feat: Add comprehensive security vulnerability scanning system

[shashax42]

Overview

This implementation introduces a comprehensive security vulnerability scanning system for the tf-shell project to strengthen security posture and automate vulnerability detection across local development and CI/CD.

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Objectives

• Automated vulnerability scanning for Python dependencies
• Code security analysis for the Python codebase
• Integration of multiple security tools (Safety, Bandit, Semgrep, pip-audit, etc.)
• GitHub Actions CI/CD security workflow setup
• Dependabot configuration for automated dependency updates
• Full documentation and testing guide
• Local developer tooling for running security scans

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Implementation Details

Files Added / Modified

• SECURITY.md — Security policy & vulnerability reporting guidelines
• .github/dependabot.yml — Dependabot automated update config
• .github/workflows/security.yml — Comprehensive security scanning workflow for CI/CD
• requirements-security.txt — Dependencies for security scanning tools
• .bandit — Bandit scanner configuration
• tools/security_scan.py — Local security scanning script
• tools/BUILD — Bazel integration for security tools
• README.md — Security section and usage instructions added
• docs/security-testing-guide.md — Detailed testing guide for the security stack
• .gitignore — Exclude generated security reports

Integrated Security Tools

• Safety — Python dependency vulnerability scanner
• Bandit — Python code security analyzer
• Semgrep — Static analysis/security rules scanning
• pip-audit — Package vulnerability auditing
• CodeQL — GitHub semantic code analysis
• TruffleHog — Secret scanning (keys, tokens, secrets)
• Dependabot — Automated dependency update PRs

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Usage

Local Scanning

# Install security tools
pip install -r requirements-security.txt

# Run the comprehensive local security scan
python tools/security_scan.py

# Or run via Bazel
bazel run //tools:security_scanner

Automated CI/CD Behavior

• Security scans run on every pull request
• Weekly scheduled security scans via GitHub Actions
• Dependabot opens weekly dependency update PRs
• Security reports uploaded as GitHub Actions artifacts (JSON/HTML outputs)

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Benefits

• Proactive Security: Continuous vulnerability monitoring
• Developer Friendly: Easy local and CI workflows for developers
• Comprehensive Coverage: Multi-layered scanning approach across deps, code, secrets, and semantic analysis
• Automated Updates: Dependabot-driven patching workflow
• Detailed Reporting: Machine-readable reports with remediation guidance
• Standards-Aligned: Aligns with security best practices

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Testing

See docs/security-testing-guide.md for a full testing matrix covering:

• Manual testing steps
• CI/CD pipeline validation
• Per-tool functional tests (Safety, Bandit, Semgrep, pip-audit, CodeQL, TruffleHog)
• Error-handling and failure-mode verification
• Performance and regression testing

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Next Steps

1. Run the security scanner against the current codebase and review results.
2. Triage and remediate initial vulnerability findings.
3. Monitor Dependabot PRs and establish an internal review/merge process.
4. Add security metrics (e.g., time-to-remediate, number of findings) to tracking dashboards.
5. Evaluate adding extra tooling if coverage gaps appear.

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Implementation Notes

• Built following TDD principles and includes comprehensive error handling.
• Tool configurations are adjustable for project needs.
• Architecture is extensible to add new scanners or reporting outputs.
• Integrates with existing Bazel build system for consistent tool invocation.

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