Because the search plugin needed it, also because it's one of the few
plugins that didn't already have it.
I also considered adding it to htmlize, but I really cannot imagine caring
what the destpage is when htmlizing. (I'll probably be poven wrong later.)
Something has changed in CGI.pm in perl 5.10. It used to not care
if STDIN was opened using :utf8, but now it'll mis-encode utf-8 values
when used that way by ikiwiki. Now I have to binmode(STDIN) before
instantiating the CGI object.
In 57bba4dac1, I changed from decoding
CGI::Formbuilder fields to utf-8, to decoding cgi parameters before setting
up the form object. As of perl 5.10, that approach no longer has any effect
(reason unknown). To get correctly encoded values in FormBuilder forms,
they must once again be decoded after the form is set up.
As noted in 57bba4da, this can cause one set of problems for
formbuilder_setup hooks if decode_form_utf8 is called before the hooks, and
a different set if it's called after. To avoid both sets of problems, call
it both before and after. (Only remaining problem is the sheer ugliness and
inefficiency of that..)
I think that these changes will also work with older perl versions, but I
haven't checked.
Also, in the case of the poll plugin, the cgi parameter needs to be
explcitly decoded before it is used to handle utf-8 values. (This may have
always been broken, not sure if it's related to perl 5.10 or not.)
Turns out duplicate index files do not need to be stored when usedirs is in
use, just when it's not. Ikiwiki is quite consistent about using page/ when
usedirs is in use. (The only exception is the search plugin, which needs
fixing.)
This also includes significant code cleanup, removal of a incorrect special
case for empty files, and addition of a workaround for a bug in the amazon
perl module.
The fix involved embedding the session id in the forms, and not allowing the
forms to be submitted if the embedded id does not match the session id.
In the case of the preferences form, if the session id is not embedded,
then the CGI parameters are cleared. This avoids a secondary attack where the
link to the preferences form prefills password or other fields, and
the user hits "submit" without noticing these prefilled values.
In the case of the editpage form, the anonok plugin can allow anyone to edit,
and so I chose not to guard against CSRF attacks against users who are not
logged in. Otherwise, it also embeds the session id and checks it.
For page editing, I assume that the user will notice if content or commit
message is changed because of CGI parameters, and won't blndly hit save page.
So I didn't block those CGI paramters. (It's even possible to use those CGI
parameters, for good, not for evil, I guess..)
The only other CSRF attack I can think of in ikiwiki involves the poll plugin.
It's certianly possible to set up a link that causes the user to unknowingly
vote in a poll. However, the poll plugin is not intended to be used for things
that people would want to attack, since anyone can after all edit the poll page
and fill in any values they like. So this "attack" is ignorable.
Joey Hess
Thomas Schwinge