TLSMGR
Section: Maintenance Commands (8)
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NAME
tlsmgr
-
Postfix TLS session cache and PRNG manager
SYNOPSIS
tlsmgr [generic Postfix daemon options]
DESCRIPTION
The
tlsmgr(8) manages the Postfix TLS session caches.
It stores and retrieves cache entries on request by
smtpd(8) and
smtp(8) processes, and periodically
removes entries that have expired.
The tlsmgr(8) also manages the PRNG (pseudo random number
generator) pool. It answers queries by the smtpd(8)
and smtp(8)
processes to seed their internal PRNG pools.
The tlsmgr(8)'s PRNG pool is initially seeded from
an external source (EGD, /dev/urandom, or regular file).
It is updated at configurable pseudo-random intervals with
data from the external source. It is updated periodically
with data from TLS session cache entries and with the time
of day, and is updated with the time of day whenever a
process requests tlsmgr(8) service.
The tlsmgr(8) saves the PRNG state to an exchange file
periodically and when the process terminates, and reads
the exchange file when initializing its PRNG.
SECURITY
The
tlsmgr(8) is not security-sensitive. The code that maintains
the external and internal PRNG pools does not "trust" the
data that it manipulates, and the code that maintains the
TLS session cache does not touch the contents of the cached
entries, except for seeding its internal PRNG pool.
The tlsmgr(8) can be run chrooted and with reduced privileges.
At process startup it connects to the entropy source and
exchange file, and creates or truncates the optional TLS
session cache files.
With Postfix version 2.5 and later, the tlsmgr(8) no
longer uses root privileges when opening cache files. These
files should now be stored under the Postfix-owned
data_directory. As a migration aid, an attempt to
open a cache file under a non-Postfix directory is redirected
to the Postfix-owned data_directory, and a warning
is logged.
DIAGNOSTICS
Problems and transactions are logged to the syslog daemon.
BUGS
There is no automatic means to limit the number of entries in the
TLS session caches and/or the size of the TLS cache files.
CONFIGURATION PARAMETERS
Changes to
main.cf are not picked up automatically,
because
tlsmgr(8) is a persistent processes. Use the
command "
postfix reload" after a configuration change.
The text below provides only a parameter summary. See
postconf(5) for more details including examples.
TLS SESSION CACHE
- lmtp_tls_loglevel (0)
-
The LMTP-specific version of the smtp_tls_loglevel
configuration parameter.
- lmtp_tls_session_cache_database (empty)
-
The LMTP-specific version of the smtp_tls_session_cache_database
configuration parameter.
- lmtp_tls_session_cache_timeout (3600s)
-
The LMTP-specific version of the smtp_tls_session_cache_timeout
configuration parameter.
- smtp_tls_loglevel (0)
-
Enable additional Postfix SMTP client logging of TLS activity.
- smtp_tls_session_cache_database (empty)
-
Name of the file containing the optional Postfix SMTP client
TLS session cache.
- smtp_tls_session_cache_timeout (3600s)
-
The expiration time of Postfix SMTP client TLS session cache
information.
- smtpd_tls_loglevel (0)
-
Enable additional Postfix SMTP server logging of TLS activity.
- smtpd_tls_session_cache_database (empty)
-
Name of the file containing the optional Postfix SMTP server
TLS session cache.
- smtpd_tls_session_cache_timeout (3600s)
-
The expiration time of Postfix SMTP server TLS session cache
information.
PSEUDO RANDOM NUMBER GENERATOR
- tls_random_source (see 'postconf -d' output)
-
The external entropy source for the in-memory tlsmgr(8) pseudo
random number generator (PRNG) pool.
- tls_random_bytes (32)
-
The number of bytes that tlsmgr(8) reads from $tls_random_source
when (re)seeding the in-memory pseudo random number generator (PRNG)
pool.
- tls_random_exchange_name (see 'postconf -d' output)
-
Name of the pseudo random number generator (PRNG) state file
that is maintained by tlsmgr(8).
- tls_random_prng_update_period (3600s)
-
The time between attempts by tlsmgr(8) to save the state of
the pseudo random number generator (PRNG) to the file specified
with $tls_random_exchange_name.
- tls_random_reseed_period (3600s)
-
The maximal time between attempts by tlsmgr(8) to re-seed the
in-memory pseudo random number generator (PRNG) pool from external
sources.
MISCELLANEOUS CONTROLS
- config_directory (see 'postconf -d' output)
-
The default location of the Postfix main.cf and master.cf
configuration files.
- data_directory (see 'postconf -d' output)
-
The directory with Postfix-writable data files (for example:
caches, pseudo-random numbers).
- daemon_timeout (18000s)
-
How much time a Postfix daemon process may take to handle a
request before it is terminated by a built-in watchdog timer.
- process_id (read-only)
-
The process ID of a Postfix command or daemon process.
- process_name (read-only)
-
The process name of a Postfix command or daemon process.
- syslog_facility (mail)
-
The syslog facility of Postfix logging.
- syslog_name (see 'postconf -d' output)
-
A prefix that is prepended to the process name in syslog
records, so that, for example, "smtpd" becomes "prefix/smtpd".
SEE ALSO
smtp(8), Postfix SMTP client
smtpd(8), Postfix SMTP server
postconf(5), configuration parameters
master(5), generic daemon options
master(8), process manager
syslogd(8), system logging
README FILES
Use "
postconf readme_directory" or
"
postconf html_directory" to locate this information.
TLS_README, Postfix TLS configuration and operation
LICENSE
The Secure Mailer license must be distributed with this software.
HISTORY
This service was introduced with Postfix version 2.2.
AUTHOR(S)
Lutz Jaenicke
BTU Cottbus
Allgemeine Elektrotechnik
Universitaetsplatz 3-4
D-03044 Cottbus, Germany
Adapted by:
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- SECURITY
-
- DIAGNOSTICS
-
- BUGS
-
- CONFIGURATION PARAMETERS
-
- TLS SESSION CACHE
-
- PSEUDO RANDOM NUMBER GENERATOR
-
- MISCELLANEOUS CONTROLS
-
- SEE ALSO
-
- README FILES
-
- LICENSE
-
- HISTORY
-
- AUTHOR(S)
-
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