ct-scout

High-performance Certificate Transparency log monitor for bug bounty hunting

ct-scout monitors Certificate Transparency logs in real-time to discover newly issued SSL/TLS certificates matching your target domains. Perfect for bug bounty hunters, security researchers, and penetration testers.

🚀 Features

⭐ NEW: Phase 2 - Enterprise Automation

• PostgreSQL/Neon Database - Persistent storage with full historical analysis
• HackerOne Integration - Auto-sync watchlist from your H1 programs
• Intigriti Integration - Auto-sync watchlist from your Intigriti programs
• Zero Configuration - Just add API tokens, programs sync automatically
• Historical Queries - Query matches by domain, program, date range
• Multi-Instance Support - Shared database enables distributed deployments

Core Capabilities

• Direct CT Log Monitoring - No external dependencies, monitors CT logs directly via RFC 6962
• 187 CT Logs Supported - Monitor up to 187 logs from Google's list (exceeds gungnir's 49-60)
• Full Certificate Metadata - Extracts domains, validity dates, fingerprints, and more
• Precertificate Support - Get notified 1-5 minutes before final certificate issuance
• State Persistence - Resume monitoring from where you left off after restarts
• Multiple Output Formats - Human-readable, JSON, CSV, or Silent mode

Reliability & Performance

• Health Tracking - Automatic 404 detection with exponential backoff
• High Throughput - 36,804+ messages/minute tested
• Efficient Resource Usage - 50-250MB memory depending on log count
• 100% Parse Success Rate - Robust X.509 certificate parsing

Filtering & Organization

• Flexible Watchlist - Match domains, hosts, IPs, and CIDR ranges
• Program-Based Organization - Tag matches by bug bounty program
• Root Domain Filtering - Filter output to specific root domains
• Deduplication - Avoid duplicate notifications

Notifications

• Webhook Support - HTTP POST with HMAC-SHA256 signatures
• Live Stats - Real-time processing statistics
• Progress Indicators - Visual feedback during operation

📦 Installation

Prerequisites

• Rust 1.70 or higher
• Cargo (comes with Rust)

Build from Source

git clone https://github.com/klumz33/ct-scout.git
cd ct-scout
cargo build --release

The binary will be at ./target/release/ct-scout

🎯 Quick Start

1. Create a Configuration File

# config.toml
[logging]
level = "info"

[watchlist]
domains = ["*.example.com", "*.target.com"]
hosts = []
ips = []
cidrs = []

[ct_logs]
poll_interval_secs = 10
batch_size = 256
parse_precerts = true
max_concurrent_logs = 50
state_file = "ct-scout-state.toml"

[output]
format = "human"  # or "json", "csv", "silent"
destination = "stdout"

2. Run ct-scout

./target/release/ct-scout --config config.toml

3. Watch for Matches

[2025-12-15 12:34:56] MATCH: new.example.com
  All Domains: new.example.com, www.new.example.com
  Issuer: Let's Encrypt
  Valid: 2025-12-15 → 2026-03-15
  Fingerprint: a1b2c3d4...

📚 Configuration Options

CT Log Coverage

Standard (Default) - 36 logs, ~95% coverage:

[ct_logs]
# Uses default settings

Match gungnir - ~49-60 logs, ~97% coverage:

[ct_logs]
include_readonly_logs = true
include_pending = true

Maximum Coverage - 187 logs, 100% of Google's list:

[ct_logs]
include_all_logs = true
max_concurrent_logs = 187

Custom Logs - Add your own:

[ct_logs]
include_all_logs = true
additional_logs = [
    "https://historical-log-1.com/ct/v1/",
    "https://historical-log-2.com/ct/v1/",
]

Output Formats

Human-readable (default):

[output]
format = "human"
destination = "stdout"

JSON (for pipelines):

[output]
format = "json"
destination = "file"
file_path = "matches.jsonl"

CSV (for spreadsheets):

[output]
format = "csv"
destination = "file"
file_path = "matches.csv"

Webhook Notifications

[webhook]
url = "https://your-webhook.com/ct-alerts"
secret = "your-secret-key"
timeout_secs = 10

Webhook payload format:

{
  "timestamp": 1734262800,
  "matched_domain": "new.example.com",
  "all_domains": ["new.example.com", "www.new.example.com"],
  "cert_index": 12345678,
  "not_before": 1734262800,
  "not_after": 1741951999,
  "fingerprint": "a1b2c3d4e5f6...",
  "program_name": "Example Bug Bounty"
}

Phase 2: Database & Platform APIs

PostgreSQL/Neon Database:

[database]
enabled = true
url = "postgresql://user:pass@neon.tech/ctscout?sslmode=require"
max_connections = 20

HackerOne Integration:

[platforms.hackerone]
enabled = true
username = "your-username"
api_token = "your-h1-api-token"

Intigriti Integration:

[platforms.intigriti]
enabled = true
api_token = "your-intigriti-token"

Full Enterprise Stack:

[logging]
level = "info"

[database]
enabled = true
url = "postgresql://neon.tech/ctscout?sslmode=require"
max_connections = 20

[platforms]
sync_interval_hours = 6

[platforms.hackerone]
enabled = true
username = "your-username"
api_token = "your-h1-token"

[platforms.intigriti]
enabled = true
api_token = "your-intigriti-token"

[ct_logs]
include_all_logs = true
max_concurrent_logs = 187
parse_precerts = true

[watchlist]
# Optional - platforms will auto-populate
domains = []

[webhook]
url = "https://your-webhook.com/alerts"
secret = "your-secret"

Result: Zero-configuration bug bounty automation with full historical tracking!

Program-Based Organization

Organize targets by bug bounty program:

[[programs]]
name = "Example Bug Bounty"
domains = ["*.example.com"]

[[programs]]
name = "Target Security Program"
domains = ["*.target.com", "*.target.io"]
hosts = ["192.0.2.0/24"]

🔍 Use Cases

Bug Bounty Hunting

Monitor target domains for newly issued certificates to discover:

• New subdomains
• Development/staging environments
• Internal infrastructure
• Third-party services

Security Research

• Track certificate issuance patterns
• Identify certificate authorities used
• Monitor for suspicious certificates
• Research domain takeover opportunities

Penetration Testing

• Expand attack surface during reconnaissance
• Discover forgotten subdomains
• Find development/test environments
• Identify certificate misconfigurations

📊 Performance

Based on production testing:

Metric	Value
Throughput	36,804+ msg/min
Parse Success Rate	100%
Memory Usage	50-250MB
CT Logs Monitored	36-187 (configurable)
Coverage	95-100% of new certs

🔧 Advanced Features

Health Tracking

ct-scout automatically handles failed CT logs:

• Exponential Backoff: 1min → 2min → 4min → ... → 1hour
• Automatic Recovery: Returns to normal when logs respond
• Health Summary: Logged every 5 minutes

State Persistence

ct-scout saves its position in each CT log:

# ct-scout-state.toml (auto-generated)
"https://ct.googleapis.com/logs/argon2024/" = 12345678
"https://ct.cloudflare.com/logs/nimbus2024/" = 87654321

Resume monitoring after restart without missing entries.

Precertificate Monitoring

Enable early detection (1-5 minutes before final certificate):

[ct_logs]
parse_precerts = true  # Default: true

📖 Documentation

• QUICKSTART.md - Detailed usage guide
• PHASE1_FINAL.md - Complete feature documentation
• GUNGNIR_SUMMARY.md - Comparison with gungnir
• CERTIFICATE_METADATA_FIX.md - Technical details

🐛 Troubleshooting

No matches found

• Check your watchlist patterns: *.example.com matches subdomains only
• Verify CT logs are responding: check INFO logs for successful polls
• Increase coverage: set include_all_logs = true

High memory usage

• Reduce max_concurrent_logs
• Decrease batch_size
• Disable precertificate parsing if not needed

CT log errors

• ct-scout automatically handles 404s and failures
• Check health summary logs (every 5 minutes)
• Failed logs will retry with exponential backoff

🗺️ Roadmap

Phase 2 (Planned)

• PostgreSQL/Neon database integration
• HackerOne API integration (auto-sync watchlist)
• Intigriti API integration
• REST API server
• WebSocket streaming
• Historical backfill mode
• Prometheus metrics

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

📄 License

MIT License - see LICENSE file for details

🙏 Acknowledgments

• Certificate Transparency project
• Google's CT log list
• Rust community

📞 Support

• Issues: GitHub Issues
• Documentation: See docs/ directory

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