Build Attestations and SLSA Provenance

February 27, 2026 · View on GitHub

Overview

All releases of European Parliament MCP Server include cryptographic attestations and SLSA Level 3 provenance, providing verifiable proof of build integrity and supply chain security.

Current Attestation Status

As of 2026-02-27 — pre-v1.0 status (package version 0.8.2)

Security Control	Status	Details
npm audit vulnerabilities	✅ 0	No known vulnerabilities in dependency tree
SLSA Level 3	✅ Achieved	Cryptographic provenance on all releases
License compliance	✅ Passing	All dependencies comply with the license allowlist
Test suite	✅ Passing	See docs/test-results/results.json for up-to-date test metrics
SAST (CodeQL)	✅ Enabled	Automated scanning on every PR and push
Secret scanning	✅ Enabled	GitHub native secret detection
Dependabot	✅ Enabled	Automated dependency update PRs
Sigstore signing	✅ Enabled	npm package and GitHub release artifacts
SHA-pinned actions	✅ Enforced	All critical GitHub Actions pinned to commit SHA (SLSA actions use vetted version tags)

Dependency Vulnerability Status (2026-02-27)

Package	Version	Status
@modelcontextprotocol/sdk	1.27.1	✅ Clean
lru-cache	11.2.6	✅ Clean
undici	7.22.0	✅ Clean
zod	4.3.6	✅ Clean

Note: High-severity vulnerabilities in rollup (GHSA-mw96-cpmx-2vgc) and minimatch (GHSA-3ppc-4f35-3m26, GHSA-7r86-cg39-jmmj, GHSA-23c5-xmqv-rm74) were remediated prior to the v1.0 release by updating transitive dependencies.

SLSA Level 3 Compliance

This project achieves SLSA Level 3 by meeting the following requirements:

Build Level Requirements

✅ Hermetic builds - Builds run in isolated GitHub Actions runners
✅ Retained provenance - Build provenance stored with each release
✅ Non-falsifiable - Cryptographically signed by GitHub's Sigstore
✅ Auditable - Complete build logs available
✅ Scripted build - Automated via GitHub Actions

Source Level Requirements

✅ Version controlled - Source in GitHub
✅ Two-person reviewed - Required PR reviews
✅ Retained history - Git history preserved

Provenance Requirements

✅ Available - Provenance in every release
✅ Authenticated - Signed with Sigstore
✅ Service generated - Generated by GitHub Actions
✅ Non-falsifiable - Tamper-proof signatures
✅ Dependencies complete - SBOM includes all dependencies

Verifying Attestations

Prerequisites

# Install GitHub CLI
gh auth login

# Or use gh CLI version 2.40.0+
gh version

Verify Build Provenance

# Download release artifacts
gh release download v1.0.0 --repo Hack23/European-Parliament-MCP-Server

# Verify build attestation
gh attestation verify european-parliament-mcp-server.tar.gz \
  --owner Hack23 \
  --repo European-Parliament-MCP-Server

# Expected output:
✓ Verification succeeded!

sha256:abc123... was attested by:
REPO                                PREDICATE_TYPE               WORKFLOW
Hack23/European-Parliament-MCP-Server  https://slsa.dev/provenance/v1  .github/workflows/slsa-provenance.yml@refs/tags/v1.0.0

Verify npm Package Provenance

# View provenance for published package
npm view european-parliament-mcp-server dist.attestations

# Verify npm package
npm audit signatures

Verify Checksums

# Verify artifact integrity
sha256sum -c checksums.txt

Attestation Contents

Each attestation includes:

Subject - Artifact name and SHA256 hash
Predicate Type - https://slsa.dev/provenance/v1
Builder - GitHub Actions workflow
Build Definition - Complete build parameters
Run Details - Workflow run metadata
External Parameters - Repository, ref, workflow
Internal Parameters - Build environment details
Resolved Dependencies - All build-time dependencies

SLSA Provenance Structure

{
  "_type": "https://in-toto.io/Statement/v1",
  "subject": [{
    "name": "european-parliament-mcp-server.tar.gz",
    "digest": {"sha256": "abc123..."}
  }],
  "predicateType": "https://slsa.dev/provenance/v1",
  "predicate": {
    "buildDefinition": {
      "buildType": "https://slsa.dev/build/v1",
      "externalParameters": {
        "workflow": {
          "ref": "refs/tags/v1.0.0",
          "repository": "https://github.com/Hack23/European-Parliament-MCP-Server"
        }
      },
      "resolvedDependencies": [...]
    },
    "runDetails": {
      "builder": {
        "id": "https://github.com/actions/runner/..."
      },
      "metadata": {
        "invocationId": "...",
        "startedOn": "2026-02-16T..."
      }
    }
  }
}

Security Benefits

Supply Chain Security

Tamper Detection - Any modification to artifacts invalidates attestation
Build Reproducibility - Complete build environment captured
Dependency Tracking - All build dependencies recorded
Source Traceability - Links artifact to exact source commit

Compliance

ISO 27001:2022 - A.8.30 Supplier relationships
NIST CSF 2.0 - SC.5: Integrity verification
CIS Controls v8.1 - Control 2.7: Software inventory
SLSA Level 3 - Full provenance and attestations

ISMS Policy Compliance

Troubleshooting

Attestation Verification Failed

If verification fails:

Ensure you're using gh CLI 2.40.0+
Check artifact hasn't been modified (verify checksum)
Confirm you're verifying against correct repository
Check GitHub Actions had proper permissions

Provenance Not Found

If provenance is missing:

Verify release was created via GitHub Actions
Check workflow had attestations: write permission
Ensure SLSA workflow completed successfully
Check release assets include provenance.intoto.jsonl