#
# /etc/pam.d/common-auth - authentication settings common to all services
#
# This file is included from other service-specific PAM config files,
# and should contain a list of the authentication modules that define
# the central authentication scheme for use on the system
# (e.g., /etc/shadow, LDAP, Kerberos, etc.).  The default is to use the
# traditional Unix authentication mechanisms.
#
# As of pam 1.0.1-6, this file is managed by pam-auth-update by default.
# To take advantage of this, it is recommended that you configure any
# local modules either before or after the default block, and use
# pam-auth-update to manage selection of other modules.  See
# pam-auth-update(8) for details.

# If pam_yubico.so returns PAM_SUCCESS, then pam_google_authenticator.so is skipped.
# All other return codes are ignored and pam_google_authenticator.so is used.
# pam_yubico.so has "forward_pass"(pam_set_item(pamh, PAM_AUTHTOK, onlypasswd)) enabled by default.
auth	[success=1 default=ignore]	pam_yubico.so id=12345 authfile=/etc/authorized_yubikeys urllist=https://api.yubico.com/wsapi/2.0/verify

# pam_google_authenticator.so is able to detect if user password is entered before TOTP.
auth	required	pam_google_authenticator.so forward_pass

# here are the per-package modules (the "Primary" block)
auth	[success=1 default=ignore]	pam_unix.so nullok_secure try_first_pass
# here's the fallback if no module succeeds
auth	requisite			pam_deny.so
# prime the stack with a positive return value if there isn't one already;
# this avoids us returning an error just because nothing sets a success code
# since the modules above will each just jump around
auth	required			pam_permit.so
# and here are more per-package modules (the "Additional" block)
# end of pam-auth-update config