IkiWiki/Plugin/htmlscrubber.pm

   1 #!/usr/bin/perl
   2 package IkiWiki::Plugin::htmlscrubber;
   3
   4 use warnings;
   5 use strict;
   6 use IkiWiki 3.00;
   7
   8 # This regexp matches urls that are in a known safe scheme.
   9 # Feel free to use it from other plugins.
  10 our $safe_url_regexp;
  11
  12 sub import {
  13         hook(type => "getsetup", id => "htmlscrubber", call => \&getsetup);
  14         hook(type => "sanitize", id => "htmlscrubber", call => \&sanitize);
  15
  16         # Only known uri schemes are allowed to avoid all the ways of
  17         # embedding javascrpt.
  18         # List at http://en.wikipedia.org/wiki/URI_scheme
  19         my $uri_schemes=join("|", map quotemeta,
  20                 # IANA registered schemes
  21                 "http", "https", "ftp", "mailto", "file", "telnet", "gopher",
  22                 "aaa", "aaas", "acap",  "cap", "cid", "crid",
  23                 "dav", "dict", "dns", "fax", "go", "h323", "im", "imap",
  24                 "ldap", "mid", "news", "nfs", "nntp", "pop", "pres",
  25                 "sip", "sips", "snmp", "tel", "urn", "wais", "xmpp",
  26                 "z39.50r", "z39.50s",
  27                 # Selected unofficial schemes
  28                 "aim", "callto", "cvs", "ed2k", "feed", "fish", "gg",
  29                 "irc", "ircs", "lastfm", "ldaps", "magnet", "mms",
  30                 "msnim", "notes", "rsync", "secondlife", "skype", "ssh",
  31                 "sftp", "smb", "sms", "snews", "webcal", "ymsgr",
  32         );
  33         # data is a special case. Allow data:image/*, but
  34         # disallow data:text/javascript and everything else.
  35         $safe_url_regexp=qr/^(?:(?:$uri_schemes):|data:image\/|[^:]+(?:$|\/))/i;
  36 }
  37
  38 sub getsetup () {
  39         return
  40                 plugin => {
  41                         safe => 1,
  42                         rebuild => undef,
  43                         section => "core",
  44                 },
  45                 htmlscrubber_skip => {
  46                         type => "pagespec",
  47                         example => "!*/Discussion",
  48                         description => "PageSpec specifying pages not to scrub",
  49                         link => "ikiwiki/PageSpec",
  50                         safe => 1,
  51                         rebuild => undef,
  52                 },
  53 }
  54
  55 sub sanitize (@) {
  56         my %params=@_;
  57
  58         if (exists $config{htmlscrubber_skip} &&
  59             length $config{htmlscrubber_skip} &&
  60             exists $params{destpage} &&
  61             pagespec_match($params{destpage}, $config{htmlscrubber_skip})) {
  62                 return $params{content};
  63         }
  64
  65         return scrubber()->scrub($params{content});
  66 }
  67
  68 my $_scrubber;
  69 sub scrubber {
  70         return $_scrubber if defined $_scrubber;
  71
  72         eval q{use HTML::Scrubber};
  73         error($@) if $@;
  74         # Lists based on http://feedparser.org/docs/html-sanitization.html
  75         # With html 5 video and audio tags added.
  76         $_scrubber = HTML::Scrubber->new(
  77                 allow => [qw{
  78                         a abbr acronym address area b big blockquote br br/
  79                         button caption center cite code col colgroup dd del
  80                         dfn dir div dl dt em fieldset font form h1 h2 h3 h4
  81                         h5 h6 hr hr/ i img input ins kbd label legend li map
  82                         menu ol optgroup option p p/ pre q s samp select small
  83                         span strike strong sub sup table tbody td textarea
  84                         tfoot th thead tr tt u ul var
  85                         video audio
  86                 }],
  87                 default => [undef, { (
  88                         map { $_ => 1 } qw{
  89                                 abbr accept accept-charset accesskey
  90                                 align alt axis border cellpadding cellspacing
  91                                 char charoff charset checked class
  92                                 clear cols colspan color compact coords
  93                                 datetime dir disabled enctype for frame
  94                                 headers height hreflang hspace id ismap
  95                                 label lang maxlength media method
  96                                 multiple name nohref noshade nowrap prompt
  97                                 readonly rel rev rows rowspan rules scope
  98                                 selected shape size span start summary
  99                                 tabindex target title type valign
 100                                 value vspace width
 101                                 autoplay loopstart loopend end
 102                                 playcount controls
 103                         } ),
 104                         "/" => 1, # emit proper <hr /> XHTML
 105                         href => $safe_url_regexp,
 106                         src => $safe_url_regexp,
 107                         action => $safe_url_regexp,
 108                         cite => $safe_url_regexp,
 109                         longdesc => $safe_url_regexp,
 110                         poster => $safe_url_regexp,
 111                         usemap => $safe_url_regexp,
 112                 }],
 113         );
 114         return $_scrubber;
 115 }
 116
 117 1