View file File name : Scrubber.pm Content :package HTML::Scrubber; # ABSTRACT: Perl extension for scrubbing/sanitizing HTML use 5.008; # enforce minimum perl version of 5.8 use strict; use warnings; use HTML::Parser 3.47 (); use HTML::Entities; use Scalar::Util ('weaken'); use List::Util 1.33 qw(any); our ( @_scrub, @_scrub_fh ); our $VERSION = '0.19'; # VERSION our $AUTHORITY = 'cpan:NIGELM'; # AUTHORITY # my my my my, these here to prevent foolishness like # http://perlmonks.org/index.pl?node_id=251127#Stealing+Lexicals (@_scrub) = ( \&_scrub, "self, event, tagname, attr, attrseq, text" ); (@_scrub_fh) = ( \&_scrub_fh, "self, event, tagname, attr, attrseq, text" ); sub new { my $package = shift; my $p = HTML::Parser->new( api_version => 3, default_h => \@_scrub, marked_sections => 0, strict_comment => 0, unbroken_text => 1, case_sensitive => 0, boolean_attribute_value => undef, empty_element_tags => 1, ); my $self = { _p => $p, _rules => { '*' => 0, }, _comment => 0, _process => 0, _r => "", _optimize => 1, _script => 0, _style => 0, }; $p->{"\0_s"} = bless $self, $package; weaken( $p->{"\0_s"} ); return $self unless @_; my (%args) = @_; for my $f (qw[ default allow deny rules process comment ]) { next unless exists $args{$f}; if ( ref $args{$f} ) { $self->$f( @{ $args{$f} } ); } else { $self->$f( $args{$f} ); } } return $self; } sub comment { return $_[0]->{_comment} if @_ == 1; $_[0]->{_comment} = $_[1]; return; } sub process { return $_[0]->{_process} if @_ == 1; $_[0]->{_process} = $_[1]; return; } sub script { return $_[0]->{_script} if @_ == 1; $_[0]->{_script} = $_[1]; return; } sub style { return $_[0]->{_style} if @_ == 1; $_[0]->{_style} = $_[1]; return; } sub allow { my $self = shift; for my $k (@_) { $self->{_rules}{ lc $k } = 1; } $self->{_optimize} = 1; # each time a rule changes, reoptimize when parse return; } sub deny { my $self = shift; for my $k (@_) { $self->{_rules}{ lc $k } = 0; } $self->{_optimize} = 1; # each time a rule changes, reoptimize when parse return; } sub rules { my $self = shift; my (%rules) = @_; for my $k ( keys %rules ) { $self->{_rules}{ lc $k } = $rules{$k}; } $self->{_optimize} = 1; # each time a rule changes, reoptimize when parse return; } sub default { return $_[0]->{_rules}{'*'} if @_ == 1; $_[0]->{_rules}{'*'} = $_[1] if defined $_[1]; $_[0]->{_rules}{'_'} = $_[2] if defined $_[2] and ref $_[2]; $_[0]->{_optimize} = 1; # each time a rule changes, reoptimize when parse return; } sub scrub_file { if ( @_ > 2 ) { return unless defined $_[0]->_out( $_[2] ); } else { $_[0]->{_p}->handler( default => @_scrub ); } $_[0]->_optimize(); #if $_[0]->{_optimize}; $_[0]->{_p}->parse_file( $_[1] ); return delete $_[0]->{_r} unless exists $_[0]->{_out}; print { $_[0]->{_out} } $_[0]->{_r} if length $_[0]->{_r}; delete $_[0]->{_out}; return 1; } sub scrub { if ( @_ > 2 ) { return unless defined $_[0]->_out( $_[2] ); } else { $_[0]->{_p}->handler( default => @_scrub ); } $_[0]->_optimize(); # if $_[0]->{_optimize}; $_[0]->{_p}->parse( $_[1] ) if defined( $_[1] ); $_[0]->{_p}->eof(); return delete $_[0]->{_r} unless exists $_[0]->{_out}; delete $_[0]->{_out}; return 1; } sub _out { my ( $self, $o ) = @_; unless ( ref $o and ref \$o ne 'GLOB' ) { open my $F, '>', $o or return; binmode $F; $self->{_out} = $F; } else { $self->{_out} = $o; } $self->{_p}->handler( default => @_scrub_fh ); return 1; } sub _validate { my ( $s, $t, $r, $a, $as ) = @_; return "<$t>" unless %$a; $r = $s->{_rules}->{$r}; my %f; for my $k ( keys %$a ) { my $check = exists $r->{$k} ? $r->{$k} : exists $r->{'*'} ? $r->{'*'} : next; if ( ref $check eq 'CODE' ) { my @v = $check->( $s, $t, $k, $a->{$k}, $a, \%f ); next unless @v; $f{$k} = shift @v; } elsif ( ref $check || length($check) > 1 ) { $f{$k} = $a->{$k} if $a->{$k} =~ m{$check}; } elsif ($check) { $f{$k} = $a->{$k}; } } if (%f) { my %seen; return "<$t $r>" if $r = join ' ', map { defined $f{$_} ? qq[$_="] . encode_entities( $f{$_} ) . q["] : $_; # boolean attribute (TODO?) } grep { exists $f{$_} and !$seen{$_}++; } @$as; } return "<$t>"; } sub _scrub_str { my ( $p, $e, $t, $a, $as, $text ) = @_; my $s = $p->{"\0_s"}; my $outstr = ''; if ( $e eq 'start' ) { if ( exists $s->{_rules}->{$t} ) # is there a specific rule { if ( ref $s->{_rules}->{$t} ) # is it complicated?(not simple;) { $outstr .= $s->_validate( $t, $t, $a, $as ); } elsif ( $s->{_rules}->{$t} ) # validate using default attribute rule { $outstr .= $s->_validate( $t, '_', $a, $as ); } } elsif ( $s->{_rules}->{'*'} ) # default allow tags { $outstr .= $s->_validate( $t, '_', $a, $as ); } } elsif ( $e eq 'end' ) { # empty tags list taken from # https://developer.mozilla.org/en/docs/Glossary/empty_element my @empty_tags = qw(area base br col embed hr img input link meta param source track wbr); return "" if $text ne '' && any { $t eq $_ } @empty_tags; # skip false closing empty tags my $place = 0; if ( exists $s->{_rules}->{$t} ) { $place = 1 if $s->{_rules}->{$t}; } elsif ( $s->{_rules}->{'*'} ) { $place = 1; } if ($place) { if ( length $text ) { $outstr .= "</$t>"; } else { substr $s->{_r}, -1, 0, ' /'; } } } elsif ( $e eq 'comment' ) { if ( $s->{_comment} ) { # only copy comments through if they are well formed... $outstr .= $text if ( $text =~ m|^<!--.*-->$|ms ); } } elsif ( $e eq 'process' ) { $outstr .= $text if $s->{_process}; } elsif ( $e eq 'text' or $e eq 'default' ) { $text =~ s/</</g; #https://rt.cpan.org/Public/Ticket/Attachment/83958/10332/scrubber.patch $text =~ s/>/>/g; $outstr .= $text; } elsif ( $e eq 'start_document' ) { $outstr = ""; } return $outstr; } sub _scrub_fh { my $self = $_[0]->{"\0_s"}; print { $self->{_out} } $self->{'_r'} if length $self->{_r}; $self->{'_r'} = _scrub_str(@_); } sub _scrub { $_[0]->{"\0_s"}->{_r} .= _scrub_str(@_); } sub _optimize { my ($self) = @_; my (@ignore_elements) = grep { not $self->{"_$_"} } qw(script style); $self->{_p}->ignore_elements(@ignore_elements); # if @ is empty, we reset ;) return unless $self->{_optimize}; #sub allow # return unless $self->{_optimize}; # till I figure it out (huh) if ( $self->{_rules}{'*'} ) { # default allow $self->{_p}->report_tags(); # so clear it } else { my (@reports) = grep { # report only tags we want $self->{_rules}{$_} } keys %{ $self->{_rules} }; $self->{_p}->report_tags( # default deny, so optimize @reports ) if @reports; } # sub deny # return unless $self->{_optimize}; # till I figure it out (huh) my (@ignores) = grep { not $self->{_rules}{$_} } grep { $_ ne '*' } keys %{ $self->{_rules} }; $self->{_p}->ignore_tags( # always ignore stuff we don't want @ignores ) if @ignores; $self->{_optimize} = 0; return; } 1; #print sprintf q[ '%-12s => %s,], "$_'", $h{$_} for sort keys %h;# perl! #perl -ne"chomp;print $_;print qq'\t\t# test ', ++$a if /ok\(/;print $/" test.pl >test2.pl #perl -ne"chomp;print $_;if( /ok\(/ ){s/\#test \d+$//;print qq'\t\t# test ', ++$a }print $/" test.pl >test2.pl #perl -ne"chomp;if(/ok\(/){s/# test .*$//;print$_,qq'\t\t# test ',++$a}else{print$_}print$/" test.pl >test2.pl __END__ =pod =encoding UTF-8 =head1 NAME HTML::Scrubber - Perl extension for scrubbing/sanitizing HTML =head1 VERSION version 0.19 =for stopwords html cpan callback homepage Perlbrew perltidy repository =head1 SYNOPSIS use HTML::Scrubber; my $scrubber = HTML::Scrubber->new( allow => [ qw[ p b i u hr br ] ] ); print $scrubber->scrub('<p><b>bold</b> <em>missing</em></p>'); # output is: <p><b>bold</b> </p> # more complex input my $html = q[ <style type="text/css"> BAD { background: #666; color: #666;} </style> <script language="javascript"> alert("Hello, I am EVIL!"); </script> <HR> a => <a href=1>link </a> br => <br> b => <B> bold </B> u => <U> UNDERLINE </U> ]; print $scrubber->scrub($html); $scrubber->deny( qw[ p b i u hr br ] ); print $scrubber->scrub($html); =head1 DESCRIPTION If you want to "scrub" or "sanitize" html input in a reliable and flexible fashion, then this module is for you. I wasn't satisfied with L<HTML::Sanitizer> because it is based on L<HTML::TreeBuilder>, so I thought I'd write something similar that works directly with L<HTML::Parser>. =head1 METHODS First a note on documentation: just study the L<EXAMPLE|"EXAMPLE"> below. It's all the documentation you could need. Also, be sure to read all the comments as well as L<How does it work?|"How does it work?">. If you're new to perl, good luck to you. =head2 new my $scrubber = HTML::Scrubber->new( allow => [ qw[ p b i u hr br ] ] ); Build a new L<HTML::Scrubber>. The arguments are the initial values for the following directives:- =over 4 =item * default =item * allow =item * deny =item * rules =item * process =item * comment =back =head2 comment warn "comments are ", $p->comment ? 'allowed' : 'not allowed'; $p->comment(0); # off by default =head2 process warn "process instructions are ", $p->process ? 'allowed' : 'not allowed'; $p->process(0); # off by default =head2 script warn "script tags (and everything in between) are supressed" if $p->script; # off by default $p->script( 0 || 1 ); B<**> Please note that this is implemented using L<HTML::Parser>'s C<ignore_elements> function, so if C<script> is set to true, all script tags encountered will be validated like all other tags. =head2 style warn "style tags (and everything in between) are supressed" if $p->style; # off by default $p->style( 0 || 1 ); B<**> Please note that this is implemented using L<HTML::Parser>'s C<ignore_elements> function, so if C<style> is set to true, all style tags encountered will be validated like all other tags. =head2 allow $p->allow(qw[ t a g s ]); =head2 deny $p->deny(qw[ t a g s ]); =head2 rules $p->rules( img => { src => qr{^(?!http://)}i, # only relative image links allowed alt => 1, # alt attribute allowed '*' => 0, # deny all other attributes }, a => { href => sub { ... }, # check or adjust with a callback }, b => 1, ... ); Updates a set of attribute rules. Each rule can be 1/0, a regular expression or a callback. Values longer than 1 char are treated as regexps. The callback is called with the following arguments: the current object, tag name, attribute name, and attribute value; the callback should return an empty list to drop the attribute, C<undef> to keep it without a value, or a new scalar value. =head2 default print "default is ", $p->default(); $p->default(1); # allow tags by default $p->default( undef, # don't change { # default attribute rules '*' => 1, # allow attributes by default } ); =head2 scrub_file $html = $scrubber->scrub_file('foo.html'); ## returns giant string die "Eeek $!" unless defined $html; ## opening foo.html may have failed $scrubber->scrub_file('foo.html', 'new.html') or die "Eeek $!"; $scrubber->scrub_file('foo.html', *STDOUT) or die "Eeek $!" if fileno STDOUT; =head2 scrub print $scrubber->scrub($html); ## returns giant string $scrubber->scrub($html, 'new.html') or die "Eeek $!"; $scrubber->scrub($html', *STDOUT) or die "Eeek $!" if fileno STDOUT; =for comment _out $scrubber->_out(*STDOUT) if fileno STDOUT; $scrubber->_out('foo.html') or die "eeek $!"; =for comment _validate Uses $self->{_rules} to do attribute validation. Takes tag, rule('_' || $tag), attrref. =for comment _scrub_str I<default> handler, used by both C<_scrub> and C<_scrub_fh>. Moved all the common code (basically all of it) into a single routine for ease of maintenance. =for comment _scrub_fh I<default> handler, does the scrubbing if we're scrubbing out to a file. Now calls C<_scrub_str> and pushes that out to a file. =for comment _scrub I<default> handler, does the scrubbing if we're returning a giant string. Now calls C<_scrub_str> and appends that to the output string. =head1 How does it work? When a tag is encountered, L<HTML::Scrubber> allows/denies the tag using the explicit rule if one exists. If no explicit rule exists, Scrubber applies the default rule. If an explicit rule exists, but it's a simple rule(1), then the default attribute rule is applied. =head2 EXAMPLE =for example begin #!/usr/bin/perl -w use HTML::Scrubber; use strict; my @allow = qw[ br hr b a ]; my @rules = ( script => 0, img => { src => qr{^(?!http://)}i, # only relative image links allowed alt => 1, # alt attribute allowed '*' => 0, # deny all other attributes }, ); my @default = ( 0 => # default rule, deny all tags { '*' => 1, # default rule, allow all attributes 'href' => qr{^(?:http|https|ftp)://}i, 'src' => qr{^(?:http|https|ftp)://}i, # If your perl doesn't have qr # just use a string with length greater than 1 'cite' => '(?i-xsm:^(?:http|https|ftp):)', 'language' => 0, 'name' => 1, # could be sneaky, but hey ;) 'onblur' => 0, 'onchange' => 0, 'onclick' => 0, 'ondblclick' => 0, 'onerror' => 0, 'onfocus' => 0, 'onkeydown' => 0, 'onkeypress' => 0, 'onkeyup' => 0, 'onload' => 0, 'onmousedown' => 0, 'onmousemove' => 0, 'onmouseout' => 0, 'onmouseover' => 0, 'onmouseup' => 0, 'onreset' => 0, 'onselect' => 0, 'onsubmit' => 0, 'onunload' => 0, 'src' => 0, 'type' => 0, } ); my $scrubber = HTML::Scrubber->new(); $scrubber->allow(@allow); $scrubber->rules(@rules); # key/value pairs $scrubber->default(@default); $scrubber->comment(1); # 1 allow, 0 deny ## preferred way to create the same object $scrubber = HTML::Scrubber->new( allow => \@allow, rules => \@rules, default => \@default, comment => 1, process => 0, ); require Data::Dumper, die Data::Dumper::Dumper($scrubber) if @ARGV; my $it = q[ <?php echo(" EVIL EVIL EVIL "); ?> <!-- asdf --> <hr> <I FAKE="attribute" > IN ITALICS WITH FAKE="attribute" </I><br> <B> IN BOLD </B><br> <A NAME="evil"> <A HREF="javascript:alert('die die die');">HREF=JAVA <!></A> <br> <A HREF="image/bigone.jpg" ONMOUSEOVER="alert('die die die');"> <IMG SRC="image/smallone.jpg" ALT="ONMOUSEOVER JAVASCRIPT"> </A> </A> <br> ]; print "#original text", $/, $it, $/; print "#scrubbed text (default ", $scrubber->default(), # no arguments returns the current value " comment ", $scrubber->comment(), " process ", $scrubber->process(), " )", $/, $scrubber->scrub($it), $/; $scrubber->default(1); # allow all tags by default $scrubber->comment(0); # deny comments print "#scrubbed text (default ", $scrubber->default(), " comment ", $scrubber->comment(), " process ", $scrubber->process(), " )", $/, $scrubber->scrub($it), $/; $scrubber->process(1); # allow process instructions (dangerous) $default[0] = 1; # allow all tags by default $default[1]->{'*'} = 0; # deny all attributes by default $scrubber->default(@default); # set the default again print "#scrubbed text (default ", $scrubber->default(), " comment ", $scrubber->comment(), " process ", $scrubber->process(), " )", $/, $scrubber->scrub($it), $/; =for example end =head2 FUN If you have L<Test::Inline> (and you've installed L<HTML::Scrubber>), try pod2test Scrubber.pm >scrubber.t perl scrubber.t =head1 SEE ALSO L<HTML::Parser>, L<Test::Inline>. The L<HTML::Sanitizer> module is no longer available on CPAN. =head1 VERSION REQUIREMENTS As of version 0.14 I have added a perl minimum version requirement of 5.8. This is basically due to failures on the smokers perl 5.6 installations - which appears to be down to installation mechanisms and requirements. Since I don't want to spend the time supporting a version that is so old (and may not work for reasons on UTF support etc), I have added a C<use 5.008;> to the main module. If this is problematic I am very willing to accept patches to fix this up, although I do not personally see a good reason to support a release that has been obsolete for 13 years. =head1 CONTRIBUTING If you want to contribute to the development of this module, the code is on L<GitHub|http://github.com/nigelm/html-scrubber>. You'll need a perl environment with L<Dist::Zilla>, and if you're just getting started, there's some documentation on using Vagrant and Perlbrew L<here|http://mrcaron.github.io/2015/03/06/Perl-CPAN-Pull-Request.html>. There is now a C<.perltidyrc> and a C<.tidyallrc> file within the repository for the standard perltidy settings used - I will apply these before new releases. Please do not let formatting prevent you from sending in patches etc - this can be sorted out as part of the release process. Info on C<tidyall> can be found at L<https://metacpan.org/pod/distribution/Code-TidyAll/bin/tidyall>. =head1 AUTHORS =over 4 =item * Ruslan Zakirov <Ruslan.Zakirov@gmail.com> =item * Nigel Metheringham <nigelm@cpan.org> =item * D. H. <podmaster@cpan.org> =back =head1 COPYRIGHT AND LICENSE This software is copyright (c) 2018 by Ruslan Zakirov, Nigel Metheringham, 2003-2004 D. H. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. =for :stopwords cpan testmatrix url annocpan anno bugtracker rt cpants kwalitee diff irc mailto metadata placeholders metacpan =head1 SUPPORT =head2 Perldoc You can find documentation for this module with the perldoc command. perldoc HTML::Scrubber =head2 Websites The following websites have more information about this module, and may be of help to you. As always, in addition to those websites please use your favorite search engine to discover more resources. =over 4 =item * MetaCPAN A modern, open-source CPAN search engine, useful to view POD in HTML format. L<https://metacpan.org/release/HTML-Scrubber> =item * Search CPAN The default CPAN search engine, useful to view POD in HTML format. L<http://search.cpan.org/dist/HTML-Scrubber> =item * RT: CPAN's Bug Tracker The RT ( Request Tracker ) website is the default bug/issue tracking system for CPAN. L<https://rt.cpan.org/Public/Dist/Display.html?Name=HTML-Scrubber> =item * AnnoCPAN The AnnoCPAN is a website that allows community annotations of Perl module documentation. L<http://annocpan.org/dist/HTML-Scrubber> =item * CPAN Ratings The CPAN Ratings is a website that allows community ratings and reviews of Perl modules. L<http://cpanratings.perl.org/d/HTML-Scrubber> =item * CPANTS The CPANTS is a website that analyzes the Kwalitee ( code metrics ) of a distribution. L<http://cpants.cpanauthors.org/dist/HTML-Scrubber> =item * CPAN Testers The CPAN Testers is a network of smoke testers who run automated tests on uploaded CPAN distributions. L<http://www.cpantesters.org/distro/H/HTML-Scrubber> =item * CPAN Testers Matrix The CPAN Testers Matrix is a website that provides a visual overview of the test results for a distribution on various Perls/platforms. L<http://matrix.cpantesters.org/?dist=HTML-Scrubber> =item * CPAN Testers Dependencies The CPAN Testers Dependencies is a website that shows a chart of the test results of all dependencies for a distribution. L<http://deps.cpantesters.org/?module=HTML::Scrubber> =back =head2 Bugs / Feature Requests Please report any bugs or feature requests by email to C<bug-html-scrubber at rt.cpan.org>, or through the web interface at L<https://rt.cpan.org/Public/Bug/Report.html?Queue=HTML-Scrubber>. You will be automatically notified of any progress on the request by the system. =head2 Source Code The code is open to the world, and available for you to hack on. Please feel free to browse it and play with it, or whatever. If you want to contribute patches, please send me a diff or prod me to pull from your repository :) L<https://github.com/nigelm/html-scrubber> git clone https://github.com/nigelm/html-scrubber.git =head1 CONTRIBUTORS =for stopwords Andrei Vereha Lee Johnson Michael Caron Nigel Metheringham Paul Cochrane Ruslan Zakirov Sergey Romanov vagrant =over 4 =item * Andrei Vereha <avereha@gmail.com> =item * Lee Johnson <lee@givengain.ch> =item * Michael Caron <michael.r.caron@gmail.com> =item * Michael Caron <mrcaron@users.noreply.github.com> =item * Nigel Metheringham <nm9762github@muesli.org.uk> =item * Paul Cochrane <paul@liekut.de> =item * Ruslan Zakirov <ruz@bestpractical.com> =item * Sergey Romanov <complefor@rambler.ru> =item * vagrant <vagrant@precise64.(none)> =back =cut