NAME
tlsmgr
-
Postfix TLS session cache and PRNG manager
SYNOPSIS
ttllssmmggrr [generic Postfix daemon options]
DESCRIPTION
The ttllssmmggrr(8) manages the Postfix TLS session caches.
It stores and retrieves cache entries on request by
ssmmttppdd(8) and ssmmttpp(8) processes, and periodically
removes entries that have expired.
The ttllssmmggrr(8) also manages the PRNG (pseudo random number
generator) pool. It answers queries by the ssmmttppdd(8)
and ssmmttpp(8)
processes to seed their internal PRNG pools.
The ttllssmmggrr(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 ttllssmmggrr(8) service.
The ttllssmmggrr(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 ttllssmmggrr(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 ttllssmmggrr(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 ttllssmmggrr(8) no
longer uses root privileges when opening cache files. These
files should now be stored under the Postfix-owned
ddaattaa__ddiirreeccttoorryy. As a migration aid, an attempt to
open a cache file under a non-Postfix directory is redirected
to the Postfix-owned ddaattaa__ddiirreeccttoorryy, 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 mmaaiinn..ccff are not picked up automatically,
because ttllssmmggrr(8) is a persistent processes. Use the
command "ppoossttffiixx rreellooaadd" after a configuration change.
The text below provides only a parameter summary. See
ppoossttccoonnff(5) for more details including examples.
TLS SESSION CACHE
-
llmmttpp__ttllss__lloogglleevveell ((00))
The LMTP-specific version of the smtp_tls_loglevel
-
configuration parameter.
-
llmmttpp__ttllss__sseessssiioonn__ccaacchhee__ddaattaabbaassee ((eemmppttyy))
The LMTP-specific version of the smtp_tls_session_cache_database
-
configuration parameter.
-
llmmttpp__ttllss__sseessssiioonn__ccaacchhee__ttiimmeeoouutt ((33660000ss))
The LMTP-specific version of the smtp_tls_session_cache_timeout
-
configuration parameter.
-
ssmmttpp__ttllss__lloogglleevveell ((00))
Enable additional Postfix SMTP client logging of TLS activity.
-
-
ssmmttpp__ttllss__sseessssiioonn__ccaacchhee__ddaattaabbaassee ((eemmppttyy))
Name of the file containing the optional Postfix SMTP client
-
TLS session cache.
-
ssmmttpp__ttllss__sseessssiioonn__ccaacchhee__ttiimmeeoouutt ((33660000ss))
The expiration time of Postfix SMTP client TLS session cache
-
information.
-
ssmmttppdd__ttllss__lloogglleevveell ((00))
Enable additional Postfix SMTP server logging of TLS activity.
-
-
ssmmttppdd__ttllss__sseessssiioonn__ccaacchhee__ddaattaabbaassee ((eemmppttyy))
Name of the file containing the optional Postfix SMTP server
-
TLS session cache.
-
ssmmttppdd__ttllss__sseessssiioonn__ccaacchhee__ttiimmeeoouutt ((33660000ss))
The expiration time of Postfix SMTP server TLS session cache
-
information.
PSEUDO RANDOM NUMBER GENERATOR
-
ttllss__rraannddoomm__ssoouurrccee ((sseeee ''ppoossttccoonnff --dd'' oouuttppuutt))
The external entropy source for the in-memory ttllssmmggrr(8) pseudo
-
random number generator (PRNG) pool.
-
ttllss__rraannddoomm__bbyytteess ((3322))
The number of bytes that ttllssmmggrr(8) reads from $tls_random_source
-
when (re)seeding the in-memory pseudo random number generator (PRNG)
pool.
-
ttllss__rraannddoomm__eexxcchhaannggee__nnaammee ((sseeee ''ppoossttccoonnff --dd'' oouuttppuutt))
Name of the pseudo random number generator (PRNG) state file
-
that is maintained by ttllssmmggrr(8).
-
ttllss__rraannddoomm__pprrnngg__uuppddaattee__ppeerriioodd ((33660000ss))
The time between attempts by ttllssmmggrr(8) to save the state of
-
the pseudo random number generator (PRNG) to the file specified
with $tls_random_exchange_name.
-
ttllss__rraannddoomm__rreesseeeedd__ppeerriioodd ((33660000ss))
The maximal time between attempts by ttllssmmggrr(8) to re-seed the
-
in-memory pseudo random number generator (PRNG) pool from external
sources.
MISCELLANEOUS CONTROLS
-
ccoonnffiigg__ddiirreeccttoorryy ((sseeee ''ppoossttccoonnff --dd'' oouuttppuutt))
The default location of the Postfix main.cf and master.cf
-
configuration files.
-
ddaattaa__ddiirreeccttoorryy ((sseeee ''ppoossttccoonnff --dd'' oouuttppuutt))
The directory with Postfix-writable data files (for example:
-
caches, pseudo-random numbers).
-
ddaaeemmoonn__ttiimmeeoouutt ((1188000000ss))
How much time a Postfix daemon process may take to handle a
-
request before it is terminated by a built-in watchdog timer.
-
pprroocceessss__iidd ((rreeaadd--oonnllyy))
The process ID of a Postfix command or daemon process.
-
-
pprroocceessss__nnaammee ((rreeaadd--oonnllyy))
The process name of a Postfix command or daemon process.
-
-
ssyysslloogg__ffaacciilliittyy ((mmaaiill))
The syslog facility of Postfix logging.
-
-
ssyysslloogg__nnaammee ((sseeee ''ppoossttccoonnff --dd'' oouuttppuutt))
The mail system name that is prepended to the process name in syslog
-
records, so that "smtpd" becomes, for example, "postfix/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 "ppoossttccoonnff rreeaaddmmee__ddiirreeccttoorryy" or
"ppoossttccoonnff hhttmmll__ddiirreeccttoorryy" to locate this information.
TLS_README, Postfix TLS configuration and operation
LICENSE
The Secure Mailer license must be distributed with this software.
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