With mandatory TLS encryption, the Postfix SMTP server will by ! default only use SSLv3 or TLSv1. SSLv2 is only used when TLS encryption is optional. 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.
For a server that is not a public Internet MX host, Postfix supports configurations with no server certificates that use only the anonymous ciphers. This is --- 704,721 ---- "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 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.
+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 the Postfix software is written. If new + protocols are added to the OpenSSL library, they cannot be excluded + without corresponding changes to the Postfix source code.
+For a server that is not a public Internet MX host, Postfix supports configurations with no server certificates that use only the anonymous ciphers. This is *************** *** 727,735 **** smtpd_tls_mandatory_ciphers = high smtpd_tls_mandatory_exclude_ciphers = aNULL, MD5 smtpd_tls_security_level = encrypt ! smtpd_tls_mandatory_protocols = TLSv1 ! # Also available with Postfix ≥ 2.5: smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3 --- 733,742 ---- smtpd_tls_mandatory_ciphers = high smtpd_tls_mandatory_exclude_ciphers = aNULL, MD5 smtpd_tls_security_level = encrypt ! # Preferred form with Postfix ≥ 2.5: smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3 + # Alternative form. + smtpd_tls_mandatory_protocols = TLSv1 *************** *** 773,780 ****
Postfix 2.8 and later, in combination with OpenSSL 0.9.7 and later allows TLS servers to preempt the TLS client's cipher preference list. ! This is only possible with SSLv3, as in SSLv2 the client chooses the ! cipher from a list supplied by the server.
By default, the OpenSSL server selects the client's most preferred cipher that the server supports. With SSLv3 and later, the server --- 780,787 ----
Postfix 2.8 and later, in combination with OpenSSL 0.9.7 and later allows TLS servers to preempt the TLS client's cipher preference list. ! This is possible only with SSLv3 and later, as in SSLv2 the client ! chooses the cipher from a list supplied by the server.
By default, the OpenSSL server selects the client's most preferred cipher that the server supports. With SSLv3 and later, the server *************** *** 1010,1018 ****
Examples:
In the example below, traffic to example.com and its sub-domains ! via the corresponding MX hosts always uses TLS. The protocol version will be ! "SSLv3" or "TLSv1" (the default setting of smtp_tls_mandatory_protocols ! excludes "SSLv2"). Only high or medium strength (i.e. 128 bit or better) ciphers will be used by default for all "encrypt" security level sessions.
--- 1017,1025 ----Examples:
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 high- or medium-strength (i.e. 128 bit or better) ciphers will be used by default for all "encrypt" security level sessions.
*************** *** 1883,1889 **** "export".With mandatory TLS encryption, the Postfix SMTP client will by ! default only use SSLv3 or TLSv1. SSLv2 is only used 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 --- 1890,1896 ---- "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 *************** *** 1897,1905 **** smtp_tls_mandatory_ciphers = medium smtp_tls_mandatory_exclude_ciphers = RC4, MD5 smtp_tls_exclude_ciphers = aNULL ! smtp_tls_mandatory_protocols = SSLv3, TLSv1 ! # Also available with Postfix ≥ 2.5: smtp_tls_mandatory_protocols = !SSLv2 # Also available with Postfix ≥ 2.6: smtp_tls_ciphers = export smtp_tls_protocols = !SSLv2 --- 1904,1913 ---- smtp_tls_mandatory_ciphers = medium smtp_tls_mandatory_exclude_ciphers = RC4, MD5 smtp_tls_exclude_ciphers = aNULL ! # Preferred form with Postfix ≥ 2.5: smtp_tls_mandatory_protocols = !SSLv2 + # Alternative form. + smtp_tls_mandatory_protocols = SSLv3, TLSv1 # Also available with Postfix ≥ 2.6: smtp_tls_ciphers = export smtp_tls_protocols = !SSLv2 diff --exclude=man --exclude=html --exclude=README_FILES --exclude=INSTALL --exclude=.indent.pro --exclude=Makefile.in -r -cr --exclude=WISHLIST /var/tmp/postfix-2.10-20120407/proto/postconf.proto ./proto/postconf.proto *** /var/tmp/postfix-2.10-20120407/proto/postconf.proto Sun Apr 1 14:32:20 2012 --- ./proto/postconf.proto Mon Apr 23 13:25:55 2012 *************** *** 10476,10482 ****
This feature is available in Postfix 2.3 and later.
! %PARAM smtp_tls_mandatory_protocols SSLv3, TLSv1List of SSL/TLS protocols that the Postfix SMTP client will use with mandatory TLS encryption. In main.cf the values are separated by --- 10476,10482 ----
This feature is available in Postfix 2.3 and later.
! %PARAM smtp_tls_mandatory_protocols !SSLv2List of SSL/TLS protocols that the Postfix SMTP client will use with mandatory TLS encryption. In main.cf the values are separated by *************** *** 10485,10496 **** empty value means allow all protocols. The valid protocol names, (see SSL_get_version(3)), are "SSLv2", "SSLv3" and "TLSv1".
With Postfix ≥ 2.5 the parameter syntax is expanded to support protocol exclusions. One can now explicitly exclude SSLv2 by setting "smtp_tls_mandatory_protocols = !SSLv2". To exclude both SSLv2 and SSLv3 set "smtp_tls_mandatory_protocols = !SSLv2, !SSLv3". Listing ! the protocols to include, rather than protocols to exclude, is still ! supported; use the form you find more intuitive.
Since SSL version 2 has known protocol weaknesses and is now deprecated, the default setting excludes "SSLv2". This means that by --- 10485,10503 ---- empty value means allow all protocols. The valid protocol names, (see SSL_get_version(3)), are "SSLv2", "SSLv3" and "TLSv1".
+Note: As of OpenSSL 1.0.1 two new protocols are defined, "TLSv1.1" + and "TLSv1.2". If an older Postfix version is linked against OpenSSL + 1.0.1 or later, these, or any other new protocol versions, are + unconditionally enabled.
+With Postfix ≥ 2.5 the parameter syntax is expanded to support protocol exclusions. One can now explicitly exclude SSLv2 by setting "smtp_tls_mandatory_protocols = !SSLv2". To exclude both SSLv2 and SSLv3 set "smtp_tls_mandatory_protocols = !SSLv2, !SSLv3". Listing ! the protocols to include, rather than protocols to exclude, is ! supported, but not recommended. The exclusion form more closely ! matches the behaviour when the OpenSSL library is newer than Postfix. !
Since SSL version 2 has known protocol weaknesses and is now deprecated, the default setting excludes "SSLv2". This means that by *************** *** 10503,10511 ****
Example:
! smtp_tls_mandatory_protocols = TLSv1 ! # Alternative form with Postfix ≥ 2.5: smtp_tls_mandatory_protocols = !SSLv2, !SSLv3
This feature is available in Postfix 2.3 and later.
--- 10510,10519 ----Example:
! # Preferred form with Postfix ≥ 2.5: smtp_tls_mandatory_protocols = !SSLv2, !SSLv3 + # Alternative form. + smtp_tls_mandatory_protocols = TLSv1
This feature is available in Postfix 2.3 and later.
*************** *** 10635,10641 ****This feature is available in Postfix 2.3 and later.
! %PARAM lmtp_tls_mandatory_protocols SSLv3, TLSv1The LMTP-specific version of the smtp_tls_mandatory_protocols configuration parameter. See there for details.
--- 10643,10649 ----This feature is available in Postfix 2.3 and later.
! %PARAM lmtp_tls_mandatory_protocols !SSLv2The LMTP-specific version of the smtp_tls_mandatory_protocols configuration parameter. See there for details.
*************** *** 10656,10662 ****This feature is available in Postfix 2.3 and later.
! %PARAM smtpd_tls_mandatory_protocols SSLv3, TLSv1The SSL/TLS protocols accepted by the Postfix SMTP server with mandatory TLS encryption. If the list is empty, the server supports all --- 10664,10670 ----
This feature is available in Postfix 2.3 and later.
! %PARAM smtpd_tls_mandatory_protocols !SSLv2The SSL/TLS protocols accepted by the Postfix SMTP server with mandatory TLS encryption. If the list is empty, the server supports all *************** *** 10665,10676 **** names separated by whitespace, commas or colons. The supported protocol names are "SSLv2", "SSLv3" and "TLSv1", and are not case sensitive.
With Postfix ≥ 2.5 the parameter syntax is expanded to support protocol exclusions. One can now explicitly exclude SSLv2 by setting "smtpd_tls_mandatory_protocols = !SSLv2". To exclude both SSLv2 and SSLv3 set "smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3". Listing ! the protocols to include, rather than protocols to exclude, is still ! supported, use the form you find more intuitive.
Since SSL version 2 has known protocol weaknesses and is now deprecated, the default setting excludes "SSLv2". This means that --- 10673,10691 ---- names separated by whitespace, commas or colons. The supported protocol names are "SSLv2", "SSLv3" and "TLSv1", and are not case sensitive.
+Note: As of OpenSSL 1.0.1 two new protocols are defined, "TLSv1.1" + and "TLSv1.2". If an older Postfix version is linked against OpenSSL + 1.0.1 or later, these, or any other new protocol versions, are + unconditionally enabled.
+With Postfix ≥ 2.5 the parameter syntax is expanded to support protocol exclusions. One can now explicitly exclude SSLv2 by setting "smtpd_tls_mandatory_protocols = !SSLv2". To exclude both SSLv2 and SSLv3 set "smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3". Listing ! the protocols to include, rather than protocols to exclude, is ! supported, but not recommended. The exclusion form more closely ! matches the behaviour when the OpenSSL library is newer than Postfix. !
Since SSL version 2 has known protocol weaknesses and is now deprecated, the default setting excludes "SSLv2". This means that *************** *** 11697,11710 **** protocol names, (see SSL_get_version(3)), are "SSLv2", "SSLv3" and "TLSv1".
To include a protocol list its name, to exclude it, prefix the name with a "!" character. To exclude SSLv2 even 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, is supported, but not recommended. OpenSSL provides no mechanisms ! for excluding protocols not known at compile-time. If Postfix is linked ! against an OpenSSL library that supports additional protocol versions, ! they cannot be excluded using either syntax.
Example:
--- 11712,11729 ---- protocol names, (see SSL_get_version(3)), are "SSLv2", "SSLv3" and "TLSv1". +Note: As of OpenSSL 1.0.1 two new protocols are defined, "TLSv1.1" + and "TLSv1.2". If an older Postfix version is linked against OpenSSL + 1.0.1 or later, these, or any other new protocol versions, are + unconditionally enabled.
+To include a protocol list its name, to exclude it, prefix the name with a "!" character. To exclude SSLv2 even 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 ! recommended. The exclusion form more closely matches the behaviour ! when the OpenSSL library is newer than Postfix.
Example:
*************** *** 11727,11740 **** "TLSv1". In smtp_tls_policy_maps table entries, "protocols" attribute values are separated by a colon.To include a protocol list its name, to exclude it, prefix the name with a "!" character. To exclude SSLv2 even 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, is supported, but not recommended. OpenSSL provides no mechanisms ! for excluding protocols not known at compile-time. If Postfix is linked ! against an OpenSSL library that supports additional protocol versions, ! they cannot be excluded using either syntax.
Example:
--- 11746,11763 ---- "TLSv1". In smtp_tls_policy_maps table entries, "protocols" attribute values are separated by a colon. +Note: As of OpenSSL 1.0.1 two new protocols are defined, "TLSv1.1" + and "TLSv1.2". If an older Postfix version is linked against OpenSSL + 1.0.1 or later, these, or any other new protocol versions, are + unconditionally enabled.
+To include a protocol list its name, to exclude it, prefix the name with a "!" character. To exclude SSLv2 even 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 ! recommended. The exclusion form more closely matches the behaviour ! when the OpenSSL library is newer than Postfix.
Example:
diff --exclude=man --exclude=html --exclude=README_FILES --exclude=INSTALL --exclude=.indent.pro --exclude=Makefile.in -r -cr --exclude=WISHLIST /var/tmp/postfix-2.10-20120407/src/global/mail_params.h ./src/global/mail_params.h *** /var/tmp/postfix-2.10-20120407/src/global/mail_params.h Wed Apr 4 13:01:58 2012 --- ./src/global/mail_params.h Sun Apr 22 17:53:38 2012 *************** *** 1257,1263 **** extern char *var_smtpd_tls_proto; #define VAR_SMTPD_TLS_MAND_PROTO "smtpd_tls_mandatory_protocols" ! #define DEF_SMTPD_TLS_MAND_PROTO "SSLv3, TLSv1" extern char *var_smtpd_tls_mand_proto; #define VAR_SMTPD_TLS_CIPH "smtpd_tls_ciphers" --- 1257,1263 ---- extern char *var_smtpd_tls_proto; #define VAR_SMTPD_TLS_MAND_PROTO "smtpd_tls_mandatory_protocols" ! #define DEF_SMTPD_TLS_MAND_PROTO "!SSLv2" extern char *var_smtpd_tls_mand_proto; #define VAR_SMTPD_TLS_CIPH "smtpd_tls_ciphers" *************** *** 1470,1478 **** extern char *var_smtp_tls_proto; #define VAR_SMTP_TLS_MAND_PROTO "smtp_tls_mandatory_protocols" ! #define DEF_SMTP_TLS_MAND_PROTO "SSLv3, TLSv1" #define VAR_LMTP_TLS_MAND_PROTO "lmtp_tls_mandatory_protocols" ! #define DEF_LMTP_TLS_MAND_PROTO "SSLv3, TLSv1" extern char *var_smtp_tls_mand_proto; #define VAR_SMTP_TLS_VFY_CMATCH "smtp_tls_verify_cert_match" --- 1470,1478 ---- extern char *var_smtp_tls_proto; #define VAR_SMTP_TLS_MAND_PROTO "smtp_tls_mandatory_protocols" ! #define DEF_SMTP_TLS_MAND_PROTO "!SSLv2" #define VAR_LMTP_TLS_MAND_PROTO "lmtp_tls_mandatory_protocols" ! #define DEF_LMTP_TLS_MAND_PROTO "!SSLv2" extern char *var_smtp_tls_mand_proto; #define VAR_SMTP_TLS_VFY_CMATCH "smtp_tls_verify_cert_match" diff --exclude=man --exclude=html --exclude=README_FILES --exclude=INSTALL --exclude=.indent.pro --exclude=Makefile.in -r -cr --exclude=WISHLIST /var/tmp/postfix-2.10-20120407/src/global/mail_version.h ./src/global/mail_version.h *** /var/tmp/postfix-2.10-20120407/src/global/mail_version.h Sat Apr 7 19:21:16 2012 --- ./src/global/mail_version.h Mon Apr 23 14:00:09 2012 *************** *** 20,26 **** * Patches change both the patchlevel and the release date. Snapshots have no * patchlevel; they change the release date only. */ ! #define MAIL_RELEASE_DATE "20120407" #define MAIL_VERSION_NUMBER "2.10" #ifdef SNAPSHOT --- 20,26 ---- * Patches change both the patchlevel and the release date. Snapshots have no * patchlevel; they change the release date only. */ ! #define MAIL_RELEASE_DATE "20120423" #define MAIL_VERSION_NUMBER "2.10" #ifdef SNAPSHOT diff --exclude=man --exclude=html --exclude=README_FILES --exclude=INSTALL --exclude=.indent.pro --exclude=Makefile.in -r -cr --exclude=WISHLIST /var/tmp/postfix-2.10-20120407/src/tls/tls.h ./src/tls/tls.h *** /var/tmp/postfix-2.10-20120407/src/tls/tls.h Wed Apr 4 13:53:48 2012 --- ./src/tls/tls.h Sun Apr 22 18:28:54 2012 *************** *** 173,180 **** #define TLS_PROTOCOL_SSLv2 (1<<0) /* SSLv2 */ #define TLS_PROTOCOL_SSLv3 (1<<1) /* SSLv3 */ #define TLS_PROTOCOL_TLSv1 (1<<2) /* TLSv1 */ #define TLS_KNOWN_PROTOCOLS \ ! ( TLS_PROTOCOL_SSLv2 | TLS_PROTOCOL_SSLv3 | TLS_PROTOCOL_TLSv1 ) extern int tls_protocol_mask(const char *); --- 173,191 ---- #define TLS_PROTOCOL_SSLv2 (1<<0) /* SSLv2 */ #define TLS_PROTOCOL_SSLv3 (1<<1) /* SSLv3 */ #define TLS_PROTOCOL_TLSv1 (1<<2) /* TLSv1 */ + #ifdef SSL_TXT_TLSV1_1 + #define TLS_PROTOCOL_TLSv1_1 (1<<3) /* TLSv1_1 */ + #else + #define TLS_PROTOCOL_TLSv1_1 0 /* Unknown */ + #endif + #ifdef SSL_TXT_TLSV1_2 + #define TLS_PROTOCOL_TLSv1_2 (1<<4) /* TLSv1_2 */ + #else + #define TLS_PROTOCOL_TLSv1_2 0 /* Unknown */ + #endif #define TLS_KNOWN_PROTOCOLS \ ! ( TLS_PROTOCOL_SSLv2 | TLS_PROTOCOL_SSLv3 | TLS_PROTOCOL_TLSv1 \ ! | TLS_PROTOCOL_TLSv1_1 | TLS_PROTOCOL_TLSv1_2 ) extern int tls_protocol_mask(const char *); diff --exclude=man --exclude=html --exclude=README_FILES --exclude=INSTALL --exclude=.indent.pro --exclude=Makefile.in -r -cr --exclude=WISHLIST /var/tmp/postfix-2.10-20120407/src/tls/tls_client.c ./src/tls/tls_client.c *** /var/tmp/postfix-2.10-20120407/src/tls/tls_client.c Mon Dec 5 16:03:07 2011 --- ./src/tls/tls_client.c Sun Apr 22 18:12:25 2012 *************** *** 859,864 **** --- 859,870 ---- if (protomask != 0) SSL_set_options(TLScontext->con, ((protomask & TLS_PROTOCOL_TLSv1) ? SSL_OP_NO_TLSv1 : 0L) + #ifdef SSL_OP_NO_TLSv1_1 + | ((protomask & TLS_PROTOCOL_TLSv1_1) ? SSL_OP_NO_TLSv1_1 : 0L) + #endif + #ifdef SSL_OP_NO_TLSv1_2 + | ((protomask & TLS_PROTOCOL_TLSv1_2) ? SSL_OP_NO_TLSv1_2 : 0L) + #endif | ((protomask & TLS_PROTOCOL_SSLv3) ? SSL_OP_NO_SSLv3 : 0L) | ((protomask & TLS_PROTOCOL_SSLv2) ? SSL_OP_NO_SSLv2 : 0L)); diff --exclude=man --exclude=html --exclude=README_FILES --exclude=INSTALL --exclude=.indent.pro --exclude=Makefile.in -r -cr --exclude=WISHLIST /var/tmp/postfix-2.10-20120407/src/tls/tls_misc.c ./src/tls/tls_misc.c *** /var/tmp/postfix-2.10-20120407/src/tls/tls_misc.c Mon Dec 5 16:03:07 2011 --- ./src/tls/tls_misc.c Sun Apr 22 18:08:04 2012 *************** *** 224,229 **** --- 224,235 ---- SSL_TXT_SSLV2, TLS_PROTOCOL_SSLv2, SSL_TXT_SSLV3, TLS_PROTOCOL_SSLv3, SSL_TXT_TLSV1, TLS_PROTOCOL_TLSv1, + #ifdef SSL_TXT_TLSV1_1 + SSL_TXT_TLSV1_1, TLS_PROTOCOL_TLSv1_1, + #endif + #ifdef SSL_TXT_TLSV1_2 + SSL_TXT_TLSV1_2, TLS_PROTOCOL_TLSv1_2, + #endif 0, TLS_PROTOCOL_INVALID, }; diff --exclude=man --exclude=html --exclude=README_FILES --exclude=INSTALL --exclude=.indent.pro --exclude=Makefile.in -r -cr --exclude=WISHLIST /var/tmp/postfix-2.10-20120407/src/tls/tls_server.c ./src/tls/tls_server.c *** /var/tmp/postfix-2.10-20120407/src/tls/tls_server.c Mon Dec 5 16:03:07 2011 --- ./src/tls/tls_server.c Sun Apr 22 18:13:25 2012 *************** *** 403,408 **** --- 403,414 ---- if (protomask != 0) SSL_CTX_set_options(server_ctx, ((protomask & TLS_PROTOCOL_TLSv1) ? SSL_OP_NO_TLSv1 : 0L) + #ifdef SSL_OP_NO_TLSv1_1 + | ((protomask & TLS_PROTOCOL_TLSv1_1) ? SSL_OP_NO_TLSv1_1 : 0L) + #endif + #ifdef SSL_OP_NO_TLSv1_2 + | ((protomask & TLS_PROTOCOL_TLSv1_2) ? SSL_OP_NO_TLSv1_2 : 0L) + #endif | ((protomask & TLS_PROTOCOL_SSLv3) ? SSL_OP_NO_SSLv3 : 0L) | ((protomask & TLS_PROTOCOL_SSLv2) ? SSL_OP_NO_SSLv2 : 0L));