NAME¶
saslauthd
—
sasl authentication server
SYNOPSIS¶
saslauthd |
-a
authmech
[-Tvdchlr ]
[-O
option ]
[-m
mux_path ]
[-n
threads ]
[-s
size ]
[-t
timeout ] |
DESCRIPTION¶
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 authentication.
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¶
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.
-a
authmech
- Use authmech as the authentication
mechanism. (See the
AUTHENTICATION
MECHANISMS section below.) This parameter is mandatory.
-O
option
- A mechanism specific option (e.g. rimap hostname or config file path)
-H
hostname
- The remote host to be contacted by the
rimap
authentication mechanism. (Deprecated, use -O instead)
-m
path
- 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 function.
-n
threads
- 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.
-s
size
- Use size as the table size of the hash
table (in kilobytes)
-t
timeout
- Use timeout as the expiration time of the
authentication cache (in seconds)
-T
- Honour time-of-day login restrictions.
-h
- Show usage information
-c
- Enable caching of authentication credentials
-l
- Disable the use of a lock file for controlling access to accept().
-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 for authentication mechanisms that make use of
the realm, however for mechanisms which don't, such as
getpwent, this is the only way to
authenticate domain-specific users sharing the same userid.
-v
- Print the version number and available authentication mechanisms on
standard error, then exit.
-d
- Debugging mode.
Logging¶
saslauthd
logs its activities via
syslogd
using the
LOG_AUTH
facility.
AUTHENTICATION MECHANISMS¶
saslauthd
supports one or more
“authentication mechanisms”, dependent upon the facilities
provided by the underlying operating system. The mechanism is selected by the
-a
flag from the following list of choices:
dce
- (AIX)
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 system's 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 hostname
argument.
The -O
flag and argument are mandatory
when using the rimap
mechanism.
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
probably not what you want to use, 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 plugin instead.
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 in the
cyrus-sasl2-doc package for the list of available parameters.
sia
- (Digital UNIX)
Authenticate using the Digital UNIX Security
Integration Architecture (a.k.a. “enhanced security”).
NOTES¶
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, anyway.)
FILES¶
- /var/run/saslauthd/mux
- The default communications socket.
- /etc/saslauthd.conf
- The default configuration file for ldap support.
SEE ALSO¶
passwd(1),
getpwent(3),
getspnam(3),
getuserpw(3),
sasl_checkpass(3)
sia_authenticate_user(3),