diff options
Diffstat (limited to 'roles/MSA/files')
5 files changed, 233 insertions, 2 deletions
diff --git a/roles/MSA/files/etc/postfix/anonymize_sender.pcre b/roles/MSA/files/etc/postfix/anonymize_sender.pcre index bd3d5f1..b91b981 100644 --- a/roles/MSA/files/etc/postfix/anonymize_sender.pcre +++ b/roles/MSA/files/etc/postfix/anonymize_sender.pcre @@ -1,7 +1,8 @@ -/^Received:\s+from\s+(?:\S+\s+\(\S+\s+\[[[:xdigit:].:]{3,39}\]\)) - (\s+\(using\s+(?:TLS|SSL)(?:v\S+)?\s+with\s+cipher\s+\S+\s+\(\S+\s+bits\)\)\s+).* +/^Received:\s+from\s+(?:\S+\s+\(\S+\s+\[(?:IPv6:)?[[:xdigit:].:]{3,39}\]\)) + (\s+\(using\s+(?:TLS|SSL)(?:v\S+)?\s+with\s+cipher\s+\S+\s+\(\S+\s+bits\) + (?:\s+key-exchange\s+\S+\s+(?:\([^)]+\)\s+)?server-signature\s+\S+\s+\(\d+\s+bits\)(?:\s+server-[[:alnum:]]+\s+\S+)*)?\)\s+).* (\bby\s+(?:\S+\.)?fripost\.org\s+\([^)]+\) \s+with\s+E?SMTPS?A\s+id\s+[[:xdigit:]]+;?\s.*)/x REPLACE Received: from [127.0.0.1] (localhost [127.0.0.1])${1}${2} /^X-Originating-IP:/ IGNORE diff --git a/roles/MSA/files/etc/postfix/check_sender_access b/roles/MSA/files/etc/postfix/check_sender_access new file mode 100644 index 0000000..07d2874 --- /dev/null +++ b/roles/MSA/files/etc/postfix/check_sender_access @@ -0,0 +1 @@ +<> REJECT Null sender not allowed diff --git a/roles/MSA/files/etc/systemd/system/postfix-sender-login.service b/roles/MSA/files/etc/systemd/system/postfix-sender-login.service new file mode 100644 index 0000000..d652f75 --- /dev/null +++ b/roles/MSA/files/etc/systemd/system/postfix-sender-login.service @@ -0,0 +1,25 @@ +[Unit] +Description=Postfix sender login socketmap +After=mail-transport-agent.target +Requires=postfix-sender-login.socket + +[Service] +User=_postfix-sender-login +StandardInput=null +SyslogFacility=mail +ExecStart=/usr/local/bin/postfix-sender-login.pl + +# Hardening +NoNewPrivileges=yes +PrivateDevices=yes +PrivateNetwork=yes +ProtectHome=yes +ProtectSystem=strict +ProtectControlGroups=yes +ProtectKernelModules=yes +ProtectKernelTunables=yes +RestrictAddressFamilies=AF_UNIX + +[Install] +WantedBy=multi-user.target +Also=postfix-sender-login.socket diff --git a/roles/MSA/files/etc/systemd/system/postfix-sender-login.socket b/roles/MSA/files/etc/systemd/system/postfix-sender-login.socket new file mode 100644 index 0000000..e8d99b5 --- /dev/null +++ b/roles/MSA/files/etc/systemd/system/postfix-sender-login.socket @@ -0,0 +1,8 @@ +[Socket] +SocketUser=postfix +SocketGroup=postfix +SocketMode=0600 +ListenStream=/var/spool/postfix-msa/private/sender-login + +[Install] +WantedBy=sockets.target diff --git a/roles/MSA/files/usr/local/bin/postfix-sender-login.pl b/roles/MSA/files/usr/local/bin/postfix-sender-login.pl new file mode 100755 index 0000000..a37f872 --- /dev/null +++ b/roles/MSA/files/usr/local/bin/postfix-sender-login.pl @@ -0,0 +1,196 @@ +#!/usr/bin/perl -T + +#---------------------------------------------------------------------- +# socketmap lookup table returning the SASL login name(s) owning a given +# sender address +# Copyright © 2017,2020 Guilhem Moulin <guilhem@fripost.org> +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. +#---------------------------------------------------------------------- + +use warnings; +use strict; + +use Errno 'EINTR'; + +use Net::LDAPI (); +use Net::LDAP::Util qw/ldap_explode_dn escape_dn_value escape_filter_value/; +use Net::LDAP::Constant qw/LDAP_NO_SUCH_OBJECT/; +use Authen::SASL (); + +# clean up PATH +$ENV{PATH} = join ':', qw{/usr/bin /bin}; +delete @ENV{qw/IFS CDPATH ENV BASH_ENV/}; + +my $nProc = 2; # number of pre-forked servers +my $maxRequests = 32; # maximum number of requests per worker +my $POSTMASTER = 'postmaster@fripost.org'; # returned for forbidden envelope sender addresses + +my $BASEDN = "ou=virtual,dc=fripost,dc=org"; +my $BUFSIZE = 65536; # try to read that many bytes at the time +my $LDAPI = "ldapi://"; +sub server(); + + +# fdopen(3) the file descriptor FD +die "This service must be socket-activated.\n" + unless defined $ENV{LISTEN_PID} and $ENV{LISTEN_PID} == $$ + and defined $ENV{LISTEN_FDS} and $ENV{LISTEN_FDS} == 1; +open my $S, '+<&=', 3 or die "fdopen: $!"; + +my @CHILDREN; +for (my $i = 0; $i < $nProc-1; $i++) { + my $pid = fork() // die "fork: $!"; + if ($pid) { + push @CHILDREN, $pid; + } else { + server(); # child, never return + exit; + } +} +server(); +waitpid $_ => 0 foreach @CHILDREN; +exit $?; + + +############################################################################# + +sub server() { + for (my $n = 0; $n < $maxRequests; $n++) { + accept(my $conn, $S) or do { + next if $! == EINTR; + die "accept: $!"; + }; + my $reply = process_request($conn); + + # encode the reply as a netstring and send it back + # https://cr.yp.to/proto/netstrings.txt + $reply = length($reply).':'.$reply.','; + my $len = length($reply); + + for (my $i = 0; $i < $len;) { + my $n = syswrite($conn, $reply, $len-$i, $i) // do { + next if $! == EINTR; + warn "Can't write: $!"; + last; + }; + $i += $n; + } + close $conn or warn "Can't close: $!"; + } +} + +sub process_request($) { + my $conn = shift; + my ($buf, $offset) = (undef, 0); + + # keep reading until the request length is determined + do { + my $n = sysread($conn, $buf, $BUFSIZE, $offset) // do { + next if $! == EINTR; + return "TEMP can't read: $!"; + }; + return "TEMP EOF" if $n == 0; + $offset += $n; + } until ($buf =~ /\A(0|[1-9][0-9]*):/); + + # keep reading until the whole request is buffered + my $strlen = length("$1") + 1; # [len]":" + my $len = $strlen + $1 + 1; # [len]":"[string]"," + while ($offset < $len) { + my $n = sysread($conn, $buf, $BUFSIZE, $offset) // do { + next if $! == EINTR; + return "TEMP can't read: $!"; + }; + return "TEMP EOF" if $n == 0; + $offset += $n; + } + + # requests are of the form $name <space> $key, cf. socketmap_table(5) + my $i = index($buf, ' ', $strlen); + return "TEMP invalid input: $buf" unless $i > $strlen and substr($buf,-1) eq ','; + my $name = substr($buf, $strlen, $i-$strlen); + my $key = substr($buf, $i, -1); + return "TEMP invalid name: $name" unless $name eq 'sender_login'; + + $key =~ /\A(.+)@([^\@]+)\z/ or return "NOTFOUND "; # invalid sender address + my ($localpart, $domainpart) = ($1, $2); + $localpart =~ s/\+.*//; # strip extension, cf. postconf(5)'s $recipient_delimiter + + my $ldap = Net::LDAPI::->new( $LDAPI ) // + return "TEMP couldn't create Net::LDAPI object"; + $ldap->bind( undef, sasl => Authen::SASL::->new(mechanism => 'EXTERNAL') ) or + return "TEMP LDAP: couldn't bind"; + + my $reply = lookup_sender($ldap, $localpart, $domainpart); + $ldap->unbind(); + return $reply; +} + +sub lookup_sender($$$) { + my ($ldap, $l, $d) = @_; + + my $filter = '(&(objectClass=FripostVirtualDomain)(fvd='.escape_filter_value($d).'))'; + my $mesg = $ldap->search( base => $BASEDN, scope => 'one', deref => 'never' + , filter => $filter + , attrs => [qw/objectClass fripostOwner fripostPostmaster/] + ); + return "TEMP LDAP error: ".$mesg->error() if $mesg->code; + my $entry = $mesg->pop_entry() // return "NOTFOUND "; # not a domain we know + return "TEMP LDAP error: multiple entry founds" if defined $mesg->pop_entry(); # sanity check + + # domain postmasters are allowed to use any sender address + my @logins = $entry->get_value('fripostPostmaster', asref => 0); + my @owners = $entry->get_value('fripostOwner', asref => 0); + + if (grep { $_ eq 'FripostVirtualAliasDomain' } $entry->get_value('objectClass', asref => 0)) { + # so are alias domain owners + push @logins, @owners; + } else { + my $dn = 'fvd='.escape_dn_value($d).','.$BASEDN; + my $filter = '(&(|(objectClass=FripostVirtualAlias)(objectClass=FripostVirtualList)(objectClass=FripostVirtualUser))(fvl='.escape_filter_value($l).'))'; + my $mesg = $ldap->search( base => $dn, scope => 'one', deref => 'never' + , filter => $filter + , attrs => [qw/objectClass fripostOwner/] + ); + unless ($mesg->code == 0 and defined ($entry = $mesg->pop_entry())) { + # domains owners are allowed to use any unkwown localpart as sender address + push @logins, @owners; + } else { + return "TEMP LDAP error: multiple entry founds" if defined $mesg->pop_entry(); # sanity check + if (grep { $_ eq 'FripostVirtualUser' } $entry->get_value('objectClass', asref => 0)) { + push @logins, $entry->dn(); + } else { + # alias/list owners can use the address as sender, and so are the domains owners + push @logins, @owners, $entry->get_value('fripostOwner', asref => 0); + } + } + } + + # convert DNs to SASL login names + my %logins; + foreach my $dn (@logins) { + next unless defined $dn; + $dn = ldap_explode_dn($dn, casefold => 'lower'); + next unless defined $dn and $#$dn == 4; + my $l = $dn->[0]->{fvl} // next; + my $d = $dn->[1]->{fvd} // next; + $logins{$l.'@'.$d} = 1; + } + + # if the entry is found in LDAP but doesn't have an owner, only + # $POSTMASTER is allowed to use it as sender address + my $reply = %logins ? join(',', keys %logins) : $POSTMASTER; + return "OK $reply"; +} |