+ my $our_pid = $$;
+
+ # situation here is wierd, running external app
+ # involves fork+exec. At some point after fork,
+ # but before exec (or during) code can die in a
+ # child. Local is no help here as die throws
+ # error out of scope and locals are reset to old
+ # values. Instead we set values, eval code, check pid
+ # on failure and reset values only in our original
+ # process
+ my ($oldv_dbh, $oldv_rth);
+ my $dbh = $RT::Handle ? $RT::Handle->dbh : undef;
+ $oldv_dbh = $dbh->{'InactiveDestroy'} if $dbh;
+ $dbh->{'InactiveDestroy'} = 1 if $dbh;
+ $oldv_rth = $RT::Handle->{'DisconnectHandleOnDestroy'} if $RT::Handle;
+ $RT::Handle->{'DisconnectHandleOnDestroy'} = 0 if $RT::Handle;
+
+ my ($reader, $writer);
+ pipe( $reader, $writer );
+
+ my @res;
+ my $want = wantarray;
+ eval {
+ my $code = shift;
+ local @ENV{ 'LANG', 'LC_ALL' } = ( 'C', 'C' );
+ unless ( defined $want ) {
+ $code->();
+ } elsif ( $want ) {
+ @res = $code->();
+ } else {
+ @res = ( scalar $code->() );
+ }
+ exit 0 if $our_pid != $$;
+ 1;
+ } or do {
+ my $err = $@;
+ $err =~ s/^Stack:.*$//ms;
+ if ( $our_pid == $$ ) {
+ $dbh->{'InactiveDestroy'} = $oldv_dbh if $dbh;
+ $RT::Handle->{'DisconnectHandleOnDestroy'} = $oldv_rth if $RT::Handle;
+ die "System Error: $err";
+ } else {
+ print $writer "System Error: $err";
+ exit 1;
+ }
+ };
+
+ close($writer);
+ $reader->blocking(0);
+ my ($response) = $reader->getline;
+ warn $response if $response;
+
+ $dbh->{'InactiveDestroy'} = $oldv_dbh if $dbh;
+ $RT::Handle->{'DisconnectHandleOnDestroy'} = $oldv_rth if $RT::Handle;
+ return $want? (@res) : $res[0];
+}
+
+=head2 mime_recommended_filename( MIME::Head|MIME::Entity )
+
+# mimic our own recommended_filename
+# since MIME-tools 5.501, head->recommended_filename requires the head are
+# mime encoded, we don't meet this yet.
+
+=cut
+
+sub mime_recommended_filename {
+ my $head = shift;
+ $head = $head->head if $head->isa('MIME::Entity');
+
+ for my $attr_name (qw( content-disposition.filename content-type.name )) {
+ my $value = Encode::decode("UTF-8",$head->mime_attr($attr_name));
+ if ( defined $value && $value =~ /\S/ ) {
+ return $value;
+ }
+ }
+ return;
+}
+
+sub assert_bytes {
+ my $string = shift;
+ return unless utf8::is_utf8($string);
+ return unless $string =~ /([^\x00-\x7F])/;
+
+ my $msg;
+ if (ord($1) > 255) {
+ $msg = "Expecting a byte string, but was passed characters";
+ } else {
+ $msg = "Expecting a byte string, but was possibly passed charcters;"
+ ." if the string is actually bytes, please use utf8::downgrade";
+ }
+ $RT::Logger->warn($msg, Carp::longmess());
+
+}
+
+
+=head2 C<constant_time_eq($a, $b)>
+
+Compares two strings for equality in constant-time. Replacement for the C<eq>
+operator designed to avoid timing side-channel vulnerabilities. Returns zero
+or one.
+
+This is intended for use in cryptographic subsystems for comparing well-formed
+data such as hashes - not for direct use with user input or as a general
+replacement for the C<eq> operator.
+
+The two string arguments B<MUST> be of equal length. If the lengths differ,
+this function will call C<die()>, as proceeding with execution would create
+a timing vulnerability. Length is defined by characters, not bytes.
+
+Strings that should be treated as binary octets rather than Unicode text
+should pass a true value for the binary flag.
+
+This code has been tested to do what it claims. Do not change it without
+thorough statistical timing analysis to validate the changes.
+
+Added to resolve CVE-2017-5361
+
+For more on timing attacks, see this Wikipedia article:
+B<https://en.wikipedia.org/wiki/Timing_attack>
+
+=cut
+
+sub constant_time_eq {
+ my ($a, $b, $binary) = @_;
+
+ my $result = 0;
+
+ # generic error message avoids potential information leaks
+ my $generic_error = "Cannot compare values";
+ die $generic_error unless defined $a and defined $b;
+ die $generic_error unless length $a == length $b;
+ die $generic_error if ref($a) or ref($b);