GPG
Installation
macOS
You can install GPG on macOS using:
$ brew install gpg
Workflow
Getting existing key
To get an existing key id use:
gpg --list-secret-keys --keyid-format LONG
The key id will be available at
gpg --list-secret-keys --keyid-format LONG /home/foo/.gnupg/pubring.gpg
------------------------------
sec rsa2048/7FFFC09ACAC05FD0 2017-06-02 [SC] [expires: 2019-06-02] 5538B0F643277336BA7F0E457FFFC09ACAC05FD0 uid [ultimate] foo <foo@[example.com](http://realaddress.com)> ssb rsa2048/95E8A289DFE77A84 2017-06-02 [E] [expires: 2019-06-02]
The key id we want, in this case is 7FFFC09ACAC05FD0.
To retrieve the public key use
gpg --armor --export 7FFFC09ACAC05FD0
And the result will be
-----BEGIN PGP PUBLIC KEY BLOCK-----
... The actual key ...
-----END PGP PUBLIC KEY BLOCK-----
Troubleshooting
macOS
Can’t access keychain from UI
If a program cannot access the keychain from the UI, probably there’s some problem in prompting you for the passphrase. You can install, for instance pinentry to solve this. Install it with
$ brew install pinentry-mac
and then register pinentry as the passphrase input option:
$ echo "pinentry-program /usr/local/bin/pinentry-mac" >> ~/.gnupg/gpg-agent.conf