* htmlscrubber security fix: Block javascript in uris.
[ikiwiki.git] / IkiWiki / Plugin / htmlscrubber.pm
index bc613f92477ef55ef384f8a1bbf2887670c0e7a7..25caa8a506cdf5ab8ea0c9b0d3e9e935f62bd6f8 100644 (file)
@@ -18,6 +18,28 @@ my $_scrubber;
 sub scrubber { #{{{
        return $_scrubber if defined $_scrubber;
        
+       # Only known uri schemes are allowed to avoid all the ways of
+       # embedding javascrpt.
+       # List at http://en.wikipedia.org/wiki/URI_scheme
+       my $uri_schemes=join("|",
+               # IANA registered schemes
+               "http", "https", "ftp", "mailto", "file", "telnet", "gopher",
+               "aaa", "aaas", "acap",  "cap", "cid", "crid", 
+               "dav", "dict", "dns", "fax", "go", "h323", "im", "imap",
+               "ldap", "mid", "news", "nfs", "nntp", "pop", "pres",
+               "sip", "sips", "snmp", "tel", "urn", "wais", "xmpp",
+               "z39.50r", "z39.50s",
+               # data is a special case. Allow data:text/<image>, but
+               # disallow data:text/javascript and everything else.
+               qr/data:text\/(?:png|gif|jpeg)/,
+               # Selected unofficial schemes
+               "about", "aim", "callto", "cvs", "ed2k", "feed", "fish", "gg",
+               "irc", "ircs", "lastfm", "ldaps", "magnet", "mms",
+               "msnim", "notes", "rsync", "secondlife", "skype", "ssh",
+               "sftp", "sms", "steam", "webcal", "ymsgr",
+       );
+       my $link=qr/^(?:$uri_schemes:|[^:]+$)/i;
+
        eval q{use HTML::Scrubber};
        error($@) if $@;
        # Lists based on http://feedparser.org/docs/html-sanitization.html
@@ -35,23 +57,27 @@ sub scrubber { #{{{
                }],
                default => [undef, { (
                        map { $_ => 1 } qw{
-                               abbr accept accept-charset accesskey action
+                               abbr accept accept-charset accesskey
                                align alt axis border cellpadding cellspacing
                                char charoff charset checked cite class
                                clear cols colspan color compact coords
                                datetime dir disabled enctype for frame
-                               headers height href hreflang hspace id ismap
+                               headers height hreflang hspace id ismap
                                label lang longdesc maxlength media method
                                multiple name nohref noshade nowrap prompt
                                readonly rel rev rows rowspan rules scope
-                               selected shape size span src start summary
+                               selected shape size span start summary
                                tabindex target title type usemap valign
                                value vspace width
-                               poster autoplay loopstart loopend end
+                               autoplay loopstart loopend end
                                playcount controls 
                        } ),
                        "/" => 1, # emit proper <hr /> XHTML
-                       }],
+                       href => $link,
+                       src => $link,
+                       action => $link,
+                       poster => $link,
+               }],
        );
        return $_scrubber;
 } # }}}