NAME

       pam_duo — PAM module for Duo authentication

SYNOPSIS

       pam_duo.so [conf=⟨FILENAME⟩]

DESCRIPTION

       pam_duo  provides  secondary  authentication  (typically  after successful password-based authentication)
       through the Duo authentication service.

OPTIONS

       PAM module configuration options supported:

       conf      Specify an alternate configuration file to load. Default is /etc/duo/pam_duo.conf

       debug     Debug mode; send log messages to stderr instead of syslog.

CONFIGURATION

       The INI-format configuration file must have a “duo” section with the following options:

       host      Duo API host (required).

       ikey      Duo integration key (required).

       skey      Duo secret key (required).

       groups    If  specified,  Duo  authentication  is  required  only  for  users  whose  primary  group   or
                 supplementary  group  list  matches  one  of  the space-separated pattern-lists (see “PATTERNS”
                 below).

       failmode  On service or configuration errors that prevent Duo authentication, fail “safe” (allow  access)
                 or “secure” (deny access). Default is “safe”.

       pushinfo  Send command to be approved via Duo Push authentication. Default is “no”.

       http_proxy
                 Use the specified HTTP proxy, same format as the HTTP_PROXY environment variable.

       autopush  Automatically send a login request to the first factor (usually push), instead of prompting the
                 user. Default is "no".

       prompts   Set the maxiumum number of prompts pam_duo will show before denying access.  Default is 3.

       fallback_local_ip
                 If  unable to detect the authorizing user's IP address, fallback on the server's IP. Default is
                 "no".

       send_gecos
                 Instead of using the unix username, send Duo the contents of the GECOS field from  /etc/passwd.
                 Default is "no".

       An example configuration file:

               [duo]
               host = api-deadbeef.duosecurity.com
               ikey = SI9F...53RI
               skey = 4MjR...Q2NmRiM2Q1Y
               pushinfo = yes
               autopush = yes

       Other authentication restrictions may be implemented using pam_listfile(8), pam_access(8), etc.

PATTERNS

       A  pattern  consists of zero or more non-whitespace characters, ‘*’ (a wildcard that matches zero or more
       characters), or ‘?’ (a wildcard that matches exactly one character).

       A pattern-list is a comma-separated list of patterns. Patterns within pattern-lists  may  be  negated  by
       preceding  them with an exclamation mark (‘!’).  For example, to specify Duo authentication for all users
       (except those that are also admins), and for guests:

             groups = users,!wheel,!*admin guests

FILES

       /etc/duo/pam_duo.conf
                 Default configuration file path

AUTHORS

       pam_duo was written by Duo Security <support@duosecurity.com>

NOTES

       When used with OpenSSH's sshd(8), only PAM-based authentication can be protected with this module; pubkey
       authentication bypasses PAM entirely. OpenSSH's PAM  integration  also  does  not  honor  an  interactive
       pam_conv(3) conversation, prohibiting real-time Duo status messages (such as during voice callback).

Debian                                          September 3, 2010                                     PAM_DUO(8)