Signing archives, packages, checksums¶

Signing ensures that the artifacts have been generated by yourself, and your users can verify that by comparing the generated signature with your public signing key.

GoReleaser provides means to sign both executables and archives.

Usage¶

Signing works in combination with checksum files, and it is generally enough to sign the checksum files only.

The default is configured to create a detached signature for the checksum files with GnuPG, and your default key.

To enable signing just add this to your configuration:

.goreleaser.yaml

signs:
  - artifacts: checksum

To customize the signing pipeline you can use the following options:

.goreleaser.yaml

signs:
  - #
    # ID of the sign config, must be unique.
    #
    # Default: 'default'.
    id: foo

    # Name of the signature file.
    #
    # Default: '${artifact}.sig'.
    # Templates: allowed.
    signature: "${artifact}_sig"

    # Path to the signature command
    #
    # Default: 'gpg'.
    cmd: gpg2

    # Command line arguments for the command
    #
    # to sign with a specific key use
    # args: ["-u", "<key id, fingerprint, email, ...>", "--output", "${signature}", "--detach-sign", "${artifact}"]
    #
    # Default: ["--output", "${signature}", "--detach-sign", "${artifact}"].
    # Templates: allowed.
    args: ["--output", "${signature}", "${artifact}", "{{ .ProjectName }}"]

    # Which artifacts to sign
    #
    # Valid options are:
    # - none        no signing
    # - all:        all artifacts
    # - checksum:   checksum files
    # - source:     source archive
    # - package:    Linux packages (deb, rpm, apk, etc)
    # - installer:  Windows MSI installers (Pro only)
    # - diskimage:  macOS DMG disk images (Pro only)
    # - archive:    archives from archive pipe
    # - sbom:       any SBOMs generated for other artifacts
    # - binary:     binaries (only when `archives.format` is 'binary', use binary_signs otherwise)
    #
    # Default: 'none'.
    artifacts: all

    # IDs of the artifacts to sign.
    #
    # If `artifacts` is checksum or source, this fields has no effect.
    ids:
      - foo
      - bar

    # Allows to further filter the artifacts.
    #
    # Artifacts that do not match this expression will be ignored.
    #
    # This feature is only available in GoReleaser Pro.
    # Since: v2.2.
    # Templates: allowed.
    if: '{{ eq .Os "linux" }}'

    # Stdin data to be given to the signature command as stdin.
    #
    # Templates: allowed.
    stdin: "{{ .Env.GPG_PASSWORD }}"

    # StdinFile file to be given to the signature command as stdin.
    stdin_file: ./.password

    # Sets a certificate that your signing command should write to.
    #
    # You can later use `${certificate}` or `.Env.certificate` in the `args` section.
    #
    # This is particularly useful for keyless signing with cosign, and should
    # not usually be used otherwise.
    #
    # Note that this should be a name, not a path.
    #
    # Templates: allowed.
    certificate: '{{ trimsuffix .Env.artifact ".tar.gz" }}.pem'

    # List of environment variables that will be passed to the signing command
    # as well as the templates.
    env:
      - FOO=bar
      - HONK=honkhonk

    # By default, the stdout and stderr of the signing cmd are discarded unless
    # GoReleaser is running with `--verbose` set.
    # You can set this to true if you want them to be displayed regardless.
    #
    # Templates: allowed (since v2.13).
    output: true

Available variable names¶

These environment variables might be available in the fields that accept templates:

${artifact}: the path to the artifact that will be signed
${artifactID}: the ID of the artifact that will be signed
${certificate}: the certificate filename, if provided
${signature}: the signature filename

Signing with cosign¶

You can sign your artifacts with cosign as well.

Cosign uses the --bundle flag, which combines the certificate and signature into a single .sigstore.json file:

.goreleaser.yaml

signs:
  - cmd: cosign
    signature: "${artifact}.sigstore.json"
    args:
      - "sign-blob"
      - "--bundle=${signature}"
      - "${artifact}"
      - "--yes"
    artifacts: checksum

Your users can then verify the signature with:

cosign verify-blob --bundle file.tar.gz.sigstore.json file.tar.gz

Signing and notarizing macOS executables¶

For signing and notarizing macOS executables, please refer to Notarize macOS applications.

Signing Docker images and manifests¶

Please refer to Docker Images Signing.

Limitations¶

You can sign with any command that either outputs a file or modify the file being signed.

If you want to sign with something that writes to STDOUT instead of a file, you can wrap the command inside a sh -c execution, for instance:

.goreleaser.yaml

signs:
  - cmd: sh
    args:
      - "-c"
      - 'echo "${artifact} is signed and I can prove it" | tee ${signature}'
    artifacts: all

And it will work just fine. Just make sure to always use the ${signature} template variable as the result file name and ${artifact} as the origin file.