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+---
+title: Path-conditional config and SSH key signing in `git`
+date: 2024-12-21
+extra:
+  kind: note
+---
+
+Today I learned about two recent-ish Git features.
+
+## Conditional configs
+
+Since Git version 2.13, it is possible to use different Git configurations based on values such as the current branch, or what's useful in my use case, path prefix:
+
+```bash
+# File: .gitconfig
+
+[includeIf "gitdir:~/Projects/Work/"]
+    path = .gitconfig-work
+```
+
+[🔗 `includeIf` in Git documentation](https://git-scm.com/docs/git-config#_includes)
+
+I personally use separate Git identities and SSH keys for personal and work projects. With `includeIf`, using the right ones is a breeze. Just make sure to `includeIf` after your default configuration, in order for precedence to function as expected.
+
+```bash
+# File: .gitconfig-work
+
+[core]
+    sshCommand = ssh -i $HOME/.ssh/<work key name> -o IdentitiesOnly=yes
+[user]
+    email = <work email>
+    signingkey = $HOME/.ssh/<work key name>
+[gpg]
+    format = ssh
+[commit]
+    gpgsign = true
+```
+
+I'm happy that this is supported natively, so I don't have to use any wrapper scripts, such as those described in [a previous note](../archive/directory-aware-git).
+
+## SSH key signing
+
+The above config snippet also includes another recent addition:
+
+```bash
+[user]
+    signingkey = $HOME/.ssh/<key name>
+[gpg]
+    format = ssh
+```
+
+[🔗 `gpg.format = ssh` in Git documentation](https://git-scm.com/docs/gitformat-signature#Documentation/gitformat-signature.txt-codesshcodeSSH)
+
+You can use the same SSH keys that you use to authenticate your pushes to sign your commits. This is a nice for multiple reasons:
+
+- Most developers already have an SSH key
+- PGP keys are not as popular as SSH keys, and suffer from usability issues
+- Managing one key is less work than managing multiple keys
+
+After configuring your key as a signing key, you need to enable commit signing either with `git commit -S` or the inaccurately named configuration value:
+
+```bash
+[commit]
+    gpgsign = true
+```
+
+Your Git server must support SSH key signing for your commits to show up as _Verified_. At least GitHub and modern versions of GitLab support this. Just make sure your corresponding public key is listed as a _Signing key_ (GitHub) or an _Authentication & signing key_ (GitLab).