saslauthd - sasl authentication server
saslauthd -a authmech [-Tvdchlr] [-O option] [-m mux_path] [-n threads]
[-s size] [-t timeout]
saslauthd is a daemon process that handles plaintext authentication
requests on behalf of the SASL library.
The server fulfills two roles: it isolates all code requiring superuser
privileges into a single process, and it can be used to provide proxy
authentication services to clients that do not understand SASL based
saslauthd should be started from the system boot scripts when going to
multi-user mode. When running against a protected authentication database
(e.g. the shadow mechanism), it must be run as the superuser.
Options named by lower-case letters configure the server itself.
Upper-case options control the behavior of specific authentication
mechanisms; their applicability to a particular authentication mechanism
is described in the AUTHENTICATION MECHANISMS section.
Use authmech as the authentication mechanism. (See the
AUTHENTICATION MECHANISMS section below.) This parameter is
A mechanism specific option (e.g. rimap hostname or config file
The remote host to be contacted by the rimap authentication
mechanism. (Depricated, use -O instead)
Use path as the pathname to the named socket to listen on for
connection requests. This must be an absolute pathname, and MUST
NOT include the trailing "/mux". Note that the default for this
value is "/var/state/saslauthd" (or what was specified at compile
time) and that this directory must exist for saslauthd to
Use threads processes for responding to authentication queries.
(default: 5) A value of zero will indicate that saslauthd should
fork an individual process for each connection. This can solve
leaks that occur in some deployments..
Use size as the table size of the hash table (in kilobytes)
Use timeout as the expiration time of the authentication cache
-T Honour time-of-day login restrictions.
-h Show usage information
-c Enable cacheing of authentication credentials
-l Disable the use of a lock file for controlling access to
-r Combine the realm with the login (with an ’@’ sign in between).
e.g. login: "foo" realm: "bar" will get passed as login:
"foo@bar". Note that the realm will still be passed, which may
lead to unexpected behavior.
-v Print the version number and available authentication mechanisms
on standard error, then exit.
-d Debugging mode.
saslauthd logs it’s activities via syslogd using the LOG_AUTH facility.
saslauthd supports one or more "authentication mechanisms", dependent
upon the facilities provided by the underlying operating system. The
mechanism is selected by the -aho flag from the following list of
Authenticate using the DCE authentication environment.
getpwent (All platforms)
Authenticate using the getpwent() library function. Typically
this authenticates against the local password file. See your
systems getpwent(3) man page for details.
kerberos4 (All platforms)
Authenticate against the local Kerberos 4 realm. (See the
NOTES section for caveats about this driver.)
kerberos5 (All platforms)
Authenticate against the local Kerberos 5 realm.
pam (Linux, Solaris)
Authenticate using Pluggable Authentication Modules (PAM).
rimap (All platforms)
Forward authentication requests to a remote IMAP server. This
driver connects to a remote IMAP server, specified using the
-O flag, and attempts to login (via an IMAP ‘LOGIN’ command)
using the credentials supplied to the local server. If the
remote authentication succeeds the local connection is also
considered to be authenticated. The remote connection is
closed as soon as the tagged response from the ‘LOGIN’ command
is received from the remote server.
The option parameter to the -O flag describes the remote
server to forward authentication requests to. hostname can be
a hostname (imap.example.com) or a dotted-quad IP address
(192.168.0.1). The latter is useful if the remote server is
multi-homed and has network interfaces that are unreachable
from the local IMAP server. The remote host is contacted on
the ‘imap’ service port. A non-default port can be specified
by appending a slash and the port name or number to the
The -O flag and argument are mandatory when using the rimap
shadow (AIX, Irix, Linux, Solaris)
Authenticate against the local "shadow password file". The
exact mechanism is system dependent. saslauthd currently
understands the getspnam() and getuserpw() library routines.
Some systems honour the -T flag.
sasldb (All platforms)
Authenticate against the SASL authentication database. Note
that this is probabally not what you want to be using, and is
even disabled at compile-time by default. If you want to use
sasldb with the SASL library, you probably want to use the
pwcheck_method of "auxprop" along with the sasldb auxprop
ldap (All platforms that support OpenLDAP 2.0 or higher)
Authenticate against an ldap server. The ldap configuration
parameters are read from /etc/saslauthd.conf. The location of
this file can be changed with the -O parameter. See the
LDAP_SASLAUTHD file included with the distribution for the
list of available parameters.
sia (Digital UNIX)
Authenticate using the Digital UNIX Security Integration
Architecture (a.k.a. "enhanced security").
The kerberos4 authentication driver consumes considerable resources. To
perform an authentication it must obtain a ticket granting ticket from
the TGT server on every authentication request. The Kerberos library
routines that obtain the TGT also create a local ticket file, on the
reasonable assumption that you will want to save the TGT for use by other
Kerberos applications. These ticket files are unusable by saslauthd ,
however there is no way not to create them. The overhead of creating and
removing these ticket files can cause serious performance degradation on
busy servers. (Kerberos was never intended to be used in this manner,
/var/run/saslauthd/mux The default communications socket.
/etc/saslauthd.conf The default configuration file for ldap support.
passwd(1), getpwent(3), getspnam(3), getuserpw(3), sasl_checkpass(3)