This mega-patch rips out the FixNesting implementation and the related
ChildDef components. The primary algorithmic change is to convert from
use of tokens to tree nodes, which are far more amenable to the style
of processing that FixNesting uses. Additionally, FixNesting has been
changed to go bottom-up rather than top-down, in order to avoid needing
to implement backtracking.
This patch simplifies a good deal of the relevant logic, since we no
longer need to continually recalculate the nesting structure when
processing things. However, the conversion to the alternate format
incurs some overhead, so for small inputs these changes are not a win.
One possibility to greatly reduce the constant factors here is to switch
to entirely using libxml's representation, and never serializing tokens;
this would require one to rewrite injectors, however.
The iterative post-order traversal in FixNesting is a bit subtle, but
we have essentially reified the stack and continuations.
We've removed support for %Core.EscapeInvalidChildren.
Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
The purpose of this addition is twofold. In trusted mode, iframes are
now unconditionally allowed.
However, many online video providers (YouTube, Vimeo) and other web
applications (Google Maps, Google Calendar, etc) provide embed code in
iframe format, which is useful functionality in untrusted mode.
You can specify iframes as trusted elements with %HTML.SafeIframe;
however, you need to additionally specify a whitelist mechanism such as
%URI.SafeIframeRegexp to say what iframe embeds are OK (by default
everything is rejected).
Note: As iframes are invalid in strict doctypes, you will not be able to
use them there.
We also added an always_load parameter to URIFilters in order to support
the strange nature of the SafeIframe URIFilter (it always needs to be
loaded, due to the inability of accessing the %HTML.SafeIframe directive
to see if it's needed!) We expect this URIFilter can expand in the future
to offer more complex validation mechanisms.
Signed-off-by: Bradley M. Froehle <brad.froehle@gmail.com>
Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
Basically, browsers don't parse what should be valid URIs correctly, so
we have to go through some backbends to accomodate them. Specifically,
for browseable URIs, the following URIs have unintended behavior:
- ///example.com
- http:/example.com
- http:///example.com
Furthermore, if the path begins with //, modifying these URLs must
be done with care, as if you remove the host-name component, the
parse tree changes.
I've modified the engine to follow correct URI semantics as much
as possible while outputting browser compatible code, and invalidate
the URI in cases where we can't deal. There has been a refactoring
of URIScheme so that this important check is always performed,
introducing a new member variable allow_empty_host which is true
on data, file, mailto and news schemes.
This also fixes bypass bugs on URI.Munge.
Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
There are some deep DOMs you can hit the maximum nesting level
limit in tokenizeDOM (we've experienced this even with maximum nesting
level of 300). Here is an iterative version of the same function with
simple queue/dequeue approach.
Signed-off-by: Maxim Krizhanovsky <darhazer@gmail.com>
The first bug is that we will repeatedly write out the result
of a customized raw definition to the filesystem, even when a cache
entry already exists.
The second bug is that caching these definitions doesn't actually
work (the cache entry is written but never used.) A new API
for retrieving raw definitions permits the user to take advantage
of caching.
Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
HTML Purifier loads itself as the first autoload function by
unregistering all existing functions and re-registering them after
registering itself.
Originally an exception was thrown when a non-static object method was
encountered as the behaviour of spl_autoload_functions() did not return
the object instance, but only the class name. This was filed on PHP
bugs (#44144).
The bug was fixed for PHP >= 5.2.11 and >= 5.3
Signed-off-by: Nick Pope <nick@nickpope.me.uk>
Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
The new logic is as follows:
* Given a URL to insert into url(), check that it is properly URL
encoded (in particular, a doublequote and backslash never occurs
within it) and then place it as url("http://example.com").
* Given a font name, if it is strictly alphanumeric, it is safe to omit
quotes. Otherwise, wrap in double quotes and replace '"' with '\22 '
(note trailing space) and '\' with '\5C ' (ditto).
We introduce expandCSSEscape() which is a hack for common parsing
idioms in CSS; this means that CSS escapes are now recognized inside
URLs as well as unquoted font names.
Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
