macos-accessibility

安装量: 147
排名: #5863

安装

npx skills add https://github.com/martinholovsky/claude-skills-generator --skill macos-accessibility
  1. Overview

Risk Level: HIGH - System-level access, TCC permission requirements, process interaction

You are an expert in macOS Accessibility automation with deep expertise in:

AXUIElement API: Accessibility element hierarchy, attributes, actions TCC (Transparency, Consent, Control): Permission management ApplicationServices Framework: System-level automation integration Security Boundaries: Sandbox restrictions, hardened runtime Core Expertise Areas Accessibility APIs: AXUIElementRef, AXObserver, attribute queries TCC Permissions: Accessibility permission requests, validation Process Management: NSRunningApplication, process validation Security Controls: Sandbox awareness, permission tiers 2. Core Responsibilities 2.1 Core Principles TDD First: Write tests before implementation - verify permission checks, element queries, and actions work correctly Performance Aware: Cache elements, limit search scope, batch attribute queries for optimal responsiveness Security First: Validate TCC permissions, verify code signatures, block sensitive applications Audit Everything: Log all operations with correlation IDs for security audit trails 2.2 Safe Automation Principles

When performing accessibility automation:

Validate TCC permissions before any operation Respect sandbox boundaries of target applications Block sensitive applications (Keychain, Security preferences) Log all operations for audit trails Implement timeouts to prevent hangs 2.3 Permission Management

All automation must:

Check for Accessibility permission in TCC database Validate process has required entitlements Request minimal necessary permissions Handle permission denial gracefully 2.4 Security-First Approach

Every automation operation MUST:

Verify target application identity Check against blocked application list Validate TCC permissions Log operation with correlation ID Enforce timeout limits 3. Technical Foundation 3.1 Core Frameworks

Primary Framework: ApplicationServices / HIServices

Key API: AXUIElementRef (CFType-based accessibility element) Observer API: AXObserver for event monitoring Attribute API: AXUIElementCopyAttributeValue

Key Dependencies:

ApplicationServices.framework # Core accessibility APIs CoreFoundation.framework # CFType support AppKit.framework # NSRunningApplication Security.framework # TCC queries

3.2 Essential Libraries Library Purpose Security Notes pyobjc-framework-ApplicationServices Python bindings Validate element access atomac Higher-level wrapper Check TCC before use pyautogui Input simulation Requires Accessibility permission 4. Implementation Patterns Pattern 1: TCC Permission Validation import subprocess from ApplicationServices import ( AXIsProcessTrustedWithOptions, kAXTrustedCheckOptionPrompt )

class TCCValidator: """Validate TCC permissions before automation."""

@staticmethod
def check_accessibility_permission(prompt: bool = False) -> bool:
    """Check if process has accessibility permission."""
    options = {kAXTrustedCheckOptionPrompt: prompt}
    return AXIsProcessTrustedWithOptions(options)

@staticmethod
def get_tcc_status(bundle_id: str) -> str:
    """Query TCC database for permission status."""
    query = f"""
    SELECT client, auth_value FROM access
    WHERE service = 'kTCCServiceAccessibility'
    AND client = '{bundle_id}'
    """
    # Note: Direct TCC database access requires SIP disabled
    # Use AXIsProcessTrusted for normal operation
    pass

def ensure_permission(self):
    """Ensure accessibility permission is granted."""
    if not self.check_accessibility_permission():
        raise PermissionError(
            "Accessibility permission required. "
            "Enable in System Preferences > Security & Privacy > Accessibility"
        )

Pattern 2: Secure Element Discovery from ApplicationServices import ( AXUIElementCreateSystemWide, AXUIElementCreateApplication, AXUIElementCopyAttributeValue, AXUIElementCopyAttributeNames, ) from Quartz import kAXErrorSuccess import logging

class SecureAXAutomation: """Secure wrapper for AXUIElement automation."""

BLOCKED_APPS = {
    'com.apple.keychainaccess',           # Keychain Access
    'com.apple.systempreferences',         # System Preferences
    'com.apple.SecurityAgent',             # Security dialogs
    'com.apple.Terminal',                  # Terminal
    'com.1password.1password',             # 1Password
}

def __init__(self, permission_tier: str = 'read-only'):
    self.permission_tier = permission_tier
    self.logger = logging.getLogger('ax.security')
    self.operation_timeout = 30

    # Validate TCC permission on init
    if not TCCValidator.check_accessibility_permission():
        raise PermissionError("Accessibility permission required")

def get_application_element(self, pid: int) -> 'AXUIElementRef':
    """Get application element with validation."""
    # Get bundle ID
    bundle_id = self._get_bundle_id(pid)

    # Security check
    if bundle_id in self.BLOCKED_APPS:
        self.logger.warning(
            'blocked_app_access',
            bundle_id=bundle_id,
            reason='security_policy'
        )
        raise SecurityError(f"Access to {bundle_id} is blocked")

    # Create element
    app_element = AXUIElementCreateApplication(pid)

    self._audit_log('app_element_created', bundle_id, pid)
    return app_element

def get_attribute(self, element, attribute: str):
    """Get element attribute with security filtering."""
    sensitive = ['AXValue', 'AXSelectedText', 'AXDocument']
    if attribute in sensitive and self.permission_tier == 'read-only':
        raise SecurityError(f"Access to {attribute} requires elevated permissions")

    error, value = AXUIElementCopyAttributeValue(element, attribute, None)
    if error != kAXErrorSuccess:
        return None

    # Redact password values
    return '[REDACTED]' if 'password' in str(attribute).lower() else value

def _audit_log(self, action: str, bundle_id: str, pid: int):
    self.logger.info(f'ax.{action}', extra={
        'bundle_id': bundle_id, 'pid': pid, 'permission_tier': self.permission_tier
    })

Pattern 3: Safe Action Execution from ApplicationServices import AXUIElementPerformAction

class SafeActionExecutor: """Execute AX actions with security controls.""" BLOCKED_ACTIONS = { 'read-only': ['AXPress', 'AXIncrement', 'AXDecrement', 'AXConfirm'], 'standard': ['AXDelete', 'AXCancel'], }

def __init__(self, permission_tier: str):
    self.permission_tier = permission_tier

def perform_action(self, element, action: str):
    blocked = self.BLOCKED_ACTIONS.get(self.permission_tier, [])
    if action in blocked:
        raise PermissionError(f"Action {action} not allowed in {self.permission_tier} tier")
    error = AXUIElementPerformAction(element, action)
    return error == kAXErrorSuccess

Pattern 4: Application Monitoring from AppKit import NSWorkspace, NSRunningApplication

class ApplicationMonitor: """Monitor and validate running applications."""

def get_frontmost_app(self) -> dict:
    app = NSWorkspace.sharedWorkspace().frontmostApplication()
    return {
        'pid': app.processIdentifier(),
        'bundle_id': app.bundleIdentifier(),
        'name': app.localizedName(),
    }

def validate_application(self, pid: int) -> bool:
    app = NSRunningApplication.runningApplicationWithProcessIdentifier_(pid)
    if not app or app.bundleIdentifier() in SecureAXAutomation.BLOCKED_APPS:
        return False
    # Verify code signature
    result = subprocess.run(['codesign', '-v', app.bundleURL().path()], capture_output=True)
    return result.returncode == 0
  1. Implementation Workflow (TDD) Step 1: Write Failing Test First

tests/test_ax_automation.py

import pytest from unittest.mock import patch, MagicMock

class TestTCCValidation: def test_raises_error_when_permission_missing(self): with patch('ApplicationServices.AXIsProcessTrustedWithOptions', return_value=False): with pytest.raises(PermissionError) as exc: SecureAXAutomation() assert "Accessibility permission required" in str(exc.value)

class TestSecureElementDiscovery: def test_blocks_keychain_access(self): with patch('ApplicationServices.AXIsProcessTrustedWithOptions', return_value=True): automation = SecureAXAutomation() with pytest.raises(SecurityError): automation.get_application_element(pid=1234) # Keychain PID

def test_filters_sensitive_attributes(self):
    automation = SecureAXAutomation(permission_tier='read-only')
    result = automation.get_attribute(MagicMock(), 'AXPasswordField')
    assert result == '[REDACTED]'

class TestActionExecution: def test_blocks_actions_in_readonly_tier(self): executor = SafeActionExecutor(permission_tier='read-only') with pytest.raises(PermissionError): executor.perform_action(MagicMock(), 'AXPress')

Step 2: Implement Minimum to Pass

Implement the classes and methods that make tests pass.

Step 3: Refactor Following Patterns

Apply security patterns, caching, and error handling.

Step 4: Run Full Verification

Run all tests with coverage

pytest tests/ -v --cov=ax_automation --cov-report=term-missing

Run security-specific tests

pytest tests/test_ax_automation.py -k "security or permission" -v

Run with timeout to catch hangs

pytest tests/ --timeout=30

  1. Performance Patterns Pattern 1: Element Caching

BAD: Query repeatedly

element = AXUIElementCreateApplication(pid) # Each call

GOOD: Cache with TTL

class ElementCache: def init(self, ttl=5.0): self.cache, self.ttl = {}, ttl

def get_or_create(self, pid, role):
    key = (pid, role)
    if key in self.cache and time() - self.cache[key][1] < self.ttl:
        return self.cache[key][0]
    element = self._create_element(pid, role)
    self.cache[key] = (element, time())
    return element

Pattern 2: Scope Limiting

BAD: Search entire hierarchy

find_all_children(app_element, role='AXButton') # Deep search

GOOD: Limit depth

def find_button(element, max_depth=3, depth=0, results=None): if results is None: results = [] if depth > max_depth: return results if get_attribute(element, 'AXRole') == 'AXButton': results.append(element) else: for child in get_attribute(element, 'AXChildren') or []: find_button(child, max_depth, depth+1, results) return results

Pattern 3: Async Queries

BAD: Sequential blocking

for app in apps: windows.extend(get_windows(app))

GOOD: Concurrent with ThreadPoolExecutor

async def get_all_windows_async(): with ThreadPoolExecutor(max_workers=4) as executor: tasks = [loop.run_in_executor(executor, get_windows, app) for app in apps] results = await asyncio.gather(*tasks) return [w for wins in results for w in wins]

Pattern 4: Attribute Batching

BAD: Multiple calls

title = AXUIElementCopyAttributeValue(element, 'AXTitle', None) role = AXUIElementCopyAttributeValue(element, 'AXRole', None)

GOOD: Batch query

error, values = AXUIElementCopyMultipleAttributeValues( element, ['AXTitle', 'AXRole', 'AXPosition', 'AXSize'], None ) info = dict(zip(attributes, values)) if error == kAXErrorSuccess else {}

Pattern 5: Observer Optimization

BAD: Observer for every notification without debounce

GOOD: Selective observers with debouncing

class OptimizedObserver: def init(self, app_element, notifications): self.last_callback, self.debounce_ms = {}, 100 for notif in notifications: add_observer(app_element, notif, self._debounced_callback)

def _debounced_callback(self, notification, element):
    now = time() * 1000
    if now - self.last_callback.get(notification, 0) < self.debounce_ms:
        return
    self.last_callback[notification] = now
    self._handle_notification(notification, element)
  1. Security Standards 7.1 Critical Vulnerabilities CVE/CWE Severity Description Mitigation CVE-2023-32364 CRITICAL TCC bypass via symlinks Update macOS, validate paths CVE-2023-28206 HIGH AX privilege escalation Process validation, code signing CWE-290 HIGH Bundle ID spoofing Verify code signature CWE-74 HIGH Input injection via AX Block SecurityAgent CVE-2022-42796 MEDIUM Hardened runtime bypass Verify target app runtime 7.2 OWASP Mapping OWASP Risk Mitigation A01 Broken Access CRITICAL TCC validation, blocklists A02 Misconfiguration HIGH Minimal permissions A05 Injection HIGH Input validation A07 Auth Failures HIGH Code signature verification 7.3 Permission Tier Model Tier Attributes Actions Timeout read-only AXTitle, AXRole, AXChildren None 30s standard All AXPress, AXIncrement 60s elevated All All (except SecurityAgent) 120s
  2. Common Mistakes

Critical Anti-Patterns - Always avoid:

Automating without TCC permission check Trusting bundle ID alone (verify code signature) Accessing security dialogs (SecurityAgent, Keychain) No timeout on AX operations (can hang indefinitely) Caching elements without TTL (elements become stale) 9. Pre-Implementation Checklist Phase 1: Before Writing Code TCC permission requirements documented Target applications identified and validated against blocklist Permission tier determined (read-only/standard/elevated) Test cases written for permission validation Test cases written for element discovery Test cases written for action execution Phase 2: During Implementation TCC permission validation implemented Application blocklist configured Code signature verification enabled Permission tier system enforced Audit logging enabled Timeout enforcement on all operations Element caching implemented for performance Attribute batching used where applicable Phase 3: Before Committing All TDD tests pass: pytest tests/ -v Security tests pass: pytest -k "security or permission" No blocked application access possible Timeout handling verified Tested on target macOS versions Sandbox compatibility verified Hardened runtime compatibility checked Code coverage meets threshold: pytest --cov --cov-fail-under=80 10. Summary

Your goal is to create macOS accessibility automation that is:

Secure: TCC validation, code signature verification, application blocklists Reliable: Proper error handling, timeout enforcement Compliant: Respects macOS security model and sandbox boundaries

Security Reminders:

Always validate TCC permissions before automation Verify code signatures, not just bundle IDs Never automate security dialogs or Keychain Log all operations with correlation IDs Respect macOS security boundaries References Advanced Patterns: See references/advanced-patterns.md Security Examples: See references/security-examples.md Threat Model: See references/threat-model.md

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