postfix: Update to version 3.8.4 + prevent smtp smuggling

  - Update from version 3.8.3 to 3.8.4
- Update of rootfile not required
- Permanent fix for smtp smuggling will be in version 3.9. However the fix has been
   backported into version 3.8.4 but with the default for the parameter of "no".
- This patch sets the defaults for all the main.cf parameters highlighted by Wietse
   Venema in http://www.postfix.org/smtp-smuggling.html
- Additionally the implementation of smtpd_forbid_bare_newline = yes has been added to
   the install.sh pak for postfix so that it will be included into any main.cf file being
   restored from backup. This parameter is available for the first time in 3.8.4 so will
   not be in any backup prior to this release and can therefore be safely applied to
   restored versions of main.cf.
- This fix in install.sh will be able to be removed when version 3.9 is released early
   in 2024 as the default for that parameter in that version onwards will then be "yes"
- Changelog
    3.8.4
	Security: with "smtpd_forbid_bare_newline = yes" (default
	 "no" for Postfix < 3.9), reply with "Error: bare <LF>
	 received" and disconnect when an SMTP client sends a line
	 ending in <LF>, violating the RFC 5321 requirement that
	 lines must end in <CR><LF>. This prevents SMTP smuggling
	 attacks that target a recipient at a Postfix server. For
	 backwards compatibility, local clients are excluded by
	 default with "smtpd_forbid_bare_newline_exclusions =
	 $mynetworks". Files: mantools/postlink, proto/postconf.proto,
	 global/mail_params.h, global/smtp_stream.c, global/smtp_stream.h,
	 smtpd/smtpd.c.

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
---
 lfs/postfix                 | 15 +++++++++++----
 src/paks/postfix/install.sh |  5 +++++
 2 files changed, 16 insertions(+), 4 deletions(-)
  

Reviewed-by: Peter Müller <peter.mueller@ipfire.org>

> - Update from version 3.8.3 to 3.8.4
> - Update of rootfile not required
> - Permanent fix for smtp smuggling will be in version 3.9. However the fix has been
>    backported into version 3.8.4 but with the default for the parameter of "no".
> - This patch sets the defaults for all the main.cf parameters highlighted by Wietse
>    Venema in http://www.postfix.org/smtp-smuggling.html
> - Additionally the implementation of smtpd_forbid_bare_newline = yes has been added to
>    the install.sh pak for postfix so that it will be included into any main.cf file being
>    restored from backup. This parameter is available for the first time in 3.8.4 so will
>    not be in any backup prior to this release and can therefore be safely applied to
>    restored versions of main.cf.
> - This fix in install.sh will be able to be removed when version 3.9 is released early
>    in 2024 as the default for that parameter in that version onwards will then be "yes"
> - Changelog
>     3.8.4
> 	Security: with "smtpd_forbid_bare_newline = yes" (default
> 	 "no" for Postfix < 3.9), reply with "Error: bare <LF>
> 	 received" and disconnect when an SMTP client sends a line
> 	 ending in <LF>, violating the RFC 5321 requirement that
> 	 lines must end in <CR><LF>. This prevents SMTP smuggling
> 	 attacks that target a recipient at a Postfix server. For
> 	 backwards compatibility, local clients are excluded by
> 	 default with "smtpd_forbid_bare_newline_exclusions =
> 	 $mynetworks". Files: mantools/postlink, proto/postconf.proto,
> 	 global/mail_params.h, global/smtp_stream.c, global/smtp_stream.h,
> 	 smtpd/smtpd.c.
> 
> Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
> ---
>  lfs/postfix                 | 15 +++++++++++----
>  src/paks/postfix/install.sh |  5 +++++
>  2 files changed, 16 insertions(+), 4 deletions(-)
> 
> diff --git a/lfs/postfix b/lfs/postfix
> index aab683f4c..7f2625a4e 100644
> --- a/lfs/postfix
> +++ b/lfs/postfix
> @@ -26,7 +26,7 @@ include Config
>  
>  SUMMARY    = A fast, secure, and flexible mailer
>  
> -VER        = 3.8.3
> +VER        = 3.8.4
>  
>  THISAPP    = postfix-$(VER)
>  DL_FILE    = $(THISAPP).tar.gz
> @@ -34,7 +34,7 @@ DL_FROM    = $(URL_IPFIRE)
>  DIR_APP    = $(DIR_SRC)/$(THISAPP)
>  TARGET     = $(DIR_INFO)/$(THISAPP)
>  PROG       = postfix
> -PAK_VER    = 43
> +PAK_VER    = 44
>  
>  DEPS       =
>  
> @@ -70,7 +70,7 @@ objects = $(DL_FILE)
>  
>  $(DL_FILE) = $(DL_FROM)/$(DL_FILE)
>  
> -$(DL_FILE)_BLAKE2 = a656606c2a46671548cb954a65d769ba5bf68a5c8f0ccdc0e753b03386956eef3e264b696a306c586f1df1b06fb173e5f3db74c6a9e4d3686c86b8f53be585ed
> +$(DL_FILE)_BLAKE2 = 200ce3d72444da05e42fc8627002d53d68c1b3d78b7f74b0130ac958c23d16454783ef4849a8c9a4e3cba8ae36646e921f7e94ac4fb819b597e1a5ab1a875272
>  
>  install : $(TARGET)
>  
> @@ -110,13 +110,20 @@ $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects))
>  	cd $(DIR_APP) && sh postfix-install -non-interactive
>  	## Install configuration
>  	rm -vf /etc/postfix/main.cf.default
> +	
> +	# update main.cf parameters to prevent smtp smuggling attack
> +	postconf -e 'smtpd_forbid_bare_newline = yes'
> +	postconf -e 'smtpd_forbid_unauth_pipelining = yes'
> +	postconf -e 'smtpd_data_restrictions = reject_unauth_pipelining'
> +	postconf -e 'smtpd_discard_ehlo_keywords = chunking'
> +	
>  	mkdir -p /var/lib/postfix
>  	chown postfix.root /var/lib/postfix
>  
>  	install -v -m 644 $(DIR_SRC)/config/backup/includes/postfix \
>  			 /var/ipfire/backup/addons/includes/postfix
>  	mv /usr/sbin/sendmail /usr/sbin/sendmail.postfix
> -
> +	
>  	#install initscripts
>  	$(call INSTALL_INITSCRIPTS,$(SERVICES))
>  
> diff --git a/src/paks/postfix/install.sh b/src/paks/postfix/install.sh
> index 1629d21c1..2e04e74a8 100644
> --- a/src/paks/postfix/install.sh
> +++ b/src/paks/postfix/install.sh
> @@ -24,6 +24,11 @@
>  . /opt/pakfire/lib/functions.sh
>  extract_files
>  restore_backup ${NAME}
> +
> +# change main.cf parameter from default value to prevent smtp smuggling attack
> +# will not be required once postfix-3.9.x is released as default will then be yes
> +postconf -e 'smtpd_forbid_bare_newline = yes'
> +
>  postalias /etc/aliases
>  # Set postfix's hostname
>  postconf -e "myhostname=$(hostname -f)"