Basierend auf den [https://blog.plitc.eu/2014/ispconfig-remove-sensitive-information-from-email-headers-with-postfix/ Blogpost] von [[Benutzer:Daniel.plominski|Daniel]] wollte ich meinen Postfix anweisen in Email die sensitive Informationen (Email Client IP usw.) zu bereinigen.

== Beispiel ==
=== IPv4 ===
<pre>
Return-Path: <c3d2@example.net>
Delivered-To: <fsteinel@example.com>
Received: from server.example.com
        by example.com (Dovecot) with LMTP id abc1De23F4G5HIJKlMNopq
        for <fsteinel@example.com>; Sun, 19 Jan 2014 16:20:08 +0100
Received: from [192.168.18.10] (wiki.c3d2.example.net [192.168.18.10])
        (Authenticated sender: c3d2)
        by server.example.com (Postfix) with ESMTPSA id 12ABC3D4567;
        Sun, 19 Jan 2014 16:20:07 +0100 (CET)
Message-ID: <1234A5B6.7890123@example.net>
Date: Sun, 19 Jan 2014 16:20:07 +0100
From: c3d2 wiki <c3d2@example.net>
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0
MIME-Version: 1.0
To: Herr F Steinel <fsteinel@example.com>
Subject: test
Content-Type: text/plain; charset=ISO-8859-15; format=flowed
Content-Transfer-Encoding: 8bit

test

</pre>
=== IPv6 ===
==== Thunderbird ====
<pre>
Return-Path: <c3d2@example.net>
Delivered-To: <fsteinel@example.com>
Received: from server.example.com
        by example.com (Dovecot) with LMTP id abc1De23F4G5HIJKlMNopq
        for <fsteinel@example.com>; Thu, 09 Apr 2015 19:19:41 +0200
Received: from [IPv6:2a00:1828:a008:103:6883:eefe:4240:6042] (unknown [IPv6:2a00:1828:a008:103:6883:eefe:4240:6042])
        (Authenticated sender: c3d2)
        by server.example.com (Postfix) with ESMTPSA id 12ABC3D4567
        for <fsteinel@example.com>; Thu,  9 Apr 2015 19:19:41 +0200 (CEST)
Message-ID: <1234A5B6.7890123@example.net>
Date: Thu, 09 Apr 2015 19:19:37 +0200
From: c3d2 wiki <c3d2@example.net>
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0
MIME-Version: 1.0
To: Herr F Steinel <fsteinel@example.com>
Subject: test
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit

test

</pre>
==== Mutt ====
<pre>
Return-Path: <c3d2@example.net>
Delivered-To: <fsteinel@example.com>
Received: from server.example.com
        by example.com (Dovecot) with LMTP id abc1De23F4G5HIJKlMNopq
        for <fsteinel@example.com>; Thu, 16 Apr 2015 19:01:03 +0200
Received: from mediamaster.example.net (unknown [IPv6:2a00:1828:a008:103:c802:e416:38c3:9462])
        (Authenticated sender: c3d2)
        by server.example.com (Postfix) with ESMTPSA id 12ABC3D4567
        for <fsteinel@example.com>; Thu, 16 Apr 2015 19:01:03 +0200 (CEST)
Date: Thu, 16 Apr 2015 19:01:01 +0200
From: c3d2 wiki <c3d2@example.net>
To: Herr F Steinel <fsteinel@example.com>
Subject: test
Message-ID: <1234A5B6.7890123@mediamaster.example.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
X-Clacks-Overhead: GNU Terry Pratchett

test

</pre>

== header_checks_auth.pcre ==
<pre>
if /^Received:/
#ipv6+thunderbird
/\s+from\s+\[IPv6:2a00:1828:a008:103:[\dA-F:]+\]\s+\(unknown\s\[IPv6:2a00:1828:a008:103:[\dA-F:]+\]\)(.*)/ REPLACE Received: from [127.0.0.1] (localhost [127.0.0.1])$1
#ipv6+mutt
/\s+from\s+[[:alpha:][:digit:]]+\.example\.com\s+\(unknown\s\[IPv6:2a00:1828:a008:103:[\dA-F:]+\]\)(.*)/ REPLACE Received: from [127.0.0.1] (localhost [127.0.0.1])$1
#ipv4
/\s+from\s+\[[.[:digit:]]{7,15}]\s+\([^)][[:alpha:][:digit:]]+\.example\.com\s\[192\.[.[:digit:]]{5,11}\]\)(.*)/ REPLACE Received: from [127.0.0.1] (localhost [127.0.0.1])$1
#print info on EVERY RECEIVED line
#/\s+/ INFO "Received found"
endif
/^\s*Mime-Version: 1\.0\.\w+/ REPLACE MIME-Version: 1.0
/^\s*User-Agent/ IGNORE
/^\s*X-Enigmail/ IGNORE
/^\s*X-Mailer/ IGNORE
/^\s*X-Originating-IP/ IGNORE
</pre>

== Tests ==
Testen der Einstellungen mit
<code>postmap -hmq - pcre:/etc/postfix/header_checks_auth.pcre < testdatei</code>
{| class="wikitable"
|-
! Parameter !! Erläuterung
|-
| -h        || Enable message header query mode.
|-
| -m        || Enable MIME parsing
|-
| -q        || Search the specified maps
|-
| -         || If a key value of - is specified, the program reads key values from the standard input stream and writes one line of key value output for each key that was found.
|}

== Links ==
*[http://article.gmane.org/gmane.mail.postfix.user/194538 "if endif" syntax]
*[http://home.deds.nl/~aeron/regex/ ipv6 regex]
*[https://git-ipuppet.immerda.ch/module-postfix/tree/templates/anonsasl_header_checks.erb puppet module für postfix] inkl. configuration Parameter "anon_sasl" um IP aus dem EMail-Header zu löschen
