Provided by: libsasl2-2_2.1.28+dfsg1-5ubuntu3.1_amd64 
NAME
libsasl - authentication library
SYNOPSIS
Cyrus SASL library handling communication between an application and the Cyrus SASL
authentication framework.
Description
This document describes generic configuration options for the Cyrus SASL authentication
library libsasl.
The library handles communication between an application and the Cyrus SASL authentication
framework. Both exchange information before libsasl can start offering authentication
services for the application.
The application, among other data, sends the service_name. The service name is the
services name as specified by IANA. SMTP servers, for example, send smtp as service_name.
This information is handed over by libsasl e.g. when Kerberos or PAM authentication takes
place.
Configuration options in general are read either from a file or passed by the application
using libsasl during library initialization.
File-Based configuration
When an application (server) starts, it initializes the libsasl library. The application
passes app_name (application name) to the SASL library. Its value is used to construct the
name of the application specific SASL configuration file. The Cyrus SASL sample-server,
for example, sends sample as app_name. Using this value the SASL library will search the
configuration directories for a file named sample.conf and read configuration options from
it.
Note
Consult the applications manual to determine what app_name it sends to the Cyrus
SASL library.
Application-Based Configuration
Configuration options for libsasl are written down together with application specific
options in the applications configuration file. The application reads them and passes them
over to libsasl when it loads the library.
Note
An example for application-based configuration is the Cyrus IMAP server imapd. SASL
configuration is written to imapd.conf and passed to the SASL library when the
imapd server starts.
Configuration Syntax
The general format of Cyrus SASL configuration file is as follows:
Configuration options
Configuration options are written each on a single physical line. Parameter and
value must be separated by a colon and a single whitespace:
parameter: value
Important
There must be no trailing whitespace after the value or Cyrus SASL will fail to
apply the value appropriately!
Comments, Empty lines and whitespace-only lines
Empty lines and whitespace-only lines are ignored, as are lines whose first non-
whitespace character is a ‘#’.
Options
There are generic options and options specific to the password verification service or
auxiliary property plugin chosen by the administrator. Such specific options are
documented in manuals listed in libsasl(5).
The following configuration parameters are generic configuration options:
authdaemond_path (default: /dev/null)
Path to Courier MTA authdaemond's unix socket. Only applicable when pwcheck_method
is set to authdaemond.
auto_transition: (default: no)
Automatically transition users to other mechanisms when they do a successful
plaintext authentication and if an auxprop plugin is used.
Important
This option does not apply to the ldapdb(5) plugin. It is a read-only plugin.
no Do not transition users to other mechanisms.
noplain
Transition users to other mechanisms, but write non-plaintext secrets only.
yes Transition users to other mechanisms.
Note
The only mechanisms (as currently implemented) which don't use plaintext secrets
are OTP and SRP.
auxprop_plugin: (default: empty)
A whitespace-separated list of one or more auxiliary plugins used if the
pwcheck_method parameter specifies auxprop as an option. Plugins will be queried in
list order. If no plugin is specified, all available plugins will be queried.
ldapdb Specify ldapdb to use the Cyrus SASL ldapdb(5) plugin.
sasldb Specify sasldb to use the Cyrus SASL sasldb(5) plugin.
sql Specify sql to use the Cyrus SASL sql(5) plugin.
log_level: (default: 1)
Specifies a numeric log level. Available log levels are:
0 Don't log anything
1 Log unusual errors
2 Log all authentication failures
3 Log non-fatal warnings
4 More verbose than 3
5 More verbose than 4
6 Traces of internal protocols
7 Traces of internal protocols, including passwords
Important
Cyrus SASL sends log messages to the application that runs it. The application
decides if it forwards such messages to the sysklogd(8) service, to which facility
they are sent and which priority is given to the message.
mech_list: (default: empty)
The optional mech_list parameter specifies a whitespace-separated list of one or
more mechanisms allowed for authentication.
pwcheck_method: (default: auxprop)
A whitespace-separated list of one or more mechanisms. Cyrus SASL provides the
following mechanisms:
authdaemond
Configures Cyrus SASL to contact the Courier MTA authdaemond(8) password
verification service for password verification.
alwaystrue
Lets the pwcheck succeed always.
auxprop
Cyrus SASL will use its own plugin infrastructure to verify passwords. The
auxprop_plugin parameter controls which plugins will be used.
pwcheck
Verify passwords using the Cyrus SASL pwcheck(8) password verification
service. The pwcheck daemon is considered deprecated and should not be used
anymore. Use the saslauthd password verification service instead.
saslauthd
Verify passwords using the Cyrus SASL saslauthd(8) password verification
service.
saslauthd_path: (default: empty)
Path to saslauthd(8) run directory (including the /mux named pipe)
See also
authdaemond(5), ldapdb(5), libsasl(5), saslauthd(8), saslauthd.conf(5), saslpasswd2(5),
sasldblistusers2(5), sasldb(5), sql(5)
Author
This manual was written for the Debian distribution because the original program does not
have a manual page. Parts of the documentation have been taken from the Cyrus SASL's
options.html.
Patrick Ben Koetter
<p@state-of-mind.de>
15 April 2022 libsasl(5)