Provided by: dacs_1.4.28b-3ubuntu1_amd64 
NAME
pamd - PAM transaction server
SYNOPSIS
pamd [dacsoptions[1]] [-daemon] [-fork] [-h hostname] [-http] [-inetd] [-nofork]
[-p portnum] [-policy name] [-secure] [-unsecure]
DESCRIPTION
This program is part of the DACS suite.
The pamd server is required by the local_pam_authenticate[2] authentication module. It
acts as a proxy for local_pam_authenticate, calling PAM functions on its behalf. The pamd
server may be started from inetd(8)[3] or from the command line, but it must be running
for DACS to perform PAM-based authentication.
Each pamd process is involved in an arbitrarily long "conversation" or "transaction" with
one or more executions of local_pam_authenticate. For instance, pamd's initial response to
local_pam_authenticate might be that it requires an account name; upon receiving the
account name from local_pam_authenticate, pamd's response might be that it requires the
password for the account; and upon receiving the password, pamd would indicate success or
failure, depending on whether an acceptable username/password pair was received. The
eventual outcome of a transaction is that authentication succeeds, fails, or could not be
completed because an error occurs.
pamd must be run on the host where pam(3)[4] processing is being performed, which is not
necessarily the same host where local_pam_authenticate is executed.
Security
• pamd will usually be run as root so that it can access the files it needs to
perform authentication.
• pamd is not a DACS web service and is not protected by DACS.
• The protocol between pamd and its client may include sensitive material, such as
passwords. If both programs are run on the same host, this is probably not an
issue. If there is any possibility of eavesdropping etc. by an attacker, however,
communication should be secured through an SSL wrapper.
• pamd should probably not be run on a world-accessible server, since it would offer
a way for attackers to try to guess passwords.
The operating system's PAM policy file is consulted - see pam.conf(5)[5]. The default PAM
service name is "dacs" (see pam_start(3)[6]), which may be used by PAM to locate the
appropriate policy file. A different policy name can be specified using the -policy flag.
The prompts that passed from PAM to pamd to local_pam_authenticate to dacs_authenticate
(or dacsauth) are simply displayed to the user. The user must understand what the prompts
mean (e.g., that "Login:" means to provide a Unix account name).
pamd can be used by non-DACS applications. The protocol, though simple, is not yet
documented other than within the source code. A program called pamd-client is available
for testing and debugging pamd; it is built when PAM support is required, but is neither
installed nor documented (see the source code for basic instructions).
OPTIONS
In addition to the standard dacsoptions[1], pamd recognizes these command line flags:
-daemon
Wait for a connection, then service the request. Mutually exclusive with -inetd.
-fork
Create a new process to service each request. It implies the -daemon flag.
-h hostname
If pamd is running on a host with multiple IP addresses, this specifies the hostname
(or IP address) to listen to for incoming requests. If not provided, the PAMD_HOST[7]
directive will be consulted; if unavailable, gethostname(3)[8] will be used.
-http
This flag is reserved for future use.
-inetd
The server assumes it has been started by inetd(8)[3] and therefore does not wait for
a connection. It exits after servicing the request. This is the default behaviour and
preferred way to configure pamd. This mode of operation assumes that an entry has been
added to inetd.conf(5)[9] that looks much like this:
dacs-pamd stream tcp nowait root /usr/local/dacs/sbin/pamd pamd -uj EXAMPLE -inetd
-nofork
This flag, which implies the -daemon, causes the pamd server to exit after servicing
one request (which is useful when debugging). This is the default behaviour of -daemon
mode.
-p portnum
This specifies the port number to listen to, overriding any PAMD_PORT[10] directive in
effect. It can also be a service name. Any otherwise unassigned port number on the
system from 49152 through 65535 (i.e., one in the dynamic and/or private range) ought
to be acceptable.
If neither this flag nor a PAMD_PORT directive is provided, the program will try to
find the port associated with the dacs-pamd service name in services(5)[11]. For
example:
dacs-pamd 17000/tcp # DACS pamd
-policy name
Use name as the PAM policy name instead of the default.
-secure
The client must supply valid DACS administrative credentials encapsulated within a
DACS cookie. This is the default.
-unsecure
Administrative credentials are not required, but if they are provided they must be
valid. This should probably be used only when testing or if client identification is
not an issue or has been addressed in some other way.
Note
When the -secure flag is in effect, pamd must be associated with a jurisdiction.
Therefore, the DACS configuration files are read and the jurisdiction must be
specified on the command line (e.g., using the -uj flag).
EXAMPLE
For testing purposes, or to better understand how pamd works, you can run it manually and
interact with it using telnet(1)[12], for example, which takes the place of
local_pam_authenticate. You must have PAM authentication configured on the host where you
run pamd and you will probably need to run it as root. This is best done using two
windows; start pamd in the first window and then telnet to it from the second window.
An interaction to perform username/password authentication will look something like the
following (substitute your jurisdiction's name for myjur, your jurisdiction's domain name
or IP address for myjur.example.com, and use a username and password pair that is
recognized on your system). The first telnet connection receives a prompt for a username
(labeled "Login:" and assigned the variable name AUTH_PROMPT_VAR1) from pamd, a
transaction identifier (TRANSID) "10.0.0.124:56372:66664:53983facb39881b2" for this
session, and port number to use for subsequent operations belonging to this transaction
(62475). The second telnet connection provides the TRANSID and username
(AUTH_PROMPT_VAR1="auggie"), and receives a prompt for a password ("Password:", assigned
the variable name AUTH_PROMPT_VAR2). The third telnet connection provides the TRANSID and
the password (AUTH_PROMPT_VAR2="doggy"), and receives the result of authentication
("Success").
# ./pamd -uj myjur -ll debug -daemon -unsecure -nofork
pamd[info]: Site config file is "/usr/local/dacs/federations/site.conf"
pamd[info]: Config file is "/usr/local/dacs/federations/dacs.conf"
pamd[info]: This is jurisdiction DSS::myjur
pamd[info]: Secure mode is off
pamd[debug]: Waiting for initial input block...
pamd[debug]: No username
pamd[debug]: Calling pam_authenticate
pamd[debug]: pamd_conv: reply to port 62475
pamd[debug]: TRANSID is "10.0.0.124:56372:66664:53983facb39881b2"
pamd[debug]: type="text"
pamd[debug]: label="Login:"
pamd[debug]: varname="AUTH_PROMPT_VAR1"
pamd[debug]: pamd_conv: waiting 60 seconds for reply
pamd[debug]: pamd_conv: received connection
pamd[debug]: Reading reply...
pamd[debug]: pamd_conv: reply to port 62475
pamd[debug]: TRANSID is "10.0.0.124:62475:66695:fc855a7d68e8b1eb"
pamd[debug]: type="password"
pamd[debug]: label="Password:"
pamd[debug]: varname="AUTH_PROMPT_VAR2"
pamd[debug]: pamd_conv: waiting 60 seconds for reply
pamd[debug]: pamd_conv: received connection
pamd[debug]: Reading reply...
pamd[debug]: Success
pamd[debug]: result="ok"
pamd[debug]: username="auggie"
% telnet myjur.example.com 17000
Trying 10.0.0.124...
Connected to bsd6.dss.bc.ca.
Escape character is '^]'.
Connection closed by foreign host.
% telnet myjur.example.com 62475
Trying 10.0.0.124...
Connected to bsd6.dss.bc.ca.
Escape character is '^]'.
TRANSID="10.0.0.124:62475:66695:fc855a7d68e8b1eb"
AUTH_PROMPT_VAR1="auggie"
Connection closed by foreign host.
% telnet myjur.example.com 62475
Trying 10.0.0.124...
Connected to bsd6.dss.bc.ca.
Escape character is '^]'.
TRANSID="10.0.0.124:62475:66695:fc855a7d68e8b1eb"
AUTH_PROMPT_VAR2="doggy"
result="ok"
username="auggie"
Connection closed by foreign host.
DIAGNOSTICS
The program exits 0 if everything was fine, 1 if an error occurred.
BUGS
The -daemon flag should cause the process to detach and put itself in the background
unless overridden by another flag; at present it must be started in the background
"manually".
The -http flag, which would allow a pamd session to be started with a web service request,
is not implemented.
SEE ALSO
dacs_authenticate(8)[13], dacsauth(1)[14], pam(3)[15], X/Open Single Sign-On Service
(XSSO) preliminary specification[16]
AUTHOR
Distributed Systems Software (www.dss.ca[17])
COPYING
Copyright2003-2013 Distributed Systems Software. See the LICENSE[18] file that accompanies
the distribution for licensing information.
NOTES
1. dacsoptions
http://dacs.dss.ca/man/dacs.1.html#dacsoptions
2. local_pam_authenticate
http://dacs.dss.ca/man/dacs_authenticate.8.html#local_pam_authenticate
3. inetd(8)
http://www.freebsd.org/cgi/man.cgi?query=inetd&apropos=0&sektion=8&manpath=FreeBSD+9.1-RELEASE&format=html
4. pam(3)
http://www.freebsd.org/cgi/man.cgi?query=pam&apropos=0&sektion=0&manpath=FreeBSD+9.1-RELEASE&format=html
5. pam.conf(5)
http://www.freebsd.org/cgi/man.cgi?query=pam.conf&apropos=0&sektion=5&manpath=FreeBSD+9.1-RELEASE&format=html
6. pam_start(3)
http://www.freebsd.org/cgi/man.cgi?query=pam_start&apropos=0&sektion=3&manpath=FreeBSD+9.1-RELEASE&format=html
7. PAMD_HOST
http://dacs.dss.ca/man/dacs.conf.5.html#PAMD_HOST
8. gethostname(3)
http://www.freebsd.org/cgi/man.cgi?query=gethostname&apropos=0&sektion=3&manpath=FreeBSD+9.1-RELEASE&format=html
9. inetd.conf(5)
http://www.freebsd.org/cgi/man.cgi?query=inetd.conf&apropos=0&sektion=5&manpath=FreeBSD+9.1-RELEASE&format=html
10. PAMD_PORT
http://dacs.dss.ca/man/dacs.conf.5.html#PAMD_PORT
11. services(5)
http://www.freebsd.org/cgi/man.cgi?query=services&apropos=0&sektion=5&manpath=FreeBSD+9.1-RELEASE&format=html
12. telnet(1)
http://www.freebsd.org/cgi/man.cgi?query=telnet&apropos=0&sektion=1&manpath=FreeBSD+9.1-RELEASE&format=html
13. dacs_authenticate(8)
http://dacs.dss.ca/man/dacs_authenticate.8.html
14. dacsauth(1)
http://dacs.dss.ca/man/dacsauth.1.html
15. pam(3)
http://www.freebsd.org/cgi/man.cgi?query=pam&apropos=0&sektion=3&manpath=FreeBSD+9.1-RELEASE&format=html
16. X/Open Single Sign-On Service (XSSO) preliminary specification
http://www.opengroup.org/pubs/catalog/p702.htm
17. www.dss.ca
http://www.dss.ca
18. LICENSE
http://dacs.dss.ca/man/../misc/LICENSE