Update modules/ROOT/pages/using-yubikeys.adoc

Syntax fixes.
Added - How to deal with a backup key.
Added - What if I have already a otp challenge response stored.
This commit is contained in:
Ulf Fischer 2023-05-08 19:50:33 +00:00
parent 978eabafe7
commit d74e5a99c2

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@ -43,6 +43,11 @@ The setup is as follows: install the PAM module, register a YubiKey with your us
The packages required for both PAM modules are available in the official repositories.
[NOTE]
===
Note that one difference of both PAM modules is, with pam_yubico you don't need to touch your yubikey, its enought if the key is inserted in your device. With pam_u2f you have to touch your key every time authentication is required.
===
==== For pam_yubico
Install the PAM yubico module from the official repositories:
@ -63,7 +68,7 @@ Install the PAM u2f module and the CLI tool from the official repositories:
There are two ways to configure the YubiKey PAM module to authenticate users. Either via the YubiCloud or using challenge-response. The YubiCloud is the standard method but depends on Yubico's cloud to validate your OTPs and hence requires constant internet access.
Create two base configuration files in /etc/pam.d. yubikey-required and yubikey-sufficient.
Create two base configuration files in /etc/pam.d/yubikey-required and yubikey-sufficient.
For YubiCloud use the following:
@ -112,7 +117,7 @@ If you want to use both methods for different use-cases just create the respecti
==== For pam_u2f
Create two base configuration files in /etc/pam.d. u2f-required and u2f-sufficient.
Create two base configuration files in /etc/pam.d/u2f-required and u2f-sufficient.
[source]
#%PAM-1.0
@ -142,11 +147,16 @@ Create a configuration file ~/.yubico/authorized_keys with your user account fol
fedora-user:cccccbcgebif[:<another-key-id>]
Alternatively, activate challenge-response in slot 2 and register with your user account.
The first command (ykman) can be skipped if you already have a challenge-response credential stored in slot 2 on your YubiKey. (Verify with 'ykman otp info')
Repeat both or only the last step if you have a backup key (strongly recommended).
[source, bash]
[…]$ ykman otp chalresp --generate --touch 2
[…]$ ykpamcfg -2
[source]
Stored initial challenge and expected response in '/home/<username>/.yubico/challenge-1...5'.
Or for any other system user using sudo.
[source, bash]
@ -163,7 +173,13 @@ If the key is PIN protected you'll be asked to enter the PIN for this operation.
[source, bash]
[…]$ mkdir -p ~/.config/Yubico
[…]$ pamu2fcfg >> ~/.config/Yubico/u2f_keys
[…]$ pamu2fcfg > ~/.config/Yubico/u2f_keys
If you have a backup key add it with the --nouser option and append it to the existing key (line). (All output should end up in the same line.)
[source, bash]
[…]$ pamu2fcfg -n >> ~/.config/Yubico/u2f_keys
=== Configure desired PAM modules