The %HTML.Forms directive enables Forms module regardless of the %HTML.Trusted
value. This adds support for form elements without enabling other unsafe
modules, such as Scripts, Iframe or Object.
To achieve the same effect without this directive one has to explicitly list
all enabled modules in %HTML.AllowedModules, and any not listed will be
removed. This however is not very convenient, as the allowed modules may vary
between doctypes.
Resolves#213.
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>
When viewing potentially hostile html, it may be helpful to see what
a given link was pointing to. This new injector takes the href
attribute and adds the text after the link, and deletes the href
attribute.
Other forms of display could easily be contrived, but this seems to be
a good basic way to present the information.
Signed-off-by: David Morton <mortonda@dgrmm.net>
Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>
By default, the DirectLex and DOMLex behavior with stray angled brackets
varied a great deal due to their implementations. A little known directive
%Core.AggressivelyFixLt attempted to match DOMLex's behavior with DirectLex's,
but it was off by default. By turning it on by default, users now enjoy these
benefits, and performance-minded users can turn it back off.
Also, several refinements to stray angled bracket parsing was made. Specifically:
* DirectLex: Handle each left angled bracket individually, which prevents
strange behavior as reported by eon.
* DOMLex: Iterate aggressive lt fix, so that stacked brackets like << are
handled.
Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>
Injector rewind: Injectors can now use the method rewind() in order to move
the input index backwards, so that they can reprocess tokens (other injectors
are not affected by a rewind). This functionality was necessary to implement
nested node removals in %AutoFormat.RemoveEmpty.
End to start ref: To facilitate rewinding, HTMLPurifier_Token_End now
maintains a reference called $start to the starting token for their node.
%AutoFormat.RemoveEmpty removes empty nodes. Lots of people have requested
it, so here is a partially effective implementation. Because it is implemented
as an Injector, it's not possible for it to handle newly introduced empty
nodes by later validators, specifically auto-closing and child validation.
The Injector is only meant to be used on HTML-ish languages.
Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>
