GPG

2020/06/29 by jean tran

Install GPG

Generate a GPG Key

1. Run the following command:

gpg --full-gen-key

1. A prompt ask you to choose between 1-4 key type:

Please select what kind of key you want:
   (1) RSA and RSA (default)
   (2) DSA and Elgamal
   (3) DSA (sign only)
   (4) RSA (sign only)
Your selection? 1

1. It is recommended to choose at least 4096:

RSA keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048) 4096
Requested keysize is 4096 bits

1. Specify GPG key expiration:

Please specify how long the key should be valid.
         0 = key does not expire
      <n>  = key expires in n days
      <n>w = key expires in n weeks
      <n>m = key expires in n months
      <n>y = key expires in n years
Key is valid for? (0) 0
Key does not expire at all

1. Asking for confirmation (y/N):

Is this correct? (y/N) y

1. Double checking your info to validate or edit:

GnuPG needs to construct a user ID to identify your key.

Real name: <your_real_name>
Email address: <your_email>
Comment:
You selected this USER-ID:
    "<your_real_name> <your_email>"

Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? O

1. Listing GPG Keys:

gpg --list-secret-keys --keyid-format LONG <your_email>

It will prompt information such as the following:

sec   rsa4096/BC4F4B77228120E9 2020-05-30 [SC]
      FBC35FE19353F84DAD4640B6BC4F4B77228120E9
uid                 [ultimate] <comment> <your_email>
ssb   rsa4096/4FF81D971F73F011 2020-05-30 [E]

1. Export public key ID

Copy the value equivalent of BC4F4B77228120E9 (replace your key ID as listed on step6)

gpg --armor --export BC4F4B77228120E9

Signing git commits

1. Add the ID to your Git configuration file config or .gitconfig (example: BC4F4B77228120E9):

[user]
  name = <your_name>
  email = <your_email>
  signingkey = <same_id_key_used_on_step7>

1. Commit can be signed by adding the following -S flag

git commit -S -m "your commit description message"

1. Case if you don't want to bother with -S flag

git config --global commit.gpgsign true

Tips & Tricks

For OSX add the following command on your .<type>rc file. (.bashrc | .zshrc)

# ioctl issue for signing GPG OSX
export GPG_TTY=$(tty)