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Verify Artifacts with Harness GitLab CI/CD

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Software artifacts are often distributed across multiple environments before they reach production. Even when an artifact has been digitally signed, organizations need a way to confirm that the signature is valid and that the artifact has not been modified after it was signed. Without signature verification, it becomes difficult to establish trust in released artifacts or detect unauthorized changes before deployment.

Harness Supply Chain Security (SCS) integrates with GitLab CI/CD to automate artifact signature verification as part of your GitLab workflow. It enables you to verify the Cosign signature bundle associated with container images or local artifacts during pipeline execution. By validating the artifact against a trusted verification key, you can confirm its authenticity and integrity before it progresses through your software delivery lifecycle.

What will you learn in this topic?​

By the end of this topic, you will be able to:

  • Set up Harness GitLab CI/CD integration from your SCS project.
  • Configure artifact verification in your GitLab workflow using the Artifact Verification component.
  • Configure artifact verification using keyless, key-based, or Secret Manager verification methods.
  • Verify the Cosign signature of container images or local artifacts before promoting or deploying them.

Before you begin​

Make a note of the following before you proceed with artifact verification using GitLab CI/CD:

  • Understand how to create Harness API keys using Personal API Keys or Service Account API Keys. For more information, see Manage API Keys and Service Account API Keys, respectively.
  • If you're using key-based or Secret Manager signing or verification, create or configure a Cosign key pair before configuring the pipeline. For step-by-step instructions, see Quickstart Signing and Verifying with Cosign, which explains how to generate a local key pair or create one using a supported KMS provider. The key should be generated using Cosign of type ecdsa-P256. You don't need to install Cosign on your GitLab runner. The harness/ssca-plugin container image used by the Harness GitLab CI/CD components includes Cosign, so no additional installation is required.
  • If you plan to use Secret Manager attestation, store your verification key in a supported secret manager. Currently, Harness supports HashiCorp Vault. For GitLab CI/CD, you point the component at the key through pipeline variables such as KMS_KEY (and VAULT_ADDR when the key is stored in HashiCorp Vault), so you don't need to configure a Harness Secret Manager connector. For setup steps specific to HashiCorp Vault, see the Add a HashiCorp Vault secret manager.
  • Ensure that your GitLab runners support Docker-in-Docker (DinD). The component runs using the docker:24-dind service. For more information, go to Use Docker-in-Docker.

Understand artifact verification with Harness GitLab CI/CD​

Harness SCS integrates with GitLab CI/CD through reusable GitLab CI/CD components. These components enable you to automate software supply chain security tasks in your GitLab pipelines, helping you generate software metadata, establish artifact trust, and enforce security controls without adding custom implementation to your CI/CD workflow.

The Artifact Verification capability enables you to verify the Cosign signature bundle associated with container images or local artifacts during pipeline execution. The component validates the signature using the configured verification method to confirm that the artifact has not been modified since it was signed. It supports keyless, key-based, and Secret Manager verification methods to verify the signature against a trusted identity or verification key. Successful verification confirms that the artifact matches its signed state before allowing it to proceed through subsequent stages of the pipeline. This verification helps establish trust in software artifacts before they are promoted or deployed.

Why use it?When to use it?How can you leverage it?
Verify the authenticity and integrity of signed software artifacts.When you want to confirm that an artifact has not been modified after it was signed.Use signature verification as a deployment gate to ensure that only authenticated artifacts progress through your software delivery pipeline.

Set up Harness GitLab CI/CD​

Before configuring artifact verification in your GitLab pipeline, set up Harness GitLab CI/CD from your SCS project. The setup guides you through creating or selecting a Harness API key and generates a project-specific YAML configuration with your Harness account ID, organization ID, project ID, and account URL already populated. You can copy this configuration into your GitLab workflow and update the remaining inputs as needed.

Complete the following steps to set up Harness GitLab CI/CD:

  1. Navigate to the Integrations page under the Manage section from the sidebar navigation of your SCS account.
  2. Click the Add Integration button to go to the Configure Integration page.
    Alternatively, you can access this page by clicking Get Started > Get Started from the sidebar navigation of your SCS account.
  3. Scroll down to the GitLab collapsible and click it to expand.
  4. Click the Configure button under Configure GitLab CI/CD in your pipeline to generate SBOM and SLSA, and sign artifacts to open the Configure Integration page, where the Artifact Security feature cards are displayed.
  5. Click the Verify Artifacts card to open the Verify Artifacts sidepanel.
  6. Click the Go to Key Generation button to create the Harness API key required to configure Harness GitLab CI/CD.
    • Select Using Service Account from the dropdown to create the API key using a service account. For more information, see Service Account API Keys.
    • Select Using Personal Account from the dropdown to create a personal API key. Personal API keys are created at the account level and inherit the permissions assigned to your user account. For more information, see Manage API Keys.
  7. Click Copy in the upper-right corner of the code block to copy the generated GitLab CI/CD configuration, and then paste it into your GitLab workflow file.

Configure artifact verification in GitLab CI/CD​

After setting up Harness GitLab CI/CD, configure the Artifact Verification component in your GitLab workflow file. Add the required GitLab CI/CD variables to your GitLab project, configure the component inputs, configure the verification method, and run the pipeline. During pipeline execution, the component verifies the Cosign signature associated with the specified artifact before allowing the pipeline to continue. For the authoritative list of component inputs and defaults, see the CI/CD Catalog at SCS GitLab Plugins.

Complete the following steps to configure artifact verification:

  1. Add the required GitLab CI/CD variables
  2. Include the Artifact Verification component
  3. Configure the verification method
  4. Review the workflow
  5. Run the pipeline

Step 1 - Add the required GitLab CI/CD variables​

Before configuring the Artifact Verification component, add the following variables to your GitLab project. For step-by-step instructions, see Define a CI/CD Variable for a project.

VariableDescriptionRequiredExampleMasked?
HARNESS_API_KEYHarness Personal API Key or Service Account API Key used to authenticate with Harness.Yespat.xxxxxxxxxYes
HARNESS_ACCOUNT_IDHarness account identifier.YesAbCdEf123456No
HARNESS_ORG_IDHarness organization identifier.YesSCS_OrgNo
HARNESS_PROJECT_IDHarness project identifier.YesSCSNo
HARNESS_ACCOUNT_URLHarness account URL.Yeshttps://example.harness.ioNo
note

These values are included in the generated YAML provided during the Set up Harness GitLab CI/CD workflow.

Step 2 - Include the Artifact Verification component​

Add an scs stage to your GitLab workflow file, or set the stage input on the component to an existing stage. Then, include the Harness Artifact Verification component in your GitLab workflow file.

The following code snippet demonstrates how to add the scs stage and include the Artifact Verification component in your GitLab workflow file. The snippet includes the minimum required component inputs because the component requires the Harness scope variables and the target artifact to run.

stages: [scs]

include:
  - component: gitlab.com/harness-scs/gitlab-plugins/artifact-verification@1.0.0
    inputs:
      HARNESS_ACCOUNT_ID: $HARNESS_ACCOUNT_ID
      HARNESS_ORG_ID: $HARNESS_ORG_ID
      HARNESS_PROJECT_ID: $HARNESS_PROJECT_ID
      HARNESS_ACCOUNT_URL: $HARNESS_ACCOUNT_URL
      TARGET: $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA

Configure the component using the GitLab CI/CD variables created in the previous step and the following component inputs.

InputDescriptionRequiredDefaultExample
HARNESS_ACCOUNT_IDHarness account ID. Pass a non-masked CI/CD variable reference.YesN/A$HARNESS_ACCOUNT_ID
HARNESS_ORG_IDHarness organization ID. Pass a non-masked CI/CD variable reference.YesN/A$HARNESS_ORG_ID
HARNESS_PROJECT_IDHarness project ID. Pass a non-masked CI/CD variable reference.YesN/A$HARNESS_PROJECT_ID
HARNESS_ACCOUNT_URLHarness base URL with scheme. Pass a non-masked CI/CD variable reference.YesN/A$HARNESS_ACCOUNT_URL
TARGETContainer image reference when SOURCE is container, or artifact file path when SOURCE is local.YesN/A$CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
VERIFYVerifies the Cosign signature associated with the artifact.Notruefalse
SOURCEArtifact source. Supported values are container and local.Nocontainerlocal
ARTIFACT_NAMEDisplay name for a local artifact. Applicable when SOURCE=local.NoFile name from TARGETpayment-service
ARTIFACT_VERSIONArtifact version. Applicable when SOURCE=local.NoN/A$CI_COMMIT_SHORT_SHA
stageGitLab pipeline stage in which the component runs.Noscssecurity
job-nameName of the GitLab job created by the component.Noscs-artifact-verificationverify-artifact
note

By default, the component verifies the signature of a container image. To verify the signature of a local artifact, set SOURCE to local. When using a local artifact, specify the artifact path in TARGET and provide an ARTIFACT_VERSION.

To verify the artifact signature, configure the verification inputs (VERIFY_WITH, OIDC_PROVIDER, FULCIO_URL, KMS_KEY, and VAULT_ADDR) as described in Step 3 - Configure the verification method.

Override the generated job​

Standard GitLab job keywords, such as needs, before_script, script, after_script, allow_failure, and tags, are not component inputs. To set them, redeclare the generated job (default name scs-artifact-verification, or the value of job-name) in your workflow file. GitLab merges your keys into the generated job.

scs-artifact-verification:
  needs: [scs-artifact-signing]
  tags: [docker, linux]
  before_script:
    - echo "Starting artifact verification"
  after_script:
    - echo "Artifact verification complete"
note

If you are verifying an image in a private registry that is not the GitLab container registry, provide the registry credentials as masked GitLab CI/CD variables so that the component can access the image.

Step 3 - Configure the verification method​

Harness supports the following verification methods:

  • Keyless verification – Uses OpenID Connect (OIDC) identities to verify artifact signatures without managing long-lived cryptographic keys.
  • Key-based verification – Uses a verification key managed through your organization's key management service.
  • Secret Manager verification – Uses a verification key stored in a supported secret manager.
note

Artifact verification always runs, and VERIFY_WITH selects the verification method. It defaults to secret-manager, which requires KMS_KEY and VAULT_ADDR. Configure one of the verification methods below before running the pipeline.

Configure the appropriate verification inputs based on the verification method you want to use.

To verify the signature using an OpenID Connect (OIDC) identity, configure keyless verification. For GitLab CI/CD, set OIDC_PROVIDER to non-harness. The harness OIDC provider is not supported as of now. Keyless verification requires GitLab 15.7 or later, because it depends on GitLab id_tokens. Configure the following inputs.

InputDescriptionRequired
VERIFY_WITHSpecifies the verification method. Set the value to keyless.Yes
OIDC_PROVIDEROIDC provider used to obtain the verification identity. For GitLab CI/CD, set the value to non-harness.Yes
FULCIO_URLFulcio certificate authority endpoint. Used when OIDC_PROVIDER is non-harness. Defaults to https://fulcio.sigstore.dev.No

Provide the OIDC token to the generated job using id_tokens. The component reads the token from PLUGIN_NON_HARNESS_OIDC_TOKEN.

stages: [scs]
 
include:
  - component: gitlab.com/harness-scs/gitlab-plugins/artifact-verification@1.0.0
    inputs:
      HARNESS_ACCOUNT_ID: $HARNESS_ACCOUNT_ID
      HARNESS_ORG_ID: $HARNESS_ORG_ID
      HARNESS_PROJECT_ID: $HARNESS_PROJECT_ID
      HARNESS_ACCOUNT_URL: $HARNESS_ACCOUNT_URL
      TARGET: $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
      VERIFY_WITH: keyless
      OIDC_PROVIDER: non-harness
 
scs-artifact-verification:
  id_tokens:
    PLUGIN_NON_HARNESS_OIDC_TOKEN:
      aud: sigstore

Step 4 - Review the workflow​

After configuring the required GitLab CI/CD variables and component inputs, your GitLab workflow file should resemble the following example. This example verifies the signature of a container image in Harness SCS using Cosign with a verification key stored in HashiCorp Vault. The Harness scope variables are wired through inputs, HARNESS_API_KEY remains a masked GitLab CI/CD variable, and the Vault variables (KMS_KEY and VAULT_ADDR) are provided for Secret Manager verification.

include:
  - component: gitlab.com/harness-scs/gitlab-plugins/artifact-verification@1.0.0
    inputs:
      HARNESS_ACCOUNT_ID: $HARNESS_ACCOUNT_ID
      HARNESS_ORG_ID: $HARNESS_ORG_ID
      HARNESS_PROJECT_ID: $HARNESS_PROJECT_ID
      HARNESS_ACCOUNT_URL: $HARNESS_ACCOUNT_URL
      TARGET: $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
      VERIFY_WITH: secret-manager
      KMS_KEY: hashivault://cosign
      VAULT_ADDR: $VAULT_ADDR

Step 5 - Run the pipeline​

Commit and push your changes to trigger the GitLab pipeline. During pipeline execution, the Artifact Verification component validates the Cosign signature associated with the specified artifact. If the signature verification succeeds, the pipeline continues to the subsequent stages. For more information on running a GitLab pipeline, see Tutorial: Create and run your first GitLab CI/CD pipeline.

After the pipeline completes, open the job execution logs and click the Harness Artifact Details link to view the generated artifact in SCS. For more information on viewing the status of a job and details of the pipeline, see View the status of your pipeline and jobs.

The Artifact Details page displays the artifact signature verification results. The verification results are also recorded in the Chain of Custody, providing an immutable audit trail of the artifact lifecycle and the associated GitLab CI/CD pipeline execution. For more information on navigating through artifacts, see Artifact Overview.

Example artifact verification workflow​

Example Artifact verification workflow for a container image

The following example demonstrates how to configure the Artifact Verification component in a GitLab workflow to verify the signature of a container image. The artifact is signed earlier in the pipeline using the Artifact Signing component, and the verification job uses needs to run after the signing job. The example uses a verification key stored in HashiCorp Vault.

stages:
  - build
  - scs
 
build-image:
  stage: build
  image: docker:24.0.5
  services:
    - docker:24.0.5-dind
  script:
    - docker build -t $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA .
    - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
 
scs-artifact-verification:
  needs: [sign-artifact]
 
include:
  - component: gitlab.com/harness-scs/gitlab-plugins/artifact-signing@1.0.0
    inputs:
      stage: scs
      job-name: sign-artifact
      HARNESS_ACCOUNT_ID: $HARNESS_ACCOUNT_ID
      HARNESS_ORG_ID: $HARNESS_ORG_ID
      HARNESS_PROJECT_ID: $HARNESS_PROJECT_ID
      HARNESS_ACCOUNT_URL: $HARNESS_ACCOUNT_URL
      TARGET: $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
      SIGN_WITH: secret-manager
      KMS_KEY: hashivault://cosign
      VAULT_ADDR: $VAULT_ADDR
 
  - component: gitlab.com/harness-scs/gitlab-plugins/artifact-verification@1.0.0
    inputs:
      stage: scs
      HARNESS_ACCOUNT_ID: $HARNESS_ACCOUNT_ID
      HARNESS_ORG_ID: $HARNESS_ORG_ID
      HARNESS_PROJECT_ID: $HARNESS_PROJECT_ID
      HARNESS_ACCOUNT_URL: $HARNESS_ACCOUNT_URL
      TARGET: $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
      VERIFY_WITH: secret-manager
      KMS_KEY: hashivault://cosign
      VAULT_ADDR: $VAULT_ADDR
Example Artifact verification workflow for a local artifact

The following example verifies the signature of a local artifact. It builds the artifact in an earlier job, passes it forward with artifacts, and uses needs so the verification job runs after the artifact is available. When SOURCE is local, TARGET is the artifact file path and ARTIFACT_VERSION is required.

stages:
  - build
  - scs
 
build-artifact:
  stage: build
  script:
    - ./build.sh -o $CI_PROJECT_DIR/target/myapp.jar
  artifacts:
    paths:
      - target/myapp.jar
 
scs-artifact-verification:
  needs: [build-artifact]
 
include:
  - component: gitlab.com/harness-scs/gitlab-plugins/artifact-verification@1.0.0
    inputs:
      HARNESS_ACCOUNT_ID: $HARNESS_ACCOUNT_ID
      HARNESS_ORG_ID: $HARNESS_ORG_ID
      HARNESS_PROJECT_ID: $HARNESS_PROJECT_ID
      HARNESS_ACCOUNT_URL: $HARNESS_ACCOUNT_URL
 
      SOURCE: local
      TARGET: $CI_PROJECT_DIR/target/myapp.jar
      ARTIFACT_VERSION: $CI_COMMIT_SHORT_SHA
      VERIFY_WITH: secret-manager
      KMS_KEY: hashivault://cosign
      VAULT_ADDR: $VAULT_ADDR

Next steps​