[tac_plus] Re: Issue with Cisco switch authentication against Microsoft Active Directory

Mon Nov 23 20:33:23 UTC 2009

Hi John,

You mean issue commands like tac_plus -C /etct/tac_plus.conf -L -p 49 -d 16
-d 256 -g ? -d 16 -d 256 side by side? It didn't make any change. I got same
log info. By the way, I also saw the log info in /var/log/message:
Nov 23 14:24:25 NMS tac_plus[3676]: Reading config
Nov 23 14:24:25 NMS tac_plus[3676]: Version F4.0.4.19 Initialized 1
Nov 23 14:24:29 NMS tac_plus[3676]: connect from 10.1.69.89 [10.1.69.89]
Nov 23 14:24:37 NMS tac_plus[3676]: login query for 'myuser' tty0 from
10.1.69.89 rejected
Nov 23 14:24:37 NMS tac_plus[3676]: login failure: myuser 10.1.69.89
(10.1.69.89) tty0

Do we have option to see the log about PAM? I haven't found where it is. if
we can check the log of PAM, then we could find something useful. Right now
the log of tac_plus didn't tell too much about why login got failure.

Lou

On Mon, Nov 23, 2009 at 2:20 PM, john heasley <heas at shrubbery.net> wrote:

> Mon, Nov 23, 2009 at 12:43:00PM -0600, Hailu Meng:
> > Thanks John for helping me check this issue.
> >
> > I just run tac_plus -C /path/to/tac_plus.conf -L -p 49 -d256 -g to see
> the
>
> try -d 16 -d 256.  which i think will log the pwd that pam received from
> the device.  make its correct.  the logs below do appear to be a
> reject/fail
> returned from pam.
>
> > log in stdout and in log file. I can't see any suspicious log information
> > here. I paste the log below:
> >
> >
> > Sat Nov 21 22:28:22 2009 [3393]: Waiting for packet
> > Sat Nov 21 22:28:27 2009 [3393]: Read AUTHEN/CONT size=23
> > Sat Nov 21 22:28:27 2009 [3393]: PACKET: key=mykey
> > Sat Nov 21 22:28:27 2009 [3393]: version 192 (0xc0), type 1, seq no 5,
> flags
> > 0x1
> > Sat Nov 21 22:28:27 2009 [3393]: session_id 3295176910 (0xc46868ce), Data
> > length
> >  11 (0xb)
> > Sat Nov 21 22:28:27 2009 [3393]: End header
> > Sat Nov 21 22:28:27 2009 [3393]: type=AUTHEN/CONT
> > Sat Nov 21 22:28:27 2009 [3393]: user_msg_len 6 (0x6), user_data_len 0
> (0x0)
> > Sat Nov 21 22:28:27 2009 [3393]: flags=0x0
> > Sat Nov 21 22:28:27 2009 [3393]: User msg:
> > Sat Nov 21 22:28:27 2009 [3393]: myusername
> > Sat Nov 21 22:28:27 2009 [3393]: User data:
> > Sat Nov 21 22:28:27 2009 [3393]: End packet
> > Sat Nov 21 22:28:27 2009 [3393]: choose_authen chose default_fn
> > Sat Nov 21 22:28:27 2009 [3393]: Calling authentication function
> > Sat Nov 21 22:28:27 2009 [3393]: Writing AUTHEN/GETPASS size=28
> > Sat Nov 21 22:28:27 2009 [3393]: PACKET: key=mykey
> > Sat Nov 21 22:28:27 2009 [3393]: version 192 (0xc0), type 1, seq no 6,
> flags
> > 0x1
> > Sat Nov 21 22:28:27 2009 [3393]: session_id 3295176910 (0xc46868ce), Data
> > length
> >  16 (0x10)
> > Sat Nov 21 22:28:27 2009 [3393]: End header
> > Sat Nov 21 22:28:27 2009 [3393]: type=AUTHEN status=5 (AUTHEN/GETPASS)
> > flags=0x1
> > Sat Nov 21 22:28:27 2009 [3393]: msg_len=10, data_len=0
> > Sat Nov 21 22:28:27 2009 [3393]: msg:
> > Sat Nov 21 22:28:27 2009 [3393]: Password:
> > Sat Nov 21 22:28:27 2009 [3393]: data:
> > Sat Nov 21 22:28:27 2009 [3393]: End packet
> > Sat Nov 21 22:28:27 2009 [3393]: Waiting for packet
> > Sat Nov 21 22:28:34 2009 [3393]: Read AUTHEN/CONT size=30
> > Sat Nov 21 22:28:34 2009 [3393]: PACKET: key=mykey
> > Sat Nov 21 22:28:34 2009 [3393]: version 192 (0xc0), type 1, seq no 7,
> flags
> > 0x1
> > Sat Nov 21 22:28:34 2009 [3393]: session_id 3295176910 (0xc46868ce), Data
> > length
> >  18 (0x12)
> > Sat Nov 21 22:28:34 2009 [3393]: End header
> > Sat Nov 21 22:28:34 2009 [3393]: type=AUTHEN/CONT
> > Sat Nov 21 22:28:34 2009 [3393]: user_msg_len 13 (0xd), user_data_len 0
> > (0x0)
> > Sat Nov 21 22:28:34 2009 [3393]: flags=0x0
> > Sat Nov 21 22:28:34 2009 [3393]: User msg:
> > Sat Nov 21 22:28:34 2009 [3393]: mypassword
> > Sat Nov 21 22:28:34 2009 [3393]: User data:
> > Sat Nov 21 22:28:34 2009 [3393]: End packet
> > Sat Nov 21 22:28:36 2009 [3393]: login query for 'myusername' tty0 from
> > 10.1.69.89 r
> > ejected
> > Sat Nov 21 22:28:36 2009 [3393]: login failure: myusername 10.1.69.89
> > (10.1.69.89) t
> > ty0
> > Sat Nov 21 22:28:36 2009 [3393]: Writing AUTHEN/FAIL size=18
> > Sat Nov 21 22:28:36 2009 [3393]: PACKET: key=mykey
> > Sat Nov 21 22:28:36 2009 [3393]: version 192 (0xc0), type 1, seq no 8,
> flags
> > 0x1
> > Sat Nov 21 22:28:36 2009 [3393]: session_id 3295176910 (0xc46868ce), Data
> > length
> >  6 (0x6)
> > Sat Nov 21 22:28:36 2009 [3393]: End header
> > Sat Nov 21 22:28:36 2009 [3393]: type=AUTHEN status=2 (AUTHEN/FAIL)
> > flags=0x0
> > Sat Nov 21 22:28:36 2009 [3393]: msg_len=0, data_len=0
> > Sat Nov 21 22:28:36 2009 [3393]: msg:
> > Sat Nov 21 22:28:36 2009 [3393]: data:
> > Sat Nov 21 22:28:36 2009 [3393]: End packet
> > Sat Nov 21 22:28:36 2009 [3393]: 10.1.69.89: disconnect
> >
> >
> >
> > On Mon, Nov 23, 2009 at 12:23 PM, john heasley <heas at shrubbery.net>
> wrote:
> >
> > > Mon, Nov 23, 2009 at 12:12:58PM -0600, Hailu Meng:
> > > > Hi Adam,
> > > >
> > > > If the ldapsearch -D "" -w "" runs successfully, what do we suppose
> to
> > > get
> > > > from the output? I just got all of the user information in that
> group.
> > > Does
> > > > that means my password and username got authenticated successfully
> > > against
> > > > AD?
> > > >
> > > > This thing drives me crazy. I need solve it through this week before
> the
> > > > holiday...
> > >
> > > i havent followed this thread, as i know nearly zero about ldap.  but,
> > > have you enabled authentication debugging in the tacacas daemon and
> > > checked the logs to determine what is coming back from pam?  it very
> > > well may be that the ldap client is working just fine, but there is a
> > > pam module bug or a bug in the tacplus daemon or that your device
> > > simply doesnt like something about the replies.
> > >
> > > > Thanks a lot for the help.
> > > >
> > > > Lou
> > > >
> > > > On Fri, Nov 20, 2009 at 7:26 AM, Hailu Meng <hailumeng at gmail.com>
> wrote:
> > > >
> > > > > Still no clue how to turn on the log. binding seems good. See my
> > > findings
> > > > > below. Thanks a lot.
> > > > >
> > > > > On Thu, Nov 19, 2009 at 9:26 PM, adam <prozaconstilts at gmail.com>
> > > wrote:
> > > > >
> > > > >> Hailu Meng wrote:
> > > > >>
> > > > >>> Adam,
> > > > >>>
> > > > >>> I tried the su - "userid" in my tacacs+ server but I don't have
> that
> > > > >>> userid in CentOS. So the CentOS just don't want me log in. I
> think
> > > this will
> > > > >>> not ask tacacs server to authenticate against AD.
> > > > >>>
> > > > >>
> > > > >> You shouldn't need to have to define the user in CentOS, that's
> the
> > > point
> > > > >> of using ldap for authentication. The user is defined in ldap, not
> in
> > > > >> CentOS. Now that I think about it, su - <user> probably wouldn't
> work
> > > > >> anyway, as AD doesn't by default have the data needed by a linux
> box
> > > to
> > > > >> allow login...but see below for more options.
> > > > >>
> > > > >>
> > > > >>
> > > > >>> Is there any other way to test ldap authentication against AD
> with
> > > the
> > > > >>> userid in AD? I tried ldapsearch. It did find my user id without
> > > problem.
> > > > >>> But I haven't found any option to try with password and
> authenticate
> > > against
> > > > >>> AD.
> > > > >>>
> > > > >>
> > > > >> Try using -D:
> > > > >>
> > > > >> from `man ldapsearch`:
> > > > >>
> > > > >> -D binddn
> > > > >>  Use the Distinguished Name binddn to bind to the LDAP directory.
> > > > >>
> > > > >> so -D cn=username,ou=my_ou,dc=my_dc should let you try to
> authenticate
> > > > >> using whatever user you want to define. Just check and double
> check
> > > you get
> > > > >> the right path in that dn.
> > > > >>
> > > > >>
> > > > >> I tried -D " cn=username,ou=my_ou,dc=my_dc " but it just returned
> lots
> > > of
> > > > > users' information. It means successful?
> > > > >
> > > > >
> > > > >>  Do you have ldap server setup or only the openldap library and
> > > openldap
> > > > >>> client? I don't understand why the log is not turned on. There
> must
> > > be some
> > > > >>> debugging info in the log which can help solve this issue.
> > > > >>>
> > > > >>
> > > > >> only the libs and client. You should not need the server. In the
> > > > >> ldapsearch, you can use -d <integer> to get debugging info for
> that
> > > search.
> > > > >> As before, higher number = more debug
> > > > >>
> > > > >>
> > > > >>  If the user can authenticate, does ethereal capture some packets
> > > about
> > > > >>> password verification? Right now I only see the packets when ldap
> > > search for
> > > > >>> my user id and gets results back from AD.
> > > > >>>
> > > > >>
> > > > >> Ethereal should catch all data flowing between the client and
> server.
> > > If
> > > > >> you can search out the user in your AD right now, then one of two
> > > things is
> > > > >> happening:
> > > > >>
> > > > >> 1. You are performing anonymous searches. In this case, no
> username
> > > and pw
> > > > >> is provided, and your AD is happy to hand over info to anyone who
> asks
> > > for
> > > > >> it. If this is the case, you will _not_ see authentication
> > > information. The
> > > > >> following MS KB article should probably help you determine on your
> AD
> > > if
> > > > >> anonymous queries are allowed:
> > > > >>
> > > > >> http://support.microsoft.com/kb/320528
> > > > >>
> > > > >> It has exact instructions for how to get it going, but you can
> follow
> > > > >> along with it to check your current settings without making any
> > > changes.
> > > > >>
> > > > >
> > > > > I checked our setting. Permission type for normal user is "Read &
> > > Execute".
> > > > > I click edit to check the detail about permission. I think it only
> > > allow the
> > > > > user to read the attributes, permission something and can't modify
> the
> > > > > AD.There is "Everyone" setting is also set as "Read & Execute". By
> the
> > > way,
> > > > > the AD is Win2003 R2.
> > > > >
> > > > >
> > > > >>
> > > > >> 2. Authentication is happening. It will be the _very_ first thing
> the
> > > > >> client and server perform, after basic connection establishment.
> Look
> > > for it
> > > > >> at the very beginning of a dump.
> > > > >>
> > > > >>
> > > > >>
> > > > >> Also, it's a bit overkill, but the following article is extremely
> > > > >> informative about all the different ways you can plug linux into
> AD
> > > for
> > > > >> authentication. It might offer some hints...
> > > > >>
> > > > >>
> > > > >>
> > > > >>
> > > > >>> Maybe I need dig into ldap.conf more. If you have any idea, let
> me
> > > know.
> > > > >>>
> > > > >>> Thank you very much.
> > > > >>>
> > > > >>> Lou
> > > > >>>
> > > > >>
> > > > >>
> > > > >>
> > > > >
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