wiki/dev_guides/commit_signing.md
2022-06-13 18:49:07 -05:00

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---
title: Signing Commits with GPG
author: Al Bowles
revision_date: 2022-06-13
rc:
prod: Rocky Linux
ver: 8
level: Final
---
# Creating your primary keypair
1. Initiate the keypair generation wizard
gpg --full-generate-key --expert
1. Select option `(9) ECC and ECC` for the key type
1. Select option `(1) Curve 25519` for the elliptic curve
1. Set a validity period of your choice, ideally less than 1 year
1. Specify real name and email address to associate with this keypair. The email address must match your verified Github email address or be set to `your-github-username@users.noreply.github.com`.
1. Type a passphrase (twice)
# Create a signing keypair
1. Add a signing subkey
gpg --expert --edit-key my@email.addr
gpg> addkey
1. Select option `(10) ECC (sign only)` for the key type
1. Select option `(1) Curve 25519` for the elliptic curve
1. Set a validity period of your choice, ideally less than 1 year
1. Accept the prompts and type a passphrase (twice)
1. Save and exit
gpg> save
# Create revocation certificate
gpg --output my_email_addr.gpg-revocation-certificate --gen-revoke my@email.addr
# Back up your keypair
Export the *primary keypair* (put these somewhere very safe along with revocation certificate)
gpg --export-secret-keys --armor my@email.addr > my_email_addr.private.gpg-key
gpg --export --armor my@email.addr > my_email_addr.public.gpg-key
# Remove the *primary keypair* from your keyring
1. Export all subkeys from the new keypair to a file
gpg --export-secret-subkeys my@email.addr > $HOME/.gnupg/subkeys
1. Delete primary key from keyring - *BE SURE TO BACK UP YOUR PRIMARY KEYPAIR FIRST!*
gpg --delete-secret-key my@email.addr
1. Re-import the previously exported keys
gpg --import $HOME/.gnupg/subkeys
1. Look for `sec#` instead of `sec` in the output - pound sign means signing subkey is *not* in the keypair located in the keyring
gpg --list-secret-keys $HOME/.gnupg/secring.gpg
# Revoking a *signing keypair*
Find the *primary keypair* and import it (preferably into an ephemeral system like a liveUSB)
gpg --import /path/to/my_email_addr.public.gpg-key /path/to/my_email_addr.private.gpg-key
gpg --edit-key my@email.addr
gpg> revkey
[ passphrase twice ]
gpg> save
# Renew an expired or expiring keypair
gpg --edit-key my@email.addr
[select a key]
gpg> expire
[specify an expiration]
gpg> save
# Create a single signed git commit
git commit -S -m "my awesome signed commit"
# Configure git to always sign commits with a specified key
$ gpg --list-secret-keys --keyid-format=long # grab the fingerprint from the 'sec' line
git config [--global] commit.gpgsign true
git config [--global] user.signingkey DEADB33FBAD1D3A
# Configure VSCode to sign commits
# User or workspace setting
"git.enableCommitSigning": true
# References
[OpenPGP Best Practices](https://riseup.net/en/security/message-security/openpgp/best-practices#key-configuration)<br>
[Github: Signing Commits](https://docs.github.com/en/enterprise-server@3.5/authentication/managing-commit-signature-verification/signing-commits)<br>
[Braincoke's Log: Create a GPG Key](https://blog.braincoke.fr/security/create-a-gpg-key/)<br>
[Creating the Perfect GPG Keypair](https://alexcabal.com/creating-the-perfect-gpg-keypair)<br>
[Digital Neanderthal: Generate GPG Keys With Curve Ed25519](https://www.digitalneanderthal.com/post/gpg/)<br>