GPG daily usage

GPG/GnuPG aka Gnu Privacy Guard is a encryption tool for email, git etc.

In this article will show you the basic usage of GPG

to ensure the passphrase can prompt in the terminal, export the following env var

GPG_TTY="$(tty)"
export GPG_TTY

basic command to use GPG

# generate the pair key
gpg --full-gen-key

# list private key
gpg --list-secret-keys

# list public key
gpg --list-keys

back and store the GPG keys

backup

1. list all key and find out which one do you want to back up

gpg --list-secret-keys --keyid-format LONG

#sec   rsa4096 2021-11-17 [SC] [expires: 2031-11-15]
#      E7384A7902979AFAA3F2AC9EB1D896545257905D
#uid           [ultimate] Kelvin Li <kelvin@memodir.com>
#ssb   rsa4096 2021-11-17 [E] [expires: 2031-11-15]

2. export the GPG key.
   this command will export all neceessary key data for restore this key

gpg -o kelvin@memodir.com-key.gpg  --export-options backup --export-secret-keys kelvin@memodir.com

enter the private key's passphrase in the prompt dialog to finish exporting key.

3. transport the key to the server/computer you want to restore

restore

1. import the key

gpg --import-options restore --import kelvin@memodir.com-key.gpg

2. enter the passphrase to import the key
3. edit the key

gpg --edit-key --import kelvin@memodir.com-key.gpg

# enter 'trust' to modify the trust value of the key
gpg > trust

# select 5 to trust ultimately

# finally confirm to input 'Y'

# quit to exit the edit mode
gpg> quit

now you should already import GPG key