policy-validator-cfn.yaml

# This workflow uses actions that are not certified by GitHub.
# They are provided by a third-party and are governed by
# separate terms of service, privacy policy, and support
# documentation.

# This workflow will validate the IAM policies in the CloudFormation (CFN) templates with using the standard and custom checks in AWS IAM Access Analyzer
# To use this workflow, you will need to complete the following set up steps before start using it:
# 1. Configure an AWS IAM role to use the Access Analyzer's ValidatePolicy, CheckNoNewAccess and CheckAccessNotGranted. This IAM role must be configured to call from the GitHub Actions, use the following [doc](https://aws.amazon.com/blogs/security/use-iam-roles-to-connect-github-actions-to-actions-in-aws/) for steps. In the below workflow, ARN of such role is stored in the GitHub secrets with name `POLICY_VALIDATOR_ROLE`
# 2. If you're using CHECK_NO_NEW_ACCESS policy-check-type, you need to create a reference policy. Use the guide [here](https://github.com/aws-samples/iam-access-analyzer-custom-policy-check-samples?tab=readme-ov-file#how-do-i-write-my-own-reference-policies) and store it your GitHub repo.
# 3. If you're using the CHECK_ACCESS_NOT_GRANTED policy-check-type, identify the list of critical actions that shouldn't be granted access by the policies in the given CFN templates.
# 4. Start using the GitHub actions by generating the GitHub events matching the defined criteria in your workflow.
name: Validate AWS IAM policies in CloudFormation templates using Policy Validator
on:
  push:
    branches: [$default-branch, $protected-branches]
  pull_request:
    # The branches below must be a subset of the branches above
    branches: [$default-branch]
env:
  AWS_ROLE: MY_ROLE # set this with the role ARN which has permissions to invoke access-analyzer:ValidatePolicy,access-analyzer:CheckNoNewAccess, access-analyzer:CheckAccessNotGranted and can be used in GitHub actions
  REGION: MY_AWS_REGION # set this to your preferred AWS region where you plan to deploy your policies, e.g. us-west-1
  TEMPLATE_PATH: FILE_PATH_TO_CFN_TEMPLATE # set to the file path to the CloudFormation template.
  ACTIONS: MY_LIST_OF_ACTIONS # set to pass list of actions in the format action1, action2,.. This is required if you are using `CHECK_ACCESS_NOT_GRANTED` policy-check-type.
  REFERENCE_POLICY: REFERENCE_POLICY # set to pass a JSON formatted file that specifies the path to the reference policy that is used for a permissions comparison. For example, if you stored such path in a GitHub secret with name REFERENCE_IDENTITY_POLICY , you can pass ${{ secrets.REFERENCE_IDENTITY_POLICY }}. If not you have the reference policy in the repository, you can directly pass it's file path. This is required if you are using `CHECK_NO_NEW_ACCESS_CHECK` policy-check-type.
  REFERENCE_POLICY_TYPE: TYPE_OF_REFERENCE_POLICY # set to pass the policy type associated with the IAM policy under analysis and the reference policy. This is required if you are using `CHECK_NO_NEW_ACCESS_CHECK` policy-check-type.
jobs:
  policy-validator:
    runs-on: ubuntu-latest # Virtual machine to run the workflow (configurable)
    # https://docs.github.com/en/actions/deployment/security-hardening-your-deployments/configuring-openid-connect-in-amazon-web-services#updating-your-github-actions-workflow
    # https://aws.amazon.com/blogs/security/use-iam-roles-to-connect-github-actions-to-actions-in-aws/
    permissions:
      id-token: write # This is required for requesting the JWT
      contents: read # This is required for actions/checkout
    name: Policy Validator checks for AWS IAM policies
    steps:
      # checkout the repo for workflow to access the contents
      - name: Checkout
        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11
      # Configure AWS Credentials. More configuration details here - https://github.com/aws-actions/configure-aws-credentials
      - name: Configure AWS Credentials
        uses: aws-actions/configure-aws-credentials@e3dd6a429d7300a6a4c196c26e071d42e0343502
        with:
          role-to-assume: ${{ env.AWS_ROLE }}
          aws-region: ${{ env.REGION }}
      # Run the VALIDATE_POLICY check. More configuration details here - https://github.com/aws-actions/cloudformation-aws-iam-policy-validator
      - name: Run AWS AccessAnalyzer ValidatePolicy check
        id: run-aws-validate-policy
        uses: aws-actions/cloudformation-aws-iam-policy-validator@10479bdc0c8322ffb6f5eaa75d096195f97b798a #v1.0.0
        with:
          policy-check-type: "VALIDATE_POLICY"
          template-path: ${{ env.TEMPLATE_PATH}}
          region: ${{ env.REGION }}
      # Print result from VALIDATE_POLICY check
      - name: Print the result for ValidatePolicy check
        if: success() || failure()
        run: echo "${{ steps.run-aws-validate-policy.outputs.result }}"
      # Run the CHECK_ACCESS_NOT_GRANTED check. More configuration details here - https://github.com/aws-actions/cloudformation-aws-iam-policy-validator
      - name: Run AWS AccessAnalyzer CheckAccessNotGranted check
        id: run-aws-check-access-not-granted
        uses: aws-actions/cloudformation-aws-iam-policy-validator@10479bdc0c8322ffb6f5eaa75d096195f97b798a #v1.0.0
        with:
          policy-check-type: "CHECK_ACCESS_NOT_GRANTED"
          template-path: ${{ env.TEMPLATE_PATH}}
          actions: ${{ env.ACTIONS }}
          region: ${{ env.REGION }}
      # Print result from CHECK_ACCESS_NOT_GRANTED check
      - name: Print the result for CheckAccessNotGranted check
        if: success() || failure()
        run: echo "${{ steps.run-aws-check-access-not-granted.outputs.result }}"
      # Run the CHECK_NO_NEW_ACCESS check. More configuration details here - https://github.com/aws-actions/cloudformation-aws-iam-policy-validator
      # reference-policy is stored in GitHub secrets
      - name: Run AWS AccessAnalyzer CheckNoNewAccess check
        id: run-aws-check-no-new-access
        uses: aws-actions/cloudformation-aws-iam-policy-validator@10479bdc0c8322ffb6f5eaa75d096195f97b798a #v1.0.0
        with:
          policy-check-type: "CHECK_NO_NEW_ACCESS"
          template-path: ${{ env.TEMPLATE_PATH}}
          reference-policy: ${{ env.REFERENCE }}
          reference-policy-type: ${{ env.REFERENCE_POLICY_TYPE }}
          region: ${{env.REGION }}
      # Print result from CHECK_NO_NEW_ACCESS check
      - name: Print the result for CheckNoNewAccess check
        if: success() || failure()
        run: echo "${{ steps.run-aws-check-no-new-access.outputs.result }}"