X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/899c319191c8f82b03f7d67f3feeeae437423e2f..26dbe8ba9a397d5d59af789c7ef3576ebdcf2db8:/doc/todo/require_CAPTCHA_to_edit.mdwn?ds=inline

diff --git a/doc/todo/require_CAPTCHA_to_edit.mdwn b/doc/todo/require_CAPTCHA_to_edit.mdwn
index 0e32afc65..83ba07eb0 100644
--- a/doc/todo/require_CAPTCHA_to_edit.mdwn
+++ b/doc/todo/require_CAPTCHA_to_edit.mdwn
@@ -2,6 +2,8 @@ I don't necessarily trust all OpenID providers to stop bots.  I note that ikiwik
 
 I imagine a plugin that modifies the login screen to use <http://recaptcha.net/>.  You would then be required to fill in the captcha as well as log in in the normal way.
 
+-- [[users/Will]]
+
 > I hate CAPTCHAs with a passion. Someone else is welcome to write such a
 > plugin.
 >
@@ -14,6 +16,28 @@ I imagine a plugin that modifies the login screen to use <http://recaptcha.net/>
 >> Something like the moinmoin global <http://master.moinmo.in/BadContent>
 >> list?
 
+>>> OpenID can be thought of as pushing the problem of determining if
+>>> someone is a human or a spambot back from the openid consumer to the
+>>> openid provider. So, providers that make it possible for spambots to
+>>> use their openids, or that are even set up explicitly for use in
+>>> spamming, would be the ones to block. Or, providers that are known to
+>>> use very good screening for humans would be the ones to allow.
+>>> (Openid delegation makes it a bit harder than just looking at the
+>>> openid url though.) --[[Joey]]
+
+>>>> Well, OpenID only addresses authentication issues, not authorisation issues.
+>>>> Given that it is trivial to set up your own OpenID provider (a full provider, not
+>>>> just a forward to another provider), I can't see a
+>>>> blacklist working in the long term (it would be like blacklisting email).
+>>>> A whitelist might work (it would not be quite as bad as whitelisting email).  In any case,
+>>>> there is now a captcha plugin for those that want it.  It is accessible
+>>>> (there is an audio option) and serves a social purpose along with
+>>>> keeping bots out (the captcha is used to help digitise hard to read
+>>>> words in books for [Carnegie Mellon University](http://www.cs.cmu.edu/) and
+>>>> [The Internet Archive](http://www.archive.org/) ).  Finally, because the actual captcha is outsourced
+>>>> it means that someone else is taking care of keeping it ahead of
+>>>> the bot authors.
+
 Okie - I have a first pass of this.  There are still some issues.
 
 Currently the code verifies the CAPTCHA.  If you get it right then you're fine.
@@ -30,7 +54,79 @@ A second issue is that the OpenID login system resets the 'required' flags
 of all the other fields, so using OpenID will cause the CAPTCHA to be
 ignored.
 
-> This is still a todo.
+> This is still not fixed.  I would have thought the following patch would
+> have fixed this second issue, but it doesn't.
+
+(code snipped as a working [[patch]] is below)
+
+>> What seems to be happing here is that the openid plugin defines a
+>> validate hook for openid_url that calls validate(). validate() in turn
+>> redirects the user to the openid server for validation, and exits. If
+>> the openid plugins' validate hook is called before your recaptcha
+>> validator, your code never gets a chance to run. I don't know how to
+>> control the other that FormBuilder validates fields, but the only fix I
+>> can see is to somehow influence that order. 
+>>
+>> Hmm, maybe you need to move your own validation code out of the validate
+>> hook. Instead, just validate the captcha in the formbuilder_setup hook.
+>> The problem with this approach is that if validation fails, you can't
+>> just flag it as invalid and let formbuilder handle that. Instead, you'd
+>> have to hack something in to redisplay the captcha by hand. --[[Joey]]
+
+>>> Fixed this.  I just modified the OpenID plugin to check if the captcha
+>>> succeeded or failed.  Seeing as the OpenID plugin is the one that is
+>>> abusing the normal validate method, I figured it was best to keep
+>>> the fix in the same place.  I also added a config switch so you can set if
+>>> the captcha is needed for OpenID logins. OpenID defaults to ignoring
+>>> the captcha.
+>>> Patch is inline below.
+>>> I think this whole thing is working now.
+
+>>>> Ok, glad it's working. Not thrilled that it needs to modify the
+>>>> openid plugin, especially as I'm not sure if i I will integrate the
+>>>> captcha plugin into mainline. Also because it's not very clean to have
+>>>> the oprnid plugin aware of another plugin like that. I'd like to
+>>>> prusue my idea of not doing the captcha validation in the validate
+>>>> hook.
+
+--- a/IkiWiki/Plugin/openid.pm
++++ b/IkiWiki/Plugin/openid.pm
+@@ -18,6 +18,7 @@ sub getopt () {
+ 	error($@) if $@;
+ 	Getopt::Long::Configure('pass_through');
+ 	GetOptions("openidsignup=s" => \$config{openidsignup});
++	GetOptions("openidneedscaptcha=s" => \$config{openidneedscaptcha});
+ }
+ 
+ sub formbuilder_setup (@) {
+@@ -61,6 +62,7 @@ sub formbuilder_setup (@) {
+ 			# Skip all other required fields in this case.
+ 			foreach my $field ($form->field) {
+ 				next if $field eq "openid_url";
++				next if $config{openidneedscaptcha} && $field eq "recaptcha";
+ 				$form->field(name => $field, required => 0,
+ 					validate => '/.*/');
+ 			}
+@@ -96,6 +98,18 @@ sub validate ($$$;$) {
+ 		}
+ 	}
+ 
++	if ($config{openidneedscaptcha} && defined $form->field("recaptcha")) {
++		foreach my $field ($form->field) {
++			next unless ($field eq "recaptcha");
++			if (! $field->validate) {
++				# if they didn't get the captcha right,
++				# then just claim we validated ok so the
++				# captcha can cause a fail
++				return 1;
++			}
++		}
++	}
++
+ 	my $check_url = $claimed_identity->check_url(
+ 		return_to => IkiWiki::cgiurl(do => "postsignin"),
+ 		trust_root => $config{cgiurl},
+
 
 Instructions
 =====
@@ -56,19 +152,19 @@ use warnings;
 use strict;
 use IkiWiki 2.00;
 
-sub import { #{{{
+sub import {
 	hook(type => "formbuilder_setup", id => "recaptcha", call => \&formbuilder_setup);
-} # }}}
+}
 
-sub getopt () { #{{{
+sub getopt () {
 	eval q{use Getopt::Long};
 	error($@) if $@;
 	Getopt::Long::Configure('pass_through');
 	GetOptions("reCaptchaPubKey=s" => \$config{reCaptchaPubKey});
 	GetOptions("reCaptchaPrivKey=s" => \$config{reCaptchaPrivKey});
-} #}}}
+}
 
-sub formbuilder_setup (@) { #{{{
+sub formbuilder_setup (@) {
 	my %params=@_;
 
 	my $form=$params{form};
@@ -178,7 +274,7 @@ EOTAGS
 				});
 		}
 	}
-} # }}}
+}
 
 # The following function is borrowed from
 # Captcha::reCAPTCHA by Andy Armstrong and are under the PERL Artistic License
@@ -229,4 +325,3 @@ sub check_answer {
 }
 
 1;
-