Use the simple signing attestation check

This page shows you how to use the Binary Authorization continuous validation (CV) simple signing attestation check. The check verifies the attestations of container images associated with Pods running in a Google Kubernetes Engine (GKE) cluster where CV is enabled.

Costs

This guide uses the following Google Cloud services:

Binary Authorization, but CV is available free of charge during the Preview stage
GKE
Cloud Key Management Service

To generate a cost estimate based on your projected usage, use the pricing calculator.

Before you begin

Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.

Install the Google Cloud CLI.

To initialize the gcloud CLI, run the following command:

gcloud init

Note: If you installed the gcloud CLI previously, make sure you have the latest version by running

gcloud components
      update

Create or select a Google Cloud project.

Create a Google Cloud project:
```
gcloud projects create PROJECT_ID
```
Replace PROJECT_ID with a name for the Google Cloud project you are creating.
Select the Google Cloud project that you created:
```
gcloud config set project PROJECT_ID
```
Replace PROJECT_ID with your Google Cloud project name.

Make sure that billing is enabled for your Google Cloud project.

Enable the Binary Authorization, Cloud Key Management Service, Google Kubernetes Engine APIs:

gcloud services enable binaryauthorization.googleapis.com cloudkms.googleapis.com container.googleapis.com

Install the Google Cloud CLI.

To initialize the gcloud CLI, run the following command:

gcloud init

Note: If you installed the gcloud CLI previously, make sure you have the latest version by running

gcloud components
      update

Create or select a Google Cloud project.

Create a Google Cloud project:
```
gcloud projects create PROJECT_ID
```
Replace PROJECT_ID with a name for the Google Cloud project you are creating.
Select the Google Cloud project that you created:
```
gcloud config set project PROJECT_ID
```
Replace PROJECT_ID with your Google Cloud project name.

Make sure that billing is enabled for your Google Cloud project.

Enable the Binary Authorization, Cloud Key Management Service, Google Kubernetes Engine APIs:

gcloud services enable binaryauthorization.googleapis.com cloudkms.googleapis.com container.googleapis.com

Ensure that the gcloud CLI is updated to the latest version.
Install the kubectl command-line tool.
If your Binary Authorization policies and GKE clusters are in different projects, make sure that Binary Authorization is enabled in both projects.

Required roles

This section shows you how to set roles for this check.

Overview

If you run all of the products that are mentioned in this guide in the same project, you don't need to set any permissions. Binary Authorization configures the roles correctly when you enable it. If you run the products in different projects, you must set roles as described in this section.

To ensure that the Binary Authorization Service Agent in each project has the necessary permissions to evaluate the CV simple signing attestation check, ask your administrator to grant the Binary Authorization Service Agent in each project the following IAM roles:

If your cluster project is different from the policy project: Binary Authorization Policy Evaluator (roles/binaryauthorization.policyEvaluator) on the cluster project Binary Authorization Service Agent, for it to access the policy project
If your attestation project is different from your policy project: Container Analysis Occurrences Viewer (roles/containeranalysis.occurrences.viewer) on the policy project Binary Authorization Service Agent, for it to access the attestation project

For more information about granting roles, see Manage access to projects, folders, and organizations.

Your administrator might also be able to give the Binary Authorization Service Agent in each project the required permissions through custom roles or other predefined roles.

Grant roles using the gcloud CLI

To ensure that the Binary Authorization Service Agent in each project has the necessary permissions to evaluate the CV simple signing attestation check, grant the Binary Authorization Service Agent in each project the following IAM roles:

Grant permission for the cluster project's Binary Authorization Service Agent to access the policy in the policy project.

Get the cluster project's Binary Authorization service agent:

PROJECT_NUMBER=$(gcloud projects list --filter="projectId:CLUSTER_PROJECT_ID" \
  --format="value(PROJECT_NUMBER)")
CLUSTER_SERVICE_ACCOUNT="service-$PROJECT_NUMBER@gcp-sa-binaryauthorization.iam.gserviceaccount.com"

Replace CLUSTER_PROJECT_ID with the project ID of the cluster.

Allow CV to evaluate the policy on the cluster:

gcloud projects add-iam-policy-binding POLICY_PROJECT_ID \
    --member="serviceAccount:$CLUSTER_SERVICE_ACCOUNT" \
    --role='roles/binaryauthorization.policyEvaluator'

Replace POLICY_PROJECT_ID with the ID of the project that contains your policy.

Allow the policy project Binary Authorization Service Agent to access the attestations in your attestation project:

Obtain the policy project's Binary Authorization service agent:

PROJECT_NUMBER=$(gcloud projects list \
  --filter="projectId:POLICY_PROJECT_ID" \
  --format="value(PROJECT_NUMBER)")
SERVICE_ACCOUNT="service-$PROJECT_NUMBER@gcp-sa-binaryauthorization.iam.gserviceaccount.com"

Replace POLICY_PROJECT_ID with the ID of the project that contains your policy.

Grant the role:

gcloud projects add-iam-policy-binding ATTESTATION_PROJECT_ID \
    --member="serviceAccount:$SERVICE_ACCOUNT" \
    --role='roles/containeranalysis.occurrences.viewer'

Replace ATTESTATION_PROJECT_ID with the ID of the project that contains your attestations.

Create a key pair

In this section, you create an Elliptic Curve Digital Signature Algorithm (ECDSA) asymmetric key pair.

You use the private key to sign the image, which creates the attestation. You include the public key in a platform policy. When CV checks the attestation, it uses the public key to verify the attestation.

You can use either Cloud Key Management Service or local keys, but we recommend that you use Cloud KMS keys for production.

PKIX Cloud KMS

To create the key pair in Cloud KMS, do the following:

Set up environment variables needed to create the key pair. To do so, we recommend that you fill in the placeholders in the following command, and then run the command.
```
KMS_KEY_PROJECT_ID=KMS_KEY_PROJECT_ID
KMS_KEYRING_NAME=KMS_KEYRING_NAME
KMS_KEY_NAME=KMS_KEY_NAME
KMS_KEY_LOCATION=global
KMS_KEY_PURPOSE=asymmetric-signing
KMS_KEY_ALGORITHM=ec-sign-p256-sha256
KMS_PROTECTION_LEVEL=software
KMS_KEY_VERSION=1
KEY_FILE=KEY_FILE
```
Replace the following:
- KMS_KEY_PROJECT_ID: your project ID
- KMS_KEYRING_NAME: a name for your Cloud KMS key ring
- KMS_KEY_NAME: a name for your Cloud KMS key
- KEY_FILE: a local path to save your Cloud KMS key

Create the key ring:

gcloud kms keyrings create ${KMS_KEYRING_NAME} \
    --location=${KMS_KEY_LOCATION} \
    --project=${KMS_KEY_PROJECT_ID}

Create the key:

gcloud kms keys create ${KMS_KEY_NAME} \
    --location=${KMS_KEY_LOCATION} \
    --keyring=${KMS_KEYRING_NAME}  \
    --purpose=${KMS_KEY_PURPOSE} \
    --default-algorithm=${KMS_KEY_ALGORITHM} \
    --protection-level=${KMS_PROTECTION_LEVEL} \
    --project=${KMS_KEY_PROJECT_ID}

Export the public key material to a file:

gcloud kms keys versions get-public-key ${KMS_KEY_VERSION} \
    --key=${KMS_KEY_NAME} \
    --keyring=${KMS_KEYRING_NAME} \
    --location=${KMS_KEY_LOCATION} \
    --output-file=${KEY_FILE} \
    --project=${KMS_KEY_PROJECT_ID}

Local key

To create the key pair locally, do the following:

Create the private key:

PRIVATE_KEY_FILE="/tmp/ec_private.pem"
openssl ecparam -genkey -name prime256v1 -noout -out ${PRIVATE_KEY_FILE}

Get the public key from the private key:

PUBLIC_KEY_FILE="/tmp/ec_public.pem"
openssl ec -in ${PRIVATE_KEY_FILE} -pubout -out ${PUBLIC_KEY_FILE}

Create a platform policy

To create a CV platform policy with a simple signing attestation check, do the following:

Create the simple signing attestation check platform policy YAML file:

PKIX Cloud KMS

cat > /tmp/my-policy.yaml << EOF
gkePolicy:
  checkSets:
  - checks:
    - simpleSigningAttestationCheck:
        containerAnalysisAttestationProjects:
        - projects/ATTESTATION_PROJECT_ID
        attestationAuthenticators:
          pkixPublicKeySet:
            pkixPublicKeys:
              publicKeyPem: |
$(awk '{printf "                %s\n", $0}' ${KEY_FILE})
              signatureAlgorithm: ECDSA_P256_SHA256
              keyId: |
                projects/${KMS_KEY_PROJECT_ID}/locations/${KMS_KEY_LOCATION}/keyRings/${KMS_KEYRING_NAME}/cryptoKeys/${KMS_KEY_NAME}/cryptoKeyVersions/${KMS_KEY_VERSION}
EOF

Replace ATTESTATION_PROJECT_ID with the ID of the project that stores attestations that are created using this Cloud KMS key.

Local key

cat > /tmp/my-policy.yaml <<EOF
gkePolicy:
  checkSets:
  - checks:
    - simpleSigningAttestationCheck:
        containerAnalysisAttestationProjects:
        - projects/ATTESTATION_PROJECT_ID
        attestationAuthenticators:
          pkixPublicKeySet:
            pkixPublicKeys:
              publicKeyPem: |
$(awk '{printf "                %s\n", $0}' /tmp/ec_public.pem)
              signatureAlgorithm: ECDSA_P256_SHA256
              keyId: |
                PUBLIC_KEY_ID
EOF

Replace the following:

ATTESTATION_PROJECT_ID: the ID of the project that stores attestations that are created using your local key
PUBLIC_KEY_ID: an ID that uniquely identifies your local key

Create the platform policy:

Before using any of the command data below, make the following replacements:
- POLICY_ID: A platform policy ID of your choice. If the policy is in another project, you can use the full resource name: projects/POLICY_PROJECT_ID/platforms/gke/policies/POLICY_ID.
- POLICY_PATH: A path to the policy file.
- POLICY_PROJECT_ID: The policy project ID.
Execute the following command:
Linux, macOS, or Cloud Shell

Note: Ensure you have initialized the Google Cloud CLI with authentication and a project by running either gcloud init; or gcloud auth login and gcloud config set project.
```
gcloud beta container binauthz policy create POLICY_ID \
    --platform=gke \
    --policy-file=POLICY_PATH \
    --project=POLICY_PROJECT_ID
```
Windows (PowerShell)

Note: Ensure you have initialized the Google Cloud CLI with authentication and a project by running either gcloud init; or gcloud auth login and gcloud config set project.
```
gcloud beta container binauthz policy create POLICY_ID `
    --platform=gke `
    --policy-file=POLICY_PATH `
    --project=POLICY_PROJECT_ID
```
Windows (cmd.exe)

Note: Ensure you have initialized the Google Cloud CLI with authentication and a project by running either gcloud init; or gcloud auth login and gcloud config set project.
```
gcloud beta container binauthz policy create POLICY_ID ^
    --platform=gke ^
    --policy-file=POLICY_PATH ^
    --project=POLICY_PROJECT_ID
```
Store the ID value for later use:
```
PUBLIC_KEY_ID="PUBLIC_KEY_ID"
```
Replace PUBLIC_KEY_ID with the ID that you specified in the keyId field in the platform policy file earlier in this guide.

The private key is used when attestations are created, as described later in this guide.

Enable CV

You can create a new cluster or update an existing cluster to use CV monitoring with check-based platform policies.

Create a cluster that uses CV monitoring

In this section, you create a cluster that uses only CV monitoring with check-based platform policies.

Before using any of the command data below, make the following replacements:

CLUSTER_NAME: a cluster name.
LOCATION: the location—for example, us-central1 or asia-south1.
POLICY_PROJECT_ID: the ID of the project where the policy is stored.
POLICY_ID: the policy ID.
CLUSTER_PROJECT_ID: the cluster project ID.

Execute the following command:

Linux, macOS, or Cloud Shell

gcloud beta container clusters create CLUSTER_NAME \
    --location=LOCATION \
    --binauthz-evaluation-mode=POLICY_BINDINGS \
    --binauthz-policy-bindings=name=projects/POLICY_PROJECT_ID/platforms/gke/policies/POLICY_ID \
    --project=CLUSTER_PROJECT_ID

Windows (PowerShell)

gcloud beta container clusters create CLUSTER_NAME `
    --location=LOCATION `
    --binauthz-evaluation-mode=POLICY_BINDINGS `
    --binauthz-policy-bindings=name=projects/POLICY_PROJECT_ID/platforms/gke/policies/POLICY_ID `
    --project=CLUSTER_PROJECT_ID

Windows (cmd.exe)

gcloud beta container clusters create CLUSTER_NAME ^
    --location=LOCATION ^
    --binauthz-evaluation-mode=POLICY_BINDINGS ^
    --binauthz-policy-bindings=name=projects/POLICY_PROJECT_ID/platforms/gke/policies/POLICY_ID ^
    --project=CLUSTER_PROJECT_ID

Create cluster that uses enforcement and CV monitoring

In this section, you create a cluster that uses both project-singleton policy enforcement and CV monitoring with check-based platform policies:

Before using any of the command data below, make the following replacements:

CLUSTER_NAME: a cluster name.
LOCATION: the location—for example, us-central1 or asia-south1.
POLICY_PROJECT_ID: the ID of the project where the policy is stored.
POLICY_ID: the policy ID.
CLUSTER_PROJECT_ID: the cluster project ID.

Execute the following command:

Linux, macOS, or Cloud Shell

gcloud beta container clusters create CLUSTER_NAME \
    --location=LOCATION \
    --binauthz-evaluation-mode=POLICY_BINDINGS_AND_PROJECT_SINGLETON_POLICY_ENFORCE \
    --binauthz-policy-bindings=name=projects/POLICY_PROJECT_ID/platforms/gke/policies/POLICY_ID \
    --project=CLUSTER_PROJECT_ID

Windows (PowerShell)

gcloud beta container clusters create CLUSTER_NAME `
    --location=LOCATION `
    --binauthz-evaluation-mode=POLICY_BINDINGS_AND_PROJECT_SINGLETON_POLICY_ENFORCE `
    --binauthz-policy-bindings=name=projects/POLICY_PROJECT_ID/platforms/gke/policies/POLICY_ID `
    --project=CLUSTER_PROJECT_ID

Windows (cmd.exe)

gcloud beta container clusters create CLUSTER_NAME ^
    --location=LOCATION ^
    --binauthz-evaluation-mode=POLICY_BINDINGS_AND_PROJECT_SINGLETON_POLICY_ENFORCE ^
    --binauthz-policy-bindings=name=projects/POLICY_PROJECT_ID/platforms/gke/policies/POLICY_ID ^
    --project=CLUSTER_PROJECT_ID

Update a cluster to use CV monitoring

In this section, you update a cluster to use CV monitoring with check-based platform policies only. If the cluster already has project-singleton policy enforcement enabled, running this command disables it. Instead, consider updating the cluster with enforcement and CV monitoring enabled.

Before using any of the command data below, make the following replacements:

CLUSTER_NAME: the cluster name
LOCATION: the location—for example: us-central1 or asia-south1
POLICY_PROJECT_ID: the ID of the project where the policy is stored
POLICY_ID: the policy ID
CLUSTER_PROJECT_ID: the cluster project ID

Execute the following command:

Linux, macOS, or Cloud Shell

gcloud beta container clusters update CLUSTER_NAME \
    --location=LOCATION \
    --binauthz-evaluation-mode=POLICY_BINDINGS \
    --binauthz-policy-bindings=name=projects/POLICY_PROJECT_ID/platforms/gke/policies/POLICY_ID \
    --project=CLUSTER_PROJECT_ID

Windows (PowerShell)

gcloud beta container clusters update CLUSTER_NAME `
    --location=LOCATION `
    --binauthz-evaluation-mode=POLICY_BINDINGS `
    --binauthz-policy-bindings=name=projects/POLICY_PROJECT_ID/platforms/gke/policies/POLICY_ID `
    --project=CLUSTER_PROJECT_ID

Windows (cmd.exe)

gcloud beta container clusters update CLUSTER_NAME ^
    --location=LOCATION ^
    --binauthz-evaluation-mode=POLICY_BINDINGS ^
    --binauthz-policy-bindings=name=projects/POLICY_PROJECT_ID/platforms/gke/policies/POLICY_ID ^
    --project=CLUSTER_PROJECT_ID

Update a cluster to use enforcement and CV monitoring

In this section, you update a cluster to use both project-singleton policy enforcement and CV monitoring with check-based platform policies.

Before using any of the command data below, make the following replacements:

CLUSTER_NAME: a cluster name
LOCATION: the location—for example: us-central1 or asia-south1
POLICY_PROJECT_ID: the ID of the project where the policy is stored
POLICY_ID: the policy ID
CLUSTER_PROJECT_ID: the cluster project ID

Execute the following command:

Linux, macOS, or Cloud Shell

gcloud beta container clusters update CLUSTER_NAME \
    --location=LOCATION \
    --binauthz-evaluation-mode=POLICY_BINDINGS_AND_PROJECT_SINGLETON_POLICY_ENFORCE \
    --binauthz-policy-bindings=name=projects/POLICY_PROJECT_ID/platforms/gke/policies/POLICY_ID \
    --project=CLUSTER_PROJECT_ID

Windows (PowerShell)

gcloud beta container clusters update CLUSTER_NAME `
    --location=LOCATION `
    --binauthz-evaluation-mode=POLICY_BINDINGS_AND_PROJECT_SINGLETON_POLICY_ENFORCE `
    --binauthz-policy-bindings=name=projects/POLICY_PROJECT_ID/platforms/gke/policies/POLICY_ID `
    --project=CLUSTER_PROJECT_ID

Windows (cmd.exe)

gcloud beta container clusters update CLUSTER_NAME ^
    --location=LOCATION ^
    --binauthz-evaluation-mode=POLICY_BINDINGS_AND_PROJECT_SINGLETON_POLICY_ENFORCE ^
    --binauthz-policy-bindings=name=projects/POLICY_PROJECT_ID/platforms/gke/policies/POLICY_ID ^
    --project=CLUSTER_PROJECT_ID

Create the Artifact Analysis note

In this section, you create an example Artifact Analysis note to link attestations. To create the note, do the following:

Create the note variables:

NOTE_PROJECT_ID=NOTE_PROJECT_ID
NOTE_ID="test-note"
NOTE_URI="projects/${NOTE_PROJECT_ID}/notes/${NOTE_ID}"
DESCRIPTION="CV test note"

Replace NOTE_PROJECT_ID: the ID of the project that contains the note.

Create the note content file:

cat > /tmp/note_payload.json << EOM
{
  "name": "${NOTE_URI}",
  "attestation": {
    "hint": {
      "human_readable_name": "${DESCRIPTION}"
    }
  }
}
EOM

Create the note:

curl -X POST \
    -H "Content-Type: application/json" \
    -H "Authorization: Bearer $(gcloud auth print-access-token)"  \
    -H "x-goog-user-project: ${NOTE_PROJECT_ID}" \
    --data-binary @/tmp/note_payload.json "https://containeranalysis.googleapis.com/v1/projects/${NOTE_PROJECT_ID}/notes/?noteId=${NOTE_ID}"

Replace NOTE_PROJECT_ID: the ID of the project that contains the note

Optional: To verify that you created the note:

curl \
    -H "Authorization: Bearer $(gcloud auth print-access-token)"  \
    -H "x-goog-user-project: NOTE_PROJECT_ID" \
"https://containeranalysis.googleapis.com/v1/projects/NOTE_PROJECT_ID/notes/"

Replace NOTE_PROJECT_ID with the ID of the project that contains the note.

Test CV

In this section, you test CV by deploying the image for which you created an attestation. In this case, the CV simple signing attestation check verifies the attestation and produces no log entry.

You then attempt to deploy a different image that has no attestation. In this case, the CV check can't find the attestation and logs the violation to Cloud Logging.

To create the variables you use to test CV, run the following commands:

IMAGE_PATH="us-docker.pkg.dev/google-samples/containers/gke/hello-app"
IMAGE_DIGEST="sha256:37e5287945774f27b418ce567cd77f4bbc9ef44a1bcd1a2312369f31f9cce567"
IMAGE_TO_ATTEST="${IMAGE_PATH}@${IMAGE_DIGEST}"

Create an attestation

To satisfy the simple signing attestation check, the image needs a valid attestation.

You can create an attestation using the gcloud CLI or the REST API.

PKIX Cloud KMS

gcloud

To create an attestation using the gcloud CLI, do the following:

Sign the image and create the attestation using Pre-Authentication Encoding (PAE) (recommended):

gcloud beta container binauthz attestations sign-and-create \
    --artifact-url=${IMAGE_TO_ATTEST} \
    --keyversion=${KMS_KEY_VERSION} \
    --keyversion-key=${KMS_KEY_NAME} \
    --keyversion-keyring=${KMS_KEYRING_NAME} \
    --keyversion-location=${KMS_KEY_LOCATION} \
    --note=${NOTE_URI} \
    --pae-encode-payload \
    --dsse-type=DSSE_TYPE

Replace DSSE_TYPE with the DSSE type for PAE encoding. The flag defaults to application/vnd.dev.cosign.simplesigning.v1+json.

REST API

To create an attestation using the REST API, do the following:

Create a signature payload file:

cat > /tmp/generated_payload.json << EOM
{
  "critical": {
    "identity": {
      "docker-reference": "${IMAGE_PATH}"
    },
    "image": {
      "docker-manifest-digest": "${IMAGE_DIGEST}"
    },
    "type": "Google Cloud BinAuthz container signature"
  }
}
EOM

Sign the payload:

gcloud kms asymmetric-sign \
    --version=${KMS_KEY_VERSION} \
    --key=${KMS_KEY_NAME} \
    --keyring=${KMS_KEYRING_NAME} \
    --location=${KMS_KEY_LOCATION} \
    --digest-algorithm=sha256 \
    --input-file=/tmp/generated_payload.json \
    --signature-file=/tmp/ec_signature \
    --project=${KMS_KEY_PROJECT_ID}

Create the attestation content:

cat > /tmp/attestation.json << EOM
{
"resourceUri": "${IMAGE_TO_ATTEST}",
"note_name": "${NOTE_URI}",
"attestation": {
  "serialized_payload": "$(base64 --wrap=0 /tmp/generated_payload.json)",
  "signatures": [{
    "public_key_id": "${PUBLIC_KEY_ID}",
    "signature": "$(base64 --wrap=0 /tmp/ec_signature)"
  }]
}
}
EOM

Create the attestation:

curl -X POST "https://containeranalysis.googleapis.com/v1/projects/${NOTE_PROJECT_ID}/occurrences/" \
  -H "Content-Type: application/json" \
  -H "X-Goog-User-Project: ${NOTE_PROJECT_ID}" \
  -H "Authorization: Bearer $(gcloud auth print-access-token)" \
  --data-binary @/tmp/attestation.json

Replace NOTE_PROJECT_ID with the ID of the project that contains the note.

Local key

gcloud

Create a signature payload file:

cat > /tmp/generated_payload.json << EOM
{
  "critical": {
    "identity": {
      "docker-reference": "${IMAGE_PATH}"
    },
    "image": {
      "docker-manifest-digest": "${IMAGE_DIGEST}"
    },
    "type": "Google Cloud BinAuthz container signature"
  }
}
EOM

Create the signature payload file:

openssl dgst -sha256 -sign ${PRIVATE_KEY_FILE} /tmp/generated_payload.json > /tmp/ec_signature

Create the attestation:

gcloud container binauthz attestations create \
    --project=ATTESTATION_PROJECT_ID \
    --artifact-url=${IMAGE_TO_ATTEST} \
    --note=${NOTE_URI} \
    --signature-file=/tmp/ec_signature \
    --public-key-id=PUBLIC_KEY_ID

REST API

Create a signature payload file:

cat > /tmp/generated_payload.json << EOM
{
  "critical": {
    "identity": {
      "docker-reference": "${IMAGE_PATH}"
    },
    "image": {
      "docker-manifest-digest": "${IMAGE_DIGEST}"
    },
    "type": "Google Cloud BinAuthz container signature"
  }
}
EOM

Create the signature payload file:

openssl dgst -sha256 -sign ${PRIVATE_KEY_FILE} /tmp/generated_payload.json > /tmp/ec_signature

Create the attestation content:

cat > /tmp/attestation.json << EOM
{
"resourceUri": "${IMAGE_TO_ATTEST}",
"note_name": "${NOTE_URI}",
"attestation": {
  "serialized_payload": "$(base64 --wrap=0 /tmp/generated_payload.json)",
  "signatures": [{
    "public_key_id": "${PUBLIC_KEY_ID}",
    "signature": "$(base64 --wrap=0 /tmp/ec_signature)"
  }]
}
}
EOM

Create the attestation:

curl -X POST "https://containeranalysis.googleapis.com/v1/projects/${NOTE_PROJECT_ID}/occurrences/" \
  -H "Content-Type: application/json" \
  -H "X-Goog-User-Project: ${NOTE_PROJECT_ID}" \
  -H "Authorization: Bearer $(gcloud auth print-access-token)" \
  --data-binary @/tmp/attestation.json

Deploy the image that has an attestation

To deploy an image for which an attestation was created, do the following:

Configure kubectl:
```
gcloud container clusters get-credentials CLUSTER_NAME \
    --location=LOCATION \
    --project=CLUSTER_PROJECT_ID
```
Replace the following:
- CLUSTER_NAME: the name of your cluster
- LOCATION: the cluster location
- CLUSTER_PROJECT_ID: the cluster project ID
Deploy a service and check the deployment against the Binary Authorization policy:
```
kubectl run hello-app-with-attestation --image=$IMAGE_PATH@$IMAGE_DIGEST
```
The Pod was deployed. Because the image has an attestation, CV doesn't produce log entries related to this Pod.

Deploy an image without an attestation

In this section, you deploy an image that doesn't have an associated attestation.

Because the policy requires attestations and this image doesn't have one, CV regularly logs the violation while the container is running.

To deploy the image, run the following command:

kubectl run hello-app-without-attestation \
    --image=gcr.io/google-samples/hello-app@sha256:845f77fab71033404f4cfceaa1ddb27b70c3551ceb22a5e7f4498cdda6c9daea

The Pod was deployed. Because the image doesn't have an attestation, CV produces log entries while the Pod is running.

View logs for CV entries

You can search Cloud Logging entries to find CV configuration errors and CV platform policy validation violations.

CV logs errors and violations to Cloud Logging within 24 hours. You can usually see entries within a few hours.

View CV configuration error logs

To view CV configuration error logs, run the following command:

gcloud logging read \
     --order="desc" \
     --freshness=7d \
     --project=CLUSTER_PROJECT_ID \
    'logName:"binaryauthorization.googleapis.com%2Fcontinuous_validation" "configErrorEvent"'

The following output shows a configuration error in which a CV platform policy isn't found:

{
  "insertId": "141d4f10-72ea-4a43-b3ec-a03da623de42",
  "jsonPayload": {
    "@type": "type.googleapis.com/google.cloud.binaryauthorization.v1beta1.ContinuousValidationEvent",
    "configErrorEvent": {
      "description": "Cannot monitor cluster 'us-central1-c.my-cluster': Resource projects/123456789/platforms/gke/policies/my-policy does not exist."
    }
  },
  "resource": {
    "type": "k8s_cluster",
    "labels": {
      "cluster_name": "my-cluster",
      "location": "us-central1-c",
      "project_id": "my-project"
    }
  },
  "timestamp": "2024-05-28T15:31:03.999566Z",
  "severity": "WARNING",
  "logName": "projects/my-project/logs/binaryauthorization.googleapis.com%2Fcontinuous_validation",
  "receiveTimestamp": "2024-05-28T16:30:56.304108670Z"
}

View CV platform policy validation violations

If no images violate the platform policies that you have enabled, no entries appear in the logs.

To view CV log entries for the last seven days, run the following command:

gcloud logging read \
     --order="desc" \
     --freshness=7d \
     --project=CLUSTER_PROJECT_ID \
    'logName:"binaryauthorization.googleapis.com%2Fcontinuous_validation" "policyName"'

Replace CLUSTER_PROJECT_ID with the cluster project ID.

Check types

CV logs check violation information to checkResults. In the entry, the value checkType indicates the check. The values for each check are as follows:

ImageFreshnessCheck
SigstoreSignatureCheck
SimpleSigningAttestationCheck
SlsaCheck
TrustedDirectoryCheck
VulnerabilityCheck

Example log

The following example CV Logging entry describes a non-conformant image that violates a trusted directory check:

{
  "insertId": "637c2de7-0000-2b64-b671-24058876bb74",
  "jsonPayload": {
    "podEvent": {
      "endTime": "2022-11-22T01:14:30.430151Z",
      "policyName": "projects/123456789/platforms/gke/policies/my-policy",
      "images": [
        {
          "result": "DENY",
          "checkResults": [
            {
              "explanation": "TrustedDirectoryCheck at index 0 with display name \"My trusted directory check\" has verdict NOT_CONFORMANT. Image is not in a trusted directory",
              "checkSetName": "My check set",
              "checkSetIndex": "0",
              "checkName": "My trusted directory check",
              "verdict": "NON_CONFORMANT",
              "checkType": "TrustedDirectoryCheck",
              "checkIndex": "0"
            }
          ],
          "image": "gcr.io/my-project/hello-app:latest"
        }
      ],
      "verdict": "VIOLATES_POLICY",
      "podNamespace": "default",
      "deployTime": "2022-11-22T01:06:53Z",
      "pod": "hello-app"
    },
    "@type": "type.googleapis.com/google.cloud.binaryauthorization.v1beta1.ContinuousValidationEvent"
  },
  "resource": {
    "type": "k8s_cluster",
    "labels": {
      "project_id": "my-project",
      "location": "us-central1-a",
      "cluster_name": "my-test-cluster"
    }
  },
  "timestamp": "2022-11-22T01:44:28.729881832Z",
  "severity": "WARNING",
  "logName": "projects/my-project/logs/binaryauthorization.googleapis.com%2Fcontinuous_validation",
  "receiveTimestamp": "2022-11-22T03:35:47.171905337Z"
}

Clean up

This section describes how to clean up the CV monitoring you configured earlier in this guide.

You can disable CV monitoring or both Binary Authorization and CV in your cluster.

Disable Binary Authorization in a cluster

To disable both CV and Binary Authorization enforcement in your cluster, run the following command:

gcloud beta container clusters update CLUSTER_NAME \
    --binauthz-evaluation-mode=DISABLED \
    --location=LOCATION \
    --project=CLUSTER_PROJECT_ID

Replace the following:

CLUSTER_NAME: the name of the cluster
LOCATION: the cluster location
CLUSTER_PROJECT_ID: the cluster project ID

Disable check-based policy monitoring in a cluster

To disable CV with check-based policies in the cluster, and re-enable enforcement using the Binary Authorization enforcement policy, run the following command:

gcloud beta container clusters update CLUSTER_NAME  \
    --binauthz-evaluation-mode=PROJECT_SINGLETON_POLICY_ENFORCE \
    --location=LOCATION \
    --project="CLUSTER_PROJECT_ID"

Replace the following:

CLUSTER_NAME: the name of the cluster
LOCATION: the cluster location
CLUSTER_PROJECT_ID: the cluster project ID

Note that --binauthz-evaluation-mode=PROJECT_SINGLETON_POLICY_ENFORCE is equivalent to the older flag --enable-binauthz.

Delete the policy

To delete the policy, run the following command. It is not necessary to delete the check-based platform policy to disable check-based policy auditing.

gcloud beta container binauthz policy delete POLICY_ID \
    --platform=gke \
    --project="POLICY_PROJECT_ID"

Replace the following:

POLICY_ID: the ID of the policy
POLICY_PROJECT_ID: the policy project ID

Use the simple signing attestation check

Costs

Before you begin

Required roles

Overview

Grant roles using the gcloud CLI

Create a key pair

PKIX Cloud KMS

Local key

Create a platform policy

PKIX Cloud KMS

Local key

Linux, macOS, or Cloud Shell

Windows (PowerShell)

Windows (cmd.exe)

Enable CV

Create a cluster that uses CV monitoring

Linux, macOS, or Cloud Shell

Windows (PowerShell)

Windows (cmd.exe)

Create cluster that uses enforcement and CV monitoring

Linux, macOS, or Cloud Shell

Windows (PowerShell)

Windows (cmd.exe)

Update a cluster to use CV monitoring

Linux, macOS, or Cloud Shell

Windows (PowerShell)

Windows (cmd.exe)

Update a cluster to use enforcement and CV monitoring

Linux, macOS, or Cloud Shell

Windows (PowerShell)

Windows (cmd.exe)

Create the Artifact Analysis note

Test CV

Create an attestation

PKIX Cloud KMS

gcloud

REST API

Local key

gcloud

REST API

Deploy the image that has an attestation

Deploy an image without an attestation

View logs for CV entries

View CV configuration error logs

View CV platform policy validation violations

Check types

Example log

Clean up

Disable Binary Authorization in a cluster

Disable check-based policy monitoring in a cluster

Delete the policy

What's next