Bug 935570: create an anti-spam extension

1 files changed, 183 insertions, 1 deletions

diff --git a/extensions/AntiSpam/Extension.pm b/extensions/AntiSpam/Extension.pm
index 5cb9928db..ef31a0b2d 100644
--- a/extensions/AntiSpam/Extension.pm
+++ b/extensions/AntiSpam/Extension.pm
@@ -12,7 +12,178 @@ use warnings;
 
 use base qw(Bugzilla::Extension);
 
-our $VERSION = '0';
+use Bugzilla::Error;
+use Bugzilla::Group;
+use Bugzilla::Util qw(remote_ip trick_taint);
+use Email::Address;
+use Encode;
+use Socket;
+use Sys::Syslog qw(:DEFAULT setlogsock);
+
+our $VERSION = '1';
+
+#
+# project honeypot integration
+#
+
+sub _project_honeypot_blocking {
+    my ($self, $api_key, $login) = @_;
+    my $ip = remote_ip();
+    return unless $ip =~ /^(\d+)\.(\d+)\.(\d+)\.(\d+)$/;
+    my $lookup = "$api_key.$4.$3.$2.$1.dnsbl.httpbl.org";
+    return unless my $packed = gethostbyname($lookup);
+    my $honeypot = inet_ntoa($packed);
+    return unless $honeypot =~ /^(\d+)\.(\d+)\.(\d+)\.(\d+)$/;
+    my ($status, $days, $threat, $type) = ($1, $2, $3, $4);
+
+    return if $status != 127
+              || $threat < Bugzilla->params->{honeypot_threat_threshold};
+
+    _syslog(sprintf("[audit] blocked <%s> from creating %s, honeypot %s", $ip, $login, $honeypot));
+    ThrowUserError('account_creation_restricted');
+}
+
+sub config_modify_panels {
+    my ($self, $args) = @_;
+    push @{ $args->{panels}->{auth}->{params} }, {
+        name    => 'honeypot_api_key',
+        type    => 't',
+        default => '',
+    };
+    push @{ $args->{panels}->{auth}->{params} }, {
+        name    => 'honeypot_threat_threshold',
+        type    => 't',
+        default => '32',
+    };
+}
+
+#
+# comment blocking
+#
+
+sub _comment_blocking {
+    my ($self, $params) = @_;
+
+    # as we want to use this sparingly, we only block comments on bugs which
+    # the user didn't report, and skip it completely if the user is in the
+    # editbugs group.
+    my $user = Bugzilla->user;
+    return if $user->in_group('editbugs');
+    # new bug
+    return unless $params->{bug_id};
+    # existing bug
+    my $bug = ref($params->{bug_id})
+              ? $params->{bug_id}
+              : Bugzilla::Bug->new($params->{bug_id});
+    return if $bug->reporter->id == $user->id;
+
+    my $blocklist = Bugzilla->dbh->selectcol_arrayref(
+        'SELECT word FROM antispam_comment_blocklist'
+    );
+    return unless @$blocklist;
+
+    my $regex = '\b(?:' . join('|', map { quotemeta } @$blocklist) . ')\b';
+    if ($params->{thetext} =~ /$regex/i) {
+        ThrowUserError('antispam_comment_blocked');
+    }
+}
+
+#
+# domain blocking
+#
+
+sub _domain_blocking {
+    my ($self, $login) = @_;
+    my $address = Email::Address->new(undef, $login);
+    my $blocked = Bugzilla->dbh->selectrow_array(
+        "SELECT 1 FROM antispam_domain_blocklist WHERE domain=?",
+        undef,
+        $address->host
+    );
+    if ($blocked) {
+        _syslog(sprintf("[audit] blocked <%s> from creating %s, blacklisted domain", remote_ip(), $login));
+        ThrowUserError('account_creation_restricted');
+    }
+}
+
+#
+# ip blocking
+#
+
+sub _ip_blocking {
+    my ($self, $login) = @_;
+    my $ip = remote_ip();
+    trick_taint($ip);
+    my $blocked = Bugzilla->dbh->selectrow_array(
+        "SELECT 1 FROM antispam_ip_blocklist WHERE ip_address=?",
+        undef,
+        $ip
+    );
+    if ($blocked) {
+        _syslog(sprintf("[audit] blocked <%s> from creating %s, blacklisted IP", $ip, $login));
+        ThrowUserError('account_creation_restricted');
+    }
+}
+
+#
+# hooks
+#
+
+sub object_end_of_create_validators {
+    my ($self, $args) = @_;
+    if ($args->{class} eq 'Bugzilla::Comment') {
+        $self->_comment_blocking($args->{params});
+    }
+}
+
+sub user_verify_login {
+    my ($self, $args) = @_;
+    if (my $api_key = Bugzilla->params->{honeypot_api_key}) {
+        $self->_project_honeypot_blocking($api_key, $args->{login});
+    }
+    $self->_ip_blocking($args->{login});
+    $self->_domain_blocking($args->{login});
+}
+
+sub editable_tables {
+    my ($self, $args) = @_;
+    my $tables = $args->{tables};
+    # allow these tables to be edited with the EditTables extension
+    $tables->{antispam_domain_blocklist} = {
+        id_field => 'id',
+        order_by => 'domain',
+        blurb    => 'List of fully qualified domain names to block at account creation time.',
+        group    => 'can_configure_antispam',
+    };
+    $tables->{antispam_comment_blocklist} = {
+        id_field => 'id',
+        order_by => 'word',
+        blurb    => "List of whole words that will cause comments containing \\b\$word\\b to be blocked.\n" .
+                    "This only applies to comments on bugs which the user didn't report.\n" .
+                    "Users in the editbugs group are exempt from comment blocking.",
+        group    => 'can_configure_antispam',
+    };
+    $tables->{antispam_ip_blocklist} = {
+        id_field => 'id',
+        order_by => 'ip_address',
+        blurb    => 'List of IPv4 addresses which are prevented from creating accounts.',
+        group    => 'can_configure_antispam',
+    };
+}
+
+#
+# installation
+#
+
+sub install_before_final_checks {
+    if (!Bugzilla::Group->new({ name => 'can_configure_antispam' })) {
+        Bugzilla::Group->create({
+            name        => 'can_configure_antispam',
+            description => 'Can configure Anti-Spam measures',
+            isbuggroup  => 0,
+        });
+    }
+}
 
 sub db_schema_abstract_schema {
     my ($self, $args) = @_;
@@ -83,4 +254,15 @@ sub db_schema_abstract_schema {
     };
 }
 
+#
+# utilities
+#
+
+sub _syslog {
+    my $message = shift;
+    openlog('apache', 'cons,pid', 'local4');
+    syslog('notice', encode_utf8($message));
+    closelog();
+}
+
 __PACKAGE__->NAME;