import { readFileSync } from 'fs';
import { resolve } from 'path';
import { createHash } from 'crypto';

interface LockfileEntry {
  version: string;
  resolved: string;
  integrity: string;
}

interface PackageJson {
  dependencies?: Record<string, string>;
  devDependencies?: Record<string, string>;
}

export function verifyLockfileIntegrity(projectRoot: string): boolean {
  const pkgPath = resolve(projectRoot, 'package.json');
  const lockPath = resolve(projectRoot, 'package-lock.json');

  try {
    const pkg: PackageJson = JSON.parse(readFileSync(pkgPath, 'utf-8'));
    const lockfile: Record<string, LockfileEntry> = JSON.parse(readFileSync(lockPath, 'utf-8'));

    const allDeps = { ...pkg.dependencies, ...pkg.devDependencies };
    let isValid = true;

    for (const [depName, depVersion] of Object.entries(allDeps)) {
      // Normalize version range to expected lockfile key
      const lockKey = `node_modules/${depName}`;
      const entry = lockfile[lockKey];

      if (!entry) {
        console.error(`❌ Dependency ${depName} missing from lockfile.`);
        isValid = false;
        continue;
      }

      // Verify integrity hash exists and is non-empty
      if (!entry.integrity || entry.integrity.length === 0) {
        console.error(`❌ Dependency ${depName} lacks integrity hash.`);
        isValid = false;
      }

      // Optional: Verify resolved URL matches expected registry
      if (!entry.resolved.startsWith('https://registry.npmjs.org/')) {
        console.warn(`⚠️ Dependency ${depName} resolved from non-standard registry: ${entry.resolved}`);
      }
    }

    if (isValid) {
      console.log('✅ Lockfile integrity verified.');
    }
    return isValid;
  } catch (error) {
    console.error('Failed to verify lockfile:', error);
    return false;
  }
}

ompliance. Generate SBOMs in SPDX or CycloneDX format on every build.

Architecture Decision: Use cyclonedx-npm for TypeScript/Node projects. It integrates directly with npm and captures transitive dependencies accurately. Store SBOMs as build artifacts, not just in logs.

GitHub Actions Integration:

name: Supply Chain Security
on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  security:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: '20'
          cache: 'npm'

      - name: Install dependencies
        run: npm ci

      - name: Generate SBOM
        run: npx @cyclonedx/cyclonedx-npm --output-file sbom.cdx.json --output-format JSON

      - name: Upload SBOM Artifact
        uses: actions/upload-artifact@v4
        with:
          name: sbom
          path: sbom.cdx.json

      - name: Scan SBOM for Vulnerabilities
        uses: aquasecurity/trivy-action@master
        with:
          scan-type: 'fs'
          scan-ref: '.'
          format: 'table'
          severity: 'CRITICAL,HIGH'

3. Signature Verification with Sigstore

For critical dependencies, verify cryptographic signatures. Sigstore provides a framework for signing and verifying software artifacts. Cosign is the primary tool for this.

Architecture Decision: Implement signature verification for high-risk dependencies or internal libraries. This prevents tampering even if a registry is compromised.

Verification Script:

import { execSync } from 'child_process';

export function verifyDependencySignature(packageName: string, publicKeyPath: string): boolean {
  try {
    // Cosign verify command checks the signature against the public key
    // Note: In production, use keyless verification with Fulcio/Rekor for broader trust
    const command = `cosign verify --key ${publicKeyPath} ${packageName}`;
    execSync(command, { stdio: 'inherit' });
    console.log(`✅ Signature verified for ${packageName}`);
    return true;
  } catch (error) {
    console.error(`❌ Signature verification failed for ${packageName}`);
    return false;
  }
}

4. Policy Enforcement with OPA

Use Open Policy Agent (OPA) or Conftest to enforce supply chain policies as code. This allows teams to define rules like "No dependencies from unverified publishers" or "Block packages with MITM risk."

Rationale: Policy as code enables consistent enforcement across all projects and prevents developers from bypassing security controls manually.

Pitfall Guide

1. Relying on npm install in CI

Mistake: Using npm install in CI/CD pipelines. Explanation: npm install may update packages if the lockfile is missing or out of sync, introducing non-deterministic builds and potential vulnerabilities. Best Practice: Always use npm ci in CI. It strictly enforces the lockfile and is faster.

2. Ignoring Transitive Dependencies

Mistake: Only scanning direct dependencies. Explanation: Attackers often target low-level transitive dependencies that are less scrutinized. A vulnerability in a leaf dependency can compromise the entire tree. Best Practice: Use tools like Trivy, Grype, or Snyk that recursively analyze the full dependency tree.

3. Assuming Popularity Equals Security

Mistake: Trusting packages solely based on download counts or GitHub stars. Explanation: High popularity makes a package a more attractive target for hijacking or typo-squatting. Popularity does not guarantee code quality or maintainer security practices. Best Practice: Evaluate maintainership health, commit frequency, and security practices, not just metrics. Use npm audit and check for known issues regardless of popularity.

4. Static SBOMs with No Consumption Strategy

Mistake: Generating SBOMs but never using them. Explanation: An SBOM is useless if it sits in an archive. It must be integrated into vulnerability management and incident response workflows. Best Practice: Automate SBOM scanning on every build. Store SBOMs in a central repository for cross-project impact analysis during incidents.

5. Dependency Confusion Vulnerabilities

Mistake: Using internal package names that conflict with public registries. Explanation: If an internal package is named @company/utils and a malicious actor publishes @company/utils to the public registry with a higher version number, npm install may fetch the malicious public package. Best Practice: Configure .npmrc to scope internal packages to a private registry exclusively. Use npm config set @company:registry https://registry.company.com.

6. Overlooking License Compliance

Mistake: Focusing only on security vulnerabilities and ignoring licenses. Explanation: Supply chain risk includes legal liability. Copyleft licenses can force open-sourcing of proprietary code. Best Practice: Integrate license scanning (e.g., license-checker) into CI. Maintain a whitelist of approved licenses.

7. Stale Dependencies

Mistake: Freezing dependencies indefinitely. Explanation: While pinning is good, never updating dependencies accumulates technical debt and misses security patches. Best Practice: Use automated tools like Renovate or Dependabot to propose updates. Review and merge updates regularly.

Production Bundle

Action Checklist

• Pin all dependencies: Remove *, ^, and ~ ranges from production package.json; rely on lockfile for exact versions.
• Enforce npm ci: Update all CI/CD pipelines to use npm ci instead of npm install.
• Generate SBOM: Integrate CycloneDX or SPDX generator into the build pipeline; upload SBOM as an artifact.
• Scan for CVEs: Add a vulnerability scanning step (Trivy/Grype) that fails the build on CRITICAL/HIGH severity issues.
• Verify Integrity: Ensure package-lock.json contains integrity hashes for all entries; audit lockfile integrity pre-build.
• Scope Private Registries: Configure .npmrc to route scoped packages to private registries to prevent dependency confusion.
• Automate Updates: Deploy Renovate or Dependabot to monitor and propose dependency updates with security patches.
• Review New Dependencies: Require security review for PRs that add new direct dependencies; check for maintenance status and reputation.

Decision Matrix

Scenario	Recommended Approach	Why	Cost Impact
Startup / MVP	Pin + Lockfile + npm audit	Speed is priority; basic hygiene prevents most low-hanging fruit.	Low
Enterprise / Regulated	Pin + SBOM + SCA Scan + License Check + OPA Policy	Compliance requires traceability and legal safety; risk tolerance is low.	Medium
Critical Infrastructure	Pin + SBOM + Sigstore Verification + Reproducible Builds	Zero trust model; must detect tampering and ensure provenance.	High
Internal Microservices	Centralized SBOM + Dependency Scanning + Private Registry	Consistency across services; prevents drift and internal supply chain risks.	Medium
Open Source Project	Automated Dependabot + SBOM Release Asset	Community trust; enables downstream consumers to verify security.	Low

Configuration Template

.npmrc for Secure Registry Routing:

@mycompany:registry=https://npm.mycompany.com/
//npm.mycompany.com/:_authToken=${NPM_TOKEN}
strict-ssl=true

renovate.json for Automated Security Updates:

{
  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
  "extends": ["config:recommended"],
  "packageRules": [
    {
      "matchDatasources": ["npm"],
      "matchUpdateTypes": ["patch", "minor"],
      "automerge": true,
      "labels": ["dependencies"]
    },
    {
      "matchDatasources": ["npm"],
      "matchUpdateTypes": ["major"],
      "automerge": false,
      "labels": ["dependencies", "security-review"]
    }
  ],
  "vulnerabilityAlerts": {
    "labels": ["security"],
    "automerge": true
  }
}

GitHub Actions: Complete Supply Chain Workflow:

name: Secure Build Pipeline
on: [push, pull_request]

jobs:
  supply-chain:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 20
          cache: npm

      - name: Audit Signatures
        run: npm audit signatures

      - name: Install Dependencies
        run: npm ci

      - name: Generate SBOM
        run: npx @cyclonedx/cyclonedx-npm -o sbom.json

      - name: Scan Vulnerabilities
        uses: aquasecurity/trivy-action@v0.16.1
        with:
          scan-type: 'fs'
          scan-ref: '.'
          exit-code: '1'
          severity: 'CRITICAL,HIGH'

      - name: Upload SBOM
        uses: actions/upload-artifact@v4
        with:
          name: sbom-${{ github.sha }}
          path: sbom.json

Quick Start Guide

1. Audit Current State: Run npm audit and npm audit signatures in your project root. Fix reported vulnerabilities and ensure signatures are valid.
2. Lock Dependencies: Run npm install to regenerate package-lock.json. Verify all entries have integrity fields. Commit the lockfile.
3. Add SBOM Generation: Install CycloneDX: npm install -D @cyclonedx/cyclonedx-npm. Add a script to package.json: "sbom": "cyclonedx-npm -o sbom.json". Run npm run sbom to test.
4. Configure CI: Add a CI step using the provided GitHub Actions template. Ensure the pipeline fails on CRITICAL/HIGH vulnerabilities.
5. Enable Automated Updates: Add renovate.json to your repository root and configure the Renovate GitHub App. Monitor the first batch of PRs to ensure compatibility.

Supply chain security is not a feature; it is a prerequisite for production readiness. Implementing these controls reduces risk, ensures compliance, and builds resilience against the evolving threat landscape targeting software dependencies.