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Security Tooling Analysis: Additional DoD Enhancements for Charon
Document Version: 1.0 Date: January 10, 2026 Author: GitHub Copilot Security Analysis Status: RECOMMENDATION - Pending Review
Executive Summary
This document evaluates three categories of security tools for potential addition to Charon's Definition of Done: Grype (vulnerability scanner), OWASP Dependency-Check (dependency scanner), and Supply Chain Security tools (SLSA/Sigstore). The analysis examines each tool's unique value proposition, overlap with existing tools (Trivy, CodeQL, Renovate), and integration complexity.
Key Findings
| Tool Category | Recommendation | Priority | Time Impact |
|---|---|---|---|
| Grype | ❌ DO NOT ADD | N/A | N/A |
| OWASP Dependency-Check | ❌ DO NOT ADD | N/A | N/A |
| Supply Chain Security (SLSA/Sigstore) | ✅ STRONGLY RECOMMEND | HIGH | +3-5 min/build |
TL;DR: Trivy already provides comprehensive vulnerability scanning. Adding Grype or OWASP Dependency-Check would be redundant. However, supply chain security tooling (SBOM generation, attestation, and provenance) offers substantial unique value and should be prioritized for implementation.
Current Security Stack Overview
Existing Tools
| Tool | Purpose | Coverage | Execution Context |
|---|---|---|---|
| Trivy | Vulnerability, secret, and misconfiguration scanning | OS packages, Go modules, npm packages, Dockerfiles, K8s manifests | GitHub Actions (PR + push), VS Code tasks |
| CodeQL | Static application security testing (SAST) | Go, JavaScript/TypeScript source code | GitHub Actions (weekly schedule, PR, push) |
| govulncheck | Go-specific vulnerability scanning | Go modules using official Go vuln DB | GitHub Actions, VS Code tasks |
| Renovate | Automated dependency updates | Go modules, npm packages, Docker images, GitHub Actions | GitHub Actions (scheduled) |
| Pre-commit hooks | Linting, formatting, basic security checks | Local development | Developer workstation |
Coverage Analysis
What's Protected:
- ✅ OS-level vulnerabilities (Alpine packages)
- ✅ Go module vulnerabilities (govulncheck + Trivy)
- ✅ npm package vulnerabilities (Trivy + npm audit)
- ✅ Container image vulnerabilities (Trivy)
- ✅ Secrets exposure (Trivy)
- ✅ Dockerfile misconfigurations (Trivy)
- ✅ Source code vulnerabilities (CodeQL)
- ✅ Automated dependency updates (Renovate)
What's Missing:
- ❌ Software Bill of Materials (SBOM) generation
- ❌ Provenance attestation (who built what, when, how)
- ❌ Build reproducibility verification
- ❌ Supply chain integrity validation
- ❌ Artifact signing and verification
Tool Analysis
1. Grype (Anchore)
Purpose and Scope
Grype is an open-source vulnerability scanner for container images, filesystems, and SBOMs. It identifies known vulnerabilities (CVEs) in OS packages and application dependencies.
Primary Use Case: Fast vulnerability scanning of container images and artifacts using multiple vulnerability databases.
Database Coverage
| Database | Coverage | Unique to Grype? |
|---|---|---|
| NVD (National Vulnerability Database) | CVEs for all software | ❌ Trivy uses this |
| Alpine SecDB | Alpine Linux packages | ❌ Trivy uses this |
| Debian Security Tracker | Debian packages | ❌ Trivy uses this |
| Red Hat Security Data | RHEL/CentOS/Fedora | ❌ Trivy uses this |
| GitHub Advisory Database | GitHub security advisories | ❌ Trivy uses this |
| NPM Audit API | npm packages | ❌ Trivy uses this |
| Ruby Advisory Database | Ruby gems | ❌ Trivy uses this |
| Rust Advisory Database | Rust crates | ❌ Trivy uses this |
Conclusion: Grype uses the same vulnerability databases as Trivy. No unique coverage.
Overlap Analysis with Trivy
| Feature | Trivy | Grype |
|---|---|---|
| Container image scanning | ✅ | ✅ |
| Filesystem scanning | ✅ | ✅ |
| SBOM scanning | ✅ | ✅ |
| OS package vulnerabilities | ✅ | ✅ |
| Go module vulnerabilities | ✅ | ✅ |
| npm vulnerabilities | ✅ | ✅ |
| Secret scanning | ✅ | ❌ |
| Misconfiguration detection | ✅ (IaC, Docker, K8s) | ❌ |
| License scanning | ✅ | ❌ |
| SARIF output for GitHub | ✅ | ✅ |
| Database freshness | Auto-updated | Auto-updated |
| GitHub Actions integration | ✅ Native | ✅ Third-party |
| Performance (Alpine scan) | ~30-60s | ~20-40s |
Overlap: ~95% functional overlap. Grype is not a superset of Trivy—it lacks secret scanning, misconfiguration detection, and license compliance features.
Unique Value Proposition
What Grype offers that Trivy doesn't:
- ❌ None. Grype uses the same CVE databases and covers the same ecosystems.
- 🤷 Marginally faster scans (~20-30% speed improvement), but Trivy already completes in under 60 seconds for Charon's image.
- ✅ SBOM-first design: Grype can scan SBOMs generated by other tools (but Trivy can too).
What Trivy offers that Grype doesn't:
- ✅ Secret scanning (API keys, tokens, passwords)
- ✅ Misconfiguration detection (Dockerfile, Kubernetes manifests, Terraform)
- ✅ License compliance scanning
- ✅ Built-in SBOM generation (CycloneDX, SPDX)
Integration Complexity
GitHub Actions
# Grype GitHub Action (hypothetical)
- name: Run Grype scan
uses: anchore/grype-action@v1
with:
image: ghcr.io/wikid82/charon:latest
severity: CRITICAL,HIGH
output-format: sarif
Complexity: Low (drop-in replacement for Trivy action) Maintenance: Requires monitoring two vulnerability scanners instead of one
VS Code Tasks
{
"label": "Security: Grype Scan",
"type": "shell",
"command": "docker run --rm -v /var/run/docker.sock:/var/run/docker.sock anchore/grype:latest charon:local",
"group": "test"
}
Complexity: Low Maintenance: Requires Docker image pulls for both Trivy and Grype
Performance Impact
- Build time addition: +30-60 seconds (if run in parallel with Trivy)
- Cache warming: Grype maintains separate vulnerability DB cache (~200MB)
- Network bandwidth: Additional DB downloads on cache miss
Estimated DoD Impact: +1-2 minutes if run sequentially, +30s if parallelized
False Positive Rate
Community Feedback:
- 🟡 Similar FP rate to Trivy (both use NVD data, which has inherent false positives)
- 🟢 VEX (Vulnerability Exploitability eXchange) support for suppressing known FPs
- 🔴 Duplicate alerts when run alongside Trivy
Example False Positives (common to both tools):
- CVEs affecting unused/optional features (e.g., TLS bugs in binaries that don't use TLS)
- Go stdlib CVEs in third-party binaries (e.g., CrowdSec) that Charon can't fix
Maintenance Burden
- Update frequency: Grype DB updated daily (similar to Trivy)
- Configuration complexity: Low (similar to Trivy)
- Breaking changes: Moderate (major version upgrades may require config updates)
- Community support: Strong (Anchore is a major player in cloud security)
Go + React/TypeScript Fit
| Language/Stack | Support Level | Notes |
|---|---|---|
| Go modules | ✅ Excellent | Parses go.mod/go.sum |
| npm (React) | ✅ Excellent | Parses package-lock.json, yarn.lock |
| Alpine Linux | ✅ Excellent | Native support for apk packages |
| Docker images | ✅ Excellent | Primary use case |
Verdict: Perfect fit, but so is Trivy.
Grype Recommendation
❌ DO NOT ADD
Rationale:
- 95% functional overlap with Trivy — nearly all features are duplicates
- No unique vulnerability database coverage — same NVD, Alpine SecDB, GitHub Advisory DB
- Missing critical features — no secret scanning, no misconfiguration detection
- Increased maintenance burden — managing two nearly-identical tools
- Potential for alert fatigue — duplicate CVE alerts from both tools
- Marginal speed improvement (~20-30%) doesn't justify added complexity
User's Willingness to Add DoD Time: While the user is open to adding DoD time for security, this time should be invested in tools that provide unique value, not redundant coverage.
Alternative Actions:
- ✅ Keep Trivy as the primary vulnerability scanner
- ✅ Ensure Trivy scans cover all required severity levels (CRITICAL, HIGH)
- ✅ Consider Trivy VEX support to suppress known false positives
- ✅ Monitor Trivy's database freshness (currently auto-updates daily)
2. OWASP Dependency-Check
Purpose and Scope
OWASP Dependency-Check is an open-source Software Composition Analysis (SCA) tool that identifies known vulnerabilities (CVEs) in project dependencies. It supports multiple ecosystems and build tools.
Primary Use Case: Scanning application dependencies during build time to detect vulnerable libraries.
Database Coverage
| Database | Coverage | Unique to OWASP DC? |
|---|---|---|
| NVD (National Vulnerability Database) | CVEs for all software | ❌ Trivy uses this |
| OSS Index (Sonatype) | Maven/npm/Python packages | 🟡 Partial (Trivy doesn't use OSS Index directly) |
| NPM Audit API | npm packages | ❌ Trivy uses this |
| Ruby Advisory Database | Ruby gems | ❌ Trivy uses this |
| RetireJS | JavaScript library CVEs | ❌ Trivy covers this via NVD |
Unique Coverage:
- 🟡 OSS Index: Sonatype's proprietary vulnerability database with additional metadata (license info, security advisories). However, OSS Index sources most data from NVD, so overlap is >90%.
Conclusion: Minimal unique coverage. Most vulnerabilities detected by OWASP DC are already caught by Trivy.
Overlap Analysis with Trivy
| Feature | Trivy | OWASP Dependency-Check |
|---|---|---|
| Go module scanning | ✅ (go.mod, go.sum) |
✅ (via experimental analyzer) |
| npm package scanning | ✅ (package-lock.json) |
✅ |
| Container image scanning | ✅ | ❌ (filesystem only) |
| OS package scanning | ✅ (Alpine, Debian, etc.) | ❌ |
| SBOM generation | ✅ (CycloneDX, SPDX) | ✅ (OWASP format) |
| SARIF output | ✅ | ✅ |
| Secret scanning | ✅ | ❌ |
| Misconfiguration scanning | ✅ | ❌ |
| License compliance | ✅ | ❌ (deprecated) |
Overlap: ~70% functional overlap, but Trivy is a superset for Charon's use case.
Unique Value Proposition
What OWASP Dependency-Check offers that Trivy doesn't:
- 🟡 OSS Index integration: Sonatype's vulnerability DB (but mostly duplicates NVD)
- 🟡 Maven-centric tooling: Better Maven
pom.xmlanalysis (not relevant for Charon—Go backend, not Java) - ❌ No unique coverage for Go or npm in Charon's stack
What Trivy offers that OWASP DC doesn't:
- ✅ Container image scanning (Charon's primary artifact)
- ✅ OS package vulnerabilities (Alpine Linux)
- ✅ Secret scanning
- ✅ Misconfiguration detection (Dockerfile, K8s manifests)
- ✅ Faster execution (30-60s vs. 2-5 minutes for DC)
Integration Complexity
GitHub Actions
# OWASP Dependency-Check Action
- name: Run OWASP Dependency-Check
uses: dependency-check/Dependency-Check_Action@main
with:
project: 'Charon'
path: '.'
format: 'SARIF'
Complexity: Moderate Issues:
- Requires NVD API key or local DB download (~500MB-1GB cache)
- First run takes 5-10 minutes to download NVD data
- Subsequent runs: 2-5 minutes
VS Code Tasks
{
"label": "Security: OWASP Dependency-Check",
"type": "shell",
"command": "dependency-check --project Charon --scan . --format SARIF --out dependency-check-report.sarif",
"group": "test"
}
Complexity: High Prerequisites:
- Install dependency-check CLI via Homebrew, Docker, or manual download
- Configure NVD API key (optional but recommended to avoid rate limits)
- Manage local NVD cache (~1GB)
Performance Impact
- Initial run: 5-10 minutes (NVD database download)
- Subsequent runs: 2-5 minutes (depends on cache freshness)
- Cache size: ~500MB-1GB (NVD data)
- Network bandwidth: High on cache miss
Estimated DoD Impact: +2-5 minutes per build (significantly slower than Trivy's 30-60s)
False Positive Rate
Community Feedback:
- 🔴 High false positive rate for npm and Go modules
- Example: Reports CVEs for dev dependencies that aren't in production builds
- Example: Flags Go stdlib CVEs in
go.modeven when not used in compiled binary
- 🔴 Poor CPE (Common Platform Enumeration) matching for non-Java ecosystems
- OWASP DC was originally designed for Java/Maven; Go and npm support is newer and less mature
- 🟢 Suppression file support (XML-based) to ignore known FPs
Example False Positive:
- OWASP DC may flag CVEs for
node_modulesdependencies that are only used in tests or dev builds, not shipped in the Docker image.
Maintenance Burden
- Update frequency: NVD data updated daily (requires re-download or API sync)
- Configuration complexity: High (XML config files, suppression files, analyzers)
- Breaking changes: Moderate (major version upgrades may break XML configs)
- Community support: Strong (OWASP Foundation backing)
Go + React/TypeScript Fit
| Language/Stack | Support Level | Notes |
|---|---|---|
| Go modules | 🟡 Experimental | Parses go.mod but less mature than Trivy's Go analyzer |
| npm (React) | ✅ Good | Parses package-lock.json, yarn.lock |
| Alpine Linux | ❌ Not supported | Cannot scan OS packages |
| Docker images | ❌ Not supported | Filesystem-only tool |
Verdict: Poor fit for Charon. Go support is experimental, and Docker image scanning (Charon's primary artifact) is not supported.
OWASP Dependency-Check Recommendation
❌ DO NOT ADD
Rationale:
- 70% functional overlap with Trivy, but Trivy is superior for Charon's stack
- No unique value for Go or npm ecosystems — Trivy's Go/npm analyzers are more mature
- Cannot scan Docker images — Charon's primary security artifact
- Significantly slower — 2-5 minutes vs. Trivy's 30-60s
- High false positive rate for non-Java ecosystems
- Complex configuration — XML-based configs vs. Trivy's simple CLI flags
- Poor fit for Alpine Linux + Docker — OWASP DC doesn't scan OS packages
User's Willingness to Add DoD Time: While the user is open to adding DoD time, OWASP Dependency-Check would add 2-5 minutes for minimal unique value. This time is better spent on supply chain security tooling (SBOM, attestation).
Alternative Actions:
- ✅ Keep Trivy as the primary dependency scanner
- ✅ Ensure Trivy scans both
backend/go.modandfrontend/package-lock.json - ✅ Enable Trivy's SBOM generation feature (already supported)
3. Supply Chain Security (SLSA, Sigstore, SBOM)
Purpose and Scope
Supply chain security tools address vulnerabilities in the build and distribution process, not just the code itself. They provide provenance attestation (proof of how an artifact was built), artifact signing (cryptographic verification), and Software Bills of Materials (SBOMs) (ingredient lists for software).
Primary Use Case: Prove that artifacts are built from trusted sources, by trusted actors, using secure processes.
Key Technologies
3.1. SLSA (Supply-chain Levels for Software Artifacts)
What it is: A security framework with 4 compliance levels (SLSA 0-4) that define best practices for securing the software supply chain.
SLSA Levels:
- SLSA 0: No guarantees (current state of most projects)
- SLSA 1: Build process documented (provenance exists)
- SLSA 2: Signed provenance, version-controlled build scripts
- SLSA 3: Source and build platform hardened, non-falsifiable provenance
- SLSA 4: Two-party review of all changes, hermetic builds
What it protects against:
- ✅ Source tampering (e.g., compromised GitHub account modifying code)
- ✅ Build tampering (e.g., malicious CI/CD job injecting backdoors)
- ✅ Artifact substitution (e.g., attacker replacing published Docker image)
- ✅ Dependency confusion (e.g., typosquatting attacks)
Relevance to Charon:
- ✅ Docker images are signed and attested
- ✅ Users can verify image provenance before deployment
- ✅ Compliance with enterprise security policies (e.g., NIST SSDF, EO 14028)
3.2. Sigstore/Cosign
What it is: Open-source keyless signing and verification for software artifacts using ephemeral keys and transparency logs.
Core Components:
- Cosign: CLI tool for signing and verifying container images, blobs, and SBOMs
- Fulcio: Certificate authority for keyless signing (OIDC-based)
- Rekor: Transparency log for immutable artifact signatures
Keyless Signing: No need to manage private keys—sign with OIDC identity (GitHub, Google, Microsoft).
What it protects against:
- ✅ Image tampering (unsigned images rejected)
- ✅ Man-in-the-middle attacks (cryptographic verification)
- ✅ Registry compromise (even if registry is hacked, signatures can't be forged)
Relevance to Charon:
- ✅ Sign Docker images automatically in GitHub Actions
- ✅ Users verify signatures before pulling images
- ✅ Integrate with admission controllers (e.g., Kyverno, OPA) for Kubernetes deployments
3.3. SBOM (Software Bill of Materials)
What it is: A machine-readable inventory of all components in a software artifact (dependencies, libraries, versions, licenses).
Formats:
- CycloneDX (OWASP standard, JSON/XML)
- SPDX (Linux Foundation standard, JSON/YAML/RDF)
What it protects against:
- ✅ Unknown vulnerabilities (enables future retrospective scanning)
- ✅ Compliance violations (tracks license obligations)
- ✅ Supply chain attacks (identifies compromised dependencies)
Relevance to Charon:
- ✅ Generate SBOM for Docker image in CI/CD
- ✅ Attach SBOM to image as attestation
- ✅ Enable users to audit Charon's dependencies
Overlap Analysis with Existing Tools
| Feature | Trivy | CodeQL | Renovate | Supply Chain Tools |
|---|---|---|---|---|
| Vulnerability scanning | ✅ | ✅ | ❌ | ❌ (not primary purpose) |
| Dependency updates | ❌ | ❌ | ✅ | ❌ |
| SBOM generation | ✅ (basic) | ❌ | ❌ | ✅ (comprehensive) |
| Provenance attestation | ❌ | ❌ | ❌ | ✅ |
| Artifact signing | ❌ | ❌ | ❌ | ✅ |
| Build reproducibility | ❌ | ❌ | ❌ | ✅ |
| Transparency logs | ❌ | ❌ | ❌ | ✅ (Rekor) |
| Keyless cryptography | ❌ | ❌ | ❌ | ✅ (Fulcio) |
Overlap: ~10% functional overlap. Supply chain tools are complementary, not replacements.
Unique Value Proposition
What supply chain security offers that current tools don't:
| Threat Model | Current Tools | Supply Chain Tools |
|---|---|---|
| Compromised maintainer account | ❌ Not detected | ✅ Provenance shows who built artifact |
| Malicious CI/CD job | ❌ Not detected | ✅ Signed provenance prevents tampering |
| Registry compromise | ❌ Not detected | ✅ Signature verification fails for tampered images |
| Dependency confusion | 🟡 Partial (Renovate checks sources) | ✅ SBOM tracks all dependencies |
| Backdoored dependency | 🟡 Partial (Trivy scans for known CVEs) | ✅ SBOM enables retrospective analysis |
| Compliance (EO 14028, NIST SSDF) | ❌ Not addressed | ✅ SLSA levels provide compliance framework |
Real-World Attacks Prevented:
- ✅ SolarWinds (2020): Provenance attestation would have shown build artifacts were tampered
- ✅ Codecov (2021): Signed artifacts would have prevented malicious script injection
- ✅ npm package hijacking: SBOM would enable tracking affected downstream projects
Integration Complexity
GitHub Actions
Step 1: Generate SBOM
Already implemented in Charon's .github/workflows/docker-build.yml:
- name: Generate SBOM
uses: anchore/sbom-action@v0.21.0
with:
image: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@${{ steps.build-and-push.outputs.digest }}
format: cyclonedx-json
output-file: sbom.cyclonedx.json
Step 2: Attest SBOM
Already implemented:
- name: Attest SBOM
uses: actions/attest-sbom@v3.0.0
with:
subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
subject-digest: ${{ steps.build-and-push.outputs.digest }}
sbom-path: sbom.cyclonedx.json
push-to-registry: true
Step 3: Sign Docker Image with Cosign (NEW)
- name: Install Cosign
uses: sigstore/cosign-installer@v3.4.0
- name: Sign image with Cosign (keyless)
env:
COSIGN_EXPERIMENTAL: 1
run: |
cosign sign --yes \
${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@${{ steps.build-and-push.outputs.digest }}
Step 4: Generate SLSA Provenance (NEW)
- name: Generate SLSA Provenance
uses: slsa-framework/slsa-github-generator/.github/workflows/generator_container_slsa3.yml@v1.9.0
with:
image: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
digest: ${{ steps.build-and-push.outputs.digest }}
registry-username: ${{ github.actor }}
registry-password: ${{ secrets.GITHUB_TOKEN }}
Complexity: Low-to-Moderate
Prerequisites: Enable GitHub Actions' id-token: write permission (already enabled)
Maintenance: Minimal (actions auto-update with Renovate)
VS Code Tasks (Verification)
{
"label": "Security: Verify Image Signature",
"type": "shell",
"command": "cosign verify --certificate-identity-regexp='https://github.com/Wikid82/charon' --certificate-oidc-issuer='https://token.actions.githubusercontent.com' ghcr.io/wikid82/charon:latest",
"group": "test"
}
Complexity: Low
Prerequisites: Install Cosign locally (brew install cosign)
Performance Impact
| Step | Time Addition | Notes |
|---|---|---|
| SBOM generation | ✅ Already implemented | No additional time (already in CI/CD) |
| SBOM attestation | ✅ Already implemented | No additional time (already in CI/CD) |
| Cosign signing | +30-60 seconds | Keyless signing via OIDC |
| SLSA provenance | +60-120 seconds | Generates and attaches provenance |
| Rekor transparency log | Included in above | Automatic with Cosign |
Total Estimated DoD Impact: +1.5-3 minutes per build
Mitigation: Run signing and provenance generation after tests pass, in parallel with other post-build steps.
False Positive Rate
N/A — Supply chain tools don't scan for vulnerabilities, so false positives are not applicable. They provide cryptographic proof of integrity, which is either valid or invalid.
Potential Issues:
- 🟡 Signature verification failure if OIDC identity changes (e.g., repo renamed)
- 🟡 Provenance mismatch if build scripts are modified without updating attestation
- 🟢 These are security failures, not false positives — they indicate tampering or misconfiguration
Maintenance Burden
| Component | Update Frequency | Configuration Complexity | Breaking Changes |
|---|---|---|---|
| Cosign | Monthly (via Renovate) | Low (CLI flags) | Low (stable API) |
| SLSA Generator | Quarterly | Low (GitHub Action) | Low (versioned) |
| SBOM Action | Monthly | Low (GitHub Action) | Low |
| Rekor | N/A (hosted by Sigstore) | None | None |
Overall Maintenance Burden: Low
- Actions auto-update with Renovate
- No local secrets to manage (keyless signing)
- Public Sigstore infrastructure (no self-hosting required)
Go + React/TypeScript Fit
| Language/Stack | Support Level | Notes |
|---|---|---|
| Go modules | ✅ Excellent | Syft (SBOM generator) parses go.mod |
| npm (React) | ✅ Excellent | Syft parses package-lock.json |
| Alpine Linux | ✅ Excellent | Syft parses apk packages |
| Docker images | ✅ Excellent | Primary use case for Cosign/SLSA |
Verdict: Perfect fit. Supply chain tools are designed for modern polyglot projects.
Supply Chain Security Recommendation
✅ STRONGLY RECOMMEND
Rationale:
- Unique value: Addresses threats that Trivy/CodeQL/Renovate don't cover (build tampering, artifact substitution)
- Minimal overlap: Complementary to existing tools, not redundant
- Low maintenance: Keyless signing eliminates secret management burden
- Compliance: Meets NIST SSDF, EO 14028, and enterprise security policies
- Industry trend: Leading cloud providers (AWS, Azure, GCP) are adopting Sigstore
- Charon already has SBOM generation: 50% of the work is done; just add signing and provenance
User's Willingness to Add DoD Time: This is the highest-value addition for the time invested (+3-5 minutes per build).
Priority Ranking
| Priority | Recommendation | Time Impact | Justification |
|---|---|---|---|
| 🔴 HIGH | Cosign Image Signing | +30-60s | Protects against image tampering, registry compromise |
| 🔴 HIGH | SLSA Provenance | +1-2 min | Proves build integrity, meets compliance requirements |
| 🟢 MEDIUM | SBOM Verification Workflow | +15-30s | Already generating SBOMs; add verification step |
| 🟡 LOW | Rekor Transparency Log Monitoring | +5-10s | Optional: Monitor Rekor for unauthorized signatures |
Recommended Implementation Plan
Phase 1: Cosign Image Signing (Week 1)
Goal: Sign all published Docker images with keyless Cosign.
Step 1.1: Add Cosign to GitHub Actions
# .github/workflows/docker-build.yml
- name: Install Cosign
uses: sigstore/cosign-installer@v3.4.0
- name: Sign Docker image
if: github.event_name != 'pull_request'
env:
COSIGN_EXPERIMENTAL: 1
run: |
cosign sign --yes \
${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@${{ steps.build-and-push.outputs.digest }}
Prerequisites:
- ✅ GitHub Actions already has
id-token: writepermission (enabled indocker-build.yml)
Step 1.2: Add VS Code Task for Signature Verification
// .vscode/tasks.json
{
"label": "Security: Verify Image Signature",
"type": "shell",
"command": ".github/skills/scripts/skill-runner.sh security-verify-signature",
"group": "test"
}
Create Skill Script:
# .github/skills/scripts/security-verify-signature-scripts/run.sh
#!/bin/bash
set -euo pipefail
IMAGE="${1:-ghcr.io/wikid82/charon:latest}"
echo "🔍 Verifying signature for $IMAGE"
cosign verify \
--certificate-identity-regexp='https://github.com/Wikid82/charon' \
--certificate-oidc-issuer='https://token.actions.githubusercontent.com' \
"$IMAGE"
echo "✅ Signature verified"
Step 1.3: Document in SECURITY.md
Add section:
### Artifact Signing
All Charon Docker images are signed with [Sigstore Cosign](https://github.com/sigstore/cosign) using keyless signing.
**Verify image signature:**
```bash
cosign verify \
--certificate-identity-regexp='https://github.com/Wikid82/charon' \
--certificate-oidc-issuer='https://token.actions.githubusercontent.com' \
ghcr.io/wikid82/charon:latest
Signatures are logged in the public Rekor transparency log.
**Estimated Time:** 2-4 hours
**DoD Impact:** +30-60 seconds per build
---
### Phase 2: SLSA Provenance (Week 2)
**Goal:** Generate SLSA Level 3 provenance for Docker images.
#### Step 2.1: Add SLSA Provenance Generation
```yaml
# .github/workflows/docker-build.yml
- name: Generate SLSA Provenance
if: github.event_name != 'pull_request'
uses: slsa-framework/slsa-github-generator/.github/workflows/generator_container_slsa3.yml@v1.9.0
with:
image: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
digest: ${{ steps.build-and-push.outputs.digest }}
registry-username: ${{ github.actor }}
registry-password: ${{ secrets.GITHUB_TOKEN }}
Step 2.2: Add SLSA Badge to README
[](https://slsa.dev)
Step 2.3: Document in SECURITY.md
### Build Provenance
Charon follows [SLSA Level 3](https://slsa.dev/spec/v1.0/levels) practices for build integrity:
- ✅ Builds run on GitHub-hosted runners (hardened build platform)
- ✅ Provenance is signed and immutable
- ✅ Source code is version-controlled
- ✅ Build process is documented and reproducible
**View provenance:**
```bash
cosign verify-attestation \
--type slsaprovenance \
--certificate-identity-regexp='https://github.com/Wikid82/charon' \
--certificate-oidc-issuer='https://token.actions.githubusercontent.com' \
ghcr.io/wikid82/charon:latest
**Estimated Time:** 4-6 hours
**DoD Impact:** +1-2 minutes per build
---
### Phase 3: SBOM Verification Workflow (Week 3)
**Goal:** Add verification step to ensure SBOM is signed and attached.
#### Step 3.1: Add SBOM Verification
```yaml
# .github/workflows/docker-build.yml
- name: Verify SBOM Attestation
if: github.event_name != 'pull_request'
run: |
cosign verify-attestation \
--type cyclonedx \
--certificate-identity-regexp='https://github.com/Wikid82/charon' \
--certificate-oidc-issuer='https://token.actions.githubusercontent.com' \
${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@${{ steps.build-and-push.outputs.digest }} | jq
Estimated Time: 1-2 hours DoD Impact: +15-30 seconds per build
Total Implementation Estimate
| Phase | Estimated Time | DoD Impact | Risk Level |
|---|---|---|---|
| Phase 1: Cosign Signing | 2-4 hours | +30-60s | 🟢 Low |
| Phase 2: SLSA Provenance | 4-6 hours | +1-2 min | 🟡 Moderate |
| Phase 3: SBOM Verification | 1-2 hours | +15-30s | 🟢 Low |
| TOTAL | 7-12 hours | +2-4 min/build | 🟢 Low |
Rollback Plan:
- Phase 1 and 2 can be disabled by removing steps from
docker-build.yml - Phase 3 is non-blocking (verification failure logs a warning, doesn't fail the build)
Updated Definition of Done (Post-Implementation)
Current DoD (Security Section)
## Security
- [ ] All security scans pass with zero CRITICAL/HIGH vulnerabilities
- [ ] Trivy container image scan (no CVEs)
- [ ] govulncheck Go module scan (no known vulnerabilities)
- [ ] CodeQL static analysis (no security findings)
- [ ] No secrets exposed in code or container image
- [ ] No misconfiguration issues (Dockerfile, K8s manifests)
- [ ] Renovate PR created for dependency updates (if applicable)
Proposed DoD (with Supply Chain Security)
## Security
- [ ] All security scans pass with zero CRITICAL/HIGH vulnerabilities
- [ ] Trivy container image scan (no CVEs)
- [ ] govulncheck Go module scan (no known vulnerabilities)
- [ ] CodeQL static analysis (no security findings)
- [ ] No secrets exposed in code or container image
- [ ] No misconfiguration issues (Dockerfile, K8s manifests)
- [ ] Renovate PR created for dependency updates (if applicable)
- [ ] **Supply Chain Security** (for Docker image releases)
- [ ] SBOM generated and attached to image
- [ ] SBOM attestation signed and verifiable
- [ ] Docker image signed with Cosign
- [ ] SLSA provenance generated and signed
- [ ] Signatures logged in Rekor transparency log
Comparison Summary
| Tool | Value | Overlap | Maintenance | Time Impact | Recommendation |
|---|---|---|---|---|---|
| Grype | ❌ Low | 95% with Trivy | Moderate | +1-2 min | ❌ DO NOT ADD |
| OWASP Dependency-Check | ❌ Low | 70% with Trivy | High | +2-5 min | ❌ DO NOT ADD |
| Supply Chain (SLSA/Cosign) | ✅ High | 10% with existing tools | Low | +3-5 min | ✅ STRONGLY RECOMMEND |
Key Decision Factors
Why NOT Grype or OWASP Dependency-Check?
- Trivy is a superset: Covers vulnerabilities + secrets + misconfigurations
- Same vulnerability databases: No unique CVE coverage
- Slower execution: 2-5 min vs. Trivy's 30-60s
- Increased maintenance: Managing multiple overlapping tools
- Alert fatigue: Duplicate CVE notifications
Why SLSA/Sigstore/SBOM?
- Unique threat model: Protects against supply chain attacks that Trivy can't detect
- Minimal overlap: Complementary to existing tools
- Compliance: Meets NIST SSDF, EO 14028 requirements
- Industry adoption: Standard practice for secure software distribution
- Low maintenance: Keyless signing, auto-updating GitHub Actions
- Already 50% done: Charon already generates SBOMs; just add signing/provenance
Conclusion
Final Recommendation:
- ❌ DO NOT ADD Grype or OWASP Dependency-Check — redundant with Trivy, no unique value
- ✅ ADD Supply Chain Security Tooling — high-value, low-maintenance, addresses unique threats
- 🎯 Prioritize Cosign signing first (highest impact, lowest time investment)
- 📊 Implement SLSA provenance next (compliance benefit, moderate time investment)
- 🔍 Add SBOM verification last (nice-to-have, minimal time investment)
Expected Benefits:
- ✅ Cryptographic proof of artifact integrity
- ✅ Compliance with federal/enterprise security mandates
- ✅ Protection against supply chain attacks (e.g., SolarWinds-style compromises)
- ✅ Transparent audit trail via Rekor transparency log
- ✅ User confidence in artifact authenticity
Total Time Investment: 7-12 hours of implementation, +3-5 minutes per build
Next Steps:
- Review this analysis with maintainers
- Approve Phase 1 (Cosign signing) for immediate implementation
- Create GitHub issues for Phase 2 and 3
- Update SECURITY.md and README.md with new capabilities
Document Status: DRAFT - Awaiting Maintainer Review Last Updated: January 10, 2026 Version: 1.0