Bitrot: prepare for future changes in OpenSSL API. Viktor
Dukhovni. File: tls_dane.c.
+
+20150501
+
+ Support for Linux 4.*, and some simplification for future
+ makedefs files. Files: makedefs, util/sys_defs.h.
+
+20150718
+
+ Security: opportunistic TLS by default uses "medium" or
+ stronger ciphers instead of "export" or stronger. See the
+ RELEASE_NOTES file for how to get the old settings back.
+ Files: global/mail_params.h, proto/TLS_README.html,
+ proto/postconf.proto, and files derived from those.
+
+20150719
+
+ Security: Postfix TLS support by default no longer uses
+ SSLv2 or SSLv3. See the RELEASE_NOTES file for how to get
+ the old settings back. Files: global/mail_params.h,
+ proto/postconf.proto, and files derived from those.
S\bSe\ber\brv\bve\ber\br-\b-s\bsi\bid\bde\be c\bci\bip\bph\bhe\ber\br c\bco\bon\bnt\btr\bro\bol\bls\bs
-The Postfix SMTP server supports 5 distinct cipher security levels as specified
-by the smtpd_tls_mandatory_ciphers configuration parameter, which determines
-the cipher grade with mandatory TLS encryption. The default value is "medium"
-which is essentially 128-bit encryption or better. With opportunistic TLS
-encryption, the minimum accepted cipher grade is typically "export". The
-corresponding smtpd_tls_ciphers parameter (Postfix >= 2.6) controls the cipher
-grade used with opportunistic TLS.
+The Postfix SMTP server supports 5 distinct cipher grades as specified by the
+smtpd_tls_mandatory_ciphers configuration parameter, which determines the
+minimum cipher grade with mandatory TLS encryption. The default minimum cipher
+grade for mandatory TLS is "medium" which is essentially 128-bit encryption or
+better. The smtpd_tls_ciphers parameter (Postfix >= 2.6) controls the minimum
+cipher grade used with opportunistic TLS. Here, the default minimum cipher
+grade is "medium" for Postfix releases after the middle of 2015, "export" for
+older Postfix releases. With Postfix < 2.6, the minimum opportunistic TLS
+cipher grade is always "export".
By default anonymous ciphers are enabled. They are automatically disabled when
remote SMTP client certificates are requested. If clients are expected to
SMTP client to check the server certificate, so excluding anonymous ciphers is
generally unnecessary.
-The "smtpd_tls_ciphers" configuration parameter (Postfix >= 2.6) provides
-control over the minimum cipher grade for opportunistic TLS. With Postfix <
-2.6, the minimum opportunistic TLS cipher grade is always "export".
-
-With mandatory TLS encryption, the Postfix SMTP server will by default disable
-SSLv2. SSLv2 is used only when TLS encryption is optional. The mandatory TLS
+With mandatory and opportunistic TLS encryption, the Postfix SMTP server by
+default disables SSLv2 and SSLv3 with Postfix releases after the middle of
+2015; older releases only disable SSLv2 for mandatory TLS. The mandatory TLS
protocol list is specified via the smtpd_tls_mandatory_protocols configuration
-parameter. The corresponding smtpd_tls_protocols parameter (Postfix >= 2.6)
-controls the SSL/TLS protocols used with opportunistic TLS.
+parameter. The smtpd_tls_protocols parameter (Postfix >= 2.6) controls the SSL/
+TLS protocols used with opportunistic TLS.
Note that the OpenSSL library only supports protocol exclusion (not inclusion).
For this reason, Postfix can exclude only protocols that are known at the time
configured by setting "smtp_tls_security_level = may". For LMTP, use the
corresponding "lmtp_" parameter.
-Since sending in the clear is acceptable, demanding stronger than default TLS
-security mostly reduces inter-operability. If you must restrict TLS protocol or
-cipher selection even with opportunistic TLS, the "smtp_tls_ciphers" and
-"smtp_tls_protocols" configuration parameters (Postfix >= 2.6) provide control
-over the protocols and cipher grade used with opportunistic TLS. With earlier
-releases the opportunistic TLS cipher grade is always "export" and no protocols
-are disabled.
+The "smtp_tls_ciphers" and "smtp_tls_protocols" configuration parameters
+(Postfix >= 2.6) provide control over the cipher grade and protocols used with
+opportunistic TLS. With earlier Postfix releases, opportunistic TLS always uses
+the cipher grade "export" and enables all protocols.
With opportunistic TLS, mail delivery continues even if the server certificate
is untrusted or bears the wrong name. When the TLS handshake fails for an
In the example below, traffic to example.com and its sub-domains via the
corresponding MX hosts always uses TLS. The SSLv2 protocol will be disabled
-(the default setting of smtp_tls_mandatory_protocols excludes "SSLv2"). Only
+(the default setting of smtp_tls_mandatory_protocols excludes SSLv2+3). Only
high- or medium-strength (i.e. 128 bit or better) ciphers will be used by
default for all "encrypt" security level sessions.
TLSA records in DNSSEC. If no TLSA records are found, the effective
security level used is may. If TLSA records are found, but none are usable,
the effective security level is encrypt. When usable TLSA records are
- obtained for the remote SMTP server, SSLv2 is automatically disabled (see
- smtp_tls_mandatory_protocols), and the server certificate must match the
- TLSA records. RFC 6698 (DANE) TLS authentication and DNSSEC support is
+ obtained for the remote SMTP server, SSLv2+3 are automatically disabled
+ (see smtp_tls_mandatory_protocols), and the server certificate must match
+ the TLSA records. RFC 6698 (DANE) TLS authentication and DNSSEC support is
available with Postfix 2.11 and later.
d\bda\ban\bne\be-\b-o\bon\bnl\bly\by
Mandatory DANE TLS. The TLS policy for the destination is obtained via TLSA
records in DNSSEC. If no TLSA records are found, or none are usable, no
connection is made to the server. When usable TLSA records are obtained for
- the remote SMTP server, SSLv2 is automatically disabled (see
+ the remote SMTP server, SSLv2+3 are automatically disabled (see
smtp_tls_mandatory_protocols), and the server certificate must match the
TLSA records. RFC 6698 (DANE) TLS authentication and DNSSEC support is
available with Postfix 2.11 and later.
C\bCl\bli\bie\ben\bnt\bt-\b-s\bsi\bid\bde\be c\bci\bip\bph\bhe\ber\br c\bco\bon\bnt\btr\bro\bol\bls\bs
-The Postfix SMTP client supports 5 distinct cipher security levels as specified
-by the smtp_tls_mandatory_ciphers configuration parameter. This setting
-controls the minimum acceptable SMTP client TLS cipher grade for use with
-mandatory TLS encryption. The default value "medium" is suitable for most
-destinations with which you may want to enforce TLS, and is beyond the reach of
-today's cryptanalytic methods. See smtp_tls_policy_maps for information on how
-to configure ciphers on a per-destination basis.
+The Postfix SMTP client supports 5 distinct cipher grades as specified by the
+smtp_tls_mandatory_ciphers configuration parameter. This setting controls the
+minimum acceptable SMTP client TLS cipher grade for use with mandatory TLS
+encryption. The default value "medium" is suitable for most destinations with
+which you may want to enforce TLS, and is beyond the reach of today's
+cryptanalytic methods. See smtp_tls_policy_maps for information on how to
+configure ciphers on a per-destination basis.
By default anonymous ciphers are allowed, and automatically disabled when
remote SMTP server certificates are verified. If you want to disable anonymous
requesting them.
The "smtp_tls_ciphers" configuration parameter (Postfix >= 2.6) provides
-control over the minimum cipher grade for opportunistic TLS. With Postfix <
-2.6, the minimum opportunistic TLS cipher grade is always "export".
+control over the minimum cipher grade for opportunistic TLS. The default
+minimum cipher grade for opportunistic TLS is "medium" for Postfix releases
+after the middle of 2015, and "export" for older releases. With Postfix < 2.6,
+the minimum opportunistic TLS cipher grade is always "export".
-With mandatory TLS encryption, the Postfix SMTP client will by default disable
-SSLv2. SSLv2 is used only when TLS encryption is optional. The mandatory TLS
-protocol list is specified via the smtp_tls_mandatory_protocols configuration
-parameter. The corresponding smtp_tls_protocols parameter (Postfix >= 2.6)
-controls the SSL/TLS protocols used with opportunistic TLS.
+With mandatory and opportunistic TLS encryption, the Postfix SMTP client will
+by default disable SSLv2 and SSLv3. The mandatory TLS protocol list is
+specified via the smtp_tls_mandatory_protocols configuration parameter. The
+corresponding smtp_tls_protocols parameter (Postfix >= 2.6) controls the SSL/
+TLS protocols used with opportunistic TLS.
Example:
# Legacy form for Postfix < 2.5:
smtp_tls_mandatory_protocols = SSLv3, TLSv1
# Also available with Postfix >= 2.6:
- smtp_tls_ciphers = export
+ smtp_tls_ciphers = medium
smtp_tls_protocols = !SSLv2
C\bCl\bli\bie\ben\bnt\bt-\b-s\bsi\bid\bde\be S\bSM\bMT\bTP\bPS\bS s\bsu\bup\bpp\bpo\bor\brt\bt
If you upgrade from Postfix 2.10 or earlier, read RELEASE_NOTES-2.11
before proceeding.
+Incompatible change with Postfix 3.0.2
+--------------------------------------
+
+As of the middle of 2015, all supported Postfix releases no longer
+enable "export" grade ciphers for opportunistic TLS, and no longer
+use the deprecated SSLv2 and SSLv3 protocols for mandatory or
+opportunistic TLS.
+
+These changes are very unlikely to cause problems with server-to-server
+communication over the Internet, but they may result in interoperability
+problems with ancient client or server implementations on internal
+networks. To address this problem, you can revert the changes with:
+
+Postfix SMTP client settings:
+
+ lmtp_tls_ciphers = export
+ smtp_tls_ciphers = export
+ lmtp_tls_protocols = !SSLv2
+ smtp_tls_protocols = !SSLv2
+ lmtp_tls_mandatory_protocols = !SSLv2
+ smtp_tls_mandatory_protocols = !SSLv2
+
+Postfix SMTP server settings:
+
+ smtpd_tls_ciphers = export
+ smtpd_tls_protocols =
+ smtpd_tls_mandatory_protocols = !SSLv2
+
+These settings, if put in main.cf, affect all Postfix SMTP client
+or server communication, which may be undesirable. To be more
+selective, use "-o name=value" parameter overrides on specific
+services in master.cf. Execute the command "postfix reload" to make
+the changes effective.
+
Notes for distribution maintainers
----------------------------------
<h3><a name="server_cipher">Server-side cipher controls</a> </h3>
-<p> The Postfix SMTP server supports 5 distinct cipher security levels
-as specified by the <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> configuration parameter,
-which determines the cipher grade with mandatory TLS encryption. The
-default value is "medium" which is essentially 128-bit encryption or better.
-With opportunistic TLS encryption, the minimum accepted cipher grade is
-typically "export". The corresponding <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a> parameter
-(Postfix ≥ 2.6) controls the cipher grade used with opportunistic
-TLS. </p>
+<p> The Postfix SMTP server supports 5 distinct cipher grades as
+specified by the <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> configuration parameter,
+which determines the minimum cipher grade with mandatory TLS
+encryption. The default minimum cipher grade for mandatory TLS is
+"medium" which is essentially 128-bit encryption or better. The
+<a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a> parameter (Postfix ≥ 2.6) controls the minimum
+cipher grade used with opportunistic TLS. Here, the default minimum
+cipher grade is "medium" for Postfix releases after the middle of
+2015, "export" for older Postfix releases. With Postfix < 2.6,
+the minimum opportunistic TLS cipher grade is always "export". </p>
<p> By default anonymous ciphers are enabled. They are automatically
disabled when remote SMTP client certificates are requested. If
a remote SMTP client to check the server certificate, so excluding
anonymous ciphers is generally unnecessary. </p>
-<p> The "<a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a>" configuration parameter (Postfix ≥
-2.6) provides control over the minimum cipher grade for opportunistic
-TLS. With
-Postfix < 2.6, the minimum opportunistic TLS cipher grade is always
-"export". </p>
-
-<p> With mandatory TLS encryption, the Postfix SMTP server will by
-default disable SSLv2. SSLv2 is used only when TLS encryption
-is optional. The mandatory TLS protocol list is specified via the
+<p> With mandatory and opportunistic TLS encryption, the Postfix
+SMTP server by default disables SSLv2 and SSLv3 with Postfix releases
+after the middle of 2015; older releases only disable SSLv2 for
+mandatory TLS. The mandatory TLS protocol list is specified via the
<a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> configuration parameter. The
-
corresponding <a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> parameter (Postfix ≥ 2.6)
+<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> parameter (Postfix ≥ 2.6)
controls the SSL/TLS protocols used with opportunistic TLS. </p>
<p> Note that the OpenSSL library only supports protocol exclusion
Opportunistic TLS can be configured by setting "<a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = may".
For LMTP, use the corresponding "lmtp_" parameter. </p>
-<p> Since sending in the clear is acceptable, demanding stronger
-than default TLS security mostly reduces inter-operability. If you
-must restrict TLS protocol or cipher selection even with opportunistic
-TLS, the "<a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>" and "<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a>" configuration
-parameters (Postfix ≥ 2.6) provide control over the protocols
-and cipher grade
-used with opportunistic TLS. With earlier releases the opportunistic TLS
-cipher grade is always "export" and no protocols are disabled. </p>
+<p> The "<a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>" and "<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a>" configuration
+parameters (Postfix ≥ 2.6) provide control over the cipher grade
+and protocols used with opportunistic TLS. With earlier Postfix
+releases, opportunistic TLS always uses the cipher grade "export"
+and enables all protocols. </p>
<p> With opportunistic TLS, mail delivery continues even if the
server certificate is untrusted or bears the wrong name.
<p> In the example below, traffic to <i>example.com</i> and its sub-domains
via the corresponding MX hosts always uses TLS. The SSLv2 protocol
will be disabled (the default setting of <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a>
-excludes "SSLv2"). Only high- or medium-strength (i.e. 128 bit or
+excludes SSLv2+3). Only high- or medium-strength (i.e. 128 bit or
better) ciphers will be used by default for all "encrypt" security
level sessions. </p>
used is <a href="#client_tls_may">may</a>. If TLSA records are
found, but none are usable, the effective security level is <a
href="#client_tls_encrypt">encrypt</a>. When usable TLSA records
-are obtained for the remote SMTP server, SSLv2 is automatically
+are obtained for the remote SMTP server, SSLv2+3 are automatically
disabled (see <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a>), and the server certificate
must match the TLSA records. <a href="http://tools.ietf.org/html/rfc6698">RFC 6698</a> (DANE) TLS authentication
and DNSSEC support is available with Postfix 2.11 and later. </dd>
The TLS policy for the destination is obtained via TLSA records in
DNSSEC. If no TLSA records are found, or none are usable, no
connection is made to the server. When usable TLSA records are
-obtained for the remote SMTP server, SSLv2 is automatically disabled
+obtained for the remote SMTP server, SSLv2+3 are automatically disabled
(see <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a>), and the server certificate must
match the TLSA records. <a href="http://tools.ietf.org/html/rfc6698">RFC 6698</a> (DANE) TLS authentication and
DNSSEC support is available with Postfix 2.11 and later. </dd>
<h3> <a name="client_cipher">Client-side cipher controls </a> </h3>
-<p> The Postfix SMTP client supports 5 distinct cipher security levels
+<p> The Postfix SMTP client supports 5 distinct cipher grades
as specified by the <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> configuration
parameter. This setting controls the minimum acceptable SMTP client
TLS cipher grade for use with mandatory TLS encryption. The default
little point in requesting them. </p>
<p> The "<a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>" configuration parameter (Postfix ≥ 2.6)
-provides control over the minimum cipher grade for opportunistic TLS. With
-Postfix < 2.6, the minimum opportunistic TLS cipher grade is always
-"export". </p>
-
-<p> With mandatory TLS encryption, the Postfix SMTP client will by
-default disable SSLv2. SSLv2 is used only when TLS encryption
-is optional. The mandatory TLS protocol list is specified via the
+provides control over the minimum cipher grade for opportunistic TLS.
+The default minimum cipher grade for opportunistic TLS is "medium"
+for Postfix releases after the middle of 2015, and "export" for
+older releases. With Postfix < 2.6, the minimum opportunistic
+TLS cipher grade is always "export". </p>
+
+<p> With mandatory and opportunistic TLS encryption, the Postfix
+SMTP client will by default disable SSLv2 and SSLv3. The mandatory
+TLS protocol list is specified via the
<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> configuration parameter. The corresponding
<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> parameter (Postfix ≥ 2.6) controls
the SSL/TLS protocols used with opportunistic TLS. </p>
# Legacy form for Postfix < 2.5:
<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = SSLv3, TLSv1
# Also available with Postfix ≥ 2.6:
- <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> = export
+ <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> = medium
<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2
</pre>
</blockquote>
policy by next-hop destination; when a non-empty value is speci-
fied, this overrides the obsolete <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> parameter.
- <b><a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> (!SSLv2)</b>
+ <b><a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> (!SSLv2, !SSLv3)</b>
List of SSL/TLS protocols that the Postfix SMTP client will use
with mandatory TLS encryption.
Available in Postfix version 2.6 and later:
- <b><a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> (!SSLv2)</b>
+ <b><a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> (!SSLv2, !SSLv3)</b>
List of TLS protocols that the Postfix SMTP client will exclude
or include with opportunistic TLS encryption.
- <b><a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> (export)</b>
+ <b><a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> (medium)</b>
The minimum TLS cipher grade that the Postfix SMTP client will
use with opportunistic TLS encryption.
</DD>
<DT><b><a name="lmtp_tls_ciphers">lmtp_tls_ciphers</a>
-(default: export)</b></DT><DD>
+(default: medium)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> configuration
parameter. See there for details. </p>
</DD>
<DT><b><a name="lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>
-(default: empty)</b></DT><DD>
+(default: medium)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a>
configuration parameter. See there for details. </p>
</DD>
<DT><b><a name="lmtp_tls_mandatory_protocols">lmtp_tls_mandatory_protocols</a>
-(default: !SSLv2)</b></DT><DD>
+(default: !SSLv2, !SSLv3)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a>
configuration parameter. See there for details. </p>
</DD>
<DT><b><a name="lmtp_tls_protocols">lmtp_tls_protocols</a>
-(default: empty)</b></DT><DD>
+(default: !SSLv2, !SSLv3)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> configuration
parameter. See there for details. </p>
</DD>
<DT><b><a name="smtp_tls_ciphers">smtp_tls_ciphers</a>
-(default: export)</b></DT><DD>
+(default: medium)</b></DT><DD>
<p> The minimum TLS cipher grade that the Postfix SMTP client
will use with opportunistic TLS encryption. Cipher types listed in
<a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> are excluded from the base definition of
-the selected cipher grade. The default value "export" ensures maximum
-inter-operability. Because encryption is optional, stronger controls
-are not appropriate, and this setting SHOULD NOT be changed unless the
-change is essential. </p>
+the selected cipher grade. The default value is "medium" for
+Postfix releases after the middle of 2015, "export" for older
+releases. </p>
<p> When TLS is mandatory the cipher grade is chosen via the
<a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> configuration parameter, see there for syntax
details. See <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> for information on how to configure
ciphers on a per-destination basis. </p>
-<p> Example: </p>
-<pre>
-<a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> = export
-</pre>
-
<p> This feature is available in Postfix 2.6 and later. With earlier Postfix
releases only the <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> parameter is implemented,
and opportunistic TLS always uses "export" or better (i.e. all) ciphers. </p>
<dl>
<dt><b>export</b></dt>
-<dd> Enable "EXPORT" grade or better OpenSSL
-ciphers. This is the default for opportunistic encryption. It is
-not recommended for mandatory encryption unless you must enforce TLS
-with "crippled" peers. The underlying cipherlist is specified via the
-<a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a> configuration parameter, which you are strongly
-encouraged to not change. </dd>
+<dd> Enable "EXPORT" grade or better OpenSSL ciphers. The underlying
+cipherlist is specified via the <a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a> configuration
+parameter, which you are strongly encouraged to not change. This
+choice is insecure and SHOULD NOT be used. </dd>
<dt><b>low</b></dt>
-<dd> Enable "LOW" grade or better OpenSSL ciphers. This
-setting is only appropriate for internal mail servers. The underlying
+<dd> Enable "LOW" grade or better OpenSSL ciphers. The underlying
cipherlist is specified via the <a href="postconf.5.html#tls_low_cipherlist">tls_low_cipherlist</a> configuration
-parameter, which you are strongly encouraged to not change. </dd>
+parameter, which you are strongly encouraged to not change. This
+choice is insecure and SHOULD NOT be used. </dd>
<dt><b>medium</b></dt>
<dd> Enable "MEDIUM" grade or better OpenSSL ciphers.
</DD>
<DT><b><a name="smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a>
-(default: !SSLv2)</b></DT><DD>
+(default: !SSLv2, !SSLv3)</b></DT><DD>
<p> List of SSL/TLS protocols that the Postfix SMTP client will use with
mandatory TLS encryption. In <a href="postconf.5.html">main.cf</a> the values are separated by
whitespace, commas or colons. In the policy table "protocols" attribute
(see <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>) the only valid separator is colon. An
empty value means allow all protocols. The valid protocol names, (see
-<b>SSL_get_version(3)</b>), are "SSLv2", "SSLv3" and "TLSv1". </p>
+<b>SSL_get_version(3)</b>), are "SSLv2", "SSLv3" and "TLSv1". The
+default value is "!SSLv2, !SSLv3" for Postfix releases after the
+middle of 2015, "!SSLv2" for older releases. </p>
<p> With Postfix ≥ 2.5 the parameter syntax was expanded to support
protocol exclusions. One can explicitly exclude "SSLv2" by setting
TLSv1, except perhaps via the policy table for destinations which
you are sure will support "TLSv1.1" or "TLSv1.2". </p>
-<p> Since SSL version 2 has known protocol weaknesses and is now
-deprecated, the default setting excludes "SSLv2". This means that by
-default, SSL version 2 will not be used at the "encrypt" security level
-and higher. </p>
-
<p> See the documentation of the <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> parameter and
<a href="TLS_README.html">TLS_README</a> for more information about security levels. </p>
</DD>
<DT><b><a name="smtp_tls_protocols">smtp_tls_protocols</a>
-(default: !SSLv2)</b></DT><DD>
+(default: !SSLv2, !SSLv3)</b></DT><DD>
<p> List of TLS protocols that the Postfix SMTP client will exclude or
-include with opportunistic TLS encryption. Starting with Postfix 2.6,
-the Postfix SMTP client will by default not use the obsolete SSLv2
-protocol. </p>
+include with opportunistic TLS encryption. The default value is
+"!SSLv2, !SSLv3" for Postfix releases after the middle of 2015,
+"!SSLv2" for older releases. Before Postfix 2.6, the Postfix SMTP
+client would use all protocols with opportunistic TLS. </p>
<p> In <a href="postconf.5.html">main.cf</a> the values are separated by whitespace, commas or
colons. In the policy table (see <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>) the only valid
"TLSv1.1" or "TLSv1.2"</p>
<p> To include a protocol list its name, to exclude it, prefix the name
-with a "!" character. To exclude SSLv2 even for opportunistic TLS set
+with a "!" character. To exclude SSLv2 for opportunistic TLS set
"<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2". To exclude both "SSLv2" and "SSLv3" set
"<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2, !SSLv3". Explicitly listing the protocols to
include, rather than protocols to exclude, is supported, but not
# can be mitigated by disabling a particular protocol or raising the
# cipher grade from "export" to "low" or "medium").
<a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> = export
-<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2
+<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2, !SSLv3
</pre>
<pre>
</DD>
<DT><b><a name="smtpd_tls_ciphers">smtpd_tls_ciphers</a>
-(default: export)</b></DT><DD>
+(default: medium)</b></DT><DD>
<p> The minimum TLS cipher grade that the Postfix SMTP server
will use with opportunistic TLS encryption. Cipher types listed in
<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> are excluded from the base definition of
-the selected cipher grade. The default value "export" ensures maximum
-inter-operability. Because encryption is optional, stronger controls
-are not appropriate, and this setting SHOULD NOT be changed unless the
-change is essential. </p>
+the selected cipher grade. The default value is "medium" for Postfix
+releases after the middle of 2015, "export" for older releases.
+</p>
<p> When TLS is mandatory the cipher grade is chosen via the
<a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> configuration parameter, see there for syntax
details. </p>
-<p> Example: </p>
-<pre>
-<a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a> = export
-</pre>
-
<p> This feature is available in Postfix 2.6 and later. With earlier Postfix
releases only the <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> parameter is implemented,
and opportunistic TLS always uses "export" or better (i.e. all) ciphers. </p>
<dl>
<dt><b>export</b></dt>
-<dd> Enable "EXPORT" grade or stronger OpenSSL ciphers.
-This is the most appropriate setting for public MX hosts, and is always
-used with opportunistic TLS encryption. The underlying cipherlist
-is specified via the <a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a> configuration parameter,
-which you are strongly encouraged to not change. </dd>
+<dd> Enable "EXPORT" grade or stronger OpenSSL ciphers. The
+underlying cipherlist is specified via the <a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a>
+configuration parameter, which you are strongly encouraged to not
+change. This choice is insecure and SHOULD NOT be used. </dd>
<dt><b>low</b></dt>
-<dd> Enable "LOW" grade or stronger OpenSSL ciphers. The
-underlying cipherlist is specified via the <a href="postconf.5.html#tls_low_cipherlist">tls_low_cipherlist</a>
-configuration parameter, which you are strongly encouraged to
-not change. </dd>
+<dd> Enable "LOW" grade or stronger OpenSSL ciphers. The underlying
+cipherlist is specified via the <a href="postconf.5.html#tls_low_cipherlist">tls_low_cipherlist</a> configuration
+parameter, which you are strongly encouraged to not change. This
+choice is insecure and SHOULD NOT be used. </dd>
<dt><b>medium</b></dt>
<dd> Enable "MEDIUM" grade or stronger OpenSSL ciphers. These use 128-bit
</DD>
<DT><b><a name="smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a>
-(default: !SSLv2)</b></DT><DD>
+(default: !SSLv2, !SSLv3)</b></DT><DD>
<p> The SSL/TLS protocols accepted by the Postfix SMTP server with
mandatory TLS encryption. If the list is empty, the server supports
all available SSL/TLS protocol versions. A non-empty value is a
list of protocol names separated by whitespace, commas or colons.
The supported protocol names are "SSLv2", "SSLv3" and "TLSv1", and
-are not case sensitive. </p>
+are not case sensitive. The default value is "!SSLv2, !SSLv3" for
+Postfix releases after the middle of 2015, "!SSLv2" for older
+releases. </p>
<p> With Postfix ≥ 2.5 the parameter syntax was expanded to support
protocol exclusions. One can explicitly exclude "SSLv2" by setting
versions of Postfix ≥ 2.10 can disable support for "TLSv1.1" or
"TLSv1.2". </p>
-<p> Since SSL version 2 has known protocol weaknesses and is now
-deprecated, the default setting excludes "SSLv2". This means that
-by default, SSL version 2 will not be used at the "encrypt" security
-level. </p>
-
<p> Example: </p>
<pre>
</DD>
<DT><b><a name="smtpd_tls_protocols">smtpd_tls_protocols</a>
-(default: empty)</b></DT><DD>
+(default: !SSLv2, !SSLv3)</b></DT><DD>
<p> List of TLS protocols that the Postfix SMTP server will exclude
-or include with opportunistic TLS encryption. This parameter SHOULD
-be left at its default empty value, allowing all protocols to be
+or include with opportunistic TLS encryption. The default value is
+"!SSLv2, !SSLv3" for Postfix releases after the middle of 2015,
+empty for older releases allowing all protocols to be
used with opportunistic TLS. A non-empty value is a list of protocol
names separated by whitespace, commas or colons. The supported
protocol names are "SSLv2", "SSLv3" and "TLSv1", and are not case
"TLSv1.2". </p>
<p> To include a protocol list its name, to exclude it, prefix the name
-with a "!" character. To exclude SSLv2 even for opportunistic TLS set
+with a "!" character. To exclude SSLv2 for opportunistic TLS set
"<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> = !SSLv2". To exclude both "SSLv2" and "SSLv3" set
"<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> = !SSLv2, !SSLv3". Explicitly listing the protocols to
include, rather than protocols to exclude, is supported, but not
<p> Example: </p>
<pre>
-<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> = !SSLv2
+<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> = !SSLv2, !SSLv3
</pre>
<p> This feature is available in Postfix 2.6 and later. </p>
(default: ALL:+RC4:@STRENGTH)</b></DT><DD>
<p> The OpenSSL cipherlist for "EXPORT" or higher grade ciphers. This
-defines the meaning of the "export" setting in <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>,
-<a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. This is
-the cipherlist for the opportunistic ("may") TLS client security
-level and is the default cipherlist for the SMTP server. You are
-strongly encouraged to not change this setting. With OpenSSL 1.0.0 and
-later the cipherlist may start with an "aNULL:" prefix, which restores
-the 0.9.8-compatible ordering of the aNULL ciphers to the top of the
-list when they are enabled. This prefix is not needed with previous
-OpenSSL releases. </p>
+defines the meaning of the "export" setting in <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a>,
+<a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>, <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a>,
+<a href="postconf.5.html#lmtp_tls_ciphers">lmtp_tls_ciphers</a>, and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. With Postfix
+releases before the middle of 2015 this is the default cipherlist
+for the opportunistic ("may") TLS client security level and also
+the default cipherlist for the SMTP server. You are strongly
+encouraged to not change this setting. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
(default: ALL:!EXPORT:!LOW:!MEDIUM:+RC4:@STRENGTH)</b></DT><DD>
<p> The OpenSSL cipherlist for "HIGH" grade ciphers. This defines
-the meaning of the "high" setting in <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>,
-<a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. You are
-strongly encouraged to not change this setting. With OpenSSL 1.0.0 and
-later the cipherlist may start with an "aNULL:" prefix, which restores
-the 0.9.8-compatible ordering of the aNULL ciphers to the top of the
-list when they are enabled. This prefix is not needed with previous
-OpenSSL releases. </p>
+the meaning of the "high" setting in <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a>,
+<a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>, <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a>,
+<a href="postconf.5.html#lmtp_tls_ciphers">lmtp_tls_ciphers</a>, and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. You are strongly
+encouraged to not change this setting. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
(default: ALL:!EXPORT:+RC4:@STRENGTH)</b></DT><DD>
<p> The OpenSSL cipherlist for "LOW" or higher grade ciphers. This defines
-the meaning of the "low" setting in <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>,
-<a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. You are
-strongly encouraged to not change this setting. With OpenSSL 1.0.0 and
-later the cipherlist may start with an "aNULL:" prefix, which restores
-the 0.9.8-compatible ordering of the aNULL ciphers to the top of the
-list when they are enabled. This prefix is not needed with previous
-OpenSSL releases. </p>
+the meaning of the "low" setting in <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a>,
+<a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>, <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a>,
+<a href="postconf.5.html#lmtp_tls_ciphers">lmtp_tls_ciphers</a>, and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. You are strongly
+encouraged to not change this setting. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
(default: ALL:!EXPORT:!LOW:+RC4:@STRENGTH)</b></DT><DD>
<p> The OpenSSL cipherlist for "MEDIUM" or higher grade ciphers. This
-defines the meaning of the "medium" setting in <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>,
-<a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. This is
-the default cipherlist for mandatory TLS encryption in the TLS
-client (with anonymous ciphers disabled when verifying server
-certificates). You are strongly encouraged to not change this
-setting. With OpenSSL 1.0.0 and later the cipherlist may start with an
-"aNULL:" prefix, which restores the 0.9.8-compatible ordering of the
-aNULL ciphers to the top of the list when they are enabled. This prefix
-is not needed with previous OpenSSL releases. </p>
+defines the meaning of the "medium" setting in <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a>,
+<a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>, <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a>,
+<a href="postconf.5.html#lmtp_tls_ciphers">lmtp_tls_ciphers</a>, and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. This is the
+default cipherlist for mandatory TLS encryption in the TLS client
+(with anonymous ciphers disabled when verifying server certificates).
+This is the default cipherlist for opportunistic TLS with Postfix
+releases after the middle of 2015. You are strongly encouraged to
+not change this setting. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
policy by next-hop destination; when a non-empty value is speci-
fied, this overrides the obsolete <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> parameter.
- <b><a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> (!SSLv2)</b>
+ <b><a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> (!SSLv2, !SSLv3)</b>
List of SSL/TLS protocols that the Postfix SMTP client will use
with mandatory TLS encryption.
Available in Postfix version 2.6 and later:
- <b><a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> (!SSLv2)</b>
+ <b><a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> (!SSLv2, !SSLv3)</b>
List of TLS protocols that the Postfix SMTP client will exclude
or include with opportunistic TLS encryption.
- <b><a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> (export)</b>
+ <b><a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> (medium)</b>
The minimum TLS cipher grade that the Postfix SMTP client will
use with opportunistic TLS encryption.
Postfix SMTP server cipher list at mandatory TLS security lev-
els.
- <b><a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> (!SSLv2)</b>
+ <b><a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> (!SSLv2, !SSLv3)</b>
The SSL/TLS protocols accepted by the Postfix SMTP server with
mandatory TLS encryption.
Available in Postfix version 2.6 and later:
- <b><a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> (empty)</b>
+ <b><a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> (!SSLv2, !SSLv3)</b>
List of TLS protocols that the Postfix SMTP server will exclude
or include with opportunistic TLS encryption.
- <b><a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a> (export)</b>
+ <b><a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a> (medium)</b>
The minimum TLS cipher grade that the Postfix SMTP server will
use with opportunistic TLS encryption.
# Officially supported usage.
0) SYSTEM=`(uname -s) 2>/dev/null`
RELEASE=`(uname -r) 2>/dev/null`
+ # No ${x%%y} support in Solaris 11 /bin/sh
+ RELEASE_MAJOR=`expr "$RELEASE" : '\([0-9]*\)'` || exit 1
VERSION=`(uname -v) 2>/dev/null`
case "$VERSION" in
dcosx*) SYSTEM=$VERSION;;
: ${SHLIB_ENV="LD_LIBRARY_PATH=`pwd`/lib"}
: ${PLUGIN_LD="${CC-gcc} -shared"}
;;
- Linux.3*) SYSTYPE=LINUX3
+ Linux.[34].*) SYSTYPE=LINUX$RELEASE_MAJOR
case "$CCARGS" in
*-DNO_DB*) ;;
*-DHAS_DB*) ;;
configuration parameter. See there for details.
.PP
This feature is available in Postfix 2.3 and later.
-.SH lmtp_tls_ciphers (default: export)
+.SH lmtp_tls_ciphers (default: medium)
The LMTP\-specific version of the smtp_tls_ciphers configuration
parameter. See there for details.
.PP
configuration parameter. See there for details.
.PP
This feature is available in Postfix 2.3 and later.
-.SH lmtp_tls_mandatory_ciphers (default: empty)
+.SH lmtp_tls_mandatory_ciphers (default: medium)
The LMTP\-specific version of the smtp_tls_mandatory_ciphers
configuration parameter. See there for details.
.PP
configuration parameter. See there for details.
.PP
This feature is available in Postfix 2.3 and later.
-.SH lmtp_tls_mandatory_protocols (default: !SSLv2)
+.SH lmtp_tls_mandatory_protocols (default: !SSLv2, !SSLv3)
The LMTP\-specific version of the smtp_tls_mandatory_protocols
configuration parameter. See there for details.
.PP
configuration parameter. See there for details.
.PP
This feature is available in Postfix 2.3 and later.
-.SH lmtp_tls_protocols (default: empty)
+.SH lmtp_tls_protocols (default: !SSLv2, !SSLv3)
The LMTP\-specific version of the smtp_tls_protocols configuration
parameter. See there for details.
.PP
.PP
This feature is available in Postfix version 2.2. It is not used with
Postfix 2.3 and later; use smtp_tls_mandatory_ciphers instead.
-.SH smtp_tls_ciphers (default: export)
+.SH smtp_tls_ciphers (default: medium)
The minimum TLS cipher grade that the Postfix SMTP client
will use with opportunistic TLS encryption. Cipher types listed in
smtp_tls_exclude_ciphers are excluded from the base definition of
-the selected cipher grade. The default value "export" ensures maximum
-inter\-operability. Because encryption is optional, stronger controls
-are not appropriate, and this setting SHOULD NOT be changed unless the
-change is essential.
+the selected cipher grade. The default value is "medium" for
+Postfix releases after the middle of 2015, "export" for older
+releases.
.PP
When TLS is mandatory the cipher grade is chosen via the
smtp_tls_mandatory_ciphers configuration parameter, see there for syntax
details. See smtp_tls_policy_maps for information on how to configure
ciphers on a per\-destination basis.
.PP
-Example:
-.nf
-.na
-.ft C
-smtp_tls_ciphers = export
-.fi
-.ad
-.ft R
-.PP
This feature is available in Postfix 2.6 and later. With earlier Postfix
releases only the smtp_tls_mandatory_ciphers parameter is implemented,
and opportunistic TLS always uses "export" or better (i.e. all) ciphers.
.PP
The following cipher grades are supported:
.IP "\fBexport\fR"
-Enable "EXPORT" grade or better OpenSSL
-ciphers. This is the default for opportunistic encryption. It is
-not recommended for mandatory encryption unless you must enforce TLS
-with "crippled" peers. The underlying cipherlist is specified via the
-tls_export_cipherlist configuration parameter, which you are strongly
-encouraged to not change.
+Enable "EXPORT" grade or better OpenSSL ciphers. The underlying
+cipherlist is specified via the tls_export_cipherlist configuration
+parameter, which you are strongly encouraged to not change. This
+choice is insecure and SHOULD NOT be used.
.br
.IP "\fBlow\fR"
-Enable "LOW" grade or better OpenSSL ciphers. This
-setting is only appropriate for internal mail servers. The underlying
+Enable "LOW" grade or better OpenSSL ciphers. The underlying
cipherlist is specified via the tls_low_cipherlist configuration
-parameter, which you are strongly encouraged to not change.
+parameter, which you are strongly encouraged to not change. This
+choice is insecure and SHOULD NOT be used.
.br
.IP "\fBmedium\fR"
Enable "MEDIUM" grade or better OpenSSL ciphers.
attribute. See smtp_tls_policy_maps for notes and examples.
.PP
This feature is available in Postfix 2.3 and later.
-.SH smtp_tls_mandatory_protocols (default: !SSLv2)
+.SH smtp_tls_mandatory_protocols (default: !SSLv2, !SSLv3)
List of SSL/TLS protocols that the Postfix SMTP client will use with
mandatory TLS encryption. In main.cf the values are separated by
whitespace, commas or colons. In the policy table "protocols" attribute
(see smtp_tls_policy_maps) the only valid separator is colon. An
empty value means allow all protocols. The valid protocol names, (see
-\\fBfBSSL_get_version\fR(3)\fR), are "SSLv2", "SSLv3" and "TLSv1".
+\\fBfBSSL_get_version\fR(3)\fR), are "SSLv2", "SSLv3" and "TLSv1". The
+default value is "!SSLv2, !SSLv3" for Postfix releases after the
+middle of 2015, "!SSLv2" for older releases.
.PP
With Postfix >= 2.5 the parameter syntax was expanded to support
protocol exclusions. One can explicitly exclude "SSLv2" by setting
TLSv1, except perhaps via the policy table for destinations which
you are sure will support "TLSv1.1" or "TLSv1.2".
.PP
-Since SSL version 2 has known protocol weaknesses and is now
-deprecated, the default setting excludes "SSLv2". This means that by
-default, SSL version 2 will not be used at the "encrypt" security level
-and higher.
-.PP
See the documentation of the smtp_tls_policy_maps parameter and
TLS_README for more information about security levels.
.PP
configurations in environments where DNS security is not assured.
.PP
This feature is available in Postfix 2.3 and later.
-.SH smtp_tls_protocols (default: !SSLv2)
+.SH smtp_tls_protocols (default: !SSLv2, !SSLv3)
List of TLS protocols that the Postfix SMTP client will exclude or
-include with opportunistic TLS encryption. Starting with Postfix 2.6,
-the Postfix SMTP client will by default not use the obsolete SSLv2
-protocol.
+include with opportunistic TLS encryption. The default value is
+"!SSLv2, !SSLv3" for Postfix releases after the middle of 2015,
+"!SSLv2" for older releases. Before Postfix 2.6, the Postfix SMTP
+client would use all protocols with opportunistic TLS.
.PP
In main.cf the values are separated by whitespace, commas or
colons. In the policy table (see smtp_tls_policy_maps) the only valid
"TLSv1.1" or "TLSv1.2"
.PP
To include a protocol list its name, to exclude it, prefix the name
-with a "!" character. To exclude SSLv2 even for opportunistic TLS set
+with a "!" character. To exclude SSLv2 for opportunistic TLS set
"smtp_tls_protocols = !SSLv2". To exclude both "SSLv2" and "SSLv3" set
"smtp_tls_protocols = !SSLv2, !SSLv3". Explicitly listing the protocols to
include, rather than protocols to exclude, is supported, but not
# can be mitigated by disabling a particular protocol or raising the
# cipher grade from "export" to "low" or "medium").
smtp_tls_ciphers = export
-smtp_tls_protocols = !SSLv2
+smtp_tls_protocols = !SSLv2, !SSLv3
.fi
.ad
.ft R
.PP
This feature is available with Postfix version 2.2. It is not used with
Postfix 2.3 and later; use smtpd_tls_mandatory_ciphers instead.
-.SH smtpd_tls_ciphers (default: export)
+.SH smtpd_tls_ciphers (default: medium)
The minimum TLS cipher grade that the Postfix SMTP server
will use with opportunistic TLS encryption. Cipher types listed in
smtpd_tls_exclude_ciphers are excluded from the base definition of
-the selected cipher grade. The default value "export" ensures maximum
-inter\-operability. Because encryption is optional, stronger controls
-are not appropriate, and this setting SHOULD NOT be changed unless the
-change is essential.
+the selected cipher grade. The default value is "medium" for Postfix
+releases after the middle of 2015, "export" for older releases.
.PP
When TLS is mandatory the cipher grade is chosen via the
smtpd_tls_mandatory_ciphers configuration parameter, see there for syntax
details.
.PP
-Example:
-.nf
-.na
-.ft C
-smtpd_tls_ciphers = export
-.fi
-.ad
-.ft R
-.PP
This feature is available in Postfix 2.6 and later. With earlier Postfix
releases only the smtpd_tls_mandatory_ciphers parameter is implemented,
and opportunistic TLS always uses "export" or better (i.e. all) ciphers.
.PP
The following cipher grades are supported:
.IP "\fBexport\fR"
-Enable "EXPORT" grade or stronger OpenSSL ciphers.
-This is the most appropriate setting for public MX hosts, and is always
-used with opportunistic TLS encryption. The underlying cipherlist
-is specified via the tls_export_cipherlist configuration parameter,
-which you are strongly encouraged to not change.
+Enable "EXPORT" grade or stronger OpenSSL ciphers. The
+underlying cipherlist is specified via the tls_export_cipherlist
+configuration parameter, which you are strongly encouraged to not
+change. This choice is insecure and SHOULD NOT be used.
.br
.IP "\fBlow\fR"
-Enable "LOW" grade or stronger OpenSSL ciphers. The
-underlying cipherlist is specified via the tls_low_cipherlist
-configuration parameter, which you are strongly encouraged to
-not change.
+Enable "LOW" grade or stronger OpenSSL ciphers. The underlying
+cipherlist is specified via the tls_low_cipherlist configuration
+parameter, which you are strongly encouraged to not change. This
+choice is insecure and SHOULD NOT be used.
.br
.IP "\fBmedium\fR"
Enable "MEDIUM" grade or stronger OpenSSL ciphers. These use 128\-bit
(see there for syntax details).
.PP
This feature is available in Postfix 2.3 and later.
-.SH smtpd_tls_mandatory_protocols (default: !SSLv2)
+.SH smtpd_tls_mandatory_protocols (default: !SSLv2, !SSLv3)
The SSL/TLS protocols accepted by the Postfix SMTP server with
mandatory TLS encryption. If the list is empty, the server supports
all available SSL/TLS protocol versions. A non\-empty value is a
list of protocol names separated by whitespace, commas or colons.
The supported protocol names are "SSLv2", "SSLv3" and "TLSv1", and
-are not case sensitive.
+are not case sensitive. The default value is "!SSLv2, !SSLv3" for
+Postfix releases after the middle of 2015, "!SSLv2" for older
+releases.
.PP
With Postfix >= 2.5 the parameter syntax was expanded to support
protocol exclusions. One can explicitly exclude "SSLv2" by setting
versions of Postfix >= 2.10 can disable support for "TLSv1.1" or
"TLSv1.2".
.PP
-Since SSL version 2 has known protocol weaknesses and is now
-deprecated, the default setting excludes "SSLv2". This means that
-by default, SSL version 2 will not be used at the "encrypt" security
-level.
-.PP
Example:
.PP
.nf
.ft R
.PP
This feature is available in Postfix 2.3 and later.
-.SH smtpd_tls_protocols (default: empty)
+.SH smtpd_tls_protocols (default: !SSLv2, !SSLv3)
List of TLS protocols that the Postfix SMTP server will exclude
-or include with opportunistic TLS encryption. This parameter SHOULD
-be left at its default empty value, allowing all protocols to be
+or include with opportunistic TLS encryption. The default value is
+"!SSLv2, !SSLv3" for Postfix releases after the middle of 2015,
+empty for older releases allowing all protocols to be
used with opportunistic TLS. A non\-empty value is a list of protocol
names separated by whitespace, commas or colons. The supported
protocol names are "SSLv2", "SSLv3" and "TLSv1", and are not case
"TLSv1.2".
.PP
To include a protocol list its name, to exclude it, prefix the name
-with a "!" character. To exclude SSLv2 even for opportunistic TLS set
+with a "!" character. To exclude SSLv2 for opportunistic TLS set
"smtpd_tls_protocols = !SSLv2". To exclude both "SSLv2" and "SSLv3" set
"smtpd_tls_protocols = !SSLv2, !SSLv3". Explicitly listing the protocols to
include, rather than protocols to exclude, is supported, but not
.nf
.na
.ft C
-smtpd_tls_protocols = !SSLv2
+smtpd_tls_protocols = !SSLv2, !SSLv3
.fi
.ad
.ft R
EC algorithms have not been disabled by the vendor.
.SH tls_export_cipherlist (default: ALL:+RC4:@STRENGTH)
The OpenSSL cipherlist for "EXPORT" or higher grade ciphers. This
-defines the meaning of the "export" setting in smtpd_tls_mandatory_ciphers,
-smtp_tls_mandatory_ciphers and lmtp_tls_mandatory_ciphers. This is
-the cipherlist for the opportunistic ("may") TLS client security
-level and is the default cipherlist for the SMTP server. You are
-strongly encouraged to not change this setting. With OpenSSL 1.0.0 and
-later the cipherlist may start with an "aNULL:" prefix, which restores
-the 0.9.8\-compatible ordering of the aNULL ciphers to the top of the
-list when they are enabled. This prefix is not needed with previous
-OpenSSL releases.
+defines the meaning of the "export" setting in smtpd_tls_ciphers,
+smtpd_tls_mandatory_ciphers, smtp_tls_ciphers, smtp_tls_mandatory_ciphers,
+lmtp_tls_ciphers, and lmtp_tls_mandatory_ciphers. With Postfix
+releases before the middle of 2015 this is the default cipherlist
+for the opportunistic ("may") TLS client security level and also
+the default cipherlist for the SMTP server. You are strongly
+encouraged to not change this setting.
.PP
This feature is available in Postfix 2.3 and later.
.SH tls_high_cipherlist (default: ALL:!EXPORT:!LOW:!MEDIUM:+RC4:@STRENGTH)
The OpenSSL cipherlist for "HIGH" grade ciphers. This defines
-the meaning of the "high" setting in smtpd_tls_mandatory_ciphers,
-smtp_tls_mandatory_ciphers and lmtp_tls_mandatory_ciphers. You are
-strongly encouraged to not change this setting. With OpenSSL 1.0.0 and
-later the cipherlist may start with an "aNULL:" prefix, which restores
-the 0.9.8\-compatible ordering of the aNULL ciphers to the top of the
-list when they are enabled. This prefix is not needed with previous
-OpenSSL releases.
+the meaning of the "high" setting in smtpd_tls_ciphers,
+smtpd_tls_mandatory_ciphers, smtp_tls_ciphers, smtp_tls_mandatory_ciphers,
+lmtp_tls_ciphers, and lmtp_tls_mandatory_ciphers. You are strongly
+encouraged to not change this setting.
.PP
This feature is available in Postfix 2.3 and later.
.SH tls_legacy_public_key_fingerprints (default: no)
This feature is available in Postfix 2.9.6 and later.
.SH tls_low_cipherlist (default: ALL:!EXPORT:+RC4:@STRENGTH)
The OpenSSL cipherlist for "LOW" or higher grade ciphers. This defines
-the meaning of the "low" setting in smtpd_tls_mandatory_ciphers,
-smtp_tls_mandatory_ciphers and lmtp_tls_mandatory_ciphers. You are
-strongly encouraged to not change this setting. With OpenSSL 1.0.0 and
-later the cipherlist may start with an "aNULL:" prefix, which restores
-the 0.9.8\-compatible ordering of the aNULL ciphers to the top of the
-list when they are enabled. This prefix is not needed with previous
-OpenSSL releases.
+the meaning of the "low" setting in smtpd_tls_ciphers,
+smtpd_tls_mandatory_ciphers, smtp_tls_ciphers, smtp_tls_mandatory_ciphers,
+lmtp_tls_ciphers, and lmtp_tls_mandatory_ciphers. You are strongly
+encouraged to not change this setting.
.PP
This feature is available in Postfix 2.3 and later.
.SH tls_medium_cipherlist (default: ALL:!EXPORT:!LOW:+RC4:@STRENGTH)
The OpenSSL cipherlist for "MEDIUM" or higher grade ciphers. This
-defines the meaning of the "medium" setting in smtpd_tls_mandatory_ciphers,
-smtp_tls_mandatory_ciphers and lmtp_tls_mandatory_ciphers. This is
-the default cipherlist for mandatory TLS encryption in the TLS
-client (with anonymous ciphers disabled when verifying server
-certificates). You are strongly encouraged to not change this
-setting. With OpenSSL 1.0.0 and later the cipherlist may start with an
-"aNULL:" prefix, which restores the 0.9.8\-compatible ordering of the
-aNULL ciphers to the top of the list when they are enabled. This prefix
-is not needed with previous OpenSSL releases.
+defines the meaning of the "medium" setting in smtpd_tls_ciphers,
+smtpd_tls_mandatory_ciphers, smtp_tls_ciphers, smtp_tls_mandatory_ciphers,
+lmtp_tls_ciphers, and lmtp_tls_mandatory_ciphers. This is the
+default cipherlist for mandatory TLS encryption in the TLS client
+(with anonymous ciphers disabled when verifying server certificates).
+This is the default cipherlist for opportunistic TLS with Postfix
+releases after the middle of 2015. You are strongly encouraged to
+not change this setting.
.PP
This feature is available in Postfix 2.3 and later.
.SH tls_null_cipherlist (default: eNULL:!aNULL)
Optional lookup tables with the Postfix SMTP client TLS security
policy by next\-hop destination; when a non\-empty value is specified,
this overrides the obsolete smtp_tls_per_site parameter.
-.IP "\fBsmtp_tls_mandatory_protocols (!SSLv2)\fR"
+.IP "\fBsmtp_tls_mandatory_protocols (!SSLv2, !SSLv3)\fR"
List of SSL/TLS protocols that the Postfix SMTP client will use with
mandatory TLS encryption.
.IP "\fBsmtp_tls_scert_verifydepth (9)\fR"
certificate fingerprints.
.PP
Available in Postfix version 2.6 and later:
-.IP "\fBsmtp_tls_protocols (!SSLv2)\fR"
+.IP "\fBsmtp_tls_protocols (!SSLv2, !SSLv3)\fR"
List of TLS protocols that the Postfix SMTP client will exclude or
include with opportunistic TLS encryption.
-.IP "\fBsmtp_tls_ciphers (export)\fR"
+.IP "\fBsmtp_tls_ciphers (medium)\fR"
The minimum TLS cipher grade that the Postfix SMTP client
will use with opportunistic TLS encryption.
.IP "\fBsmtp_tls_eccert_file (empty)\fR"
.IP "\fBsmtpd_tls_mandatory_exclude_ciphers (empty)\fR"
Additional list of ciphers or cipher types to exclude from the
Postfix SMTP server cipher list at mandatory TLS security levels.
-.IP "\fBsmtpd_tls_mandatory_protocols (!SSLv2)\fR"
+.IP "\fBsmtpd_tls_mandatory_protocols (!SSLv2, !SSLv3)\fR"
The SSL/TLS protocols accepted by the Postfix SMTP server with
mandatory TLS encryption.
.IP "\fBsmtpd_tls_received_header (no)\fR"
for \fBcheck_ccert_access\fR and \fBpermit_tls_clientcerts\fR.
.PP
Available in Postfix version 2.6 and later:
-.IP "\fBsmtpd_tls_protocols (empty)\fR"
+.IP "\fBsmtpd_tls_protocols (!SSLv2, !SSLv3)\fR"
List of TLS protocols that the Postfix SMTP server will exclude
or include with opportunistic TLS encryption.
-.IP "\fBsmtpd_tls_ciphers (export)\fR"
+.IP "\fBsmtpd_tls_ciphers (medium)\fR"
The minimum TLS cipher grade that the Postfix SMTP server
will use with opportunistic TLS encryption.
.IP "\fBsmtpd_tls_eccert_file (empty)\fR"
<h3><a name="server_cipher">Server-side cipher controls</a> </h3>
-<p> The Postfix SMTP server supports 5 distinct cipher security levels
-as specified by the smtpd_tls_mandatory_ciphers configuration parameter,
-which determines the cipher grade with mandatory TLS encryption. The
-default value is "medium" which is essentially 128-bit encryption or better.
-With opportunistic TLS encryption, the minimum accepted cipher grade is
-typically "export". The corresponding smtpd_tls_ciphers parameter
-(Postfix ≥ 2.6) controls the cipher grade used with opportunistic
-TLS. </p>
+<p> The Postfix SMTP server supports 5 distinct cipher grades as
+specified by the smtpd_tls_mandatory_ciphers configuration parameter,
+which determines the minimum cipher grade with mandatory TLS
+encryption. The default minimum cipher grade for mandatory TLS is
+"medium" which is essentially 128-bit encryption or better. The
+smtpd_tls_ciphers parameter (Postfix ≥ 2.6) controls the minimum
+cipher grade used with opportunistic TLS. Here, the default minimum
+cipher grade is "medium" for Postfix releases after the middle of
+2015, "export" for older Postfix releases. With Postfix < 2.6,
+the minimum opportunistic TLS cipher grade is always "export". </p>
<p> By default anonymous ciphers are enabled. They are automatically
disabled when remote SMTP client certificates are requested. If
a remote SMTP client to check the server certificate, so excluding
anonymous ciphers is generally unnecessary. </p>
-<p> The "smtpd_tls_ciphers" configuration parameter (Postfix ≥
-2.6) provides control over the minimum cipher grade for opportunistic
-TLS. With
-Postfix < 2.6, the minimum opportunistic TLS cipher grade is always
-"export". </p>
-
-<p> With mandatory TLS encryption, the Postfix SMTP server will by
-default disable SSLv2. SSLv2 is used only when TLS encryption
-is optional. The mandatory TLS protocol list is specified via the
+<p> With mandatory and opportunistic TLS encryption, the Postfix
+SMTP server by default disables SSLv2 and SSLv3 with Postfix releases
+after the middle of 2015; older releases only disable SSLv2 for
+mandatory TLS. The mandatory TLS protocol list is specified via the
smtpd_tls_mandatory_protocols configuration parameter. The
-corresponding smtpd_tls_protocols parameter (Postfix ≥ 2.6)
+smtpd_tls_protocols parameter (Postfix ≥ 2.6)
controls the SSL/TLS protocols used with opportunistic TLS. </p>
<p> Note that the OpenSSL library only supports protocol exclusion
Opportunistic TLS can be configured by setting "smtp_tls_security_level = may".
For LMTP, use the corresponding "lmtp_" parameter. </p>
-<p> Since sending in the clear is acceptable, demanding stronger
-than default TLS security mostly reduces inter-operability. If you
-must restrict TLS protocol or cipher selection even with opportunistic
-TLS, the "smtp_tls_ciphers" and "smtp_tls_protocols" configuration
-parameters (Postfix ≥ 2.6) provide control over the protocols
-and cipher grade
-used with opportunistic TLS. With earlier releases the opportunistic TLS
-cipher grade is always "export" and no protocols are disabled. </p>
+<p> The "smtp_tls_ciphers" and "smtp_tls_protocols" configuration
+parameters (Postfix ≥ 2.6) provide control over the cipher grade
+and protocols used with opportunistic TLS. With earlier Postfix
+releases, opportunistic TLS always uses the cipher grade "export"
+and enables all protocols. </p>
<p> With opportunistic TLS, mail delivery continues even if the
server certificate is untrusted or bears the wrong name.
<p> In the example below, traffic to <i>example.com</i> and its sub-domains
via the corresponding MX hosts always uses TLS. The SSLv2 protocol
will be disabled (the default setting of smtp_tls_mandatory_protocols
-excludes "SSLv2"). Only high- or medium-strength (i.e. 128 bit or
+excludes SSLv2+3). Only high- or medium-strength (i.e. 128 bit or
better) ciphers will be used by default for all "encrypt" security
level sessions. </p>
used is <a href="#client_tls_may">may</a>. If TLSA records are
found, but none are usable, the effective security level is <a
href="#client_tls_encrypt">encrypt</a>. When usable TLSA records
-are obtained for the remote SMTP server, SSLv2 is automatically
+are obtained for the remote SMTP server, SSLv2+3 are automatically
disabled (see smtp_tls_mandatory_protocols), and the server certificate
must match the TLSA records. RFC 6698 (DANE) TLS authentication
and DNSSEC support is available with Postfix 2.11 and later. </dd>
The TLS policy for the destination is obtained via TLSA records in
DNSSEC. If no TLSA records are found, or none are usable, no
connection is made to the server. When usable TLSA records are
-obtained for the remote SMTP server, SSLv2 is automatically disabled
+obtained for the remote SMTP server, SSLv2+3 are automatically disabled
(see smtp_tls_mandatory_protocols), and the server certificate must
match the TLSA records. RFC 6698 (DANE) TLS authentication and
DNSSEC support is available with Postfix 2.11 and later. </dd>
<h3> <a name="client_cipher">Client-side cipher controls </a> </h3>
-<p> The Postfix SMTP client supports 5 distinct cipher security levels
+<p> The Postfix SMTP client supports 5 distinct cipher grades
as specified by the smtp_tls_mandatory_ciphers configuration
parameter. This setting controls the minimum acceptable SMTP client
TLS cipher grade for use with mandatory TLS encryption. The default
little point in requesting them. </p>
<p> The "smtp_tls_ciphers" configuration parameter (Postfix ≥ 2.6)
-provides control over the minimum cipher grade for opportunistic TLS. With
-Postfix < 2.6, the minimum opportunistic TLS cipher grade is always
-"export". </p>
-
-<p> With mandatory TLS encryption, the Postfix SMTP client will by
-default disable SSLv2. SSLv2 is used only when TLS encryption
-is optional. The mandatory TLS protocol list is specified via the
+provides control over the minimum cipher grade for opportunistic TLS.
+The default minimum cipher grade for opportunistic TLS is "medium"
+for Postfix releases after the middle of 2015, and "export" for
+older releases. With Postfix < 2.6, the minimum opportunistic
+TLS cipher grade is always "export". </p>
+
+<p> With mandatory and opportunistic TLS encryption, the Postfix
+SMTP client will by default disable SSLv2 and SSLv3. The mandatory
+TLS protocol list is specified via the
smtp_tls_mandatory_protocols configuration parameter. The corresponding
smtp_tls_protocols parameter (Postfix ≥ 2.6) controls
the SSL/TLS protocols used with opportunistic TLS. </p>
# Legacy form for Postfix < 2.5:
smtp_tls_mandatory_protocols = SSLv3, TLSv1
# Also available with Postfix ≥ 2.6:
- smtp_tls_ciphers = export
+ smtp_tls_ciphers = medium
smtp_tls_protocols = !SSLv2
</pre>
</blockquote>
<p> This feature is available in Postfix 2.3 and later. </p>
-%PARAM smtp_tls_mandatory_protocols !SSLv2
+%PARAM smtp_tls_mandatory_protocols !SSLv2, !SSLv3
<p> List of SSL/TLS protocols that the Postfix SMTP client will use with
mandatory TLS encryption. In main.cf the values are separated by
whitespace, commas or colons. In the policy table "protocols" attribute
(see smtp_tls_policy_maps) the only valid separator is colon. An
empty value means allow all protocols. The valid protocol names, (see
-<b>SSL_get_version(3)</b>), are "SSLv2", "SSLv3" and "TLSv1". </p>
+<b>SSL_get_version(3)</b>), are "SSLv2", "SSLv3" and "TLSv1". The
+default value is "!SSLv2, !SSLv3" for Postfix releases after the
+middle of 2015, "!SSLv2" for older releases. </p>
<p> With Postfix ≥ 2.5 the parameter syntax was expanded to support
protocol exclusions. One can explicitly exclude "SSLv2" by setting
TLSv1, except perhaps via the policy table for destinations which
you are sure will support "TLSv1.1" or "TLSv1.2". </p>
-<p> Since SSL version 2 has known protocol weaknesses and is now
-deprecated, the default setting excludes "SSLv2". This means that by
-default, SSL version 2 will not be used at the "encrypt" security level
-and higher. </p>
-
<p> See the documentation of the smtp_tls_policy_maps parameter and
TLS_README for more information about security levels. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
-%PARAM lmtp_tls_mandatory_protocols !SSLv2
+%PARAM lmtp_tls_mandatory_protocols !SSLv2, !SSLv3
<p> The LMTP-specific version of the smtp_tls_mandatory_protocols
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
-%PARAM smtpd_tls_mandatory_protocols !SSLv2
+%PARAM smtpd_tls_mandatory_protocols !SSLv2, !SSLv3
<p> The SSL/TLS protocols accepted by the Postfix SMTP server with
mandatory TLS encryption. If the list is empty, the server supports
all available SSL/TLS protocol versions. A non-empty value is a
list of protocol names separated by whitespace, commas or colons.
The supported protocol names are "SSLv2", "SSLv3" and "TLSv1", and
-are not case sensitive. </p>
+are not case sensitive. The default value is "!SSLv2, !SSLv3" for
+Postfix releases after the middle of 2015, "!SSLv2" for older
+releases. </p>
<p> With Postfix ≥ 2.5 the parameter syntax was expanded to support
protocol exclusions. One can explicitly exclude "SSLv2" by setting
versions of Postfix ≥ 2.10 can disable support for "TLSv1.1" or
"TLSv1.2". </p>
-<p> Since SSL version 2 has known protocol weaknesses and is now
-deprecated, the default setting excludes "SSLv2". This means that
-by default, SSL version 2 will not be used at the "encrypt" security
-level. </p>
-
<p> Example: </p>
<pre>
# can be mitigated by disabling a particular protocol or raising the
# cipher grade from "export" to "low" or "medium").
smtp_tls_ciphers = export
-smtp_tls_protocols = !SSLv2
+smtp_tls_protocols = !SSLv2, !SSLv3
</pre>
<pre>
<dl>
<dt><b>export</b></dt>
-<dd> Enable "EXPORT" grade or stronger OpenSSL ciphers.
-This is the most appropriate setting for public MX hosts, and is always
-used with opportunistic TLS encryption. The underlying cipherlist
-is specified via the tls_export_cipherlist configuration parameter,
-which you are strongly encouraged to not change. </dd>
+<dd> Enable "EXPORT" grade or stronger OpenSSL ciphers. The
+underlying cipherlist is specified via the tls_export_cipherlist
+configuration parameter, which you are strongly encouraged to not
+change. This choice is insecure and SHOULD NOT be used. </dd>
<dt><b>low</b></dt>
-<dd> Enable "LOW" grade or stronger OpenSSL ciphers. The
-underlying cipherlist is specified via the tls_low_cipherlist
-configuration parameter, which you are strongly encouraged to
-not change. </dd>
+<dd> Enable "LOW" grade or stronger OpenSSL ciphers. The underlying
+cipherlist is specified via the tls_low_cipherlist configuration
+parameter, which you are strongly encouraged to not change. This
+choice is insecure and SHOULD NOT be used. </dd>
<dt><b>medium</b></dt>
<dd> Enable "MEDIUM" grade or stronger OpenSSL ciphers. These use 128-bit
<dl>
<dt><b>export</b></dt>
-<dd> Enable "EXPORT" grade or better OpenSSL
-ciphers. This is the default for opportunistic encryption. It is
-not recommended for mandatory encryption unless you must enforce TLS
-with "crippled" peers. The underlying cipherlist is specified via the
-tls_export_cipherlist configuration parameter, which you are strongly
-encouraged to not change. </dd>
+<dd> Enable "EXPORT" grade or better OpenSSL ciphers. The underlying
+cipherlist is specified via the tls_export_cipherlist configuration
+parameter, which you are strongly encouraged to not change. This
+choice is insecure and SHOULD NOT be used. </dd>
<dt><b>low</b></dt>
-<dd> Enable "LOW" grade or better OpenSSL ciphers. This
-setting is only appropriate for internal mail servers. The underlying
+<dd> Enable "LOW" grade or better OpenSSL ciphers. The underlying
cipherlist is specified via the tls_low_cipherlist configuration
-parameter, which you are strongly encouraged to not change. </dd>
+parameter, which you are strongly encouraged to not change. This
+choice is insecure and SHOULD NOT be used. </dd>
<dt><b>medium</b></dt>
<dd> Enable "MEDIUM" grade or better OpenSSL ciphers.
%PARAM tls_high_cipherlist ALL:!EXPORT:!LOW:!MEDIUM:+RC4:@STRENGTH
<p> The OpenSSL cipherlist for "HIGH" grade ciphers. This defines
-the meaning of the "high" setting in smtpd_tls_mandatory_ciphers,
-smtp_tls_mandatory_ciphers and lmtp_tls_mandatory_ciphers. You are
-strongly encouraged to not change this setting. With OpenSSL 1.0.0 and
-later the cipherlist may start with an "aNULL:" prefix, which restores
-the 0.9.8-compatible ordering of the aNULL ciphers to the top of the
-list when they are enabled. This prefix is not needed with previous
-OpenSSL releases. </p>
+the meaning of the "high" setting in smtpd_tls_ciphers,
+smtpd_tls_mandatory_ciphers, smtp_tls_ciphers, smtp_tls_mandatory_ciphers,
+lmtp_tls_ciphers, and lmtp_tls_mandatory_ciphers. You are strongly
+encouraged to not change this setting. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
%PARAM tls_medium_cipherlist ALL:!EXPORT:!LOW:+RC4:@STRENGTH
<p> The OpenSSL cipherlist for "MEDIUM" or higher grade ciphers. This
-defines the meaning of the "medium" setting in smtpd_tls_mandatory_ciphers,
-smtp_tls_mandatory_ciphers and lmtp_tls_mandatory_ciphers. This is
-the default cipherlist for mandatory TLS encryption in the TLS
-client (with anonymous ciphers disabled when verifying server
-certificates). You are strongly encouraged to not change this
-setting. With OpenSSL 1.0.0 and later the cipherlist may start with an
-"aNULL:" prefix, which restores the 0.9.8-compatible ordering of the
-aNULL ciphers to the top of the list when they are enabled. This prefix
-is not needed with previous OpenSSL releases. </p>
+defines the meaning of the "medium" setting in smtpd_tls_ciphers,
+smtpd_tls_mandatory_ciphers, smtp_tls_ciphers, smtp_tls_mandatory_ciphers,
+lmtp_tls_ciphers, and lmtp_tls_mandatory_ciphers. This is the
+default cipherlist for mandatory TLS encryption in the TLS client
+(with anonymous ciphers disabled when verifying server certificates).
+This is the default cipherlist for opportunistic TLS with Postfix
+releases after the middle of 2015. You are strongly encouraged to
+not change this setting. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
%PARAM tls_low_cipherlist ALL:!EXPORT:+RC4:@STRENGTH
<p> The OpenSSL cipherlist for "LOW" or higher grade ciphers. This defines
-the meaning of the "low" setting in smtpd_tls_mandatory_ciphers,
-smtp_tls_mandatory_ciphers and lmtp_tls_mandatory_ciphers. You are
-strongly encouraged to not change this setting. With OpenSSL 1.0.0 and
-later the cipherlist may start with an "aNULL:" prefix, which restores
-the 0.9.8-compatible ordering of the aNULL ciphers to the top of the
-list when they are enabled. This prefix is not needed with previous
-OpenSSL releases. </p>
+the meaning of the "low" setting in smtpd_tls_ciphers,
+smtpd_tls_mandatory_ciphers, smtp_tls_ciphers, smtp_tls_mandatory_ciphers,
+lmtp_tls_ciphers, and lmtp_tls_mandatory_ciphers. You are strongly
+encouraged to not change this setting. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
%PARAM tls_export_cipherlist ALL:+RC4:@STRENGTH
<p> The OpenSSL cipherlist for "EXPORT" or higher grade ciphers. This
-defines the meaning of the "export" setting in smtpd_tls_mandatory_ciphers,
-smtp_tls_mandatory_ciphers and lmtp_tls_mandatory_ciphers. This is
-the cipherlist for the opportunistic ("may") TLS client security
-level and is the default cipherlist for the SMTP server. You are
-strongly encouraged to not change this setting. With OpenSSL 1.0.0 and
-later the cipherlist may start with an "aNULL:" prefix, which restores
-the 0.9.8-compatible ordering of the aNULL ciphers to the top of the
-list when they are enabled. This prefix is not needed with previous
-OpenSSL releases. </p>
+defines the meaning of the "export" setting in smtpd_tls_ciphers,
+smtpd_tls_mandatory_ciphers, smtp_tls_ciphers, smtp_tls_mandatory_ciphers,
+lmtp_tls_ciphers, and lmtp_tls_mandatory_ciphers. With Postfix
+releases before the middle of 2015 this is the default cipherlist
+for the opportunistic ("may") TLS client security level and also
+the default cipherlist for the SMTP server. You are strongly
+encouraged to not change this setting. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
-%PARAM lmtp_tls_mandatory_ciphers
+%PARAM lmtp_tls_mandatory_ciphers medium
<p> The LMTP-specific version of the smtp_tls_mandatory_ciphers
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
-%PARAM smtp_tls_protocols !SSLv2
+%PARAM smtp_tls_protocols !SSLv2, !SSLv3
<p> List of TLS protocols that the Postfix SMTP client will exclude or
-include with opportunistic TLS encryption. Starting with Postfix 2.6,
-the Postfix SMTP client will by default not use the obsolete SSLv2
-protocol. </p>
+include with opportunistic TLS encryption. The default value is
+"!SSLv2, !SSLv3" for Postfix releases after the middle of 2015,
+"!SSLv2" for older releases. Before Postfix 2.6, the Postfix SMTP
+client would use all protocols with opportunistic TLS. </p>
<p> In main.cf the values are separated by whitespace, commas or
colons. In the policy table (see smtp_tls_policy_maps) the only valid
"TLSv1.1" or "TLSv1.2"</p>
<p> To include a protocol list its name, to exclude it, prefix the name
-with a "!" character. To exclude SSLv2 even for opportunistic TLS set
+with a "!" character. To exclude SSLv2 for opportunistic TLS set
"smtp_tls_protocols = !SSLv2". To exclude both "SSLv2" and "SSLv3" set
"smtp_tls_protocols = !SSLv2, !SSLv3". Explicitly listing the protocols to
include, rather than protocols to exclude, is supported, but not
<p> This feature is available in Postfix 2.6 and later. </p>
-%PARAM smtpd_tls_protocols
+%PARAM smtpd_tls_protocols !SSLv2, !SSLv3
<p> List of TLS protocols that the Postfix SMTP server will exclude
-or include with opportunistic TLS encryption. This parameter SHOULD
-be left at its default empty value, allowing all protocols to be
+or include with opportunistic TLS encryption. The default value is
+"!SSLv2, !SSLv3" for Postfix releases after the middle of 2015,
+empty for older releases allowing all protocols to be
used with opportunistic TLS. A non-empty value is a list of protocol
names separated by whitespace, commas or colons. The supported
protocol names are "SSLv2", "SSLv3" and "TLSv1", and are not case
"TLSv1.2". </p>
<p> To include a protocol list its name, to exclude it, prefix the name
-with a "!" character. To exclude SSLv2 even for opportunistic TLS set
+with a "!" character. To exclude SSLv2 for opportunistic TLS set
"smtpd_tls_protocols = !SSLv2". To exclude both "SSLv2" and "SSLv3" set
"smtpd_tls_protocols = !SSLv2, !SSLv3". Explicitly listing the protocols to
include, rather than protocols to exclude, is supported, but not
<p> Example: </p>
<pre>
-smtpd_tls_protocols = !SSLv2
+smtpd_tls_protocols = !SSLv2, !SSLv3
</pre>
<p> This feature is available in Postfix 2.6 and later. </p>
-%PARAM lmtp_tls_protocols
+%PARAM lmtp_tls_protocols !SSLv2, !SSLv3
<p> The LMTP-specific version of the smtp_tls_protocols configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
-%PARAM smtp_tls_ciphers export
+%PARAM smtp_tls_ciphers medium
<p> The minimum TLS cipher grade that the Postfix SMTP client
will use with opportunistic TLS encryption. Cipher types listed in
smtp_tls_exclude_ciphers are excluded from the base definition of
-the selected cipher grade. The default value "export" ensures maximum
-inter-operability. Because encryption is optional, stronger controls
-are not appropriate, and this setting SHOULD NOT be changed unless the
-change is essential. </p>
+the selected cipher grade. The default value is "medium" for
+Postfix releases after the middle of 2015, "export" for older
+releases. </p>
<p> When TLS is mandatory the cipher grade is chosen via the
smtp_tls_mandatory_ciphers configuration parameter, see there for syntax
details. See smtp_tls_policy_maps for information on how to configure
ciphers on a per-destination basis. </p>
-<p> Example: </p>
-<pre>
-smtp_tls_ciphers = export
-</pre>
-
<p> This feature is available in Postfix 2.6 and later. With earlier Postfix
releases only the smtp_tls_mandatory_ciphers parameter is implemented,
and opportunistic TLS always uses "export" or better (i.e. all) ciphers. </p>
-%PARAM smtpd_tls_ciphers export
+%PARAM smtpd_tls_ciphers medium
<p> The minimum TLS cipher grade that the Postfix SMTP server
will use with opportunistic TLS encryption. Cipher types listed in
smtpd_tls_exclude_ciphers are excluded from the base definition of
-the selected cipher grade. The default value "export" ensures maximum
-inter-operability. Because encryption is optional, stronger controls
-are not appropriate, and this setting SHOULD NOT be changed unless the
-change is essential. </p>
+the selected cipher grade. The default value is "medium" for Postfix
+releases after the middle of 2015, "export" for older releases.
+</p>
<p> When TLS is mandatory the cipher grade is chosen via the
smtpd_tls_mandatory_ciphers configuration parameter, see there for syntax
details. </p>
-<p> Example: </p>
-<pre>
-smtpd_tls_ciphers = export
-</pre>
-
<p> This feature is available in Postfix 2.6 and later. With earlier Postfix
releases only the smtpd_tls_mandatory_ciphers parameter is implemented,
and opportunistic TLS always uses "export" or better (i.e. all) ciphers. </p>
-%PARAM lmtp_tls_ciphers export
+%PARAM lmtp_tls_ciphers medium
<p> The LMTP-specific version of the smtp_tls_ciphers configuration
parameter. See there for details. </p>
extern char *var_smtpd_tls_CApath;
#define VAR_SMTPD_TLS_PROTO "smtpd_tls_protocols"
-#define DEF_SMTPD_TLS_PROTO ""
+#define DEF_SMTPD_TLS_PROTO "!SSLv2, !SSLv3"
extern char *var_smtpd_tls_proto;
#define VAR_SMTPD_TLS_MAND_PROTO "smtpd_tls_mandatory_protocols"
-#define DEF_SMTPD_TLS_MAND_PROTO "!SSLv2"
+#define DEF_SMTPD_TLS_MAND_PROTO "!SSLv2, !SSLv3"
extern char *var_smtpd_tls_mand_proto;
#define VAR_SMTPD_TLS_CIPH "smtpd_tls_ciphers"
-#define DEF_SMTPD_TLS_CIPH "export"
+#define DEF_SMTPD_TLS_CIPH "medium"
extern char *var_smtpd_tls_ciph;
#define VAR_SMTPD_TLS_MAND_CIPH "smtpd_tls_mandatory_ciphers"
extern char *var_smtp_tls_CApath;
#define VAR_SMTP_TLS_CIPH "smtp_tls_ciphers"
-#define DEF_SMTP_TLS_CIPH "export"
+#define DEF_SMTP_TLS_CIPH "medium"
#define VAR_LMTP_TLS_CIPH "lmtp_tls_ciphers"
-#define DEF_LMTP_TLS_CIPH "export"
+#define DEF_LMTP_TLS_CIPH "medium"
extern char *var_smtp_tls_ciph;
#define VAR_SMTP_TLS_MAND_CIPH "smtp_tls_mandatory_ciphers"
extern char *var_smtp_tls_policy;
#define VAR_SMTP_TLS_PROTO "smtp_tls_protocols"
-#define DEF_SMTP_TLS_PROTO "!SSLv2"
+#define DEF_SMTP_TLS_PROTO "!SSLv2, !SSLv3"
#define VAR_LMTP_TLS_PROTO "lmtp_tls_protocols"
-#define DEF_LMTP_TLS_PROTO "!SSLv2"
+#define DEF_LMTP_TLS_PROTO "!SSLv2, !SSLv3"
extern char *var_smtp_tls_proto;
#define VAR_SMTP_TLS_MAND_PROTO "smtp_tls_mandatory_protocols"
-#define DEF_SMTP_TLS_MAND_PROTO "!SSLv2"
+#define DEF_SMTP_TLS_MAND_PROTO "!SSLv2, !SSLv3"
#define VAR_LMTP_TLS_MAND_PROTO "lmtp_tls_mandatory_protocols"
-#define DEF_LMTP_TLS_MAND_PROTO "!SSLv2"
+#define DEF_LMTP_TLS_MAND_PROTO "!SSLv2, !SSLv3"
extern char *var_smtp_tls_mand_proto;
#define VAR_SMTP_TLS_VFY_CMATCH "smtp_tls_verify_cert_match"
* Patches change both the patchlevel and the release date. Snapshots have no
* patchlevel; they change the release date only.
*/
-#define MAIL_RELEASE_DATE "20150412"
-#define MAIL_VERSION_NUMBER "3.0.1"
+#define MAIL_RELEASE_DATE "20150720"
+#define MAIL_VERSION_NUMBER "3.0.2"
#ifdef SNAPSHOT
#define MAIL_VERSION_DATE "-" MAIL_RELEASE_DATE
/* Optional lookup tables with the Postfix SMTP client TLS security
/* policy by next-hop destination; when a non-empty value is specified,
/* this overrides the obsolete smtp_tls_per_site parameter.
-/* .IP "\fBsmtp_tls_mandatory_protocols (!SSLv2)\fR"
+/* .IP "\fBsmtp_tls_mandatory_protocols (!SSLv2, !SSLv3)\fR"
/* List of SSL/TLS protocols that the Postfix SMTP client will use with
/* mandatory TLS encryption.
/* .IP "\fBsmtp_tls_scert_verifydepth (9)\fR"
/* certificate fingerprints.
/* .PP
/* Available in Postfix version 2.6 and later:
-/* .IP "\fBsmtp_tls_protocols (!SSLv2)\fR"
+/* .IP "\fBsmtp_tls_protocols (!SSLv2, !SSLv3)\fR"
/* List of TLS protocols that the Postfix SMTP client will exclude or
/* include with opportunistic TLS encryption.
-/* .IP "\fBsmtp_tls_ciphers (export)\fR"
+/* .IP "\fBsmtp_tls_ciphers (medium)\fR"
/* The minimum TLS cipher grade that the Postfix SMTP client
/* will use with opportunistic TLS encryption.
/* .IP "\fBsmtp_tls_eccert_file (empty)\fR"
/* .IP "\fBsmtpd_tls_mandatory_exclude_ciphers (empty)\fR"
/* Additional list of ciphers or cipher types to exclude from the
/* Postfix SMTP server cipher list at mandatory TLS security levels.
-/* .IP "\fBsmtpd_tls_mandatory_protocols (!SSLv2)\fR"
+/* .IP "\fBsmtpd_tls_mandatory_protocols (!SSLv2, !SSLv3)\fR"
/* The SSL/TLS protocols accepted by the Postfix SMTP server with
/* mandatory TLS encryption.
/* .IP "\fBsmtpd_tls_received_header (no)\fR"
/* for \fBcheck_ccert_access\fR and \fBpermit_tls_clientcerts\fR.
/* .PP
/* Available in Postfix version 2.6 and later:
-/* .IP "\fBsmtpd_tls_protocols (empty)\fR"
+/* .IP "\fBsmtpd_tls_protocols (!SSLv2, !SSLv3)\fR"
/* List of TLS protocols that the Postfix SMTP server will exclude
/* or include with opportunistic TLS encryption.
-/* .IP "\fBsmtpd_tls_ciphers (export)\fR"
+/* .IP "\fBsmtpd_tls_ciphers (medium)\fR"
/* The minimum TLS cipher grade that the Postfix SMTP server
/* will use with opportunistic TLS encryption.
/* .IP "\fBsmtpd_tls_eccert_file (empty)\fR"
/*
* LINUX.
*/
-#if defined(LINUX2) || defined(LINUX3)
+#if defined(LINUX2) || defined(LINUX3) || defined(LINUX4)
#define SUPPORTED
#include <sys/types.h>
#define UINT32_TYPE unsigned int
projects / thirdparty / postfix.git / commitdiff
