added Authentication-Results header, with provider

dkim, dmarc, fcrdns (iprev), spf, and smtp-auth
This commit is contained in:
Matt Simerson 2013-05-01 00:35:49 -07:00
parent c80bcf8e47
commit 3973f9ae80
6 changed files with 123 additions and 29 deletions

View File

@ -271,6 +271,34 @@ sub store_deferred_reject {
return (DECLINED);
}
sub store_auth_results {
my ($self, $value) = @_;
my @headers = $self->transaction->header->get('Authentication-Results');
chomp @headers;
my @deleteme;
for ( my $i = 0; $i < scalar @headers; $i++ ) {
my @values = split /;/, $headers[$i];
if ( $self->config->('me') ne $values[0] ) { # some other MTA
# we generally want to remove Authentication-Results headers added by other
# MTAs (so our downstream can trust the A-R header we insert), but we also
# don't want to invalidate DKIM signatures.
# TODO: parse the DKIM signature(s) to see if A-R header is signed
if ( ! $self->transaction->header->get('DKIM-Signature') ) {
$self->log(LOGINFO, "deleted auth-results from $_");
push @deleteme, $i;
};
next;
};
push @values, $value;
$self->log(LOGINFO, "appended to auth-results: $value");
$self->transaction->header->replace('Authentication->Results', join('; ', @values ), $i);
}
foreach ( @deleteme ) {
$self->transaction->header->delete('Authentication-Results', $_);
};
};
sub init_resolver {
my $self = shift;
my $timeout = $self->{_args}{dns_timeout} || shift || 5;

View File

@ -770,6 +770,7 @@ sub data_respond {
my $esmtp = substr($smtp, 0, 1) eq "E";
my $authheader = '';
my $sslheader = '';
my $auth_result = 'none';
if (defined $self->connection->notes('tls_enabled')
and $self->connection->notes('tls_enabled'))
@ -780,15 +781,28 @@ sub data_respond {
. " encrypted) ";
}
if (defined $self->{_auth} and $self->{_auth} == OK) {
$smtp .= "A" if $esmtp; # RFC3848
$authheader =
"(smtp-auth username $self->{_auth_user}, mechanism $self->{_auth_mechanism})\n";
if (defined $self->{_auth} ) {
my $mech = $self->{_auth_mechanism};
my $user = $self->{_auth_user};
$auth_result = "auth=";
if ( $self->{_auth} == OK) {
$smtp .= "A" if $esmtp; # RFC3848
$authheader = "(smtp-auth username $user, mechanism $mech)\n";
$auth_result .= 'pass';
}
else {
$auth_result .= 'fail';
};
$auth_result .= " ($mech) smtp.auth=$user";
}
$header->add("Received",
$header->add('Received',
$self->received_line($smtp, $authheader, $sslheader), 0);
# RFC 5451: used in AUTH, DKIM, DOMAINKEYS, SENDERID, SPF
$header->add('Authentication-Results',
join('; ', $self->config('me'), $auth_result ) );
# if we get here without seeing a terminator, the connection is
# probably dead.
unless ($complete) {

View File

@ -222,6 +222,9 @@ sub validate_it {
my $result = $dkim->result;
my $mess = $self->get_details($dkim);
$self->store_auth_results("dkim=" .$dkim->result_detail . " header.i=@".$dkim->signature->domain);
#$self->add_header($mess);
foreach my $t (qw/ pass fail invalid temperror none /) {
next if $t ne $result;
my $handler = 'handle_sig_' . $t;
@ -286,8 +289,7 @@ sub handle_sig_fail {
my ($self, $dkim, $mess) = @_;
$self->adjust_karma(-1);
return
$self->get_reject("DKIM signature invalid: " . $dkim->result_detail,
return $self->get_reject("signature invalid: " . $dkim->result_detail,
$mess);
}
@ -316,12 +318,10 @@ sub handle_sig_invalid {
$self->log(LOGINFO, $mess);
if ($prs->{accept}) {
$self->add_header($mess);
$self->log(LOGERROR, "error, invalid signature but accept policy!?");
return DECLINED;
}
elsif ($prs->{neutral}) {
$self->add_header($mess);
$self->log(LOGERROR, "error, invalid signature but neutral policy?!");
return DECLINED;
}
@ -333,7 +333,6 @@ sub handle_sig_invalid {
# this should never happen
$self->log(LOGINFO, "error, invalid signature, unhandled");
$self->add_header($mess);
return DECLINED;
}
@ -527,8 +526,6 @@ sub get_selector {
sub add_header {
my $self = shift;
my $header = shift or return;
# consider adding Authentication-Results header, (RFC 5451)
$self->qp->transaction->header->add('X-DKIM-Authentication', $header, 0);
}

View File

@ -122,24 +122,31 @@ sub data_post_handler {
# evaluation returned a "pass" result.
my $spf_dom = $transaction->notes('spf_pass_host');
my $effective_policy = ( $self->{_args}{is_subdomain} && defined $policy->{sp} )
? $policy->{sp} : $policy->{p};
# 5. Conduct identifier alignment checks.
return DECLINED
if $self->is_aligned($from_dom, $org_dom, $policy, $spf_dom );
if ( $self->is_aligned($from_dom, $org_dom, $policy, $spf_dom ) ) {
$self->store_auth_results("dmarc=pass (p=$effective_policy) d=$from_dom");
return DECLINED;
};
# 6. Apply policy. Emails that fail the DMARC mechanism check are
# disposed of in accordance with the discovered DMARC policy of the
# Domain Owner. See Section 6.2 for details.
if ( $self->{_args}{is_subdomain} && defined $policy->{sp} ) {
return DECLINED if lc $policy->{sp} eq 'none';
if ( lc $effective_policy eq 'none' ) {
$self->store_auth_results("dmarc=fail (p=none) d=$from_dom");
return DECLINED;
};
return DECLINED if lc $policy->{p} eq 'none';
my $pct = $policy->{pct} || 100;
if ( $pct != 100 && int(rand(100)) >= $pct ) {
$self->log("fail, tolerated, policy, sampled out");
$self->store_auth_results("dmarc=sampled_out (p=$effective_policy) d=$from_dom");
return DECLINED;
};
$self->store_auth_results("dmarc=fail (p=$effective_policy) d=$from_dom");
return $self->get_reject("failed DMARC policy");
}

View File

@ -88,6 +88,38 @@ From Wikipedia summary:
3. Any A or AAAA record returned by the second query is then compared against the original IP address (check_ip_match), and if there is a match, then the FCrDNS check passes.
=head1 iprev
# https://www.ietf.org/rfc/rfc5451.txt
2.4.3. "iprev" Results
The result values are used by the "iprev" method, defined in
Section 3, are as follows:
pass: The DNS evaluation succeeded, i.e., the "reverse" and
"forward" lookup results were returned and were in agreement.
fail: The DNS evaluation failed. In particular, the "reverse" and
"forward" lookups each produced results but they were not in
agreement, or the "forward" query completed but produced no
result, e.g., a DNS RCODE of 3, commonly known as NXDOMAIN, or an
RCODE of 0 (NOERROR) in a reply containing no answers, was
returned.
temperror: The DNS evaluation could not be completed due to some
error that is likely transient in nature, such as a temporary DNS
error, e.g., a DNS RCODE of 2, commonly known as SERVFAIL, or
other error condition resulted. A later attempt may produce a
final result.
permerror: The DNS evaluation could not be completed because no PTR
data are published for the connecting IP address, e.g., a DNS
RCODE of 3, commonly known as NXDOMAIN, or an RCODE of 0 (NOERROR)
in a reply containing no answers, was returned. This prevented
completion of the evaluation.
=cut
=head1 AUTHOR
@ -136,9 +168,8 @@ sub connect_handler {
sub data_post_handler {
my ($self, $transaction) = @_;
my $match = $self->connection->notes('fcrdns_match') || 0;
$transaction->header->add('X-Fcrdns', $match ? 'Yes' : 'No', 0);
my $match = $self->connection->notes('fcrdns_match') || 'error';
$self->store_auth_results("iprev=$match");
return (DECLINED);
}
@ -182,13 +213,25 @@ sub has_reverse_dns {
my $res = $self->init_resolver();
my $ip = $self->qp->connection->remote_ip;
my $query = $res->query($ip) or do {
my $query = $res->query($ip, 'PTR') or do {
if ($res->errorstring eq 'NXDOMAIN') {
$self->adjust_karma(-1);
$self->connection->notes('fcrdns_match', 'permerror');
$self->log(LOGINFO, "fail, no rDNS: " . $res->errorstring);
return;
}
$self->log(LOGINFO, "fail, error getting rDNS: " . $res->errorstring);
if ( $res->errorstring eq 'SERVFAIL' ) {
$self->log(LOGINFO, "fail, error getting rDNS: " . $res->errorstring);
$self->connection->notes('fcrdns_match', 'temperror');
}
elsif ( $res->errorstring eq 'NOERROR' ) {
$self->log(LOGINFO, "fail, no PTR (NOERROR)" );
$self->connection->notes('fcrdns_match', 'permerror');
}
else {
$self->connection->notes('fcrdns_match', 'fail');
$self->log(LOGINFO, "fail, error getting rDNS: " . $res->errorstring);
};
return;
};
@ -203,6 +246,7 @@ sub has_reverse_dns {
if (!$hits) {
$self->adjust_karma(-1);
$self->log(LOGINFO, "fail, no PTR records");
$self->connection->notes('fcrdns_match', 'permerror');
return;
}
@ -218,11 +262,13 @@ sub has_forward_dns {
foreach my $host (keys %{$self->{_args}{ptr_hosts}}) {
$host .= '.' if '.' ne substr($host, -1, 1); # fully qualify name
my $query = $res->search($host) or do {
my $query = $res->query($host) or do {
if ($res->errorstring eq 'NXDOMAIN') {
$self->connection->notes('fcrdns_match', 'permerror');
$self->log(LOGDEBUG, "host $host does not exist");
next;
}
$self->connection->notes('fcrdns_match', 'fail');
$self->log(LOGDEBUG, "query for $host failed (",
$res->errorstring, ")");
next;
@ -235,11 +281,13 @@ sub has_forward_dns {
$self->check_ip_match($rr->address) and return 1;
}
if ($hits) {
$self->connection->notes('fcrdns_match', 'fail');
$self->log(LOGDEBUG, "PTR host has forward DNS") if $hits;
return 1;
}
}
$self->adjust_karma(-1);
$self->connection->notes('fcrdns_match', 'fail');
$self->log(LOGINFO, "fail, no PTR hosts have forward DNS");
return;
}
@ -250,7 +298,7 @@ sub check_ip_match {
if ($ip eq $self->qp->connection->remote_ip) {
$self->log(LOGDEBUG, "forward ip match");
$self->connection->notes('fcrdns_match', 1);
$self->connection->notes('fcrdns_match', 'pass');
$self->adjust_karma(1);
return 1;
}
@ -262,7 +310,7 @@ sub check_ip_match {
if ($dns_net eq $rem_net) {
$self->log(LOGNOTICE, "forward network match");
$self->connection->notes('fcrdns_match', 1);
$self->connection->notes('fcrdns_match', 'pass');
return 1;
}
return;

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@ -133,10 +133,12 @@ sub mail_handler {
return (DECLINED, "SPF - no response");
}
$self->store_auth_results("spf=$code smtp.mailfrom=".$sender->host);
if ($code eq 'pass') {
$self->adjust_karma(1);
$transaction->notes('spf_pass_host', lc $sender->host);
$self->log(LOGINFO, "pass, $code: $why");
$self->log(LOGINFO, "pass, $why");
return (DECLINED);
}
@ -235,8 +237,6 @@ sub data_post_handler {
$transaction->header->add('Received-SPF', $result->received_spf_header, 0);
# consider also adding SPF status to Authentication-Results header
return DECLINED;
}