From c36e878d76827fc7062558f1edada05d7ba38880 Mon Sep 17 00:00:00 2001
From: Marek Walczak <2558195+mwlczk@users.noreply.github.com>
Date: Thu, 22 Feb 2018 08:36:12 +0100
Subject: [PATCH] Nist tls (#831)

* remove two ciphers according to https://www.htbridge.com/ssl/ (NIST, HIPAA)
* added a switch via an environment variable to choose between modern and intermediate ciphers
---
 README.md                                   |  7 +++++
 target/dovecot/10-ssl.conf                  |  4 +--
 target/postfix/main.cf                      |  8 ++---
 target/start-mailserver.sh                  | 33 ++++++++++++++++++++-
 test/config/dovecot-lmtp/conf.d/10-ssl.conf |  4 +--
 5 files changed, 47 insertions(+), 9 deletions(-)

diff --git a/README.md b/README.md
index 318ea8ca..2a0aca54 100644
--- a/README.md
+++ b/README.md
@@ -247,6 +247,13 @@ Otherwise, `iptables` won't be able to ban IPs.
 
 Please read [the SSL page in the wiki](https://github.com/tomav/docker-mailserver/wiki/Configure-SSL) for more information.
 
+##### TLS_LEVEL
+
+  - **empty** => modern
+  - modern => Enables TLSv1.2 and modern ciphers only. (default)
+  - intermediate => Enables TLSv1, TLSv1.1 and TLSv1.2 and broad compatibility ciphers.
+  - old => NOT implemented. If you really need it, then customize the TLS ciphers overriding postfix and dovecot settings [ wiki](https://github.com/tomav/docker-mailserver/wiki/
+
 ##### PERMIT_DOCKER
 
 Set different options for mynetworks option (can be overwrite in postfix-main.cf)
diff --git a/target/dovecot/10-ssl.conf b/target/dovecot/10-ssl.conf
index 2d6fd178..5823a66d 100644
--- a/target/dovecot/10-ssl.conf
+++ b/target/dovecot/10-ssl.conf
@@ -46,10 +46,10 @@ ssl_key = </etc/dovecot/ssl/dovecot.key
 ssl_dh_parameters_length = 2048
 
 # SSL protocols to use
-ssl_protocols = !SSLv3
+ssl_protocols = !SSLv3,!TLSv1,!TLSv1.1
 
 # SSL ciphers to use
-ssl_cipher_list = ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:!DSS
+ssl_cipher_list = ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256
 
 # Prefer the server's order of ciphers over client's.
 ssl_prefer_server_ciphers = yes
diff --git a/target/postfix/main.cf b/target/postfix/main.cf
index cfbfbc8f..8e1b9fb4 100644
--- a/target/postfix/main.cf
+++ b/target/postfix/main.cf
@@ -28,12 +28,12 @@ smtpd_tls_loglevel = 1
 smtp_tls_security_level = may
 smtp_tls_loglevel = 1
 tls_ssl_options = NO_COMPRESSION
-tls_high_cipherlist=ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-CCM8:ECDHE-ECDSA-AES256-CCM:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA256:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256
+tls_high_cipherlist=ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256
 tls_preempt_cipherlist = yes
-smtpd_tls_protocols=!SSLv2,!SSLv3
-smtp_tls_protocols=!SSLv2,!SSLv3
+smtpd_tls_protocols=!SSLv2,!SSLv3,!TLSv1,!TLSv1.1
+smtp_tls_protocols=!SSLv2,!SSLv3,!TLSv1,!TLSv1.1
 smtpd_tls_mandatory_ciphers = high
-smtpd_tls_mandatory_protocols = !SSLv2,!SSLv3
+smtpd_tls_mandatory_protocols = !SSLv2,!SSLv3,!TLSv1,!TLSv1.1
 smtpd_tls_exclude_ciphers = aNULL, LOW, EXP, MEDIUM, ADH, AECDH, MD5, DSS, ECDSA, CAMELLIA128, 3DES, CAMELLIA256, RSA+AES, eNULL
 smtpd_tls_dh1024_param_file = /etc/postfix/dhparams.pem
 smtpd_tls_CApath = /etc/ssl/certs
diff --git a/target/start-mailserver.sh b/target/start-mailserver.sh
index 4fec625e..54c3b91c 100644
--- a/target/start-mailserver.sh
+++ b/target/start-mailserver.sh
@@ -24,6 +24,7 @@ DEFAULT_VARS["SMTP_ONLY"]="${SMTP_ONLY:="0"}"
 DEFAULT_VARS["DMS_DEBUG"]="${DMS_DEBUG:="0"}"
 DEFAULT_VARS["OVERRIDE_HOSTNAME"]="${OVERRIDE_HOSTNAME}"
 DEFAULT_VARS["POSTSCREEN_ACTION"]="${POSTSCREEN_ACTION:="enforce"}"
+DEFAULT_VARS["TLS_LEVEL"]="${TLS_LEVEL:="modern"}"
 ##########################################################################
 # << DEFAULT VARS
 ##########################################################################
@@ -731,7 +732,37 @@ function _setup_dkim() {
 function _setup_ssl() {
 	notify 'task' 'Setting up SSL'
 
-	# SSL Configuration
+  # TLS strength/level configuration
+  case $TLS_LEVEL in
+    "modern" )
+      # Postfix configuration
+      sed -i -r 's/^smtpd_tls_mandatory_protocols=.*$/smtpd_tls_mandatory_protocols=!SSLv2,!SSLv3,!TLSv1,!TLSv1.1/' /etc/postfix/main.cf
+      sed -i -r 's/^smtpd_tls_protocols=.*$/smtpd_tls_protocols=!SSLv2,!SSLv3,!TLSv1,!TLSv1.1/' /etc/postfix/main.cf
+      sed -i -r 's/^smtp_tls_protocols=.*$/smtp_tls_protocols=!SSLv2,!SSLv3,!TLSv1,!TLSv1.1/' /etc/postfix/main.cf
+      sed -i -r 's/^tls_high_cipherlist=.*$/tls_high_cipherlist=ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256/' /etc/postfix/main.cf
+
+      # Dovecot configuration
+      sed -i -r 's/^ssl_protocols = .*$/ssl_protocols = !SSLv3,!TLSv1,!TLSv1.1/' /etc/dovecot/conf.d/10-ssl.conf
+      sed -i -r 's/^ssl_cipher_list = .*$/ssl_cipher_list = ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256/' /etc/dovecot/conf.d/10-ssl.conf
+
+      notify 'inf' "TLS configured with 'modern' ciphers"
+    ;;
+    "intermediate" )
+      # Postfix configuration
+      sed -i -r 's/^smtpd_tls_mandatory_protocols=.*$/smtpd_tls_mandatory_protocols=!SSLv2,!SSLv3/' /etc/postfix/main.cf
+      sed -i -r 's/^smtpd_tls_protocols=.*$/smtpd_tls_protocols=!SSLv2,!SSLv3/' /etc/postfix/main.cf
+      sed -i -r 's/^smtp_tls_protocols=.*$/smtp_tls_protocols=!SSLv2,!SSLv3/' /etc/postfix/main.cf
+      sed -i -r 's/^tls_high_cipherlist=.*$/tls_high_cipherlist=ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA:!DSS/' /etc/postfix/main.cf
+
+      # Dovecot configuration
+      sed -i -r 's/^ssl_protocols = .*$/ssl_protocols = !SSLv3/' /etc/dovecot/conf.d/10-ssl.conf
+      sed -i -r 's/^ssl_cipher_list = .*$/ssl_cipher_list = ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA:!DSS/' /etc/dovecot/conf.d/10-ssl.conf
+
+      notify 'inf' "TLS configured with 'intermediate' ciphers"
+    ;;
+  esac
+
+	# SSL certificate Configuration
 	case $SSL_TYPE in
 		"letsencrypt" )
 			# letsencrypt folders and files mounted in /etc/letsencrypt
diff --git a/test/config/dovecot-lmtp/conf.d/10-ssl.conf b/test/config/dovecot-lmtp/conf.d/10-ssl.conf
index 1c6d8a32..f4d5884f 100644
--- a/test/config/dovecot-lmtp/conf.d/10-ssl.conf
+++ b/test/config/dovecot-lmtp/conf.d/10-ssl.conf
@@ -46,10 +46,10 @@ ssl_key = </etc/dovecot/ssl/dovecot.key
 #ssl_dh_parameters_length = 1024
 
 # SSL protocols to use
-ssl_protocols = !SSLv3
+ssl_protocols = !SSLv3,!TLSv1,!TLSv1.1
 
 # SSL ciphers to use
-ssl_cipher_list = ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA:!DSS
+ssl_cipher_list = ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256
 
 # Prefer the server's order of ciphers over client's.
 ssl_prefer_server_ciphers = yes