# 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

```bash
# 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

```bash
./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

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

### Add New CLI Commands

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

### Add Mock Server Endpoints

```javascript
// 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!