Integrating Sast Into GitHub Actions Pipeline

# .github/workflows/codeql-analysis.yml
name: "CodeQL Analysis"

on:
  push:
    branches: [main, develop]
  pull_request:
    branches: [main]
  schedule:
    - cron: '30 2 * * 1'  # Weekly Monday 2:30 AM

jobs:
  analyze:
    name: Analyze (${{ matrix.language }})
    runs-on: ubuntu-latest
    permissions:
      actions: read
      contents: read
      security-events: write

    strategy:
      fail-fast: false
      matrix:
        language: ['javascript', 'python']

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Initialize CodeQL
        uses: github/codeql-action/init@v3
        with:
          languages: ${{ matrix.language }}
          queries: security-extended,security-and-quality

      - name: Autobuild
        uses: github/codeql-action/autobuild@v3

      - name: Perform CodeQL Analysis
        uses: github/codeql-action/analyze@v3
        with:
          category: "/language:${{ matrix.language }}"

# .github/workflows/semgrep.yml
name: "Semgrep SAST Scan"

on:
  pull_request:
    branches: [main, develop]
  push:
    branches: [main]

jobs:
  semgrep:
    name: Semgrep Scan
    runs-on: ubuntu-latest
    permissions:
      security-events: write
      contents: read

    container:
      image: semgrep/semgrep:latest

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Run Semgrep
        run: |
          semgrep ci \
            --config auto \
            --config p/owasp-top-ten \
            --config p/cwe-top-25 \
            --sarif --output semgrep-results.sarif \
            --severity ERROR \
            --error
        env:
          SEMGREP_APP_TOKEN: ${{ secrets.SEMGREP_APP_TOKEN }}

      - name: Upload SARIF
        if: always()
        uses: github/codeql-action/upload-sarif@v3
        with:
          sarif_file: semgrep-results.sarif
          category: semgrep

# .semgrep/custom-rules.yml
rules:
  - id: hardcoded-database-url
    patterns:
      - pattern: |
          $DB_URL = "...$PROTO://...:...$PASS@..."
    message: |
      Hardcoded database connection string with credentials detected.
      Use environment variables or a secrets manager instead.
    languages: [python, javascript, typescript]
    severity: ERROR
    metadata:
      cwe: "CWE-798: Use of Hard-coded Credentials"
      owasp: "A07:2021 - Identification and Authentication Failures"

  - id: unsafe-deserialization
    patterns:
      - pattern-either:
          - pattern: pickle.loads(...)
          - pattern: yaml.load(..., Loader=yaml.Loader)
          - pattern: yaml.load(..., Loader=yaml.FullLoader)
    message: |
      Unsafe deserialization detected. Use safe alternatives to prevent
      remote code execution vulnerabilities.
    languages: [python]
    severity: ERROR
    metadata:
      cwe: "CWE-502: Deserialization of Untrusted Data"

  - id: missing-csrf-protection
    patterns:
      - pattern: |
          @app.route("...", methods=["POST"])
          def $FUNC(...):
              ...
      - pattern-not-inside: |
          @csrf.exempt
          ...
    message: "POST endpoint may lack CSRF protection."
    languages: [python]
    severity: WARNING

# Use GitHub CLI to set branch protection requiring SAST checks
gh api repos/{owner}/{repo}/branches/main/protection \
  --method PUT \
  --field required_status_checks='{"strict":true,"contexts":["Analyze (javascript)","Analyze (python)","Semgrep Scan"]}' \
  --field enforce_admins=true \
  --field required_pull_request_reviews='{"required_approving_review_count":1}'

# codeql-config.yml - Custom CodeQL configuration
name: "Custom CodeQL Config"
queries:
  - uses: security-extended
  - uses: security-and-quality
  - excludes:
      id: js/unused-local-variable
paths-ignore:
  - '**/test/**'
  - '**/tests/**'
  - '**/vendor/**'
  - '**/node_modules/**'
  - '**/*.test.js'
  - '**/*.spec.py'

# Example: Suppressing a known false positive in Semgrep
import subprocess

def run_safe_command(cmd_list):
    # nosemgrep: python.lang.security.audit.dangerous-subprocess-use
    result = subprocess.run(cmd_list, capture_output=True, text=True, shell=False)
    return result.stdout

# Query SARIF results via GitHub API for reporting
gh api repos/{owner}/{repo}/code-scanning/alerts \
  --jq '.[] | select(.state=="open") | {rule: .rule.id, severity: .rule.security_severity_level, file: .most_recent_instance.location.path, line: .most_recent_instance.location.start_line}'

# Count open alerts by severity
gh api repos/{owner}/{repo}/code-scanning/alerts \
  --jq '[.[] | select(.state=="open")] | group_by(.rule.security_severity_level) | map({severity: .[0].rule.security_severity_level, count: length})'