Verify SLSA with Harness GitHub Actions

Use Harness GitHub Actions to Verify SLSA Provenance

Harness GitHub Actions provide a seamless way to integrate Harness's Software Supply Chain Security (SCS) capabilities directly into GitHub workflows. You can use this GitHub Action to perform various supply chain security tasks. The Harness GitHub Action includes multiple sub-actions, each designed for specific tasks. This document focuses on the harness/github-actions/slsa-verification sub-action, which is used to generate an SBOM and attest it if needed.

The harness/github-actions/slsa-verification verifies the SLSA provenance attestation by pulling the .att file from the configured container registry. It uses the public key from the key pair that was used for signing the attestation to perform the verification.

Requirements

Here are the prerequisites for using the GitHub Action.

1. Harness Account: Ensure you have a Harness account with the SCS license enabled.

2. Harness Account Details: Save the following Harness account details, which are required for all sub-actions. It is recommended to securely store these values using GitHub Secrets.

Key	Value Example	Description	Required
HARNESS_ACCOUNT_URL	https://example.harness.io	The URL of your Harness account.	Yes
HARNESS_ACCOUNT_ID	ppdfedDDDL_dharzdPs_JtWT7g	The unique identifier for your Harness account.	Yes
HARNESS_ORG_ID	SCS	The identifier for your Harness organization.	Yes
HARNESS_PROJECT_ID	SCS_ORG	The identifier for your Harness project within the organization.	Yes
HARNESS_API_KEY	${{ secrets.SCS_API_KEY }}	The API key for authenticating with Harness. Create an API key using a Service Account (recommended) or a Personal Account , and then add the key to GitHub Actions Secrets with "HARNESS_API_KEY" as the key name.	Yes
VAULT_ADDR	https://myvault.example.com	The URL of your Vault	No

1. Security Keys: For attestation generation and verification, Key pair is required. The key should be generated using Cosign of type ecdsa-P256. Currently, HashiCorp Vault is supported for storing and retrieving the key. Additional Key Management Services (KMS) will be supported in the future.

Usage example

- name: SLSA Verification
  uses: harness/github-actions/slsa-verification@1.1.0
  with:
    HARNESS_ACCOUNT_URL: https://myaccount.harness.io
    HARNESS_ACCOUNT_ID: my_account_id_9YpRharzPs
    HARNESS_ORG_ID: my_org_id_default
    HARNESS_PROJECT_ID: example_project_id
    HARNESS_API_KEY: ${{ secrets.API_KEY_SAVED_AS_GH_SECRET }}
    VAULT_ADDR: ${{ secrets.VAULT_URL }}
    TARGET: example_image:latest
    VERIFY: true
    KMS_KEY: path/to/your/key

Configuration

Make sure to include the required configurations from the Requirements section in your workflow. Below are the specific configurations for the slsa-verification sub-action.

Key	Value Example	Description	Required
TARGET	example_image:latest	The target artifact (Docker image) for which SLSA provenance verification is performed.	Yes
VERIFY	true or false	Boolean flag to determine if verification is required.	Yes
KMS_KEY	path/to/your/key	Path to the public key used for verifying the attestation.	No

Sample workflow

Here is a sample workflow using the harness/github-actions/slsa-verification

name: SLSA Provenance Verification Workflow

on:
  push:
    branches: [main]

jobs:
  combined-workflow:
    runs-on: ubuntu-latest
    env:
      HARNESS_ACCOUNT_URL: 'https://app.harness.io'
      HARNESS_ACCOUNT_ID: '_mya_account_cbjhwbcw'
      HARNESS_ORG_ID: 'SCS'
      HARNESS_PROJECT_ID: 'SCS_ID'
      HARNESS_API_KEY: ${{ secrets.SCS_API_KEY }}

    steps:
      # Step 1: Checkout the main repository
      - name: Checkout Main Repository
        uses: actions/checkout@v3

      # Step 2: Clone Additional Repository
      - name: Clone Additional Repository
        run: |
          git clone https://github.com/lavakush07/easybuggy-vulnerable-application
          echo "Cloned additional repository: docker-nginx"

      # Step 3: Log in to Docker Hub
      - name: Log in to Docker Hub
        uses: docker/login-action@v2
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}

      - name: Set Vault Environment Variables
        run: |
          echo "DOCKER_USERNAME=${{ secrets.DOCKER_USERNAME }}" >> $GITHUB_ENV
          echo "DOCKER_PASSWORD=${{ secrets.DOCKER_PASSWORD }}" >> $GITHUB_ENV

      # Step 4: Build and Tag Docker Image
      - name: Build and Tag Docker Image
        run: |
          cd <repo-name>
          docker build -t <image-name>:<tag> .
          echo "Docker image built and tagged as <image-name>:<tag>"

      # Step 5: Push the Docker Image to Docker Hub
      - name: Push Docker Image
        run: |
          docker push <image-name>:<tag>
          echo "Docker image pushed to Docker Hub"

      # Step 6: Log in to Vault
      - name: Log in to Vault
        uses: hashicorp/vault-action@v2
        id: vault_login
        with:
          url: ${{ secrets.VAULT_URL }}
          method: token
          token: ${{ secrets.VAULT_TOKEN }}

      # Step 7: Set Vault Environment Variables
      - name: Set Vault Environment Variables
        run: |
          echo "VAULT_ADDR=${{ secrets.VAULT_URL }}" >> $GITHUB_ENV
          echo "VAULT_TOKEN=${{ steps.vault_login.outputs.token }}" >> $GITHUB_ENV

      # Step 8: Retrieve KMS key (Cosign) from Vault
    
      - name: Retrieve Cosign Public Key from Vault
        run: |
          export COSIGN_KEY=$(vault kv get -field=public_key -mount="secret1/cosign-key" "cosign-key")
          echo "COSIGN_KEY=$COSIGN_KEY" >> $GITHUB_ENV

      - name: Verify Vault Login and Print Token
        run: |
          echo "Vault login successful."
          echo "Vault Token: ${{ steps.vault_login.outputs.token }}"
        env:
          VAULT_TOKEN: ${{ steps.vault_login.outputs.token }}  # Ensuring token is accessible

      # Step 9: Set Vault Environment Variables
      - name: Set Vault Environment Variables
        run: |
          echo "VAULT_ADDR=${{ secrets.VAULT_URL }}" >> $GITHUB_ENV
          echo "VAULT_TOKEN=${{ secrets.VAULT_TOKEN }}" >> $GITHUB_ENV

      # # Step 10: Run SBOM Orchestration Action
      - name: SLSA Verification
         uses: harness/github-actions/slsa-verification@1.1.0
         with:
           HARNESS_ACCOUNT_URL: https://app.harness.io
           HARNESS_ACCOUNT_ID: vpCkHKsDSxK9_KYfjCTMKA
           HARNESS_ORG_ID: SCS
           HARNESS_PROJECT_ID: Exploratory
           HARNESS_API_KEY: ${{ secrets.SCS_API_KEY }}
           TARGET: <image-name>:<tag>
           VERIFY: true
           KMS_KEY: 'cosign'