From: Joey Hess <joey@kodama.kitenet.net>
Date: Sun, 10 Feb 2008 18:22:25 +0000 (-0500)
Subject: cherry-pick uri security fix
X-Git-Tag: 2.31.1~1
X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/commitdiff_plain/df512e55dfbbb912cdf4aee5db48622301bb29ac?hp=-c

cherry-pick uri security fix
---

df512e55dfbbb912cdf4aee5db48622301bb29ac
diff --git a/IkiWiki/Plugin/htmlscrubber.pm b/IkiWiki/Plugin/htmlscrubber.pm
index bc613f924..25caa8a50 100644
--- a/IkiWiki/Plugin/htmlscrubber.pm
+++ b/IkiWiki/Plugin/htmlscrubber.pm
@@ -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;
 } # }}}
diff --git a/debian/changelog b/debian/changelog
index b21cdb441..8683bbc1f 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,10 @@
+ikiwiki (2.31.1) unstable; urgency=low
+
+  * htmlscrubber security fix: Block javascript in uris.
+  * Add htmlscrubber test suite.
+
+ -- Joey Hess <joeyh@debian.org>  Sun, 10 Feb 2008 13:21:35 -0500
+
 ikiwiki (2.31) unstable; urgency=low
 
   [ Joey Hess ]
diff --git a/doc/plugins/htmlscrubber.mdwn b/doc/plugins/htmlscrubber.mdwn
index 6ce297a86..d7bcf8099 100644
--- a/doc/plugins/htmlscrubber.mdwn
+++ b/doc/plugins/htmlscrubber.mdwn
@@ -36,3 +36,4 @@ plugin is active:
 * <span style="background: url(javascript:window.location='http://example.org/')">CSS script test</span>
 * <span style="&#x61;&#x6e;&#x79;&#x3a;&#x20;&#x65;&#x78;&#x70;&#x72;&#x65;&#x73;&#x73;&#x69;&#x6f;&#x6e;&#x28;&#x77;&#x69;&#x6e;&#x64;&#x6f;&#x77;&#x2e;&#x6c;&#x6f;&#x63;&#x61;&#x74;&#x69;&#x6f;&#x6e;&#x3d;&#x27;&#x68;&#x74;&#x74;&#x70;&#x3a;&#x2f;&#x2f;&#x65;&#x78;&#x61;&#x6d;&#x70;&#x6c;&#x65;&#x2e;&#x6f;&#x72;&#x67;&#x2f;&#x27;&#x29;">entity-encoded CSS script test</span>
 * <span style="&#97;&#110;&#121;&#58;&#32;&#101;&#120;&#112;&#114;&#101;&#115;&#115;&#105;&#111;&#110;&#40;&#119;&#105;&#110;&#100;&#111;&#119;&#46;&#108;&#111;&#99;&#97;&#116;&#105;&#111;&#110;&#61;&#39;&#104;&#116;&#116;&#112;&#58;&#47;&#47;&#101;&#120;&#97;&#109;&#112;&#108;&#101;&#46;&#111;&#114;&#103;&#47;&#39;&#41;">entity-encoded CSS script test</span>
+* <a href="javascript&#x3A;alert('foo')">click me</a>
diff --git a/t/htmlize.t b/t/htmlize.t
index a9ccfedcb..edf357010 100755
--- a/t/htmlize.t
+++ b/t/htmlize.t
@@ -1,7 +1,7 @@
 #!/usr/bin/perl
 use warnings;
 use strict;
-use Test::More tests => 4;
+use Test::More tests => 26;
 use Encode;
 
 BEGIN { use_ok("IkiWiki"); }
@@ -19,3 +19,52 @@ is(IkiWiki::htmlize("foo", "mdwn", readfile("t/test1.mdwn")),
 	"utf8; bug #373203");
 ok(IkiWiki::htmlize("foo", "mdwn", readfile("t/test2.mdwn")),
 	"this file crashes markdown if it's fed in as decoded utf-8");
+
+sub gotcha {
+	my $html=IkiWiki::htmlize("foo", "mdwn", shift);
+	return $html =~ /GOTCHA/;
+}
+ok(!gotcha(q{<a href="javascript:alert('GOTCHA')">click me</a>}),
+	"javascript url");
+ok(!gotcha(q{<a href="javascript&#x3A;alert('GOTCHA')">click me</a>}),
+	"partially encoded javascript url");
+ok(!gotcha(q{<a href="jscript:alert('GOTCHA')">click me</a>}),
+	"jscript url");
+ok(!gotcha(q{<a href="vbscript:alert('GOTCHA')">click me</a>}),
+	"vbscrpt url");
+ok(!gotcha(q{<a href="java	script:alert('GOTCHA')">click me</a>}),
+	"java-tab-script url");
+ok(!gotcha(q{<span style="&#x61;&#x6e;&#x79;&#x3a;&#x20;&#x65;&#x78;&#x70;&#x72;&#x65;&#x73;&#x73;&#x69;&#x6f;(GOTCHA)&#x6e;&#x28;&#x77;&#x69;&#x6e;&#x64;&#x6f;&#x77;&#x2e;&#x6c;&#x6f;&#x63;&#x61;&#x74;&#x69;&#x6f;&#x6e;&#x3d;&#x27;&#x68;&#x74;&#x74;&#x70;&#x3a;&#x2f;&#x2f;&#x65;&#x78;&#x61;&#x6d;&#x70;&#x6c;&#x65;&#x2e;&#x6f;&#x72;&#x67;&#x2f;&#x27;&#x29;">foo</span>}),
+	"entity-encoded CSS script test");
+ok(!gotcha(q{<span style="&#97;&#110;&#121;&#58;&#32;&#101;&#120;&#112;&#114;&#101;&#115;&#115;&#105;&#111;&#110;(GOTCHA)&#40;&#119;&#105;&#110;&#100;&#111;&#119;&#46;&#108;&#111;&#99;&#97;&#116;&#105;&#111;&#110;&#61;&#39;&#104;&#116;&#116;&#112;&#58;&#47;&#47;&#101;&#120;&#97;&#109;&#112;&#108;&#101;&#46;&#111;&#114;&#103;&#47;&#39;&#41;">foo</span>}),
+	"another entity-encoded CSS script test");
+ok(!gotcha(q{<script>GOTCHA</script>}),
+	"script tag");
+ok(!gotcha(q{<form action="javascript:alert('GOTCHA')">foo</form>}),
+	"form action with javascript");
+ok(!gotcha(q{<video poster="javascript:alert('GOTCHA')" href="foo.avi">foo</video>}),
+	"video poster with javascript");
+ok(!gotcha(q{<span style="background: url(javascript:window.location=GOTCHA)">a</span>}),
+	"CSS script test");
+ok(! gotcha(q{<img src="data:text/javascript:GOTCHA">}),
+	"data:text/javascript (jeez!)");
+ok(gotcha(q{<img src="data:text/png:GOTCHA">}), "data:text/png");
+ok(gotcha(q{<img src="data:text/gif:GOTCHA">}), "data:text/gif");
+ok(gotcha(q{<img src="data:text/jpeg:GOTCHA">}), "data:text/jpeg");
+ok(gotcha(q{<p>javascript:alert('GOTCHA')</p>}),
+	"not javascript AFAIK (but perhaps some web browser would like to
+	be perverse and assume it is?)");
+ok(gotcha(q{<img src="javascript.png?GOTCHA">}), "not javascript");
+ok(gotcha(q{<a href="javascript.png?GOTCHA">foo</a>}), "not javascript");
+is(IkiWiki::htmlize("foo", "mdwn",
+	q{<img alt="foo" src="foo.gif">}),
+	q{<img alt="foo" src="foo.gif">}, "img with alt tag allowed");
+is(IkiWiki::htmlize("foo", "mdwn",
+	q{<a href="http://google.com/">}),
+	q{<a href="http://google.com/">}, "absolute url allowed");
+is(IkiWiki::htmlize("foo", "mdwn",
+	q{<a href="foo.html">}),
+	q{<a href="foo.html">}, "relative url allowed");
+is(IkiWiki::htmlize("foo", "mdwn",
+	q{<span class="foo">bar</span>}),
+	q{<span class="foo">bar</span>}, "class attribute allowed");