# vim: set tabstop=4 shiftwidth=4 expandtab syntax=perl: use MIME::Base64(); use Digest::SHA(); # # local_filter_cancel # sub local_filter_cancel { unless($hdr{Control} =~ m/^cancel\s+(<[^>]+>)/i) { return "Cancel with broken target ID"; } return verify_cancel(\%hdr, $1, 'Cancel'); } sub local_filter_after_emp { if (exists( $hdr{'Supersedes'} )) { #return verify_cancel(\%hdr, $hdr{'Supersedes'}, 'Supersedes'); # verify_cancel is called, but not returned, so the # posting is unconditionally accepted # verify_cancel calls INN:cancel() if verification suceeds verify_cancel(\%hdr, $hdr{'Supersedes'}, 'Supersedes'); } return undef; } sub verify_cancel($$$) { my $r_hdr = shift || die; my $target = shift; my $descr = shift; my $headers = INN::head($target) || return "$descr of non-existing ID $target"; my %headers; for my $line(split(/\s*\n/, $headers)) { if ($line =~ m/^([[:alnum:]-]+):\s+(.*)/) { $headers{$1} = $2; $lastkey = $1; } elsif ($line =~ m/^\s+(.*)/ and defined($lastkey)) { $headers{$lastkey} .= ' ' . $1; } } my $lock = $headers{'Cancel-Lock'}; if (defined($lock)) { my $key = $r_hdr->{'Cancel-Key'} || return "$descr of $target without Cancel-Key"; #return verify_cancel_key($key, $lock, ' target=' . $target); return verify_cancel_key($key, $lock, $target); } else { # -thh # no cancel-lock: go ahead and cancel anyway! INN::cancel($target); } return undef; } sub verify_cancel_key($$$) { my $cancel_key = shift; my $cancel_lock = shift; my $msg = shift; $msg = '' unless(defined($msg)); # -thh my $target = $msg; $msg = ' target=' . $msg; my %lock; for my $l(split(/\s+/, $cancel_lock)) { next unless($l =~ m/^(sha1|md5):(\S+)/); $lock{$2} = $1; } for my $k(split(/\s+/, $cancel_key)) { unless($k =~ m/^(sha1|md5):(\S+)/) { INN::syslog('notice', "Invalid Cancel-Key syntax '$k'.$msg"); next; } my $key; if ($1 eq 'sha1') { $key = Digest::SHA::sha1($2); } elsif ($1 eq 'md5') { $key = Digest::MD5::md5($2); } $key = MIME::Base64::encode_base64($key, ''); if (exists($lock{$key})) { # INN::syslog('notice', "Valid Cancel-Key $key found.$msg"); # -thh # article is canceled now INN::cancel($target) if ($target); return undef; } } INN::syslog('notice', "No Cancel-Key[$cancel_key] matches Cancel-Lock[$cancel_lock]$msg" ); return "No Cancel-Key matches Cancel-Lock.$msg"; } 1;