Commit | Line | Data |
9e447f9d |
1 | #!/usr/bin/perl |
2 | |
3 | package Catalyst::Plugin::Session; |
4 | use base qw/Class::Accessor::Fast/; |
5 | |
6 | use strict; |
7 | use warnings; |
8 | |
9 | use NEXT; |
10 | use Catalyst::Exception (); |
9a9252c2 |
11 | use Digest (); |
12 | use overload (); |
d44bc687 |
13 | use Object::Signature (); |
9e447f9d |
14 | |
5d8cc4c7 |
15 | our $VERSION = "0.05"; |
37160715 |
16 | |
ab634fee |
17 | my @session_data_accessors; # used in delete_session |
9e447f9d |
18 | BEGIN { |
4207ce8d |
19 | __PACKAGE__->mk_accessors( |
ab634fee |
20 | "_session_delete_reason", |
21 | @session_data_accessors = qw/ |
4207ce8d |
22 | _sessionid |
23 | _session |
24 | _session_expires |
25 | _session_data_sig |
4207ce8d |
26 | _flash |
f4d79f85 |
27 | _flash_keep_keys |
28 | _flash_key_hashes |
e5b2372a |
29 | _tried_loading_session |
4207ce8d |
30 | / |
31 | ); |
9e447f9d |
32 | } |
33 | |
34 | sub setup { |
9a9252c2 |
35 | my $c = shift; |
36 | |
37 | $c->NEXT::setup(@_); |
38 | |
39 | $c->check_session_plugin_requirements; |
40 | $c->setup_session; |
41 | |
42 | return $c; |
9e447f9d |
43 | } |
44 | |
45 | sub check_session_plugin_requirements { |
9a9252c2 |
46 | my $c = shift; |
9e447f9d |
47 | |
9a9252c2 |
48 | unless ( $c->isa("Catalyst::Plugin::Session::State") |
49 | && $c->isa("Catalyst::Plugin::Session::Store") ) |
50 | { |
51 | my $err = |
52 | ( "The Session plugin requires both Session::State " |
53 | . "and Session::Store plugins to be used as well." ); |
9e447f9d |
54 | |
9a9252c2 |
55 | $c->log->fatal($err); |
56 | Catalyst::Exception->throw($err); |
57 | } |
9e447f9d |
58 | } |
59 | |
60 | sub setup_session { |
9a9252c2 |
61 | my $c = shift; |
9e447f9d |
62 | |
9a9252c2 |
63 | my $cfg = ( $c->config->{session} ||= {} ); |
9e447f9d |
64 | |
9a9252c2 |
65 | %$cfg = ( |
66 | expires => 7200, |
67 | verify_address => 1, |
68 | %$cfg, |
69 | ); |
9e447f9d |
70 | |
9a9252c2 |
71 | $c->NEXT::setup_session(); |
9e447f9d |
72 | } |
73 | |
19c130c2 |
74 | sub prepare_action { |
75 | my $c = shift; |
76 | |
4207ce8d |
77 | if ( $c->config->{session}{flash_to_stash} |
e5b2372a |
78 | and $c->sessionid |
4207ce8d |
79 | and my $flash_data = $c->flash ) |
80 | { |
19c130c2 |
81 | @{ $c->stash }{ keys %$flash_data } = values %$flash_data; |
82 | } |
83 | |
84 | $c->NEXT::prepare_action(@_); |
85 | } |
86 | |
9e447f9d |
87 | sub finalize { |
9a9252c2 |
88 | my $c = shift; |
9e447f9d |
89 | |
9b0fa2a6 |
90 | $c->_save_session; |
91 | $c->_save_flash; |
92 | |
93 | $c->NEXT::finalize(@_); |
94 | } |
95 | |
96 | sub _save_session { |
97 | my $c = shift; |
4207ce8d |
98 | |
e5b2372a |
99 | if ( my $sid = $c->sessionid ) { |
9e447f9d |
100 | |
6687905d |
101 | # all sessions are extended at the end of the request |
102 | my $now = time; |
103 | |
104 | if ( my $expires = $c->session_expires ) { |
105 | $c->store_session_data( "expires:$sid" => $expires ); |
106 | } |
7a02371f |
107 | |
6687905d |
108 | if ( my $session_data = $c->_session ) { |
d44bc687 |
109 | |
110 | no warnings 'uninitialized'; |
4207ce8d |
111 | if ( Object::Signature::signature($session_data) ne |
112 | $c->_session_data_sig ) |
113 | { |
d44bc687 |
114 | $session_data->{__updated} = $now; |
115 | $c->store_session_data( "session:$sid" => $session_data ); |
116 | } |
ea972e9a |
117 | } |
9a9252c2 |
118 | } |
9b0fa2a6 |
119 | } |
9a9252c2 |
120 | |
9b0fa2a6 |
121 | sub _save_flash { |
122 | my $c = shift; |
123 | |
e5b2372a |
124 | if ( my $sid = $c->sessionid ) { |
23fbca00 |
125 | if ( my $flash_data = $c->_flash ) { |
f4d79f85 |
126 | |
127 | my $hashes = $c->_flash_key_hashes || {}; |
128 | my $keep = $c->_flash_keep_keys || {}; |
129 | foreach my $key ( keys %$hashes ) { |
130 | if ( !exists $keep->{$key} and Object::Signature::signature( \$flash_data->{$key} ) eq $hashes->{$key} ) { |
131 | delete $flash_data->{$key}; |
132 | } |
133 | } |
4207ce8d |
134 | |
23fbca00 |
135 | if (%$flash_data) { |
136 | $c->store_session_data( "flash:$sid", $flash_data ); |
137 | } |
138 | else { |
139 | $c->delete_session_data("flash:$sid"); |
140 | } |
ea972e9a |
141 | } |
9b0fa2a6 |
142 | } |
9e447f9d |
143 | } |
144 | |
e5b2372a |
145 | sub _load_session_expires { |
146 | my $c = shift; |
147 | |
148 | if ( my $sid = $c->sessionid ) { |
149 | my $expires = $c->get_session_data("expires:$sid") || 0; |
150 | |
151 | if ( $expires >= time() ) { |
152 | return $c->extend_session_expires( $expires ); |
153 | } else { |
154 | $c->delete_session( "session expired" ); |
155 | return 0; |
156 | } |
157 | } else { |
158 | $c->_session_expires( 0 ); |
159 | return 0; |
160 | } |
161 | } |
162 | |
b7acf64e |
163 | sub _load_session { |
164 | my $c = shift; |
165 | |
e5b2372a |
166 | if ( my $sid = $c->sessionid ) { |
6687905d |
167 | if ( $c->session_expires ) { # > 0 |
0974ac06 |
168 | |
2e412459 |
169 | my $session_data = $c->get_session_data("session:$sid") || return; |
6687905d |
170 | $c->_session($session_data); |
3f182468 |
171 | |
6687905d |
172 | no warnings 'uninitialized'; # ne __address |
173 | if ( $c->config->{session}{verify_address} |
174 | && $session_data->{__address} ne $c->request->address ) |
175 | { |
176 | $c->log->warn( |
177 | "Deleting session $sid due to address mismatch (" |
178 | . $session_data->{__address} . " != " |
47ca362e |
179 | . $c->request->address . ")" |
6687905d |
180 | ); |
181 | $c->delete_session("address mismatch"); |
182 | return; |
183 | } |
4207ce8d |
184 | |
6687905d |
185 | $c->log->debug(qq/Restored session "$sid"/) if $c->debug; |
168d6819 |
186 | $c->_session_data_sig( Object::Signature::signature($session_data) ) if $session_data; |
6687905d |
187 | $c->_expire_session_keys; |
4207ce8d |
188 | |
6687905d |
189 | return $session_data; |
3f182468 |
190 | } |
9a9252c2 |
191 | } |
29d15411 |
192 | |
4207ce8d |
193 | return; |
b7acf64e |
194 | } |
9a9252c2 |
195 | |
9b0fa2a6 |
196 | sub _load_flash { |
197 | my $c = shift; |
198 | |
e5b2372a |
199 | if ( my $sid = $c->sessionid ) { |
4207ce8d |
200 | if ( my $flash_data = $c->_flash |
201 | || $c->_flash( $c->get_session_data("flash:$sid") ) ) |
202 | { |
f4d79f85 |
203 | $c->_flash_key_hashes({ map { $_ => Object::Signature::signature( \$flash_data->{$_} ) } keys %$flash_data }); |
e5b2372a |
204 | |
9b0fa2a6 |
205 | return $flash_data; |
206 | } |
207 | } |
208 | |
209 | return undef; |
210 | } |
211 | |
d44bc687 |
212 | sub _expire_session_keys { |
b7acf64e |
213 | my ( $c, $data ) = @_; |
214 | |
215 | my $now = time; |
216 | |
e5b2372a |
217 | my $expire_times = ( $data || $c->_session || {} )->{__expire_keys} || {}; |
218 | foreach my $key ( grep { $expire_times->{$_} < $now } keys %$expire_times ) { |
b7acf64e |
219 | delete $c->_session->{$key}; |
e5b2372a |
220 | delete $expire_times->{$key}; |
b7acf64e |
221 | } |
9e447f9d |
222 | } |
223 | |
224 | sub delete_session { |
9a9252c2 |
225 | my ( $c, $msg ) = @_; |
9e447f9d |
226 | |
9a9252c2 |
227 | # delete the session data |
e5b2372a |
228 | my $sid = $c->sessionid || return; |
4207ce8d |
229 | $c->delete_session_data("${_}:${sid}") for qw/session expires flash/; |
9e447f9d |
230 | |
e5b2372a |
231 | $c->delete_session_id; |
232 | |
9a9252c2 |
233 | # reset the values in the context object |
ab634fee |
234 | # see the BEGIN block |
235 | $c->$_(undef) for @session_data_accessors; |
6687905d |
236 | |
29d15411 |
237 | $c->_session_delete_reason($msg); |
238 | } |
239 | |
240 | sub session_delete_reason { |
241 | my $c = shift; |
242 | |
e5b2372a |
243 | $c->session_is_valid; # check that it was loaded |
29d15411 |
244 | |
4207ce8d |
245 | $c->_session_delete_reason(@_); |
9e447f9d |
246 | } |
247 | |
6687905d |
248 | sub session_expires { |
e5b2372a |
249 | my $c = shift; |
6687905d |
250 | |
e5b2372a |
251 | if ( defined( my $expires = $c->_session_expires ) ) { |
252 | return $expires; |
253 | } else { |
254 | return $c->_load_session_expires; |
255 | } |
256 | } |
6687905d |
257 | |
e5b2372a |
258 | sub extend_session_expires { |
259 | my ( $c, $expires ) = @_; |
e5b2372a |
260 | $c->_session_expires( my $updated = $c->calculate_extended_session_expires( $expires ) ); |
4c79feb6 |
261 | $c->extend_session_id( $c->sessionid, $updated ); |
e5b2372a |
262 | return $updated; |
263 | } |
6687905d |
264 | |
e5b2372a |
265 | sub calculate_initial_session_expires { |
266 | my $c = shift; |
267 | return ( time() + $c->config->{session}{expires} ); |
268 | } |
269 | |
270 | sub calculate_extended_session_expires { |
271 | my ( $c, $prev ) = @_; |
272 | $c->calculate_initial_session_expires; |
273 | } |
274 | |
275 | sub reset_session_expires { |
276 | my ( $c, $sid ) = @_; |
277 | $c->_session_expires( my $exp = $c->calculate_initial_session_expires ); |
278 | $exp; |
6687905d |
279 | } |
280 | |
0974ac06 |
281 | sub sessionid { |
4207ce8d |
282 | my $c = shift; |
e5b2372a |
283 | |
284 | return $c->_sessionid || do { |
285 | unless ( $c->_tried_loading_session ) { |
286 | $c->_tried_loading_session(1); |
287 | if ( defined( my $sid = $c->get_session_id ) ) { |
288 | if ( $c->validate_session_id($sid) ) { |
289 | $c->_sessionid( $sid ); |
290 | return $sid; |
291 | } else { |
292 | my $err = "Tried to set invalid session ID '$sid'"; |
293 | $c->log->error($err); |
294 | Catalyst::Exception->throw($err); |
295 | } |
296 | } else { |
297 | return; |
298 | } |
4207ce8d |
299 | } |
300 | } |
e5b2372a |
301 | } |
302 | |
303 | sub session_is_valid { |
304 | my $c = shift; |
4207ce8d |
305 | |
e5b2372a |
306 | $c->_load_session unless $c->_session; # check expiry and also __address, etc |
4207ce8d |
307 | |
e5b2372a |
308 | if ( $c->_session ) { |
309 | return 1; |
310 | } else { |
311 | return; |
312 | } |
0974ac06 |
313 | } |
314 | |
315 | sub validate_session_id { |
4207ce8d |
316 | my ( $c, $sid ) = @_; |
0974ac06 |
317 | |
4207ce8d |
318 | $sid and $sid =~ /^[a-f\d]+$/i; |
0974ac06 |
319 | } |
320 | |
9e447f9d |
321 | sub session { |
9a9252c2 |
322 | my $c = shift; |
9e447f9d |
323 | |
29d15411 |
324 | $c->_session || $c->_load_session || do { |
78476ce0 |
325 | $c->create_session_id; |
29d15411 |
326 | $c->initialize_session_data; |
4207ce8d |
327 | }; |
9e447f9d |
328 | } |
329 | |
f4d79f85 |
330 | sub keep_flash { |
331 | my ( $c, @keys ) = @_; |
2e412459 |
332 | my $href = $c->_flash_keep_keys || $c->_flash_keep_keys({}); |
333 | (@{$href}{@keys}) = ((undef) x @keys); |
f4d79f85 |
334 | } |
335 | |
873f7011 |
336 | sub flash { |
337 | my $c = shift; |
78476ce0 |
338 | $c->_flash || $c->_load_flash || do { |
339 | $c->create_session_id; |
340 | $c->_flash( {} ); |
4207ce8d |
341 | } |
873f7011 |
342 | } |
343 | |
b7acf64e |
344 | sub session_expire_key { |
345 | my ( $c, %keys ) = @_; |
346 | |
347 | my $now = time; |
4207ce8d |
348 | @{ $c->session->{__expire_keys} }{ keys %keys } = |
349 | map { $now + $_ } values %keys; |
b7acf64e |
350 | } |
351 | |
9e447f9d |
352 | sub initialize_session_data { |
9a9252c2 |
353 | my $c = shift; |
9e447f9d |
354 | |
9a9252c2 |
355 | my $now = time; |
9e447f9d |
356 | |
4207ce8d |
357 | return $c->_session( |
358 | { |
359 | __created => $now, |
360 | __updated => $now, |
361 | |
362 | ( |
363 | $c->config->{session}{verify_address} |
364 | ? ( __address => $c->request->address ) |
365 | : () |
366 | ), |
367 | } |
368 | ); |
9e447f9d |
369 | } |
370 | |
9e447f9d |
371 | sub generate_session_id { |
372 | my $c = shift; |
373 | |
374 | my $digest = $c->_find_digest(); |
375 | $digest->add( $c->session_hash_seed() ); |
376 | return $digest->hexdigest; |
377 | } |
378 | |
78476ce0 |
379 | sub create_session_id { |
380 | my $c = shift; |
381 | |
e5b2372a |
382 | my $sid = $c->generate_session_id; |
78476ce0 |
383 | |
e5b2372a |
384 | $c->log->debug(qq/Created session "$sid"/) if $c->debug; |
78476ce0 |
385 | |
e5b2372a |
386 | $c->_sessionid($sid); |
387 | $c->reset_session_expires; |
388 | $c->set_session_id($sid); |
389 | |
390 | return $sid; |
78476ce0 |
391 | } |
392 | |
9e447f9d |
393 | my $counter; |
9a9252c2 |
394 | |
9e447f9d |
395 | sub session_hash_seed { |
9a9252c2 |
396 | my $c = shift; |
397 | |
398 | return join( "", ++$counter, time, rand, $$, {}, overload::StrVal($c), ); |
9e447f9d |
399 | } |
400 | |
401 | my $usable; |
9a9252c2 |
402 | |
9e447f9d |
403 | sub _find_digest () { |
9a9252c2 |
404 | unless ($usable) { |
d44bc687 |
405 | foreach my $alg (qw/SHA-1 SHA-256 MD5/) { |
4207ce8d |
406 | if ( eval { Digest->new($alg) } ) { |
5faaa4b0 |
407 | $usable = $alg; |
408 | last; |
409 | } |
7d139eeb |
410 | } |
4207ce8d |
411 | Catalyst::Exception->throw( |
9a9252c2 |
412 | "Could not find a suitable Digest module. Please install " |
4207ce8d |
413 | . "Digest::SHA1, Digest::SHA, or Digest::MD5" ) |
414 | unless $usable; |
9a9252c2 |
415 | } |
9e447f9d |
416 | |
417 | return Digest->new($usable); |
418 | } |
419 | |
99b2191e |
420 | sub dump_these { |
421 | my $c = shift; |
422 | |
423 | ( |
424 | $c->NEXT::dump_these(), |
425 | |
426 | $c->sessionid |
427 | ? ( [ "Session ID" => $c->sessionid ], [ Session => $c->session ], ) |
428 | : () |
429 | ); |
430 | } |
431 | |
e5b2372a |
432 | |
433 | sub get_session_id { shift->NEXT::get_session_id(@_) } |
434 | sub set_session_id { shift->NEXT::set_session_id(@_) } |
435 | sub delete_session_id { shift->NEXT::delete_session_id(@_) } |
4c79feb6 |
436 | sub extend_session_id { shift->NEXT::extend_session_id(@_) } |
e5b2372a |
437 | |
9e447f9d |
438 | __PACKAGE__; |
439 | |
440 | __END__ |
441 | |
442 | =pod |
443 | |
444 | =head1 NAME |
445 | |
446 | Catalyst::Plugin::Session - Generic Session plugin - ties together server side |
fb1a4ac3 |
447 | storage and client side state required to maintain session data. |
9e447f9d |
448 | |
449 | =head1 SYNOPSIS |
450 | |
8f0b4c16 |
451 | # To get sessions to "just work", all you need to do is use these plugins: |
452 | |
453 | use Catalyst qw/ |
454 | Session |
455 | Session::Store::FastMmap |
456 | Session::State::Cookie |
457 | /; |
458 | |
459 | # you can replace Store::FastMmap with Store::File - both have sensible |
460 | # default configurations (see their docs for details) |
461 | |
462 | # more complicated backends are available for other scenarios (DBI storage, |
463 | # etc) |
464 | |
465 | |
466 | # after you've loaded the plugins you can save session data |
467 | # For example, if you are writing a shopping cart, it could be implemented |
468 | # like this: |
9e447f9d |
469 | |
229a5b53 |
470 | sub add_item : Local { |
471 | my ( $self, $c ) = @_; |
472 | |
473 | my $item_id = $c->req->param("item"); |
474 | |
8f0b4c16 |
475 | # $c->session is a hash ref, a bit like $c->stash |
476 | # the difference is that it' preserved across requests |
229a5b53 |
477 | |
478 | push @{ $c->session->{items} }, $item_id; |
479 | |
480 | $c->forward("MyView"); |
481 | } |
482 | |
483 | sub display_items : Local { |
484 | my ( $self, $c ) = @_; |
485 | |
486 | # values in $c->session are restored |
487 | $c->stash->{items_to_display} = |
8f0b4c16 |
488 | [ map { MyModel->retrieve($_) } @{ $c->session->{items} } ]; |
229a5b53 |
489 | |
490 | $c->forward("MyView"); |
491 | } |
492 | |
9e447f9d |
493 | =head1 DESCRIPTION |
494 | |
495 | The Session plugin is the base of two related parts of functionality required |
496 | for session management in web applications. |
497 | |
498 | The first part, the State, is getting the browser to repeat back a session key, |
499 | so that the web application can identify the client and logically string |
500 | several requests together into a session. |
501 | |
502 | The second part, the Store, deals with the actual storage of information about |
503 | the client. This data is stored so that the it may be revived for every request |
504 | made by the same client. |
505 | |
506 | This plugin links the two pieces together. |
507 | |
8f0b4c16 |
508 | =head1 RECCOMENDED BACKENDS |
509 | |
510 | =over 4 |
511 | |
512 | =item Session::State::Cookie |
513 | |
514 | The only really sane way to do state is using cookies. |
515 | |
516 | =item Session::Store::File |
517 | |
518 | A portable backend, based on Cache::File. |
519 | |
520 | =item Session::Store::FastMmap |
521 | |
522 | A fast and flexible backend, based on Cache::FastMmap. |
523 | |
524 | =back |
525 | |
9e447f9d |
526 | =head1 METHODS |
527 | |
528 | =over 4 |
529 | |
530 | =item sessionid |
531 | |
532 | An accessor for the session ID value. |
533 | |
534 | =item session |
535 | |
536 | Returns a hash reference that might contain unserialized values from previous |
537 | requests in the same session, and whose modified value will be saved for future |
538 | requests. |
539 | |
540 | This method will automatically create a new session and session ID if none |
541 | exists. |
542 | |
ab634fee |
543 | =item session_expires |
544 | |
545 | =item session_expires $reset |
546 | |
547 | This method returns the time when the current session will expire, or 0 if |
548 | there is no current session. If there is a session and it already expired, it |
549 | will delete the session and return 0 as well. |
550 | |
551 | If the C<$reset> parameter is true, and there is a session ID the expiry time |
552 | will be reset to the current time plus the time to live (see |
553 | L</CONFIGURATION>). This is used when creating a new session. |
554 | |
07e714d2 |
555 | =item flash |
556 | |
557 | This is like Ruby on Rails' flash data structure. Think of it as a stash that |
44ab6d1c |
558 | lasts for longer than one request, letting you redirect instead of forward. |
559 | |
560 | The flash data will be cleaned up only on requests on which actually use |
561 | $c->flash (thus allowing multiple redirections), and the policy is to delete |
bf6bd311 |
562 | all the keys which haven't changed since the flash data was loaded at the end |
563 | of every request. |
07e714d2 |
564 | |
565 | sub moose : Local { |
566 | my ( $self, $c ) = @_; |
567 | |
568 | $c->flash->{beans} = 10; |
569 | $c->response->redirect( $c->uri_for("foo") ); |
570 | } |
571 | |
572 | sub foo : Local { |
573 | my ( $self, $c ) = @_; |
574 | |
575 | my $value = $c->flash->{beans}; |
576 | |
577 | # ... |
578 | |
579 | $c->response->redirect( $c->uri_for("bar") ); |
580 | } |
581 | |
582 | sub bar : Local { |
583 | my ( $self, $c ) = @_; |
584 | |
585 | if ( exists $c->flash->{beans} ) { # false |
586 | |
587 | } |
588 | } |
589 | |
bf6bd311 |
590 | =item keep_flash @keys |
591 | |
592 | If you wawnt to keep a flash key for the next request too, even if it hasn't |
593 | changed, call C<keep_flash> and pass in the keys as arguments. |
594 | |
9e447f9d |
595 | =item session_delete_reason |
596 | |
597 | This accessor contains a string with the reason a session was deleted. Possible |
598 | values include: |
599 | |
600 | =over 4 |
601 | |
602 | =item * |
603 | |
604 | C<address mismatch> |
605 | |
606 | =item * |
607 | |
608 | C<session expired> |
609 | |
610 | =back |
611 | |
b7acf64e |
612 | =item session_expire_key $key, $ttl |
613 | |
614 | Mark a key to expire at a certain time (only useful when shorter than the |
615 | expiry time for the whole session). |
616 | |
617 | For example: |
618 | |
619 | __PACKAGE__->config->{session}{expires} = 1000000000000; # forever |
620 | |
621 | # later |
622 | |
623 | $c->session_expire_key( __user => 3600 ); |
624 | |
625 | Will make the session data survive, but the user will still be logged out after |
626 | an hour. |
627 | |
628 | Note that these values are not auto extended. |
629 | |
8f0b4c16 |
630 | =back |
631 | |
10c72079 |
632 | =head1 INTERNAL METHODS |
8f0b4c16 |
633 | |
634 | =over 4 |
635 | |
9e447f9d |
636 | =item setup |
637 | |
638 | This method is extended to also make calls to |
639 | C<check_session_plugin_requirements> and C<setup_session>. |
640 | |
641 | =item check_session_plugin_requirements |
642 | |
643 | This method ensures that a State and a Store plugin are also in use by the |
644 | application. |
645 | |
646 | =item setup_session |
647 | |
648 | This method populates C<< $c->config->{session} >> with the default values |
649 | listed in L</CONFIGURATION>. |
650 | |
651 | =item prepare_action |
652 | |
68fd02ae |
653 | This methoid is extended. |
654 | |
655 | It's only effect is if the (off by default) C<flash_to_stash> configuration |
656 | parameter is on - then it will copy the contents of the flash to the stash at |
657 | prepare time. |
9e447f9d |
658 | |
659 | =item finalize |
660 | |
661 | This method is extended and will extend the expiry time, as well as persist the |
662 | session data if a session exists. |
663 | |
664 | =item delete_session REASON |
665 | |
666 | This method is used to invalidate a session. It takes an optional parameter |
667 | which will be saved in C<session_delete_reason> if provided. |
668 | |
669 | =item initialize_session_data |
670 | |
671 | This method will initialize the internal structure of the session, and is |
672 | called by the C<session> method if appropriate. |
673 | |
68fd02ae |
674 | =item create_session_id |
675 | |
676 | Creates a new session id using C<generate_session_id> if there is no session ID |
677 | yet. |
678 | |
ab634fee |
679 | =item validate_session_id SID |
680 | |
681 | Make sure a session ID is of the right format. |
682 | |
683 | This currently ensures that the session ID string is any amount of case |
684 | insensitive hexadecimal characters. |
685 | |
229a5b53 |
686 | =item generate_session_id |
687 | |
688 | This method will return a string that can be used as a session ID. It is |
689 | supposed to be a reasonably random string with enough bits to prevent |
690 | collision. It basically takes C<session_hash_seed> and hashes it using SHA-1, |
691 | MD5 or SHA-256, depending on the availibility of these modules. |
692 | |
693 | =item session_hash_seed |
694 | |
695 | This method is actually rather internal to generate_session_id, but should be |
696 | overridable in case you want to provide more random data. |
697 | |
698 | Currently it returns a concatenated string which contains: |
699 | |
700 | =over 4 |
701 | |
702 | =item * |
703 | |
704 | A counter |
705 | |
706 | =item * |
707 | |
708 | The current time |
709 | |
710 | =item * |
711 | |
712 | One value from C<rand>. |
713 | |
714 | =item * |
715 | |
716 | The stringified value of a newly allocated hash reference |
717 | |
718 | =item * |
719 | |
720 | The stringified value of the Catalyst context object |
721 | |
722 | =back |
723 | |
724 | In the hopes that those combined values are entropic enough for most uses. If |
725 | this is not the case you can replace C<session_hash_seed> with e.g. |
726 | |
727 | sub session_hash_seed { |
728 | open my $fh, "<", "/dev/random"; |
729 | read $fh, my $bytes, 20; |
730 | close $fh; |
731 | return $bytes; |
732 | } |
733 | |
734 | Or even more directly, replace C<generate_session_id>: |
735 | |
736 | sub generate_session_id { |
737 | open my $fh, "<", "/dev/random"; |
738 | read $fh, my $bytes, 20; |
739 | close $fh; |
740 | return unpack("H*", $bytes); |
741 | } |
742 | |
743 | Also have a look at L<Crypt::Random> and the various openssl bindings - these |
744 | modules provide APIs for cryptographically secure random data. |
745 | |
99b2191e |
746 | =item dump_these |
747 | |
748 | See L<Catalyst/dump_these> - ammends the session data structure to the list of |
749 | dumped objects if session ID is defined. |
750 | |
9e447f9d |
751 | =back |
752 | |
a92c8aeb |
753 | =head1 USING SESSIONS DURING PREPARE |
754 | |
755 | The earliest point in time at which you may use the session data is after |
756 | L<Catalyst::Plugin::Session>'s C<prepare_action> has finished. |
757 | |
758 | State plugins must set $c->session ID before C<prepare_action>, and during |
759 | C<prepare_action> L<Catalyst::Plugin::Session> will actually load the data from |
760 | the store. |
761 | |
762 | sub prepare_action { |
763 | my $c = shift; |
764 | |
765 | # don't touch $c->session yet! |
b1cd7d77 |
766 | |
a92c8aeb |
767 | $c->NEXT::prepare_action( @_ ); |
768 | |
769 | $c->session; # this is OK |
770 | $c->sessionid; # this is also OK |
771 | } |
772 | |
9e447f9d |
773 | =head1 CONFIGURATION |
774 | |
229a5b53 |
775 | $c->config->{session} = { |
776 | expires => 1234, |
777 | }; |
9e447f9d |
778 | |
779 | All configuation parameters are provided in a hash reference under the |
780 | C<session> key in the configuration hash. |
781 | |
782 | =over 4 |
783 | |
784 | =item expires |
785 | |
786 | The time-to-live of each session, expressed in seconds. Defaults to 7200 (two |
787 | hours). |
788 | |
789 | =item verify_address |
790 | |
8c7e922c |
791 | When true, C<<$c->request->address>> will be checked at prepare time. If it is |
792 | not the same as the address that initiated the session, the session is deleted. |
9e447f9d |
793 | |
68fd02ae |
794 | =item flash_to_stash |
795 | |
796 | This option makes it easier to have actions behave the same whether they were |
797 | forwarded to or redirected to. On prepare time it copies the contents of |
798 | C<flash> (if any) to the stash. |
799 | |
9e447f9d |
800 | =back |
801 | |
802 | =head1 SPECIAL KEYS |
803 | |
804 | The hash reference returned by C<< $c->session >> contains several keys which |
805 | are automatically set: |
806 | |
807 | =over 4 |
808 | |
809 | =item __expires |
810 | |
ab634fee |
811 | This key no longer exists. Use C<session_expires> instead. |
9e447f9d |
812 | |
813 | =item __updated |
814 | |
d44bc687 |
815 | The last time a session was saved to the store. |
9e447f9d |
816 | |
817 | =item __created |
818 | |
819 | The time when the session was first created. |
820 | |
821 | =item __address |
822 | |
823 | The value of C<< $c->request->address >> at the time the session was created. |
8c7e922c |
824 | This value is only populated if C<verify_address> is true in the configuration. |
9e447f9d |
825 | |
826 | =back |
827 | |
c80e9f04 |
828 | =head1 CAVEATS |
829 | |
a552e4b5 |
830 | =head2 Round the Robin Proxies |
831 | |
c80e9f04 |
832 | C<verify_address> could make your site inaccessible to users who are behind |
833 | load balanced proxies. Some ISPs may give a different IP to each request by the |
834 | same client due to this type of proxying. If addresses are verified these |
835 | users' sessions cannot persist. |
836 | |
837 | To let these users access your site you can either disable address verification |
838 | as a whole, or provide a checkbox in the login dialog that tells the server |
839 | that it's OK for the address of the client to change. When the server sees that |
840 | this box is checked it should delete the C<__address> sepcial key from the |
841 | session hash when the hash is first created. |
842 | |
a552e4b5 |
843 | =head2 Race Conditions |
844 | |
845 | In this day and age where cleaning detergents and dutch football (not the |
846 | american kind) teams roam the plains in great numbers, requests may happen |
847 | simultaneously. This means that there is some risk of session data being |
848 | overwritten, like this: |
849 | |
850 | =over 4 |
851 | |
852 | =item 1. |
853 | |
854 | request a starts, request b starts, with the same session id |
855 | |
856 | =item 2. |
857 | |
858 | session data is loaded in request a |
859 | |
860 | =item 3. |
861 | |
862 | session data is loaded in request b |
863 | |
864 | =item 4. |
865 | |
866 | session data is changed in request a |
867 | |
868 | =item 5. |
869 | |
870 | request a finishes, session data is updated and written to store |
871 | |
872 | =item 6. |
873 | |
874 | request b finishes, session data is updated and written to store, overwriting |
875 | changes by request a |
876 | |
877 | =back |
878 | |
879 | If this is a concern in your application, a soon to be developed locking |
880 | solution is the only safe way to go. This will have a bigger overhead. |
881 | |
882 | For applications where any given user is only making one request at a time this |
883 | plugin should be safe enough. |
884 | |
d45028d6 |
885 | =head1 AUTHORS |
886 | |
baa9db9c |
887 | =over 4 |
888 | |
889 | =item Andy Grundman |
890 | |
891 | =item Christian Hansen |
892 | |
893 | =item Yuval Kogman, C<nothingmuch@woobling.org> (current maintainer) |
894 | |
895 | =item Sebastian Riedel |
896 | |
897 | =back |
898 | |
899 | And countless other contributers from #catalyst. Thanks guys! |
d45028d6 |
900 | |
cc40ae4b |
901 | =head1 COPYRIGHT & LICENSE |
d45028d6 |
902 | |
903 | Copyright (c) 2005 the aforementioned authors. All rights |
904 | reserved. This program is free software; you can redistribute |
905 | it and/or modify it under the same terms as Perl itself. |
906 | |
9e447f9d |
907 | =cut |
908 | |
909 | |