gpg-genkeys.sh

# create master key with only certify capability

$ gpg --quick-generate-key "Rafael Alvarez <[email protected]>" rsa4096 cert 1y                         
gpg: key CA8AF23220D60863 marked as ultimately trusted
gpg: revocation certificate stored as '/home/ralvarez/.gnupg/openpgp-revocs.d/AD07FCBA7DBE90338618549CCA8AF23220D60863.rev'
public and secret key created and signed.

Note that this key cannot be used for encryption.  You may want to use
the command "--edit-key" to generate a subkey for this purpose.
pub   rsa4096 2019-08-18 [C] [expires: 2020-08-17]
      AD07FCBA7DBE90338618549CCA8AF23220D60863
uid                      Rafael Alvarez <[email protected]>

# create rest of identities
$ gpg --quick-adduid AD07FCBA7DBE90338618549CCA8AF23220D60863 "Rafael Alvarez <[email protected]>"        
$ gpg --quick-adduid AD07FCBA7DBE90338618549CCA8AF23220D60863 "Rafael Alvarez <[email protected]>"

# create one subkey for one specific capability

$ gpg --quick-addkey AD07FCBA7DBE90338618549CCA8AF23220D60863 rsa3072 sign 1y
$ gpg --quick-addkey AD07FCBA7DBE90338618549CCA8AF23220D60863 rsa3072 encrypt 1y 
$ gpg --quick-addkey AD07FCBA7DBE90338618549CCA8AF23220D60863 rsa3072 auth 1y        

$ gpg --edit-key [email protected]                                                              
gpg (GnuPG) 2.2.17; Copyright (C) 2019 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Secret key is available.

sec  rsa4096/CA8AF23220D60863
     created: 2019-08-18  expires: 2020-08-17  usage: C   
     trust: ultimate      validity: ultimate
ssb  rsa3072/63C3E0F03696977F
     created: 2019-08-18  expires: 2020-08-17  usage: S   
ssb  rsa3072/850A5A6F516C26B0
     created: 2019-08-18  expires: 2020-08-17  usage: E   
ssb  rsa3072/CCB9A0245AB8A500
     created: 2019-08-18  expires: 2020-08-17  usage: A   
[ unknown] (1). Rafael Alvarez <[email protected]>
[ultimate] (2)  Rafael Alvarez <[email protected]>
[ unknown] (3)  Rafael Alvarez <[email protected]>

gpg> trust 
sec  rsa4096/CA8AF23220D60863
     created: 2019-08-18  expires: 2020-08-17  usage: C   
     trust: ultimate      validity: ultimate
ssb  rsa3072/63C3E0F03696977F
     created: 2019-08-18  expires: 2020-08-17  usage: S   
ssb  rsa3072/850A5A6F516C26B0
     created: 2019-08-18  expires: 2020-08-17  usage: E   
ssb  rsa3072/CCB9A0245AB8A500
     created: 2019-08-18  expires: 2020-08-17  usage: A   
[ unknown] (1). Rafael Alvarez <[email protected]>
[ultimate] (2)  Rafael Alvarez <[email protected]>
[ unknown] (3)  Rafael Alvarez <[email protected]>

Please decide how far you trust this user to correctly verify other users' keys
(by looking at passports, checking fingerprints from different sources, etc.)

  1 = I don't know or won't say
  2 = I do NOT trust
  3 = I trust marginally
  4 = I trust fully
  5 = I trust ultimately
  m = back to the main menu

Your decision? 5
Do you really want to set this key to ultimate trust? (y/N) y

sec  rsa4096/CA8AF23220D60863
     created: 2019-08-18  expires: 2020-08-17  usage: C   
     trust: ultimate      validity: ultimate
ssb  rsa3072/63C3E0F03696977F
     created: 2019-08-18  expires: 2020-08-17  usage: S   
ssb  rsa3072/850A5A6F516C26B0
     created: 2019-08-18  expires: 2020-08-17  usage: E   
ssb  rsa3072/CCB9A0245AB8A500
     created: 2019-08-18  expires: 2020-08-17  usage: A   
[ unknown] (1). Rafael Alvarez <[email protected]>
[ultimate] (2)  Rafael Alvarez <[email protected]>
[ unknown] (3)  Rafael Alvarez <[email protected]>

gpg> save
Key not changed so no update needed.

$ gpg --list-keys                         
gpg: checking the trustdb
gpg: marginals needed: 3  completes needed: 1  trust model: pgp
gpg: depth: 0  valid:   2  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 2u
gpg: next trustdb check due at 2020-08-17
/home/ralvarez/.gnupg/pubring.kbx
---------------------------------
pub   rsa2048 2003-12-10 [SC] [expires: 2034-08-14]
      3660BC4AB81D3472B1FFF0ADC8C71A9539BB323D
uid           [ultimate] Juan Alvarez <[email protected]>
uid           [ultimate] Juan Alvarez <[email protected]>
uid           [ultimate] Juan Alvarez <[email protected]>
sub   rsa2048 2003-12-10 [E]

pub   rsa4096 2019-08-18 [C] [expires: 2020-08-17]
      AD07FCBA7DBE90338618549CCA8AF23220D60863
uid           [ultimate] Rafael Alvarez <[email protected]>
uid           [ultimate] Rafael Alvarez <[email protected]>
uid           [ultimate] Rafael Alvarez <[email protected]>
sub   rsa3072 2019-08-18 [S] [expires: 2020-08-17]
sub   rsa3072 2019-08-18 [E] [expires: 2020-08-17]
sub   rsa3072 2019-08-18 [A] [expires: 2020-08-17]