# GPG Cheat Sheet

## Change expiration date of a key

    $ gpg --list-secret-keys
    sec   4096R/EAE1BF07 2013-07-04 [expires: 2017-07-05]
    uid                  Charles-Henri Bruyand <charleshenri.bruyand@gmail.com>
    uid                  Charles-Henri Bruyand <chbruyand@mayhem.fr>
    ssb   4096R/B92D1CF4 2013-07-04

Edit the key

    $ gpg --edit-key EAE1BF07

List the key and subkeys

    gpg> list

    pub  4096R/EAE1BF07  created: 2013-07-04  expires: 2017-07-05  usage: SC
                         trust: ultimate      validity: ultimate
    sub  4096R/B92D1CF4  created: 2013-07-04  expires: 2017-07-05  usage: E
    [ultimate] (1). Charles-Henri Bruyand <chbruyand@mayhem.fr>
    [ultimate] (2)  Charles-Henri Bruyand <charleshenri.bruyand@gmail.com>

Select the primary key

    gpg> key 0

    pub  4096R/EAE1BF07  created: 2013-07-04  expires: 2017-07-05  usage: SC
                         trust: ultimate      validity: ultimate
    sub  4096R/B92D1CF4  created: 2013-07-04  expires: 2017-07-05  usage: E
    [ultimate] (1). Charles-Henri Bruyand <chbruyand@mayhem.fr>
    [ultimate] (2)  Charles-Henri Bruyand <charleshenri.bruyand@gmail.com>

Use the `expire` command to update the expiration date

```
gpg> expire
Changing expiration time for the primary key.
gpg: WARNING: no user ID has been marked as primary.  This command may
              cause a different user ID to become the assumed primary.
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) 1y
Key expires at Thu Jun 21 11:39:25 2018 CEST
Is this correct? (y/N) y

You need a passphrase to unlock the secret key for
user: "Charles-Henri Bruyand <chbruyand@mayhem.fr>"
4096-bit RSA key, ID EAE1BF07, created 2013-07-04


pub  4096R/EAE1BF07  created: 2013-07-04  expires: 2018-06-21  usage: SC
                     trust: ultimate      validity: ultimate
sub  4096R/B92D1CF4  created: 2013-07-04  expires: 2017-07-05  usage: E
[ultimate] (1)  Charles-Henri Bruyand <chbruyand@mayhem.fr>
[ultimate] (2). Charles-Henri Bruyand <charleshenri.bruyand@gmail.com>
```

Repeat the operation to edit subkeys using the `key` command to select them by index

```
gpg> expire
Changing expiration time for a subkey.
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) 1y
Key expires at Thu Jun 21 11:41:31 2018 CEST
Is this correct? (y/N) y

You need a passphrase to unlock the secret key for
user: "Charles-Henri Bruyand <chbruyand@mayhem.fr>"
4096-bit RSA key, ID EAE1BF07, created 2013-07-04


pub  4096R/EAE1BF07  created: 2013-07-04  expires: 2018-06-21  usage: SC
                     trust: ultimate      validity: ultimate
sub* 4096R/B92D1CF4  created: 2013-07-04  expires: 2018-06-21  usage: E
[ultimate] (1)* Charles-Henri Bruyand <chbruyand@mayhem.fr>
[ultimate] (2). Charles-Henri Bruyand <charleshenri.bruyand@gmail.com>
```

Save your changes

    gpg> save

And don't forget tu publish your updated public key

    $ gpg --keyserver pgp.mit.edu --send-keys EAE1BF07