1TLSMGR(8) System Manager's Manual TLSMGR(8)
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6 tlsmgr - Postfix TLS session cache and PRNG manager
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9 tlsmgr [generic Postfix daemon options]
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12 The tlsmgr(8) manages the Postfix TLS session caches. It stores and
13 retrieves cache entries on request by smtpd(8) and smtp(8) processes,
14 and periodically removes entries that have expired.
15 The tlsmgr(8) also manages the PRNG (pseudo random number generator)
17 pool. It answers queries by the smtpd(8) and smtp(8) processes to seed
18 their internal PRNG pools.
19 The tlsmgr(8)'s PRNG pool is initially seeded from an external source
21 (EGD, /dev/urandom, or regular file). It is updated at configurable
22 pseudo-random intervals with data from the external source. It is
23 updated periodically with data from TLS session cache entries and with
24 the time of day, and is updated with the time of day whenever a process
25 requests tlsmgr(8) service.
26 The tlsmgr(8) saves the PRNG state to an exchange file periodically and
28 when the process terminates, and reads the exchange file when initial‐
29 izing its PRNG.
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32 The tlsmgr(8) is not security-sensitive. The code that maintains the
33 external and internal PRNG pools does not "trust" the data that it
34 manipulates, and the code that maintains the TLS session cache does not
35 touch the contents of the cached entries, except for seeding its inter‐
36 nal PRNG pool.
37 The tlsmgr(8) can be run chrooted and with reduced privileges. At
39 process startup it connects to the entropy source and exchange file,
40 and creates or truncates the optional TLS session cache files.
41 With Postfix version 2.5 and later, the tlsmgr(8) no longer uses root
43 privileges when opening cache files. These files should now be stored
44 under the Postfix-owned data_directory. As a migration aid, an attempt
45 to open a cache file under a non-Postfix directory is redirected to the
46 Postfix-owned data_directory, and a warning is logged.
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49 Problems and transactions are logged to the syslog daemon.
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52 There is no automatic means to limit the number of entries in the TLS
53 session caches and/or the size of the TLS cache files.
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56 Changes to main.cf are not picked up automatically, because tlsmgr(8)
57 is a persistent processes. Use the command "postfix reload" after a
58 configuration change.
59 The text below provides only a parameter summary. See postconf(5) for
61 more details including examples.
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64 lmtp_tls_loglevel (0)
65 The LMTP-specific version of the smtp_tls_loglevel configuration
66 parameter.
67 lmtp_tls_session_cache_database (empty)
69 The LMTP-specific version of the smtp_tls_session_cache_database
70 configuration parameter.
71 lmtp_tls_session_cache_timeout (3600s)
73 The LMTP-specific version of the smtp_tls_session_cache_timeout
74 configuration parameter.
75 smtp_tls_loglevel (0)
77 Enable additional Postfix SMTP client logging of TLS activity.
78 smtp_tls_session_cache_database (empty)
80 Name of the file containing the optional Postfix SMTP client TLS
81 session cache.
82 smtp_tls_session_cache_timeout (3600s)
84 The expiration time of Postfix SMTP client TLS session cache
85 information.
86 smtpd_tls_loglevel (0)
88 Enable additional Postfix SMTP server logging of TLS activity.
89 smtpd_tls_session_cache_database (empty)
91 Name of the file containing the optional Postfix SMTP server TLS
92 session cache.
93 smtpd_tls_session_cache_timeout (3600s)
95 The expiration time of Postfix SMTP server TLS session cache
96 information.
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99 tls_random_source (see 'postconf -d' output)
100 The external entropy source for the in-memory tlsmgr(8) pseudo
101 random number generator (PRNG) pool.
102 tls_random_bytes (32)
104 The number of bytes that tlsmgr(8) reads from $tls_random_source
105 when (re)seeding the in-memory pseudo random number generator
106 (PRNG) pool.
107 tls_random_exchange_name (see 'postconf -d' output)
109 Name of the pseudo random number generator (PRNG) state file
110 that is maintained by tlsmgr(8).
111 tls_random_prng_update_period (3600s)
113 The time between attempts by tlsmgr(8) to save the state of the
114 pseudo random number generator (PRNG) to the file specified with
115 $tls_random_exchange_name.
116 tls_random_reseed_period (3600s)
118 The maximal time between attempts by tlsmgr(8) to re-seed the
119 in-memory pseudo random number generator (PRNG) pool from exter‐
120 nal sources.
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123 config_directory (see 'postconf -d' output)
124 The default location of the Postfix main.cf and master.cf con‐
125 figuration files.
126 data_directory (see 'postconf -d' output)
128 The directory with Postfix-writable data files (for example:
129 caches, pseudo-random numbers).
130 daemon_timeout (18000s)
132 How much time a Postfix daemon process may take to handle a
133 request before it is terminated by a built-in watchdog timer.
134 process_id (read-only)
136 The process ID of a Postfix command or daemon process.
137 process_name (read-only)
139 The process name of a Postfix command or daemon process.
140 syslog_facility (mail)
142 The syslog facility of Postfix logging.
143 syslog_name (see 'postconf -d' output)
145 A prefix that is prepended to the process name in syslog
146 records, so that, for example, "smtpd" becomes "prefix/smtpd".
147 Available in Postfix 3.3 and later:
149 service_name (read-only)
151 The master.cf service name of a Postfix daemon process.
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154 smtp(8), Postfix SMTP client
155 smtpd(8), Postfix SMTP server
156 postconf(5), configuration parameters
157 master(5), generic daemon options
158 master(8), process manager
159 syslogd(8), system logging
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162 Use "postconf readme_directory" or "postconf html_directory" to locate
163 this information.
164 TLS_README, Postfix TLS configuration and operation
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167 The Secure Mailer license must be distributed with this software.
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170 This service was introduced with Postfix version 2.2.
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173 Lutz Jaenicke
174 BTU Cottbus
175 Allgemeine Elektrotechnik
176 Universitaetsplatz 3-4
177 D-03044 Cottbus, Germany
178 Adapted by:
180 Wietse Venema
181 IBM T.J. Watson Research
182 P.O. Box 704
183 Yorktown Heights, NY 10598, USA
184 Wietse Venema
186 Google, Inc.
187 111 8th Avenue
188 New York, NY 10011, USA
189 TLSMGR(8)