(simulator)

. On simulators,

isAvailable

returns

false

, silently taking the fallback path in all simulator testing. ✅ Correct pattern: Use

#if targetEnvironment(simulator)

to throw/return a clear error at compile time, check

SecureEnclave.isAvailable

only in device builds. → secure-enclave.md

Mistake #3 — Importing external keys into the Secure Enclave. AI generates

SecureEnclave.P256.Signing.PrivateKey(rawRepresentation: someData)

. SE keys must be generated inside the hardware — there is no

init(rawRepresentation:)

on SE types.

init(dataRepresentation:)

accepts only the opaque encrypted blob from a previously created SE key. ✅ Correct pattern: Generate inside SE, persist opaque

dataRepresentation

to keychain, restore via

init(dataRepresentation:)

. → secure-enclave.md

Mistake #4 — Using
SecureEnclave.AES
or SE for symmetric encryption. AI generates references to non-existent SE symmetric APIs. The SE's internal AES engine is not exposed as a developer API. Pre-iOS 26, the SE supports only P256 signing and key agreement. iOS 26 adds ML-KEM and ML-DSA, not symmetric primitives. ✅ Correct pattern: Use SE for signing/key agreement; derive a

SymmetricKey

via ECDH + HKDF for encryption. → secure-enclave.md, cryptokit-symmetric.md

Mistake #5 — Omitting
kSecAttrAccessible
in
SecItemAdd
. AI builds add dictionaries without an accessibility attribute. The system applies

kSecAttrAccessibleWhenUnlocked

by default, which breaks background operations and makes security policy invisible in code review. ✅ Correct pattern: Always set

kSecAttrAccessible

explicitly. → keychain-access-control.md

Mistake #6 — Using
SecItemAdd
without handling
errSecDuplicateItem
. AI checks only for

errSecSuccess

, or uses delete-then-add. Without duplicate handling, the second save silently fails. Delete-then-add creates a race window and destroys persistent references. ✅ Correct pattern: Add-or-update pattern. → keychain-fundamentals.md

Mistake #7 — Specifying explicit nonces for AES-GCM encryption. AI creates a nonce manually and passes it to

AES.GCM.seal

. Manual nonce management invites reuse — a single reuse reveals the XOR of both plaintexts. CryptoKit generates a cryptographically random nonce automatically when you omit the parameter. ✅ Correct pattern: Call

AES.GCM.seal(plaintext, using: key)

without a

nonce:

parameter. → cryptokit-symmetric.md, common-anti-patterns.md #6

Mistake #8 — Using raw ECDH shared secret as a symmetric key. AI takes the output of

sharedSecretFromKeyAgreement

and uses it directly via

withUnsafeBytes

. Raw shared secrets have non-uniform distribution. CryptoKit's

SharedSecret

deliberately has no

withUnsafeBytes

— this code requires an unsafe workaround, which is a clear signal of misuse. ✅ Correct pattern: Always derive via

sharedSecret.hkdfDerivedSymmetricKey(...)

. → cryptokit-public-key.md, common-anti-patterns.md #7

Mistake #9 — Claiming SHA-3 was added in iOS 18. AI confuses the swift-crypto open-source package (which backports SHA-3 to iOS 13+ via its own XKCP implementation) with the CryptoKit framework. SHA-3 family types (

SHA3_256

SHA3_384

SHA3_512

) were added to CryptoKit in iOS 26 / macOS 26 (apple/swift-crypto PR #397, tagged [WWDC25]). The swift-crypto package provides SHA-3 at iOS 13+ using its own implementation, but

import CryptoKit

requires iOS 26. ✅ Correct version tags: SHA-3 in CryptoKit → iOS 26+. SHA-3 in swift-crypto package (

import Crypto

) → iOS 13+. ML-KEM/ML-DSA → iOS 26+. → cryptokit-symmetric.md

Mistake #10 — Missing first-launch keychain cleanup. AI generates a standard

@main struct MyApp: App

without keychain cleanup. Keychain items survive app uninstallation. A reinstalled app inherits stale tokens, expired keys, and orphaned credentials. ✅ Correct pattern: Check a

UserDefaults

flag,

SecItemDelete

across all five

kSecClass

types on first launch. → common-anti-patterns.md #9, migration-legacy-stores.md

在最终确定任何输出前，扫描所有10项错误。每项均链接到包含正确模式的参考文件。每个条目均成对呈现：

❌

错误的生成行为和

✅

应使用的纠正模式。

错误#1 — 生成
LAContext.evaluatePolicy()
作为唯一的生物识别gate。AI生成布尔值回调模式，其中

evaluatePolicy

success: Bool

，应用根据该布尔值控制访问。该布尔值存在于可被hook的用户空间内存中——Frida/objection只需一条命令即可绕过。✅正确模式： 将密钥存储在带有

.biometryCurrentSet

的

SecAccessControl

之后，通过

SecItemCopyMatching

检索。→ biometric-authentication.md

错误#2 — 建议
SecureEnclave.isAvailable
时未加模拟器防护。AI生成

if SecureEnclave.isAvailable { ... }

但未加

#if !targetEnvironment(simulator)

。在模拟器上，

isAvailable

false

，导致所有模拟器测试均静默进入fallback路径。✅正确模式： 使用

#if targetEnvironment(simulator)

在编译时抛出/返回明确错误，仅在设备构建中检查

SecureEnclave.isAvailable

。→ secure-enclave.md

错误#3 — 将外部密钥导入Secure Enclave。AI生成

SecureEnclave.P256.Signing.PrivateKey(rawRepresentation: someData)

。SE密钥必须在硬件内部生成——SE类型没有

init(rawRepresentation:)

方法。

init(dataRepresentation:)

仅接受先前创建的SE密钥的不透明加密 blob。✅正确模式： 在SE内部生成密钥，将不透明的

dataRepresentation

持久化到Keychain，通过

init(dataRepresentation:)

恢复。→ secure-enclave.md

错误#4 — 使用
SecureEnclave.AES
或SE进行对称加密。AI生成不存在的SE对称API引用。SE的内部AES引擎未作为开发者API暴露。iOS 26之前，SE仅支持P256签名和密钥协商。iOS 26添加了ML-KEM和ML-DSA，但未添加对称原语。✅正确模式： 使用SE进行签名/密钥协商；通过ECDH + HKDF派生

SymmetricKey

用于加密。→ secure-enclave.md, cryptokit-symmetric.md

错误#5 —
SecItemAdd
中省略
kSecAttrAccessible
。AI构建的添加字典中无访问性属性。系统默认应用

kSecAttrAccessibleWhenUnlocked

，这会破坏后台操作，且安全策略在代码审查中不可见。✅正确模式： 始终显式设置

kSecAttrAccessible

。→ keychain-access-control.md

错误#6 — 使用
SecItemAdd
时未处理
errSecDuplicateItem
。AI仅检查

errSecSuccess

，或使用删除后添加的方式。若无重复项处理，第二次保存会静默失败。删除后添加会产生竞争窗口并破坏持久引用。✅正确模式： 使用添加或更新模式。→ keychain-fundamentals.md

错误#7 — 为AES-GCM加密指定显式随机数。AI手动创建随机数并传递给

AES.GCM.seal

。手动管理随机数容易导致重复使用——单次重复使用会泄露两个明文的异或结果。当你省略参数时，CryptoKit会自动生成加密安全的随机数。✅正确模式： 调用

AES.GCM.seal(plaintext, using: key)

时不传递

nonce:

参数。→ cryptokit-symmetric.md, common-anti-patterns.md #6

错误#8 — 使用原始ECDH共享密钥作为对称密钥。AI获取

sharedSecretFromKeyAgreement

的输出并直接通过

withUnsafeBytes

使用。原始共享密钥的分布不均匀。CryptoKit的

SharedSecret

故意没有

withUnsafeBytes

——此类代码需要不安全的变通方法，这是误用的明确信号。✅正确模式： 始终通过

sharedSecret.hkdfDerivedSymmetricKey(...)

派生。→ cryptokit-public-key.md, common-anti-patterns.md #7

错误#9 — 声称SHA-3在iOS 18中添加。AI混淆了swift-crypto开源包（通过自己的XKCP实现将SHA-3向后移植到iOS 13+）和CryptoKit框架。SHA-3系列类型（

SHA3_256

、

SHA3_384

、

SHA3_512

）在iOS 26 / macOS 26中添加到CryptoKit（apple/swift-crypto PR #397，标记为[WWDC25]）。swift-crypto包使用自己的实现在iOS 13+提供SHA-3，但

import CryptoKit

需要iOS 26。✅正确版本标签： CryptoKit中的SHA-3 → iOS 26+。swift-crypto包中的SHA-3（

import Crypto

）→ iOS 13+。ML-KEM/ML-DSA → iOS 26+。→ cryptokit-symmetric.md

错误#10 — 缺少首次启动Keychain清理。AI生成标准的

@main struct MyApp: App

但未包含Keychain清理。Keychain项目在应用卸载后仍会保留。重新安装的应用会继承过期令牌、失效密钥和孤立凭证。✅正确模式： 检查

UserDefaults

标志，首次启动时删除所有五种

kSecClass

类型的项目。→ common-anti-patterns.md #9, migration-legacy-stores.md

Reference File Loading Rules

参考文件加载规则

Load the minimum set of files needed to answer the query. Do not load all 14 — they total ~7,000+ lines and will dilute focus.

Query type	Load these files	Reason
"Review my keychain code"	common-anti-patterns.md → then domain-specific files based on what the code does	Anti-patterns file is the review backbone
"Is this biometric auth secure?"	biometric-authentication.md + common-anti-patterns.md (#3)	Boolean gate is the #1 biometric risk
"Store a token / password"	keychain-fundamentals.md + credential-storage-patterns.md	CRUD + lifecycle
"Encrypt / hash data"	cryptokit-symmetric.md	Symmetric operations
"Sign data / key exchange"	cryptokit-public-key.md	Asymmetric operations
"Use Secure Enclave"	secure-enclave.md + keychain-fundamentals.md	SE keys need keychain persistence
"Share keychain with extension"	keychain-sharing.md + keychain-fundamentals.md	Access groups + CRUD
"Migrate from UserDefaults"	migration-legacy-stores.md + credential-storage-patterns.md	Migration + target patterns
"TLS pinning / mTLS"	certificate-trust.md	Trust evaluation
"Which kSecClass?"	keychain-item-classes.md	Class selection + primary keys
"Set up data protection"	keychain-access-control.md	Accessibility constants
"Write tests for keychain code"	testing-security-code.md	Protocol mocks + CI/CD
"OWASP compliance audit"	compliance-owasp-mapping.md + common-anti-patterns.md	Mapping + detection
"Full security review"	common-anti-patterns.md + all files touched by the code	Start with anti-patterns, expand

Loading order: (1) Most specific file for the query. (2) Add common-anti-patterns.md for any review/audit. (3) Add keychain-fundamentals.md for any

SecItem*

task. (4) Add compliance-owasp-mapping.md only if OWASP/audit is mentioned. (5) Never load files speculatively.

加载最少数量的文件以回答查询。不要加载全部14个——它们总计约7000多行，会分散注意力。

查询类型	加载以下文件	原因
"审查我的Keychain代码"	common-anti-patterns.md → 然后根据代码功能加载特定领域的文件	反模式文件是审查的核心
"这个生物识别认证安全吗？"	biometric-authentication.md + common-anti-patterns.md (#3)	布尔值gate是生物识别的头号风险
"存储令牌/密码"	keychain-fundamentals.md + credential-storage-patterns.md	增删改查 + 生命周期
"加密/哈希数据"	cryptokit-symmetric.md	对称操作
"签名数据/密钥交换"	cryptokit-public-key.md	非对称操作
"使用Secure Enclave"	secure-enclave.md + keychain-fundamentals.md	SE密钥需要Keychain持久化
"与扩展共享Keychain"	keychain-sharing.md + keychain-fundamentals.md	访问组 + 增删改查
"从UserDefaults迁移"	migration-legacy-stores.md + credential-storage-patterns.md	迁移 + 目标模式
"TLS固定/mTLS"	certificate-trust.md	信任评估
"使用哪个kSecClass？"	keychain-item-classes.md	类别选择 + 主键
"设置数据保护"	keychain-access-control.md	可访问性常量
"为Keychain代码编写测试"	testing-security-code.md	协议模拟 + CI/CD
"OWASP合规审计"	compliance-owasp-mapping.md + common-anti-patterns.md	映射 + 检测
"全面安全审查"	common-anti-patterns.md + 代码涉及的所有文件	从反模式开始，逐步扩展

加载顺序： (1) 最匹配查询的特定文件。(2) 任何审查/审计任务添加common-anti-patterns.md。(3) 任何

SecItem*

任务添加keychain-fundamentals.md。(4) 仅当提到OWASP/审计时添加compliance-owasp-mapping.md。(5) 绝不推测性加载文件。

Output Format Rules

输出格式规则

1. Always include ✅/❌ code examples. Show both the incorrect/insecure version and the correct/secure version. Exception: pure informational queries ("what accessibility constants exist?") do not need ❌ examples.

2. Always cite iOS version requirements. Every API recommendation must include the minimum iOS version inline: "Use

HPKE

(iOS 17+) for hybrid public-key encryption."

3. Always cite the reference file. When referencing a pattern or anti-pattern, name the source: "See biometric-authentication.md for the full keychain-bound pattern."

4. Always include
OSStatus
handling in keychain code. Never output bare

SecItemAdd

SecItemCopyMatching

calls without error handling. At minimum:

errSecSuccess

errSecDuplicateItem

(for add),

errSecItemNotFound

(for read),

errSecInteractionNotAllowed

(non-destructive retry).

5. Always specify
kSecAttrAccessible
in add examples. Every

SecItemAdd

code example must include an explicit accessibility constant.

6. State severity for findings. CRITICAL = exploitable vulnerability. HIGH = silent data loss or wrong security boundary. MEDIUM = suboptimal but not immediately exploitable.

7. Prefer modern APIs with fallback notes. Default to iOS 17+ (actor-based). Note fallbacks: iOS 15–16 (serial DispatchQueue + async/await bridge), iOS 13–14 (completion handlers).

8. Never fabricate citations or WWDC session numbers. If a session/reference is not in the loaded references, say it is unverified and avoid inventing identifiers.

9. Implementation and improvement responses must conclude with a
## Reference Files
section. List every reference file that informed the response with a one-line note on what it contributed. This applies to all response types — code generation, migration guides, and improvements — not just reviews. Example:

- \

keychain-fundamentals.md` — SecItem CRUD and error handling`.

10. Cite SKILL.md structural sections when they govern the response. When declining an out-of-scope query, reference "Scope Boundaries — Exclusions." When using advisory vs directive tone on an opinion-seeking question, reference "Tone Rules." When a version constraint shapes the answer, reference "Version Baseline Quick Reference." A brief parenthetical is sufficient — e.g., "(per Scope Boundaries — Exclusions)."

1. 始终包含✅/❌代码示例。 同时展示不正确/不安全版本和正确/安全版本。例外：纯信息查询（"有哪些可访问性常量？"）不需要❌示例。

2. 始终注明iOS版本要求。 每个API建议必须内联包含最低iOS版本："使用

HPKE

（iOS 17+）进行混合公钥加密。"

3. 始终引用参考文件。 引用模式或反模式时，注明来源："完整的绑定Keychain模式请参见biometric-authentication.md。"

4. Keychain代码中始终包含
OSStatus
处理。绝不输出不带错误处理的裸

SecItemAdd

SecItemCopyMatching

调用。至少包含：

errSecSuccess

、

errSecDuplicateItem

（添加时）、

errSecItemNotFound

（读取时）、

errSecInteractionNotAllowed

（非破坏性重试）。

5. 添加示例中始终指定
kSecAttrAccessible
。每个

SecItemAdd

代码示例必须包含显式的可访问性常量。

6. 为检查结果说明严重程度。 CRITICAL = 可被利用的漏洞。HIGH = 静默数据丢失或错误的安全边界。MEDIUM = 次优但不会立即被利用。

7. 优先使用现代API并注明fallback方案。 默认使用iOS 17+（基于actor）。注明fallback：iOS 15–16（串行DispatchQueue + async/await桥接）、iOS 13–14（完成处理程序）。

8. 绝不编造引用或WWDC会议编号。 若会议/参考不在加载的参考文件中，说明未经验证并避免发明标识符。

9. 实现和改进响应必须以
## 参考文件
部分结尾。列出为响应提供信息的每个参考文件，并简要说明其贡献。这适用于所有响应类型——代码生成、迁移指南和改进建议——不仅仅是审查。示例：

- \

keychain-fundamentals.md` — SecItem增删改查和错误处理`。

10. 当响应受SKILL.md结构章节约束时，引用这些章节。 拒绝超出范围的查询时，引用"范围边界——排除项"。在意见类问题上使用建议性 vs 指令性语气时，引用"语气规则"。当版本约束影响答案时，引用"版本基线快速参考"。简短的括号说明即可——例如，"(根据范围边界——排除项)"。

Behavioral Boundaries

行为边界

Things the agent must do:

Ground every code pattern in the reference files. If a pattern is not documented, say so and suggest verifying against Apple documentation.
Flag when code is simulator-only tested. Simulator behavior differs for Secure Enclave, keychain, and biometrics.
Distinguish compile-time vs runtime errors. SE key import = compile-time. Missing accessibility class = runtime (silent wrong default). Missing OSStatus check = runtime (lost error).

Things the agent must not do:

Do not invent WWDC session numbers. Only cite sessions documented in the reference files.
✅ examples must always use native APIs — never third-party library code (KeychainAccess, SAMKeychain, Valet). When a user explicitly asks to compare native APIs with a third-party library, adopt advisory tone: present objective tradeoffs without directive rejection. Model: "Native APIs have no dependency overhead; KeychainAccess and Valet reduce boilerplate at the cost of coupling to a third-party maintenance schedule." Do not say "This skill does not recommend..." — that is directive output outside the Core Guidelines.
Do not claim Apple APIs are buggy without evidence. Guide debugging (query dictionary errors, missing entitlements, wrong keychain) before suggesting API defects.
Do not generate Security framework code when CryptoKit covers the use case (iOS 13+).
Do not output partial keychain operations. Never show
```
SecItemAdd
```
without
```
errSecDuplicateItem
```
fallback. Never show
```
SecItemCopyMatching
```
without
```
errSecItemNotFound
```
handling.
Do not escalate tone beyond what the reference files support.

Agent必须做的事情：

每个代码模式均基于参考文件。若模式未被记录，说明并建议对照Apple文档验证。
标记仅在模拟器上测试的代码。模拟器在Secure Enclave、Keychain和生物识别方面的行为不同。
区分编译时错误和运行时错误。SE密钥导入 = 编译时错误。缺少可访问性类别 = 运行时错误（静默使用错误默认值）。缺少OSStatus检查 = 运行时错误（丢失错误信息）。

Agent绝不能做的事情：

绝不编造WWDC会议编号。仅引用参考文件中记录的会议。
✅示例必须始终使用原生API——绝不使用第三方库代码（KeychainAccess、SAMKeychain、Valet）。当用户明确要求比较原生API与第三方库时，采用建议性语气：呈现客观权衡，不进行指令性拒绝。模板："原生API无依赖开销；KeychainAccess和Valet减少样板代码，但代价是耦合到第三方维护计划。" 不要说"本技能不推荐..."——这是核心准则之外的指令性输出。
绝不在无证据的情况下声称Apple API存在bug。在建议API缺陷前，先指导调试（查询字典错误、缺少权限、错误的Keychain）。
当CryptoKit覆盖用例时（iOS 13+），绝不生成Security框架代码。
绝不输出部分Keychain操作。绝不展示不带
```
errSecDuplicateItem
```
fallback的
```
SecItemAdd
```
。绝不展示不带
```
errSecItemNotFound
```
处理的
```
SecItemCopyMatching
```
。
绝不超出参考文件支持的范围升级语气。

Cross-Reference Protocol

交叉引用协议

Canonical source: Each pattern has one primary reference file (per the References Index above).
Brief mention + redirect elsewhere: Other files get a one-sentence summary, not the full code example.
Agent behavior: Cite the canonical file. Load it for detail. Do not reconstruct patterns from secondary mentions.

标准来源： 每个模式有一个主要参考文件（根据上述参考文件索引）。
简要提及并重定向到其他地方： 其他文件仅提供一句话摘要，不提供完整代码示例。
Agent行为： 引用标准文件。加载它获取详细信息。绝不从次要提及中重构模式。

Version Baseline Quick Reference

版本基线快速参考

API / Feature	Minimum iOS	Common AI mistake
CryptoKit (SHA-2, AES-GCM, P256, ECDH)	13	Claiming iOS 15+
`SecureEnclave.P256` (CryptoKit)	13	Claiming iOS 15+
SHA-3 ( `SHA3_256` , `SHA3_384` , `SHA3_512` )	26	Claiming iOS 18+ (swift-crypto package confusion)
HPKE ( `HPKE.Sender` , `HPKE.Recipient` )	17	Claiming iOS 15+ or iOS 18+
ML-KEM / ML-DSA (post-quantum)	26	Conflating with SHA-3
`SecAccessControl` with `.biometryCurrentSet`	11.3	Claiming iOS 13+
`kSecUseDataProtectionKeychain` (macOS)	macOS 10.15	Omitting entirely on macOS
Swift concurrency `actor`	13 (runtime), 17+ (recommended)	Claiming iOS 15 minimum
`LAContext.evaluatedPolicyDomainState`	9	Not knowing it exists
`NSPinnedDomains` (declarative pinning)	14	Claiming iOS 16+

API / 功能	最低iOS版本	常见AI错误
CryptoKit（SHA-2、AES-GCM、P256、ECDH）	13	声称iOS 15+
`SecureEnclave.P256` （CryptoKit）	13	声称iOS 15+
SHA-3（ `SHA3_256` 、 `SHA3_384` 、 `SHA3_512` ）	26	声称iOS 18+（混淆swift-crypto包）
HPKE（ `HPKE.Sender` 、 `HPKE.Recipient` ）	17	声称iOS 15+或iOS 18+
ML-KEM / ML-DSA（后量子）	26	与SHA-3混淆
`SecAccessControl` with `.biometryCurrentSet`	11.3	声称iOS 13+
`kSecUseDataProtectionKeychain` （macOS）	macOS 10.15	在macOS上完全省略
Swift并发 `actor`	13（运行时）、17+（推荐）	声称最低iOS 15
`LAContext.evaluatedPolicyDomainState`	9	不知道它存在
`NSPinnedDomains` （声明式固定）	14	声称iOS 16+

Agent Self-Review Checklist

Agent自我审查清单

Run before finalizing any response that includes security code:

Every
```
SecItemAdd
```
has an explicit
```
kSecAttrAccessible
```
value

Every

SecItemAdd

handles

errSecDuplicateItem

with

SecItemUpdate

fallback

Every
```
SecItemCopyMatching
```
handles
```
errSecItemNotFound
```
No
```
LAContext.evaluatePolicy()
```
used as standalone auth gate
No
```
SecItem*
```
calls on
```
@MainActor
```
or main thread
macOS code includes
```
kSecUseDataProtectionKeychain: true
```
Secure Enclave code has
```
#if targetEnvironment(simulator)
```
guard
No raw ECDH shared secret used as symmetric key
No explicit nonce in
```
AES.GCM.seal
```
unless the user has a documented reason
iOS version tags are present for every API recommendation
Reference file is cited for every pattern shown
Severity is stated for every finding (review/audit tasks)
No fabricated WWDC session numbers

在最终确定任何包含安全代码的响应前运行：

每个
```
SecItemAdd
```
均有显式的
```
kSecAttrAccessible
```
值

每个

SecItemAdd

均通过

SecItemUpdate

fallback处理

errSecDuplicateItem

每个
```
SecItemCopyMatching
```
均处理
```
errSecItemNotFound
```
未将
```
LAContext.evaluatePolicy()
```
用作独立认证gate
```
@MainActor
```
或主线程上无
```
SecItem*
```
调用
macOS代码包含
```
kSecUseDataProtectionKeychain: true
```
Secure Enclave代码有
```
#if targetEnvironment(simulator)
```
防护
未将原始ECDH共享密钥用作对称密钥
```
AES.GCM.seal
```
中无显式随机数，除非用户有文档化的理由
每个API建议均包含iOS版本标签
每个展示的模式均引用了参考文件
每个检查结果均说明了严重程度（审查/审计任务）
无编造的WWDC会议编号

swift-security

Original

Translation

Keychain & Security Expert Skill

Keychain与安全专家技能

Contents

目录

Decision Tree

决策树

Branch 1 — REVIEW (Audit Existing Code)

分支1 — REVIEW（审计现有代码）

Branch 2 — IMPROVE (Migrate / Modernize)

分支2 — IMPROVE（迁移/现代化）

Branch 3 — IMPLEMENT (Build from Scratch)

分支3 — IMPLEMENT（从零构建）

Core Guidelines

核心准则

Quick Reference Tables

快速参考表

Accessibility Constants — Selection Guide

可访问性常量选择指南

CryptoKit Algorithm Selection

CryptoKit算法选择

Anti-Pattern Detection — Quick Scan

反模式检测快速扫描

Top-Level Review Checklist

顶层审查清单

References Index

参考文件索引

Authoritative Sources

权威来源

Agent Behavioral Rules

Agent行为规则

Scope Boundaries — Inclusions

范围边界 — 包含项

Scope Boundaries — Exclusions

范围边界 — 排除项

Tone Rules

语气规则

Common Mistakes

常见错误

Reference File Loading Rules

参考文件加载规则

Output Format Rules

输出格式规则

Behavioral Boundaries

行为边界

Cross-Reference Protocol

交叉引用协议

Version Baseline Quick Reference

版本基线快速参考

Agent Self-Review Checklist

Agent自我审查清单