4a9e00c226
Resolves TWO Critical CodeQL SSRF findings by implementing four-layer defense-in-depth architecture with connection-time validation and handler-level pre-validation. Phase 1 - url_testing.go: - Created ssrfSafeDialer() with atomic DNS resolution - Eliminates TOCTOU/DNS rebinding vulnerabilities - Validates IPs at connection time (runtime protection layer) Phase 2 - settings_handler.go: - Added security.ValidateExternalURL() pre-validation - Breaks CodeQL taint chain before network requests - Maintains API backward compatibility (200 OK for blocks) Defense-in-depth layers: 1. Admin access control (authorization) 2. Format validation (scheme, paths) 3. SSRF pre-validation (DNS + IP blocking) 4. Runtime re-validation (TOCTOU defense) Attack protections: - DNS rebinding/TOCTOU eliminated - URL parser differentials blocked - Cloud metadata endpoints protected - 13+ private CIDR ranges blocked (RFC 1918, link-local, etc.) Test coverage: - Backend: 85.1% → 86.4% (+1.3%) - Patch: 70% → 86.4% (+16.4%) - 31/31 SSRF test assertions passing - Added 38 new test cases across 10 functions Security validation: - govulncheck: zero vulnerabilities - Pre-commit: passing - All linting: passing Industry compliance: - OWASP SSRF prevention best practices - CWE-918 mitigation (CVSS 9.1) - Defense-in-depth architecture Refs: #450
Implementation Documentation Archive
This directory contains archived implementation documentation and historical records of feature development in Charon.
Purpose
These documents serve as historical references for:
- Feature implementation details and decisions
- Migration summaries and upgrade paths
- Investigation reports and debugging sessions
- Phase completion records
Document Index
Documents will be organized here after migration from the project root:
| Document | Description |
|---|---|
AGENT_SKILLS_MIGRATION_SUMMARY.md |
Agent skills system migration details |
BULK_ACL_FEATURE.md |
Bulk ACL feature implementation |
I18N_IMPLEMENTATION_SUMMARY.md |
Internationalization implementation |
IMPLEMENTATION_SUMMARY.md |
General implementation summary |
INVESTIGATION_SUMMARY.md |
Investigation and debugging records |
ISSUE_16_ACL_IMPLEMENTATION.md |
Issue #16 ACL implementation details |
PHASE_*_COMPLETE.md |
Phase completion documentation |
QA_*.md |
QA audit and verification reports |
SECURITY_*.md |
Security implementation records |
WEBSOCKET_FIX_SUMMARY.md |
WebSocket fix implementation |
Note
These are historical implementation records. For current documentation, refer to:
/docs/- Main documentation/README.md- Project overview/CONTRIBUTING.md- Contribution guidelines/CHANGELOG.md- Version history