gpg/README.md

About

GitHub Action to easily import a GPG key.

---

• Features
• Prerequisites
• Usage
  • Workflow
  • Sign commits
  • Use a subkey
  • Set key's trust level
• Customizing
  • inputs
  • outputs
• Contributing
• License

Features

• Works on Linux, macOS and Windows virtual environments
• Allow seeding the internal cache of gpg-agent with provided passphrase
• Signing-only subkeys support
• Purge imported GPG key, cache information and kill agent from runner
• (Git) Enable signing for Git commits, tags and pushes
• (Git) Configure and check committer info against GPG key

Prerequisites

First, generate a GPG key and export the GPG private key as an ASCII armored version to your clipboard:

# macOS
gpg --armor --export-secret-key joe@foo.bar | pbcopy

# Ubuntu (assuming GNU base64)
gpg --armor --export-secret-key joe@foo.bar -w0 | xclip

# Arch
gpg --armor --export-secret-key joe@foo.bar | xclip -selection clipboard -i

# FreeBSD (assuming BSD base64)
gpg --armor --export-secret-key joe@foo.bar | xclip

Paste your clipboard as a secret named GPG_PRIVATE_KEY for example. Create another secret with the PASSPHRASE if applicable.

Usage

Workflow

name: import-gpg

on:
  push:
    branches: master

jobs:
  import-gpg:
    runs-on: ubuntu-latest
    steps:
      -
        name: Checkout
        uses: actions/checkout@v4
      -
        name: Import GPG key
        uses: crazy-max/ghaction-import-gpg@v6
        with:
          gpg_private_key: ${{ secrets.GPG_PRIVATE_KEY }}
          passphrase: ${{ secrets.PASSPHRASE }}
      -
        name: List keys
        run: gpg -K

Sign commits

name: import-gpg

on:
  push:
    branches: master

jobs:
  sign-commit:
    runs-on: ubuntu-latest
    steps:
      -
        name: Checkout
        uses: actions/checkout@v4
      -
        name: Import GPG key
        uses: crazy-max/ghaction-import-gpg@v6
        with:
          gpg_private_key: ${{ secrets.GPG_PRIVATE_KEY }}
          passphrase: ${{ secrets.PASSPHRASE }}
          git_user_signingkey: true
          git_commit_gpgsign: true
      -
        name: Sign commit and push changes
        run: |
          echo foo > bar.txt
          git add .
          git commit -S -m "This commit is signed!"
          git push          

Use a subkey

With the input fingerprint, you can specify which one of the subkeys in a GPG key you want to use for signing.

name: import-gpg

on:
  push:
    branches: master

jobs:
  import-gpg:
    runs-on: ubuntu-latest
    steps:
      -
        name: Checkout
        uses: actions/checkout@v4
      -
        name: Import GPG key
        uses: crazy-max/ghaction-import-gpg@v6
        with:
          gpg_private_key: ${{ secrets.GPG_PRIVATE_KEY }}
          passphrase: ${{ secrets.PASSPHRASE }}
          fingerprint: "C17D11ADF199F12A30A0910F1F80449BE0B08CB8"
      -
        name: List keys
        run: gpg -K

For example, given this GPG key with a signing subkey:

pub   ed25519 2021-09-24 [C]
      87F257B89CE462100BEC0FFE6071D218380FDCC8
      Keygrip = F5C3ABFAAB36B427FD98C4EDD0387E08EA1E8092
uid           [ unknown] Joe Bar <joe@bar.foo>
sub   ed25519 2021-09-24 [S]
      C17D11ADF199F12A30A0910F1F80449BE0B08CB8
      Keygrip = DEE0FC98F441519CA5DE5D79773CB29009695FEB

You can use the subkey with signing capability whose fingerprint is C17D11ADF199F12A30A0910F1F80449BE0B08CB8.

Set key's trust level

With the trust_level input, you can specify the trust level of the GPG key.

Valid values are:

• 1: unknown
• 2: never
• 3: marginal
• 4: full
• 5: ultimate

name: import-gpg

on:
  push:
    branches: master

jobs:
  import-gpg:
    runs-on: ubuntu-latest
    steps:
      -
        name: Checkout
        uses: actions/checkout@v4
      -
        name: Import GPG key
        uses: crazy-max/ghaction-import-gpg@v6
        with:
          gpg_private_key: ${{ secrets.GPG_PRIVATE_KEY }}
          passphrase: ${{ secrets.PASSPHRASE }}
          trust_level: 5

Customizing

inputs

The following inputs can be used as step.with keys

Name	Type	Description
gpg_private_key	String	GPG private key exported as an ASCII armored version or its base64 encoding (required)
passphrase	String	Passphrase of the GPG private key
trust_level	String	Set key's trust level
git_config_global	Bool	Set Git config global (default false)
git_user_signingkey	Bool	Set GPG signing keyID for this Git repository (default false)
git_commit_gpgsign	Bool	Sign all commits automatically. (default false)
git_tag_gpgsign	Bool	Sign all tags automatically. (default false)
git_push_gpgsign	String	Sign all pushes automatically. (default if-asked)
git_committer_name	String	Set commit author's name (defaults to the name associated with the GPG key)
git_committer_email	String	Set commit author's email (defaults to the email address associated with the GPG key)
workdir	String	Working directory (below repository root) (default .)
fingerprint	String	Specific fingerprint to use (subkey)

Note

git_user_signingkey needs to be enabled for git_commit_gpgsign, git_tag_gpgsign, git_push_gpgsign, git_committer_name, git_committer_email inputs.

outputs

Following outputs are available

Name	Type	Description
fingerprint	String	Fingerprint of the GPG key (recommended as user ID)
keyid	String	Low 64 bits of the X.509 certificate SHA-1 fingerprint
name	String	Name associated with the GPG key
email	String	Email address associated with the GPG key

Notes

Make sure to add the corresponding public key to your GitHub account. This is easy to forget, since unlike SSH keys, where you only need to upload 1 thing to GitHub, in this case, you need to upload both the public and private keys to enable this workflow.

Contributing

Want to contribute? Awesome! The most basic way to show your support is to star the project, or to raise issues. You can also support this project by becoming a sponsor on GitHub or by making a PayPal donation to ensure this journey continues indefinitely!

Thanks again for your support, it is much appreciated! 🙏

License

MIT. See LICENSE for more details.