cosign_dockerfile_verify.md

cosign dockerfile verify

Verify a signature on the base image specified in the Dockerfile

Synopsis

Verify signature and annotations on images in a Dockerfile by checking claims against the transparency log.

Shell-like variables in the Dockerfile's FROM lines will be substituted with values from the OS ENV.

cosign dockerfile verify [flags]

Examples

  cosign dockerfile verify --key <key path>|<key url>|<kms uri> <path/to/Dockerfile>

  # verify cosign claims and signing certificates on the FROM images in the Dockerfile
  cosign dockerfile verify <path/to/Dockerfile>

  # only verify the base image (the last FROM image)
  cosign dockerfile verify --base-image-only <path/to/Dockerfile>

  # additionally verify specified annotations
  cosign dockerfile verify -a key1=val1 -a key2=val2 <path/to/Dockerfile>

  # (experimental) additionally, verify with the transparency log
  COSIGN_EXPERIMENTAL=1 cosign dockerfile verify <path/to/Dockerfile>

  # verify images with public key
  cosign dockerfile verify --key cosign.pub <path/to/Dockerfile>

  # verify images with public key provided by URL
  cosign dockerfile verify --key https://host.for/<FILE> <path/to/Dockerfile>

  # verify images with public key stored in Azure Key Vault
  cosign dockerfile verify --key azurekms://[VAULT_NAME][VAULT_URI]/[KEY] <path/to/Dockerfile>

  # verify images with public key stored in AWS KMS
  cosign dockerfile verify --key awskms://[ENDPOINT]/[ID/ALIAS/ARN] <path/to/Dockerfile>

  # verify images with public key stored in Google Cloud KMS
  cosign dockerfile verify --key gcpkms://projects/[PROJECT]/locations/global/keyRings/[KEYRING]/cryptoKeys/[KEY] <path/to/Dockerfile>

  # verify images with public key stored in Hashicorp Vault
  cosign dockerfile verify --key hashivault://[KEY] <path/to/Dockerfile>

Options

      --allow-insecure-registry                                                                  whether to allow insecure connections to registries. Don't use this for anything but testing
  -a, --annotations strings                                                                      extra key=value pairs to sign
      --attachment string                                                                        related image attachment to sign (sbom), default none
      --attachment-tag-prefix [AttachmentTagPrefix]sha256-[TargetImageDigest].[AttachmentName]   optional custom prefix to use for attached image tags. Attachment images are tagged as: [AttachmentTagPrefix]sha256-[TargetImageDigest].[AttachmentName]
      --base-image-only                                                                          only verify the base image (the last FROM image in the Dockerfile)
      --certificate string                                                                       path to the public certificate
      --certificate-chain string                                                                 path to a list of CA certificates in PEM format which will be needed when building the certificate chain for the signing certificate. Must start with the parent intermediate CA certificate of the signing certificate and end with the root certificate
      --certificate-email string                                                                 the email expected in a valid Fulcio certificate
      --certificate-oidc-issuer string                                                           the OIDC issuer expected in a valid Fulcio certificate, e.g. https://token.actions.githubusercontent.com or https://oauth2.sigstore.dev/auth
      --check-claims                                                                             whether to check the claims found (default true)
      --enforce-sct                                                                              whether to enforce that a certificate contain an embedded SCT, a proof of inclusion in a certificate transparency log
  -h, --help                                                                                     help for verify
      --k8s-keychain                                                                             whether to use the kubernetes keychain instead of the default keychain (supports workload identity).
      --key string                                                                               path to the public key file, KMS URI or Kubernetes Secret
      --local-image                                                                              whether the specified image is a path to an image saved locally via 'cosign save'
  -o, --output string                                                                            output format for the signing image information (json|text) (default "json")
      --rekor-url string                                                                         [EXPERIMENTAL] address of rekor STL server (default "https://rekor.sigstore.dev")
      --signature string                                                                         signature content or path or remote URL
      --signature-digest-algorithm string                                                        digest algorithm to use when processing a signature (sha224|sha256|sha384|sha512) (default "sha256")
      --sk                                                                                       whether to use a hardware security key
      --slot string                                                                              security key slot to use for generated key (default: signature) (authentication|signature|card-authentication|key-management)

Options inherited from parent commands

      --output-file string   log output to a file
  -t, --timeout duration     timeout for commands (default 3m0s)
  -d, --verbose              log debug output
  -y, --yes                  skip confirmation prompts for non-destructive operations

SEE ALSO

• cosign dockerfile - Provides utilities for discovering images in and performing operations on Dockerfiles