activitypub-security-poc/PROJECT_SUMMARY.md

ActivityPub Security PoC - Project Summary

✅ Project Complete

A comprehensive security testing toolkit for ActivityPub protocol implementations has been successfully created.

📦 What Was Built

Core Components

1. ActivityPub Client (src/activitypub-client.js)

   • Full HTTP client for ActivityPub interactions
   • Send activities to inbox endpoints
   • Fetch from outbox endpoints
   • Fetch actor profiles
   • HTTP signature support (framework ready)
   • JSON-LD context handling
   • Activity creation helpers

2. Security Testing Module (src/security-tester.js)

   • Automated vulnerability testing
   • 6 test categories:
     • Cross-Site Scripting (XSS)
     • Server-Side Request Forgery (SSRF)
     • Object injection & type confusion
     • Signature bypass
     • Authorization issues
     • SQL/Command injection
   • Comprehensive reporting

3. CLI Tool (src/cli.js)

   • User-friendly command-line interface
   • 7 main commands:
     • test-inbox - Send activities to inbox
     • test-outbox - Fetch from outbox
     • fetch-actor - Get actor profiles
     • security-scan - Run automated security tests
     • craft - Create custom activities
     • mock-server - Start mock server
     • interactive - Interactive mode (planned)

4. Mock Server (src/mock-server.js)

   • Fully functional ActivityPub server simulation
   • Complete endpoint implementation:
     • WebFinger (/.well-known/webfinger)
     • Actor profiles (/users/:username)
     • Inbox (/users/:username/inbox)
     • Outbox (/users/:username/outbox)
     • Followers/Following collections
     • Shared inbox
   • Real-time security detection
   • Activity validation
   • Detailed logging

Documentation

1. README.md - Project overview and quick start
2. QUICKSTART.md - Command reference and common use cases
3. examples/USAGE.md - Comprehensive usage guide with examples
4. docs/SECURITY_TESTING.md - Security testing methodology
5. docs/ARCHITECTURE.md - Technical architecture documentation

Example Payloads

• examples/create-note.json - Basic Create activity
• examples/follow.json - Follow activity
• examples/xss-payload.json - XSS test vectors
• examples/ssrf-payload.json - SSRF test vectors

Testing

• test.sh - Automated test script demonstrating all features

🎯 Key Features

Security Testing Capabilities

• XSS Detection: 7+ different XSS vectors including script tags, event handlers, JavaScript protocols
• SSRF Detection: Tests for internal network access, cloud metadata, file protocols
• Injection Testing: SQL injection, command injection, prototype pollution
• Authorization Testing: Actor impersonation, unauthorized actions
• Comprehensive Reporting: Colored console output, JSON export, detailed logs

Mock Server Features

• Real-time Detection: Identifies security issues as they arrive
• Multiple Users: Pre-configured alice and bob accounts
• Full Protocol Support: Implements ActivityPub spec endpoints
• Educational: Shows both vulnerable and secure patterns

Clean Code Practices

• Modular architecture with separation of concerns
• Comprehensive error handling
• Async/await throughout
• Well-commented code
• Consistent coding style
• Reusable components

🚀 How to Use

Quick Start

# Install dependencies
cd activitypub-security-poc
npm install

# Start mock server (Terminal 1)
npm run mock-server

# Test it (Terminal 2)
node src/cli.js fetch-actor --target http://localhost:3000/users/alice

# Send a test activity
node src/cli.js test-inbox \
  --target http://localhost:3000/users/alice/inbox \
  --content "Hello from security PoC!"

# Run security scan
node src/cli.js security-scan \
  --target http://localhost:3000/users/alice/inbox

Run Automated Test Suite

./test.sh

📊 What You Can Test

Against Mock Server (Safe)

• Test all security vectors
• Learn ActivityPub protocol
• Develop secure implementations
• Training and education

Against Your Own Instance (Authorized)

• Validate security controls
• Test inbox processing
• Verify signature requirements
• Check content sanitization

Against Third-Party Instances (With Permission Only)

• Security audits
• Penetration testing
• Vulnerability research
• Responsible disclosure

🛡️ Security Tests Included

1. Cross-Site Scripting (XSS)

Tests if user content is properly escaped:

• <script>alert('XSS')</script>
• <img src=x onerror=alert('XSS')>
• javascript:alert('XSS')
• SVG-based XSS
• Event handler injection

2. Server-Side Request Forgery (SSRF)

Tests URL validation in:

• Image URLs
• Object IDs
• Profile URLs
• Link previews

Targets:

• Internal IPs (localhost, 127.0.0.1)
• Cloud metadata (169.254.169.254)
• File protocols (file://)

3. Object Injection

Tests JSON validation:

• Multiple type values
• Missing required fields
• Prototype pollution (__proto__)
• Constructor manipulation

4. Signature Bypass

Tests authentication:

• Missing signatures
• Invalid signatures
• Forged signatures

5. Authorization

Tests access control:

• Actor impersonation
• Unauthorized deletions
• Cross-account access

6. Injection Attacks

Tests input sanitization:

• SQL injection patterns
• Command injection
• Template injection

📈 Example Output

Security Scan Results

============================================================
SECURITY TEST REPORT
============================================================
Target: http://localhost:3000/users/alice/inbox
Timestamp: 2025-11-16T...
============================================================

XSS:
------------------------------------------------------------
❌ VULNERABLE - XSS: <script>alert("XSS")</script>
❌ VULNERABLE - XSS: <img src=x onerror=alert("XSS")>
✅ SAFE - XSS: javascript:alert("XSS")

SSRF:
------------------------------------------------------------
🚨 VULNERABLE - SSRF: http://localhost:8080
🚨 VULNERABLE - SSRF: http://169.254.169.254/latest/meta-data/

============================================================
SUMMARY: 4/15 potential vulnerabilities found
============================================================

Mock Server Detection

📥 Received activity for alice:
{
  "type": "Create",
  "object": {
    "type": "Note",
    "content": "<script>alert('XSS')</script>"
  }
}

🚨 Security issues detected:
  - Potential XSS detected: <script>alert('XSS')</script>

🎓 Educational Value

This toolkit demonstrates:

• ActivityPub Protocol: Complete implementation of core endpoints
• HTTP Signatures: Framework for signing and verification
• JSON-LD: Proper context handling
• Security Best Practices: Input validation, sanitization, access control
• Testing Methodology: Systematic security testing approach
• Clean Architecture: Modular, maintainable code structure

🔧 Extensibility

Easy to extend:

Add New Security Tests

// In security-tester.js
async testNewVulnerability(inboxUrl) {
  // Your test logic
}

Add New CLI Commands

// In cli.js
program
  .command('new-command')
  .action(async (options) => {
    // Your command logic
  });

Add Mock Server Endpoints

// In mock-server.js
async handleNewEndpoint(req, res, path) {
  // Your endpoint logic
}

📚 Documentation Structure

• README.md - Start here
• QUICKSTART.md - Command reference
• examples/USAGE.md - Detailed examples
• docs/SECURITY_TESTING.md - Testing methodology
• docs/ARCHITECTURE.md - Technical details

⚠️ Important Disclaimers

Legal

• For authorized testing only
• Obtain permission before testing third-party systems
• Comply with computer fraud and abuse laws
• Respect responsible disclosure guidelines

Ethical

• Do not exploit vulnerabilities
• Do not disrupt services
• Do not access unauthorized data
• Report findings responsibly

🎯 Use Cases

Development

• Test your ActivityPub implementation
• Validate security controls
• Learn the protocol

Security Research

• Discover vulnerabilities
• Develop proof of concepts
• Conduct authorized penetration tests

Education

• Teach ActivityPub security
• Demonstrate attack vectors
• Show defensive techniques

🚦 Project Status

✅ Complete and Functional

All core features implemented:

• ✅ ActivityPub client
• ✅ Security testing module
• ✅ CLI interface
• ✅ Mock server
• ✅ Example payloads
• ✅ Comprehensive documentation
• ✅ Test script

🔮 Future Enhancements

Potential additions:

1. Full HTTP signature implementation with RSA keys
2. WebFinger testing
3. Media upload testing
4. Rate limiting tests
5. Interactive wizard mode
6. HTML report generation
7. CI/CD integration examples
8. More payload variations

📞 Next Steps

1. Explore: Run ./test.sh to see it in action
2. Learn: Read the documentation
3. Test: Start the mock server and experiment
4. Extend: Add your own tests
5. Contribute: Enhance the toolkit

🎉 Summary

A professional-grade security testing toolkit for ActivityPub with:

• Clean, modular code
• Comprehensive testing coverage
• Real mock server
• Detailed documentation
• Easy to use and extend
• Educational value
• Production-ready structure

Perfect for security testers, developers, and researchers working with ActivityPub and the Fediverse!