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<!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html> <head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<title> Postfix manual - tlsproxy(8) </title>
</head> <body> <pre>
TLSPROXY(8)                                                        TLSPROXY(8)

<b>NAME</b>
       tlsproxy - Postfix TLS proxy

<b>SYNOPSIS</b>
       <b>tlsproxy</b> [generic Postfix daemon options]

<b>DESCRIPTION</b>
       The  <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  server implements a server-side TLS proxy. It is used
       by <a href="postscreen.8.html"><b>postscreen</b>(8)</a> to talk SMTP-over-TLS with remote  SMTP  clients  that
       are  not  whitelisted  (including  clients  whose  whitelist status has
       expired), but it should also work for non-SMTP protocols.

       Although one <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> process can serve  multiple  sessions  at  the
       same  time,  it  is  a  good  idea  to allow the number of processes to
       increase with load, so that the service remains responsive.

<b>PROTOCOL EXAMPLE</b>
       The example below  concerns  <a href="postscreen.8.html"><b>postscreen</b>(8)</a>.  However,  the  <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>
       server is agnostic of the application protocol, and the example is eas-
       ily adapted to other applications.

       After receiving a  valid  remote  SMTP  client  STARTTLS  command,  the
       <a href="postscreen.8.html"><b>postscreen</b>(8)</a>  server sends the remote SMTP client endpoint string, the
       requested role (server), and  the  requested  timeout  to  <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>.
       <a href="postscreen.8.html"><b>postscreen</b>(8)</a>   then   receives   a  "TLS  available"  indication  from
       <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>.  If the TLS service is available, <a href="postscreen.8.html"><b>postscreen</b>(8)</a> sends  the
       remote SMTP client file descriptor to <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>, and sends the plain-
       text 220 greeting to the remote SMTP client.  This triggers TLS negoti-
       ations between the remote SMTP client and <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>.  Upon completion
       of the TLS-level handshake, <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  translates  between  plaintext
       from/to <a href="postscreen.8.html"><b>postscreen</b>(8)</a> and ciphertext to/from the remote SMTP client.

<b>SECURITY</b>
       The  <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  server is moderately security-sensitive.  It talks to
       untrusted clients on the network. The process can be  run  chrooted  at
       fixed low privilege.

<b>DIAGNOSTICS</b>
       Problems and transactions are logged to <b>syslogd</b>(8).

<b>CONFIGURATION PARAMETERS</b>
       Changes to <a href="postconf.5.html"><b>main.cf</b></a> are not picked up automatically, as <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> pro-
       cesses may run for a long time depending on mail server load.  Use  the
       command "<b>postfix reload</b>" to speed up a change.

       The  text  below provides only a parameter summary. See <a href="postconf.5.html"><b>postconf</b>(5)</a> for
       more details including examples.

<b>STARTTLS SUPPORT CONTROLS</b>
       <b><a href="postconf.5.html#tlsproxy_tls_CAfile">tlsproxy_tls_CAfile</a> ($<a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a>)</b>
              A file containing (PEM  format)  CA  certificates  of  root  CAs
              trusted to sign either remote SMTP client certificates or inter-
              mediate CA certificates.

       <b><a href="postconf.5.html#tlsproxy_tls_CApath">tlsproxy_tls_CApath</a> ($<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a>)</b>
              A directory containing (PEM format) CA certificates of root  CAs
              trusted to sign either remote SMTP client certificates or inter-
              mediate CA certificates.

       <b><a href="postconf.5.html#tlsproxy_tls_always_issue_session_ids">tlsproxy_tls_always_issue_session_ids</a>     ($<a href="postconf.5.html#smtpd_tls_always_issue_session_ids">smtpd_tls_always_issue_ses</a>-</b>
       <b><a href="postconf.5.html#smtpd_tls_always_issue_session_ids">sion_ids</a>)</b>
              Force the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server to issue a TLS session  id,
              even when TLS session caching is turned off.

       <b><a href="postconf.5.html#tlsproxy_tls_ask_ccert">tlsproxy_tls_ask_ccert</a> ($<a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a>)</b>
              Ask a remote SMTP client for a client certificate.

       <b><a href="postconf.5.html#tlsproxy_tls_ccert_verifydepth">tlsproxy_tls_ccert_verifydepth</a> ($<a href="postconf.5.html#smtpd_tls_ccert_verifydepth">smtpd_tls_ccert_verifydepth</a>)</b>
              The verification depth for remote SMTP client certificates.

       <b><a href="postconf.5.html#tlsproxy_tls_cert_file">tlsproxy_tls_cert_file</a> ($<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a>)</b>
              File  with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server RSA certificate in PEM
              format.

       <b><a href="postconf.5.html#tlsproxy_tls_ciphers">tlsproxy_tls_ciphers</a> ($<a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a>)</b>
              The minimum TLS cipher grade that the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server
              will use with opportunistic TLS encryption.

       <b><a href="postconf.5.html#tlsproxy_tls_dcert_file">tlsproxy_tls_dcert_file</a> ($<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>)</b>
              File  with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server DSA certificate in PEM
              format.

       <b><a href="postconf.5.html#tlsproxy_tls_dh1024_param_file">tlsproxy_tls_dh1024_param_file</a> ($<a href="postconf.5.html#smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a>)</b>
              File with DH parameters  that  the  Postfix  <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  server
              should use with non-export EDH ciphers.

       <b><a href="postconf.5.html#tlsproxy_tls_dh512_param_file">tlsproxy_tls_dh512_param_file</a> ($<a href="postconf.5.html#smtpd_tls_dh512_param_file">smtpd_tls_dh512_param_file</a>)</b>
              File  with  DH  parameters  that  the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server
              should use with export-grade EDH ciphers.

       <b><a href="postconf.5.html#tlsproxy_tls_dkey_file">tlsproxy_tls_dkey_file</a> ($<a href="postconf.5.html#smtpd_tls_dkey_file">smtpd_tls_dkey_file</a>)</b>
              File with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server DSA private key in  PEM
              format.

       <b><a href="postconf.5.html#tlsproxy_tls_eccert_file">tlsproxy_tls_eccert_file</a> ($<a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a>)</b>
              File  with  the  Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server ECDSA certificate in
              PEM format.

       <b><a href="postconf.5.html#tlsproxy_tls_eckey_file">tlsproxy_tls_eckey_file</a> ($<a href="postconf.5.html#smtpd_tls_eckey_file">smtpd_tls_eckey_file</a>)</b>
              File with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server ECDSA  private  key  in
              PEM format.

       <b><a href="postconf.5.html#tlsproxy_tls_eecdh_grade">tlsproxy_tls_eecdh_grade</a> ($<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a>)</b>
              The  Postfix  <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  server  security  grade for ephemeral
              elliptic-curve Diffie-Hellman (EECDH) key exchange.

       <b><a href="postconf.5.html#tlsproxy_tls_exclude_ciphers">tlsproxy_tls_exclude_ciphers</a> ($<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a>)</b>
              List of ciphers or cipher types to exclude from the  <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>
              server cipher list at all TLS security levels.

       <b><a href="postconf.5.html#tlsproxy_tls_fingerprint_digest">tlsproxy_tls_fingerprint_digest</a> ($<a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a>)</b>
              The   message   digest   algorithm   to  construct  remote  SMTP
              client-certificate fingerprints.

       <b><a href="postconf.5.html#tlsproxy_tls_key_file">tlsproxy_tls_key_file</a> ($<a href="postconf.5.html#smtpd_tls_key_file">smtpd_tls_key_file</a>)</b>
              File with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server RSA private key in  PEM
              format.

       <b><a href="postconf.5.html#tlsproxy_tls_loglevel">tlsproxy_tls_loglevel</a> ($<a href="postconf.5.html#smtpd_tls_loglevel">smtpd_tls_loglevel</a>)</b>
              Enable  additional  Postfix  <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  server  logging of TLS
              activity.

       <b><a href="postconf.5.html#tlsproxy_tls_mandatory_ciphers">tlsproxy_tls_mandatory_ciphers</a> ($<a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>)</b>
              The minimum TLS cipher grade that the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server
              will use with mandatory TLS encryption.

       <b><a href="postconf.5.html#tlsproxy_tls_mandatory_exclude_ciphers">tlsproxy_tls_mandatory_exclude_ciphers</a>               ($<a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_manda</a>-</b>
       <b><a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">tory_exclude_ciphers</a>)</b>
              Additional  list  of ciphers or cipher types to exclude from the
              <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server cipher list at mandatory TLS security levels.

       <b><a href="postconf.5.html#tlsproxy_tls_mandatory_protocols">tlsproxy_tls_mandatory_protocols</a> ($<a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a>)</b>
              The SSL/TLS protocols accepted by the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server
              with mandatory TLS encryption.

       <b><a href="postconf.5.html#tlsproxy_tls_protocols">tlsproxy_tls_protocols</a> ($<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a>)</b>
              List of TLS protocols that the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  server  will
              exclude or include with opportunistic TLS encryption.

       <b><a href="postconf.5.html#tlsproxy_tls_req_ccert">tlsproxy_tls_req_ccert</a> ($<a href="postconf.5.html#smtpd_tls_req_ccert">smtpd_tls_req_ccert</a>)</b>
              With  mandatory  TLS  encryption,  require a trusted remote SMTP
              client certificate in order to allow TLS connections to proceed.

       <b><a href="postconf.5.html#tlsproxy_tls_security_level">tlsproxy_tls_security_level</a> ($<a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a>)</b>
              The  SMTP TLS security level for the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server;
              when a non-empty value is specified, this overrides the obsolete
              parameters <a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a> and <a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a>.

       Available in Postfix version 2.11 and later:

       <b><a href="postconf.5.html#tlsmgr_service_name">tlsmgr_service_name</a> (tlsmgr)</b>
              The name of the <a href="tlsmgr.8.html"><b>tlsmgr</b>(8)</a> service entry in <a href="master.5.html">master.cf</a>.

<b>OBSOLETE STARTTLS SUPPORT CONTROLS</b>
       These  parameters  are supported for compatibility with <a href="smtpd.8.html"><b>smtpd</b>(8)</a> legacy
       parameters.

       <b><a href="postconf.5.html#tlsproxy_use_tls">tlsproxy_use_tls</a> ($<a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a>)</b>
              Opportunistic TLS: announce  STARTTLS  support  to  remote  SMTP
              clients, but do not require that clients use TLS encryption.

       <b><a href="postconf.5.html#tlsproxy_enforce_tls">tlsproxy_enforce_tls</a> ($<a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a>)</b>
              Mandatory TLS: announce STARTTLS support to remote SMTP clients,
              and require that clients use TLS encryption.

<b>RESOURCE CONTROLS</b>
       <b><a href="postconf.5.html#tlsproxy_watchdog_timeout">tlsproxy_watchdog_timeout</a> (10s)</b>
              How much time a <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> process may take to process local or
              remote I/O before it is terminated by a built-in watchdog timer.

<b>MISCELLANEOUS CONTROLS</b>
       <b><a href="postconf.5.html#config_directory">config_directory</a> (see 'postconf -d' output)</b>
              The default location of the Postfix <a href="postconf.5.html">main.cf</a> and  <a href="master.5.html">master.cf</a>  con-
              figuration files.

       <b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
              The process ID of a Postfix command or daemon process.

       <b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
              The process name of a Postfix command or daemon process.

       <b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
              The syslog facility of Postfix logging.

       <b><a href="postconf.5.html#syslog_name">syslog_name</a> (see 'postconf -d' output)</b>
              A  prefix  that  is  prepended  to  the  process  name in syslog
              records, so that, for example, "smtpd" becomes "prefix/smtpd".

       Available in Postfix 3.3 and later:

       <b><a href="postconf.5.html#service_name">service_name</a> (read-only)</b>
              The <a href="master.5.html">master.cf</a> service name of a Postfix daemon process.

<b>SEE ALSO</b>
       <a href="postscreen.8.html">postscreen(8)</a>, Postfix zombie blocker
       <a href="smtpd.8.html">smtpd(8)</a>, Postfix SMTP server
       <a href="postconf.5.html">postconf(5)</a>, configuration parameters
       syslogd(5), system logging

<b>LICENSE</b>
       The Secure Mailer license must be distributed with this software.

<b>HISTORY</b>
       This service was introduced with Postfix version 2.8.

<b>AUTHOR(S)</b>
       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

                                                                   TLSPROXY(8)
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