5 CGI::Auth::Flexible - web authentication optionally using cookies
9 my $verifier = CGI::Auth::Flexible->new_verifier(setting => value,...);
10 my $authreq = $verifier->new_request($cgi);
13 $authreq->check_ok() or return;
15 # sophisticated applications
16 my $divert_kind = $authreq->check_divert();
17 if ($divert_kind) { ... print diversion page and quit ... }
19 # while handling the request
20 $user = $authreq->get_username();
21 $authreq->check_mutate();
25 CGI::Auth::Flexible is a library which you can use to add a
26 forms/cookie-based login facility to a Perl web application.
28 CGI::Auth::Flexible doesn't interfere with your application's URL path
29 namespace and just needs a few (configurable) form parameter and
30 cookie name(s) for its own use. It tries to avoid making assumptions
31 about the implementation structure of your application.
33 Because CGI::Auth::Flexible is licenced under the AGPLv3, you will
34 probably need to provide a facility to allow users (even ones not
35 logged in) to download the source code for your web app. Conveniently
36 by default CGI::Auth::Flexible provides (for pure Perl webapps) a
37 mechanism for users to get the source.
39 CGI::Auth::Flexible is designed to try to stop you accidentally
40 granting access by misunderstanding the API. (Also it, of course,
41 guards against cross-site scripting.) You do need to make sure to
42 call CGI::Auth::Flexible before answering AJAX requests as well as
43 before generating HTML pages, of course, and to call it in every
44 entrypoint to your system.
48 As a minimum you need to do all of the things on this checklist, where
49 applicable. The items marked SECURITY are the ones that you might
50 forget: without them your application may appear to work, but will be
57 Call C<new_verifier> (once at application startup)
61 Call C<new_request> (once per request)
65 B<SECURITY>: Call C<check_ok> or C<check_divert> on every request, and
66 honour the return value.
70 If you're using C<check_ok>, implement either the
71 C<username_password_error> or C<login_ok> hook and provide it as
72 a setting to C<new_verifier>.
76 Provide the setting C<dir> (or provide absolute paths for all the
77 other relevant settings).
81 Call C<get_username> when you need to know who's logged in.
85 B<SECURITY>: Call C<check_mutate> or C<mutate_ok>, if you specified
86 C<promise_check_mutate>.
90 B<SECURITY>: Call C<check_nonpage> for every request which is not a page load
91 (if your application has any of those).
95 When generating URLs and forms (including AJAX requests), include the
96 hidden form parameter using C<secret_hidden_val> or
97 C<secret_hidden_html> when appropriate (see below).
101 B<SECURITY>: If you do not override the source provision facility (see
102 L</SOURCE CODE DOWNLOAD>), check that the assumptions it makes aren't
103 going to leak security-critical data.
107 Set up HTTPS on your webserver, or set the C<encrypted_only> setting
112 These points will now be covered in more detail.
114 =head2 INITIALISATION
116 Your application should, on startup (eg, when it is loaded by
118 C<< $verifier = CGI::Auth::Flexible->new_verifier(settings...) >>.
119 This call can be expensive and is best amortised.
121 The resulting verifier object can be used to process individual
122 requests, in each case with
123 C<< $authreq = CGI::Auth::Flexible->new_request($cgi) >>.
127 =head2 CHECKING AND RESPONSE GENERATION
129 If the user is logged in, your application is to handle the request.
130 Otherwise, the user needs to be presented with a login form or error
131 message, as appropriate. CGI::Auth::Flexible provides two alternative
134 =head3 Simple applications
136 The simplist usage is to call C<< $request->check_ok() >> which will
137 check the user's authentication. If the user is not logged in it will
138 generate a login form (or redirection or other appropriate page) and
139 return false; your application should not then processing that request
140 any further. If the user is logged in it will return true.
142 Various hooks are provided to customise the responses generated by
145 After C<check_ok> returns true you should go ahead and process the
146 request; you can use C<< $request->get_username >> to find out which
147 user the request came from.
149 =head2 Sophisticated applications
151 If you want to handle the control flow and to generate login forms,
152 redirections, etc., yourself, you can say
153 C<< $divert = $request->check_divert >>. This returns undef if
154 the user is logged in, or I<divert spec> if some kind of login
155 page or diversion should be generated. See L</DIVERT SPEC> below for
156 details of how to deal with the return value.
158 =head2 MUTATING OPERATIONS AND EXTERNAL LINKS
160 =head3 Mutation-ignorant applications
162 By default CGI::Auth::Flexible does not permit external links into
163 your site. All GET requests give a "click to continue" page which
164 submits a form which loads your app's main page. In this
165 configuration all your application's forms and AJAX requests should
166 use C<POST>. This restriction arises from complicated deficiencies
167 in the web's security architecture.
169 Such applications are also not able to provide user-specific CSS
170 stylesheets, javascript, favicons, etc.
172 =head3 Mutation-aware applications
174 The alternative is for your application to always make a special check
175 when the incoming request is going to do some kind of action (such as
176 modifying the user's setup, purchasing goods, or whatever) rather than
177 just retrieve and/or display information. We term such requests
180 Then non-mutating pages can be linked to from other, untrustworthy,
183 To support external links, and C<GET> requests, pass
184 C<< promise_check_mutate => 1 >> in I<settings>, and then call
185 C<< $authreq->check_mutate() >> before taking any actions. If the
186 incoming request is not suitable then C<< $authreq->check_mutate() >>
189 There have to be no mutating C<GET> requests in your application (but
190 you shouldn't have any of those anyway); if there are, they won't
191 work. (CGI::Auth::Flexible will spot them and cause them to fail,
192 rather than allow them to be insecure.)
194 =head2 GENERATING URLS, FORMS AND AJAX QUERIES
196 When you generate a URL, C<POST> form or AJAX request you may need to
197 include a secret hidden form parameter for the benefit of
198 CGI::Auth::Generic. This form parameter will be checked by
199 C<check_ok>/C<check_divert> and should be ignored by your application.
201 By default the hidden parameter is called C<caf_assochash>.
203 After calling C<check_ok> or C<check_divert> the value to put in your
204 form can be obtained from C<secret_hidden_val>; C<secret_hidden_html>
205 will generate the whole HTML C<< <input...> >> element.
207 =head3 Mutation-ignorant applications
209 For mutation-ignorant applications (see above), all forms etc. should
210 include the hidden parameter (and as discussed, they must all use
211 POST rather than GET).
213 =head3 Mutation-aware applications
215 For mutation-aware applications, whether to include the secret
216 parameter depends on the kind of request. CGI::Auth::Flexible knows
217 when it is necessary. You should find out by calling
220 If it is inconvenient to call C<need_add_hidden> at runtime, you can
221 rely instead on the following promises: All POST requests (which
222 includes all mutating requests) need the parameter. The return value
223 of need_add_hidden depends only on the $method and $reqtype
224 parameters, so you can query it once and remember the answer.
225 HTML page load GETs do not need the parameter. It is better to
226 err on the side of including the parameter.
228 If you really must, you can call C<need_add_hidden> "on the bench"
229 during development and bake the answer into your application code
230 structure. However, if you do that and a new vulnerability was
231 discovered which is fixed by changing the answer, updating
232 CGI::Auth::Flexible wouldn't be sufficient to fix it.
234 =head3 Mutation-aware applications - non-page requests
236 If your mutation-aware application supports non-page resources (AJAX
237 and JSON requests, stylesheets, favicons, etc.) it must inform
238 CGI::Auth::Flexible when it is handling such a request, by calling
241 Normally C<check_nonpage> will simply return (and you can ignore the
242 return value). However, if there is an attack (or, perhaps, a bug) it
243 will die, stopping the attack.
245 (You do not need to call C<check_nonpage> for POST requests, but it is
248 =head3 Mutation-aware applications - novel kinds of request
250 If you want to support a kind of request perhaps not yet known about
251 by CGI::Auth::Flexible, you can provide information about that new
252 request kind using C<update_get_need_add_hidden>.
256 CGI::Auth::Flexible needs to store various information in plain files;
257 it does this in the directory specified by the C<dir> parameter.
259 =head1 SOURCE CODE DOWNLOAD
261 By default, CGI::Auth::Flexible provides a facility for users to
262 download the source code for the running version of your web
265 This facility makes a number of important assumptions which you need
266 to check. Note that if the provided facility is not sufficient
267 because your application is more sophisticated than it copes with (or
268 if you disable the builtin facility), you may need to implement a
269 functioning alternative to avoid violating the AGPLv3 licence.
271 Here are the most important (default) assumptions:
277 Your app's source code is available by looking at @INC, $0 and
278 S<$ENV{'SCRIPT_FILENAME'}> (the B<source items>). See
279 C<srcdump_listitems>. Where these point to files or directories under
280 revision control, the source item is the whole containing vcs tree.
284 Specifically, there are no compiled or autogenerated Perl
285 files, Javascript resources, etc., which are not contained in one of
286 the source item directories. (Files which came with your operating
287 system install don't need to be shipped as they fall under the system
292 You have not installed any modified versions of system
293 libraries (including system-supplied Perl modules) in C</usr> outside
294 C</usr/local>. See C<srcdump_system_dir>.
298 For each source item in a dvcs, the entire dvcs history does
299 not contain anything confidential (or libellous). Also, all files which
300 contain secrets are in the dvcs's I<.ignore> file. See
301 C<srcdump_vcsscript_git> et al.
305 For each source item NOT in a dvcs, there are no confidential
306 files with the world-readable bit set (being in a world-inaccessible
307 directory is not sufficient). See C<srcdump_excludes>.
311 You have none of your app's source code in C</etc>.
315 You don't regard pathnames on your server as secret.
319 You don't intentionally load Perl code by virtue of C<.>
320 being in C<@INC> by default. (See C<srcdump_filter_cwd>.)
324 =head1 MAIN FUNCTIONS AND METHODS
328 =item C<< CGI::Auth::Flexible->new_verifier(setting => value, ...) >>
330 Initialises an instance and returns a verifier object.
331 The arguments are setting pairs like a hash initialiser.
332 See L</SETTINGS> below.
334 =item C<< $verifier->new_request($cgi) >>
336 Prepares to process a request. I<$cgi> should normally
337 be the query object from L<CGI(3perl)>. Most of the default
338 hook methods assume that it is; however if you replace enough of
339 the hook methods then you can pass any value you like and it
340 will be passed to your hooks.
342 The return value is the authentication request object (I<$authreq>)
343 which is used to check the incoming request and will contain
344 information about its credentials.
346 =item C<< $authreq->check_divert() >>
348 Checks whether the user is logged in. Returns undef if the user is
349 logged in and we should service the request. Otherwise returns a
350 divert spec (see L</DIVERT SPEC>) saying what should happen instead.
352 This method may die if it doesn't like the request, in which case
353 the request needs to be rejected.
355 =item C<< $authreq->check_ok() >>
357 Checks whether the user is logged in. Returns true if the user is
358 logged in and we should service the request.
360 Otherwise it handles the request itself, generating any appropriate
361 redirect, login form, or continuation page. It then returns false and
362 the application should not process the request further.
364 =item C<< $verifier->disconnect() >>
366 Discards the resources (open files, etc.) in the verifier object.
370 =head1 REQUEST-RELATED FUNCTIONS AND METHODS
372 All of these are only valid after C<check_divert> or C<check_ok> has
373 been called. (In the case of C<check_ok> it won't normally be sensible
374 to call these functions unless C<check_ok> returned true.)
376 =item C<< $authreq->get_divert() >>
378 Returns the value previously returned by C<check_divert>.
380 =item C<< $authreq->get_username() >>
382 Returns the name of the logged-in user. If the user was not logged
383 in (or their session had timed out, or something), returns undef.
385 =item C<< $authreq->check_mutate() >>
387 Declares to CGI::Auth::Generic that the request being handled will
388 "mutate". That is, it will modify some server-side state (eg, adding
389 items to shopping baskets, posting messages to blogs, sending emails,
392 If you have set the setting C<promise_check_mutate> you must call
393 C<check_mutate> whenever appropriate. If you haven't then it's
394 irrelevant. See L<MUTATING OPERATIONS AND EXTERNAL LINKS>.
396 C<check_mutate> will either return successfully, indicating that all
397 is well and the request should proceed, or it will die. If it dies
398 that means that the request was improper, which can only result from a
399 bug or an attack. So an "internal server error" is a suitable
402 =item C<< $authreq->check_nonpage($method, $reqtype) >>
404 Declares to CGI::Auth::Generic that the request is not a page request,
405 but rather a request of type I<$reqtype>.
407 If your application has set the setting C<promise_check_mutate>,
408 whenever it is handling anything except an HTML page loads, it must
409 call this function. See L</REQUEST TYPES>, and
410 L<GENERATING URLS, FORMS AND AJAX QUERIES>.
412 C<check_nonpage> will either return successfully, indicating that all
413 is well and the request should proceed, or it will die, like
416 =head1 RESPONSE-RELATED FUNCTIONS AND METHODS
418 =item C<< $authreq->url_with_query_params($params, [$nonpagetype]) >>
420 Convenience function which returns a url for a GET request to this
423 I<$params> is a hashref specifying the parameters and the PATH_INFO.
424 The keys are the parameter names, and the values are array refs with
425 the parameter value(s) (as strings, as yet unquoted). (They are array
426 refs because it is possible to pass multiple values for the same
427 parameter in a single request; normally each arrayref would be a
430 The request path will be the path to the application. If a parameter
431 with name C<< '' >> is supplied, it is taken as the PATH_INFO - its
432 value will be appended to the application path. (It should normally
433 start with C<< / >>, and only one value should be supplied.)
435 =item C<< something->need_add_hidden($method, $reqtype) >>
437 Enquires whether a request of type I<$reqtype> using HTTP method
438 I<$method> needs the hidden form parameter. See L</REQUEST TYPES>.
440 =item C<< something->secret_hidden_val() >>
442 Returns the value of the hidden form parameter. This should be
443 included in all POST requests to your application (and thus be a
444 hidden form parameter in all forms).
446 It should also be in some (maybe all) GET requests. If your
447 application is mutation-ignorant, it should be in all GET requests.
448 If you are mutation-aware, you need to consult C<need_add_hidden>.
450 The name of the hidden parameter is the setting C<assoc_param_name>,
451 C<caf_hassochash> by default. xxx rename param and setting
453 =item C<< something->secret_hidden_html() >>
455 Returns the HTML for an C<INPUT> element specifying the hidden form
458 =item C<< something->secret_cookie_val() >>
460 Returns the value of the secret cookie. CGI::Auth::Flexible sets this
461 cookie in the forms generated by C<check_ok>. You may also set it
462 yourself (and indeed you must do so if you use C<check_divert>).
466 =head1 OTHER FUNCTIONS AND METHODS
470 =item C<< $verifier_or_authreq->hash($data) >>
472 Hashes the supplied data using the hash function specified by the
473 C<hash_algorithm> setting, and converts the result to a string of hex
476 =item C<< something->update_get_need_add_hidden($reqtype, $value, [$force]) >>
478 Updates CGI::Auth::Generic's knowledge about the various kinds of
479 request, and whether they need the hidden form parameter. This
480 function applies only to GET requests - POST requests always use the
483 I<$reqtype> is the request type (the value which will be passed to
484 C<check_nonpage> and C<need_add_hidden>. If you are supporting a new
485 I<$reqtype> you shouuld coordinate with CGI::Auth::Flexible upstrea,
486 or other users, to assign a unique request type name.
488 This method may be called on an authreq or a verifier, in which case
489 it will affect all authreqs using the same verifier. Or it may be
490 called on the class as a whole, in which case it will affect the
491 global default list for all verifiers.
493 If I<$force> is supplied and true, this will override
494 CGI::Auth::Flexible's existing knowledge. Otherwise this new setting
495 will be ignored if CGI::Auth::Flexible already knows about the request
496 type. (When called on a verifier or authreq, it will ignore the
497 update in favour of existing knowledge recorded both globally in the
498 class or due to previous requests on the same verifier.)
500 See L</REQUEST TYPES>.
502 =item C<< CGI::Auth::Flexible::srcdump_dir_cpio($cgi,$verifier,$dumpdir,$dir,$outfn,$how,$script) >>
504 Helper function for implementing the C<srcdump_process_item> hook.
505 Generates a tarball using cpio and includes it in the prepared source
508 The arguments are mostly the same as for that hook. C<$dir> is the
509 root directory at which to start the archive. C<$how> is a short text
510 string which will be mentioned in the log.
512 C<$script> is a shell script fragment which must output a
513 nul-separated list of filenames (e.g. the output of C<find -print0>).
514 It is textually surrounded by C<( )> and will be executed with C<set -e>
515 in force. Its cwd will be C<$dir>.
517 =item C<< $verifier_or_authreq->($data) | CGI::Auth::Flexible-> >>
519 Hashes the supplied data using the hash function specified by the
520 C<hash_algorithm> setting, and converts the result to a string of hex
527 The C<$reqtype> values understood by C<check_nonpage> are strings.
534 A top-level HTML page load. May contain confidential information for
535 the benefit of the logged-in user.
539 An HTML frame. May contain confidential information for
540 the benefit of the logged-in user.
544 An HTML iframe. May contain confidential information for
545 the benefit of the logged-in user.
549 Source dump request, whether for the licence or actual source code
550 tarball; returned value is not secret.
554 CSS stylesheet. B<MUST NOT> contain any confidential data. If the
555 stylesheet depends on the user, then attackers may be able to
556 determine what stylesheet the user is using. Hopefully this is not a
561 "Favicon" - icon for display in the browser's url bar etc. We aren't
562 currently aware of a way that attackers can get a copy of this.
566 C<robots.txt>. Should not contain any confidential data (obviously).
570 Inline image, for an C<< <img src=...> >> element.
572 Unfortunately it is not possible to sensibly show top-level
573 confidential images (that is, have the user's browser directly visit a
574 url which resolves to an image rather than an HTML page with an inline
575 image). This is because images need to have a per-session hidden form
576 parameter to avoid cross-site scripting, which breaks bookmarks etc.
580 JavaScript for a C<< <script> >> element. (Possibly confidential for
585 C<< XMLHttpRequest >> returning XML data. (Possibly
586 confidential for the user.)
590 C<< XMLHttpRequest >> returning JSON data. (Possibly
591 confidential for the user.)
595 C<< XMLHttpRequest >> returning data of some other kind. (Possibly
596 confidential for the user.)
602 C<new_verifier> and C<new_request> each take a list of settings, as
603 a list of pairs C<< key => value >> (like a Perl hash assignment).
605 The settings supplied to C<new_verifier> are stored in the verifier
606 and will apply to all authreqs made from it unless overridden in the
607 call to C<new_request>
609 When a setting is described as a hook function, it should be a
610 coderef. The first argument will be the query object from
611 L<CGI(3perl)> (strictly, it will be whatever value was passed to
612 C<new_request>). The second argument will be the authreq object (the
613 return value from C<new_request>).
614 Ie, C<< sub some_hook ($$...) { my ($cgi,$authreq,@stuff) = @_ ... >>
616 In bullet point headings, the hook functions are shown in the form
617 C<< some_hook($cgi,$authreq,@stuff) >> even though this would not be
618 legal syntax. This should be read to mean that the
619 %implicit_settings_hash{'some_hook'}($cgi,$authreq,@stuff)
620 would be a legal call. (However, the settings hash is not exposed.)
622 When a hook's default implementation is mentioned and named, that
623 function won't also be described in the section on the module's
628 =head2 GENERAL SETTINGS
632 The directory CGI::Auth::Generic should use for its data storage.
633 This is actually just a default absolute path used when the other
634 path settings are relative values.
636 Must be an absolute filename.
640 CGI::Auth::Flexible needs a database for recording users' login
641 session. This database needs to be shared across all instances of the
642 web application, so in a multi-node cluster it needs to be your actual
645 CGI::Auth::Flexible will create the table and index it needs if they
646 don't already exist, and will manage their contents. You do not need
647 to integrate them into the rest of your webapp's data storage. (In
648 particular, there is no need for transactional integrity across
649 changes made by CAF and your own application.)
651 By default, CAF uses a sqlite3 database stored on local disk in the
652 file named by C<assocdb_path>. This will be suitable for all
653 applications which run on a single host.
655 This value, if supplied, should be a DBI handle for the database.
659 This is the DSN to pass to C<< DBI->connect >>. Used only if
660 C<assocdb_dbh> is not supplied.
662 =item C<assocdb_path>
664 Path to the sqlite3 database used for CAF's session storage. The
665 default is currently C<caf-assocs.db> but will change in the future.
667 Used only if neither C<assocdb_dbh> or C<assocdb_dsn> are supplied.
669 If this is a relative path, it is in C<dir>.
671 =item C<assocdb_table>
673 Prefix for the SQL tables and indices to use (and to create, if
676 See L</DATABASE TABLES>.
680 Path to the keys file used by CAF. This arrangement will change in
681 the future. See L</BUGS>.
683 =item C<random_source>
685 Special file to read random numbers from. Should return
686 cryptographically secure (pseudo)-random bytes, unpredictable to
687 adversaries (even ones on the same machine).
689 On Linux, there is no device which is properly suitable. This is a
690 bug in Linux. You can use C</dev/random> which can block
691 unnecessarily even though the kernel PRNG has been properly seeded and
692 is fine, or C</dev/urandom> which might return values which attackers
693 can predict if the kernel PRNG has not been properly seeded.
695 The default is C</dev/urandom>.
699 Length of the assoc secret. Defaults to 128.
701 =item C<hash_algorithm>
703 Must be a string suitable for use with C<new Digest>.
704 Defaults to C<SHA-256>.
706 =item C<login_timeout>
708 A user will be logged out this many seconds after they first logged
709 in. Default: 86400 (one day).
711 =item C<login_form_timeout>
713 A login form becomes invalid this many seconds after it has been sent.
714 Default: 3600 seconds (one hour).
716 =item C<key_rollover>
718 The key used for generating assoc secrets is rolled over approximately
719 this often (in seconds). Default: 86400.
721 =item C<assoc_param_name>
723 Name of the hidden form parameter. Default: C<caf_assochash>.
727 Name of the cookie used for login sessions. Default:
730 =item C<password_param_name>
732 Name of the password field in the login form. Default: C<password>.
734 Used by C<login_ok_password> (the default C<login_ok> hook),
735 C<gen_plain_login_form> and the default C<is_login> hook.
737 =item C<username_param_names>
739 Arrayref of name(s) of username form parameters.
741 The first entry is used by C<login_ok_password> (the default
742 C<login_ok> hook) to pass to the C<username_password_error> hook and
743 used as the username if all is well.
745 All the entries are used by C<gen_plain_login_fork> (the default
746 C<gen_login_form> hook for C<check_ok>) to generate form entry fields.
748 The default is C<['username']>.
750 =item C<logout_param_names>
752 Arrayref of name(s) of form parameters indicating that the request is
755 Used by the default C<is_logout> hook.
757 If you want users to be able to explicitly log out, you need to
758 provide a logout button, something like
759 C<< <input type="submit" name="caf_logout" ...>>
761 The default is C<['caf_logout']>
763 =item C<logged_param_names>
765 Arrayref of name(s) of form parameters indicating that user has just
766 logged out. (During the logout process, the actual logout action is a
767 POST request, whose response redirects to the "you have been logged
768 out" page; these form parameters are for this second page.)
770 Used by the default C<is_loggedout> hook.
772 The first entry is used by C<check_ok> to generate the redirection.
774 The default is C<['caf_loggedout']>
776 =item C<promise_check_mutate>
778 Boolean. If true, is a declaration by the application that it is
779 mutatin-aware. See L</MUTATING OPERATIONS AND EXTERNAL LINKS>.
783 =item C<encrypted_only>
785 Boolean. If true, CAF will insist that all transactions be done over
786 an encrypted http connection. It will redirect unencrypted requests
787 to the https instance of the applicattion, and will set the encrypted
788 only flag on its cookie.
794 =item C<< get_url($cgi,$authreq) >>
796 Hook which returns the URL of this web application. By default, we
797 call C<< $cgi->url() >> for each request, but you can fix this if you
800 =item C<< is_login,is_logout,is_loggedout($cgi,$authreq) >>
802 Hook which returns a boolean indicating whether the request was,
803 respectively: a login form submission (ie, username and password); a
804 logout request (submission resulting from the user pressing the
805 "logout" button); "logged out" page (redirection from the logout
808 The default is to check whether any of the corresponding request
809 parameters (C<< login_param_names >> etc.) was supplied, using the
814 =head2 SETTINGS (HOOKS) RELATED TO THE CGI REQUEST OBJECT
818 =item C<< get_param($cgi,$authreq,$param) >>
820 Returns the value of a single-valued form parameter.
821 The default is to call C<< $cgi->param($param) >>.
822 The semantics are the same as that of C<CGI::param>.
824 =item C<< get_params($cgi,$authreq) >>
826 Returns a hash of the parameters. The return value is a hashref whose
827 keys are the parameter names and whose values are arrayrefs, one entry
828 in the arrayref for each value.
830 The default is to call C<< $cgi->Vars() >>, expect the
831 results to look like those from C<CGI::Vars>, and massage them into
832 the required form with split.
834 =item C<< get_path_info($cgi,$authreq) >>
836 Returns the PATH_INFO of the request. The default is to
837 call C<< $cgi->path_info() >>.
839 =item C<< get_cookie($cgi,$authreq) >>
841 Returns the value of the CAF cookie sent with the request, or undef if
842 none was supplied. The default is to call C<<
843 $cgi->cookie($cookie_name) >> (where C<$cookie_name> is from the
844 setting of the same name). The return value should be the scalar
847 =item C<< get_method($cgi,$authreq) >>
849 Returns the HTTP method as a string. The default is to call
850 C<< $cgi->request_method() >>.
854 =item C<< is_https($cgi,$authreq) >>
856 Returns a boolean indicating whether the request was over an encrypted
857 channel. The default is C<< !!$cgi->https() >>. See C<encrypted_only>.
861 =head2 SETTINGS RELATED TO HTML GENERATION
863 These are only used if you call C<check_ok> (or other functions
864 mentioned in this section).
866 Settings whose names are of the form C<gen_...> are hooks which each
867 return an array of strings, normally HTML strings, for use by
868 C<check_ok> (or, in turn, other hooks, or your application). These
869 are often documented simply by showing the output produced. In many
870 cases parts of the output are in turn obtained from other hooks. In
871 some cases the default implementations have been given names for
872 convenient use by your application. They will be called in array
875 We'll write C<gettext(something)> even though actually there is a hook
876 to control the translation function used.
880 =item C<handle_divert>($cgi,$authreq,$divert))
882 C<check_ok> calls this hook before producing output of its own. If
883 you want to handle some but not all diversions yourself, you may set
884 this hook. The hook should either do nothing and return false, or
885 return true if it has handled the request (or arrange for the request
886 to be handled). If the hook returns true then C<check_ok> simply
889 =item C<gen_login_form>($cgi,$authreq,$divert))
891 Default: a table (used mostly for layout) containing input fields for
892 a login form. Must be within a C<< <form> >> element, but doesn't
893 generate it. Has text fields for every entry in
894 C<username_param_names> (in each case associated with a description
895 C<< gettext(ucfirst $parameter_name) >>, a password field (with
896 description C<gettext("Password")>, and a login submit button (with
897 description C<gettext("Login")>.
899 Default is available as the module function C<gen_plain_login_form>.
901 =item C<gen_login_link>($cgi,$authreq))
905 <a href="http:...">gettext(Log in again to continue.)</a>
907 Default is available as the module function C<gen_plain_login_link>.
909 =item C<gen_postmainpage_form>($cgi,$authreq,$params))
911 Default: form contents (but not the C<< <form> >> element):
913 C<$params> (in the form returned by the C<get_params> hook) as hidden
916 <input type="submit" ... value=getext('Continue')>
918 Default is available as the module function C<gen_postmainpage_form>.
920 =item C<gen_start_html>($cgi,$authreq,$title)
922 Default: C<$cgi->start_html($title)>
924 =item C<gen_end_html>($cgi,$authreq,$title)
926 Default: C<$cgi->end_html($title)>
928 =item C<gen_footer_html>($cgi,$authreq)>
933 Powered by Free / Libre / Open Source Software
934 according to the [gen_licence_link_html].
935 [gen_source_link_html].
938 Default is available as the module function C<gen_plain_footer_html>.
940 =item C<gen_licence_link_html>($cgi,$authreq)>
942 Default: uses C<url_with_query_params> to generate a URL for
943 downloading the licence, and returns:
944 <a href="...">GNU Affero GPL</a>
946 Default is available as the module function C<gen_plain_licence_link_html>.
948 =item C<gen_source_link_html>($cgi,$authreq)>
950 Default: uses C<url_with_query_params> to generate a URL for
951 downloading the source, and returns:
952 <a href="...">Source available</a>
954 Default is available as the module function C<gen_plain_source_link_html>.
956 =item C<form_entry_size>
958 Size of generated text entry fields. Default is 60.
960 =item C<dummy_param_name_prefix>
962 Some of CAF's HTML-generating functions need to invent form parameter
963 names. They will all start with this string. Default: C<caf__>.
965 =head2 SETTINGS FOR SOURCE CODE DOWNLOAD FACILITY
969 =item C<srcdump_param_name>
971 Form parameter name used to indicate that this is a source download
972 request. If this parameter is supplied, C<check_ok> and
973 C<check_divert> will arrange for the applicaton source code to be
974 delivered as the response (in C<check_ok>'s case by doing it itself
975 and in C<check_divert>'s case by asking your application to do so.
977 Default is C<caf_srcdump>.
979 =item C<srcdump_path>
981 Path to the directory used for storing pre-prepared source downloads.
982 Defaults to C<caf-srcdump>.
984 If this is a relative path, it is in C<dir>.
986 =item C<srcdump_dump($cgi,$authreq,$srcobj)>
988 Dump the source code (C<$srcobj='source'> or licence data
989 (C<$srcobj='licence'>). The default implementation checks that
990 C<$srcobj> has reasonable syntax and uses the files C<$srcobj.data>
991 and C<$srcobj.ctype> with the C<dump> hook.
993 =item C<dump($cgi,$authreq,$contenttype,$datafilehandle)>
995 Responds to the request by sending the contents of $datafilehandle
996 (which should just have been opened) and specifying a content type of
999 The default implmentation uses the C<print> hook, and also calls
1000 C<$cgi->header('-type' => $contenttype>, and is available as the
1001 module function C<dump_plain>.
1003 =item C<srcdump_prepare($cgi,$verifier)>
1005 Prepares the source code for download when requested. Invoked by
1006 C<new_verifier>, always, immediately before it returns the
1007 just-created verifier object.
1009 The default implementation is the module function
1010 C<srcdump_dirscan_prepare>, which prepares a manifest, licence file
1011 and source code tarball of tarballs, as follows:
1013 It processes each entry in the return value from C<srcdump_listitems>.
1014 These are the software's include directories and any other directories
1015 containing source code. It handles C<.> specially (see
1016 C<srcdump_filter_cwd>).
1018 For each entry it looks, relative to that, for the licence as a file
1019 with a name mentioned in C<srcdump_licence_files>. The first such
1020 file found is considered to be the licence. It then calls the hook
1021 C<srcdump_process_item> for the entry.
1023 The licence, a manifest file, and all the outputs generated by the
1024 calls to C<srcdump_process_item>, are tarred up and compressed as a
1025 single source tarball.
1027 It uses the directory named by C<srcdump_path> as its directory for
1028 working and output files. It uses the filename patterns
1029 C<generate.*>, C<licence.*>, C<s.[a-z][a-z][a-z].*>, C<manifest.*>,
1030 C<source.*> in that directory.
1032 =item C<srcdump_process_item>($cgi,$verifier,$dumpdir,$item,\&outfn,\$needlicence,\%dirsdone)>
1034 Processes a single include directory or software entry, so as to
1035 include the source code found there. Called only by the default
1036 implementation of C<srcdump_prepare>.
1038 C<$dumpdir> is the directory for working and output files. C<$item>
1039 is the real (no symlinks) absolute path to the item.
1041 C<\$needlicence> is a ref to a scalar: this scalar is undef if we have
1042 already found the licence file; otherwise it is the filename to which
1043 the licence should be copied. If the referent is undef on entry,
1044 C<srcdump_process_item> needs to see if it finds the licence; if it
1045 does it should copy it to the named file and then set the scalar to
1048 C<\%dirsdone> is a ref to the hash used by C<srcdump_prepare> to avoid
1049 including a single directory more than once. If
1050 C<srcdump_process_item> decides to process a directory other than
1051 C<$item> it should check this hash with the real absolute path of the
1052 other directoy as a key: if the hash entry is true, it has already
1053 been done and should be skipped; otherwise the hash entry should be set.
1055 C<\&outfn> is a coderef which C<srcdump_process_item> should call each
1056 time it wants to generate a file which should be included as part of
1057 the source code. It should be called using one of these patterns:
1058 $outfn->("message for log");
1059 $outfile = $outfn->("message for log", "extension");
1060 The former simply logs this message (along with the associated
1061 C<$item>, so there is no need to mention that). The latter logs the
1062 message but also generates and returns a filename which should then
1063 be created and filled with some appropriate data. C<"extension">
1064 should be a string for the file extension, eg C<"txt">. The output
1065 can be written directly to the named file: there is no need to
1066 write to a temporary file and rename.
1068 The default implementation is the module function
1069 C<srcdump_process_item>.
1071 It skips directories for which C<srcdump_system_dir> returns true.
1073 It then searches the item and its parent
1074 directories for a vcs metadata directory (one of the names in
1075 C<srcdump_vcs_dirs>); if found, it calls the C<srcdump_byvcs> hook
1076 (after checking and updaeing C<%dirsdone>).
1077 Otherwise it calls the C<srcdump_novcs> hook.
1079 =item C<srcdump_novcs($cgi,$verifier,$dumpdir,$item,$outfn)>
1081 Called by the default implementation of C<srcdump_process_item>, with
1082 the same arguments, if it doesn't find vcs metadata.
1084 The default implementation is the module function C<srcdump_novcs>.
1086 If C<$item> is a directory, it uses C<srcdump_dir_cpio> to prepare a
1087 tarball of all the files under C<$item> which have the world read bit
1088 set. Directories are not included (and their permissions are
1089 disregarded). The contents of C<srcdump_excludes> are excluded.
1091 If it's a plain file it uses C<srcdump_file> to include the file.
1093 =item C<srcdump_byvcs($cgi,$verifier,$dumpdir,$item,$outfn,$vcs)>
1095 Called by the default implementation of C<srcdump_process_item>, with
1096 the same arguments, if it finds vcs metadata. The additional argument
1097 C<$vcs> is derived from the entry of C<srcump_vcs_dirs> which was
1098 used: it's the first sequence of word characters, lowercased.
1100 The default implementation is the module function C<srcdump_byvcs>.
1101 It simply calls C<srcdump_dir_cpio> with a script from the setting
1102 C<srcdump_vcsscript>.
1104 =item C<srcdump_vcs_dirs>
1106 Array ref of leaf names of vcs metadata directories. Used by the
1107 default implementation of C<srcdump_process_item>. The default value
1108 is C<['.git','.hg','.bzr','.svn']>.
1110 =item C<srcdump_vcs_script>
1112 Hash ref of scripts for generating vcs metadata. Used by the default
1113 implementation of C<srcdump_byvcs>. The keys are values of C<$vcs>
1114 (see C<srcdump_byvcs>); the values are scripts as for
1115 C<srcdump_dir_cpio>.
1117 The default has an entry only for C<git>:
1119 git ls-files -z --others --exclude-from=.gitignore
1122 =item C<srcdump_excludes>
1124 Array ref of exclude glob patterns, used by the default implementation
1125 of C<srcdump_novcs>. The default value is C<['*~','*.bak','*.tmp','#*#']>.
1127 Entries must not contain C<'> or C<\>.
1129 =item C<srcdump_listitems($cgi,$verifier)>
1131 Returns an array of directories which might contain source code of the
1132 web application and which should be therefore be considered for
1133 including in the source code delivery.
1135 Used by the default implementation of C<srcdump_prepare>.
1137 Entries must be directories, plain files, or nonexistent; they may
1138 also be symlinks which resolve to one of those.
1140 If C<.> is included it may be treated specially - see
1141 C<srcdump_filter_cwd>.
1143 The default implementation returns
1144 C<(@INC, $ENV{'SCRIPT_FILENAME'}, $0)>.
1146 =item C<srcdump_system_dir($cgi,$verifier,$dir)>
1148 Determines whether C<$dir> is a "system directory", in which any
1149 source code used by the application should nevertheless not be
1150 included in the source code dump.
1152 Used by the default implementation of C<srcdump_item>.
1154 The default implementation is as follows: Things in C</etc/> are
1155 system directories. Things in C</usr/> are too, unless they are in
1156 C</usr/local/> or C</usr/lib/cgi*>.
1158 =item C<srcdump_filter_cwd>
1160 Boolean which controls the handling of C<.> if it appears in the
1161 return value from C<srcdump_listitems>. Used only by the default
1162 implementation of C<srcdump_prepare>.
1164 If set to false, C<.> is treated normally and no special action is
1167 However often the current directory may be C</>, or a data directory,
1168 or some other directory containing data which is confidential, or
1169 should not be included in the public source code distribution for
1170 other reasons. And for historical reasons Perl has C<@INC> containing
1171 C<.> by default (which is arguably dangerous and wrong).
1173 So the default this setting is true, which has the following effects:
1175 C<.> is not searched for source code even if it appears in C<@INC>.
1176 C<.> is removed from C<@INC> and C<%INC> is checked to see if any
1177 modules appear to have already been loaded by virtue of C<.> appearing
1178 in C<@INC> and if they have it is treated as a fatal error.
1180 Only the literal string C<.> is affected. If the cwd is included by
1181 any other name it is not treated specially regardless of this setting.
1185 =head1 DATABASE TABLES
1187 In a simple application, you do not need to worry about this. But if
1188 your application runs on multiple frontend hosts with a shared
1189 database, you may need to create for yourself the tables and indices
1190 used by CGI::Auth::Flexible.
1192 xxx document _db_setup_do
1193 xxx make _db_setup_do explicitly overrideable
1197 xxx remaining settings
1199 username_password_error
1206 xxx $message argument to $outfn->() is not for log, it's for manifest
1207 xxx document syntax of $message argument to $outfn->()
1212 xxx bugs wrong default random on Linux
1213 xxx bugs wrong default random on *BSD
1214 xxx bugs keys not shared should be in db
1215 xxx rename caf-assocs.db
1216 xxx rename caf_assocsecret default cookie name
1217 xxx mention relationship between login_timeout and cookies