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 |
4207ce8d |
29 | / |
30 | ); |
9e447f9d |
31 | } |
32 | |
33 | sub setup { |
9a9252c2 |
34 | my $c = shift; |
35 | |
36 | $c->NEXT::setup(@_); |
37 | |
38 | $c->check_session_plugin_requirements; |
39 | $c->setup_session; |
40 | |
41 | return $c; |
9e447f9d |
42 | } |
43 | |
44 | sub check_session_plugin_requirements { |
9a9252c2 |
45 | my $c = shift; |
9e447f9d |
46 | |
9a9252c2 |
47 | unless ( $c->isa("Catalyst::Plugin::Session::State") |
48 | && $c->isa("Catalyst::Plugin::Session::Store") ) |
49 | { |
50 | my $err = |
51 | ( "The Session plugin requires both Session::State " |
52 | . "and Session::Store plugins to be used as well." ); |
9e447f9d |
53 | |
9a9252c2 |
54 | $c->log->fatal($err); |
55 | Catalyst::Exception->throw($err); |
56 | } |
9e447f9d |
57 | } |
58 | |
59 | sub setup_session { |
9a9252c2 |
60 | my $c = shift; |
9e447f9d |
61 | |
9a9252c2 |
62 | my $cfg = ( $c->config->{session} ||= {} ); |
9e447f9d |
63 | |
9a9252c2 |
64 | %$cfg = ( |
65 | expires => 7200, |
66 | verify_address => 1, |
67 | %$cfg, |
68 | ); |
9e447f9d |
69 | |
9a9252c2 |
70 | $c->NEXT::setup_session(); |
9e447f9d |
71 | } |
72 | |
19c130c2 |
73 | sub prepare_action { |
74 | my $c = shift; |
75 | |
4207ce8d |
76 | if ( $c->config->{session}{flash_to_stash} |
77 | and $c->_sessionid |
78 | and my $flash_data = $c->flash ) |
79 | { |
19c130c2 |
80 | @{ $c->stash }{ keys %$flash_data } = values %$flash_data; |
81 | } |
82 | |
83 | $c->NEXT::prepare_action(@_); |
84 | } |
85 | |
9e447f9d |
86 | sub finalize { |
9a9252c2 |
87 | my $c = shift; |
9e447f9d |
88 | |
9b0fa2a6 |
89 | $c->_save_session; |
90 | $c->_save_flash; |
91 | |
92 | $c->NEXT::finalize(@_); |
93 | } |
94 | |
95 | sub _save_session { |
96 | my $c = shift; |
4207ce8d |
97 | |
ea972e9a |
98 | if ( my $sid = $c->_sessionid ) { |
9e447f9d |
99 | |
6687905d |
100 | # all sessions are extended at the end of the request |
101 | my $now = time; |
102 | |
103 | if ( my $expires = $c->session_expires ) { |
104 | $c->store_session_data( "expires:$sid" => $expires ); |
105 | } |
7a02371f |
106 | |
6687905d |
107 | if ( my $session_data = $c->_session ) { |
d44bc687 |
108 | |
109 | no warnings 'uninitialized'; |
4207ce8d |
110 | if ( Object::Signature::signature($session_data) ne |
111 | $c->_session_data_sig ) |
112 | { |
d44bc687 |
113 | $session_data->{__updated} = $now; |
114 | $c->store_session_data( "session:$sid" => $session_data ); |
115 | } |
ea972e9a |
116 | } |
9a9252c2 |
117 | } |
9b0fa2a6 |
118 | } |
9a9252c2 |
119 | |
9b0fa2a6 |
120 | sub _save_flash { |
121 | my $c = shift; |
122 | |
ea972e9a |
123 | if ( my $sid = $c->_sessionid ) { |
23fbca00 |
124 | if ( my $flash_data = $c->_flash ) { |
f4d79f85 |
125 | |
126 | my $hashes = $c->_flash_key_hashes || {}; |
127 | my $keep = $c->_flash_keep_keys || {}; |
128 | foreach my $key ( keys %$hashes ) { |
129 | if ( !exists $keep->{$key} and Object::Signature::signature( \$flash_data->{$key} ) eq $hashes->{$key} ) { |
130 | delete $flash_data->{$key}; |
131 | } |
132 | } |
4207ce8d |
133 | |
23fbca00 |
134 | if (%$flash_data) { |
135 | $c->store_session_data( "flash:$sid", $flash_data ); |
136 | } |
137 | else { |
138 | $c->delete_session_data("flash:$sid"); |
139 | } |
ea972e9a |
140 | } |
9b0fa2a6 |
141 | } |
9e447f9d |
142 | } |
143 | |
b7acf64e |
144 | sub _load_session { |
145 | my $c = shift; |
146 | |
29d15411 |
147 | if ( my $sid = $c->_sessionid ) { |
6687905d |
148 | if ( $c->session_expires ) { # > 0 |
0974ac06 |
149 | |
2e412459 |
150 | my $session_data = $c->get_session_data("session:$sid") || return; |
6687905d |
151 | $c->_session($session_data); |
3f182468 |
152 | |
6687905d |
153 | no warnings 'uninitialized'; # ne __address |
154 | if ( $c->config->{session}{verify_address} |
155 | && $session_data->{__address} ne $c->request->address ) |
156 | { |
157 | $c->log->warn( |
158 | "Deleting session $sid due to address mismatch (" |
159 | . $session_data->{__address} . " != " |
2e412459 |
160 | . $c->request->address . ")" . Carp::longmess, |
6687905d |
161 | ); |
162 | $c->delete_session("address mismatch"); |
163 | return; |
164 | } |
4207ce8d |
165 | |
6687905d |
166 | $c->log->debug(qq/Restored session "$sid"/) if $c->debug; |
168d6819 |
167 | $c->_session_data_sig( Object::Signature::signature($session_data) ) if $session_data; |
6687905d |
168 | $c->_expire_session_keys; |
4207ce8d |
169 | |
6687905d |
170 | return $session_data; |
3f182468 |
171 | } |
9a9252c2 |
172 | } |
29d15411 |
173 | |
4207ce8d |
174 | return; |
b7acf64e |
175 | } |
9a9252c2 |
176 | |
9b0fa2a6 |
177 | sub _load_flash { |
178 | my $c = shift; |
179 | |
180 | if ( my $sid = $c->_sessionid ) { |
4207ce8d |
181 | if ( my $flash_data = $c->_flash |
182 | || $c->_flash( $c->get_session_data("flash:$sid") ) ) |
183 | { |
f4d79f85 |
184 | $c->_flash_key_hashes({ map { $_ => Object::Signature::signature( \$flash_data->{$_} ) } keys %$flash_data }); |
9b0fa2a6 |
185 | return $flash_data; |
186 | } |
187 | } |
188 | |
189 | return undef; |
190 | } |
191 | |
d44bc687 |
192 | sub _expire_session_keys { |
b7acf64e |
193 | my ( $c, $data ) = @_; |
194 | |
195 | my $now = time; |
196 | |
4207ce8d |
197 | my $expiry = ( $data || $c->_session || {} )->{__expire_keys} || {}; |
198 | foreach my $key ( grep { $expiry->{$_} < $now } keys %$expiry ) { |
b7acf64e |
199 | delete $c->_session->{$key}; |
200 | delete $expiry->{$key}; |
201 | } |
9e447f9d |
202 | } |
203 | |
204 | sub delete_session { |
9a9252c2 |
205 | my ( $c, $msg ) = @_; |
9e447f9d |
206 | |
9a9252c2 |
207 | # delete the session data |
29d15411 |
208 | my $sid = $c->_sessionid || return; |
4207ce8d |
209 | $c->delete_session_data("${_}:${sid}") for qw/session expires flash/; |
9e447f9d |
210 | |
9a9252c2 |
211 | # reset the values in the context object |
ab634fee |
212 | # see the BEGIN block |
213 | $c->$_(undef) for @session_data_accessors; |
6687905d |
214 | |
29d15411 |
215 | $c->_session_delete_reason($msg); |
216 | } |
217 | |
218 | sub session_delete_reason { |
219 | my $c = shift; |
220 | |
4207ce8d |
221 | $c->_load_session |
222 | if ( $c->_sessionid && !$c->_session ); # must verify session data |
29d15411 |
223 | |
4207ce8d |
224 | $c->_session_delete_reason(@_); |
9e447f9d |
225 | } |
226 | |
6687905d |
227 | sub session_expires { |
228 | my ( $c, $should_create ) = @_; |
229 | |
230 | $c->_session_expires || do { |
231 | if ( my $sid = $c->_sessionid ) { |
232 | my $now = time; |
233 | |
234 | if ( !$should_create ) { |
235 | if ( ( $c->get_session_data("expires:$sid") || 0 ) < $now ) { |
236 | |
237 | # session expired |
238 | $c->log->debug("Deleting session $sid (expired)") |
239 | if $c->debug; |
240 | $c->delete_session("session expired"); |
241 | return 0; |
242 | } |
243 | } |
244 | |
245 | return $c->_session_expires( |
246 | $now + $c->config->{session}{expires} ); |
247 | } |
248 | }; |
249 | } |
250 | |
0974ac06 |
251 | sub sessionid { |
4207ce8d |
252 | my $c = shift; |
253 | |
254 | if (@_) { |
bab8b74b |
255 | if($c->_sessionid()) { |
256 | $c->log->warn('Session ID already set, ignoring.'); |
257 | return $c->_sessionid(); |
258 | } |
4207ce8d |
259 | if ( $c->validate_session_id( my $sid = shift ) ) { |
260 | $c->_sessionid($sid); |
29d15411 |
261 | return unless defined wantarray; |
4207ce8d |
262 | } |
263 | else { |
264 | my $err = "Tried to set invalid session ID '$sid'"; |
265 | $c->log->error($err); |
266 | Catalyst::Exception->throw($err); |
267 | } |
268 | } |
269 | |
270 | $c->_load_session |
271 | if ( $c->_sessionid && !$c->_session ); # must verify session data |
272 | |
273 | return $c->_sessionid; |
0974ac06 |
274 | } |
275 | |
276 | sub validate_session_id { |
4207ce8d |
277 | my ( $c, $sid ) = @_; |
0974ac06 |
278 | |
4207ce8d |
279 | $sid and $sid =~ /^[a-f\d]+$/i; |
0974ac06 |
280 | } |
281 | |
9e447f9d |
282 | sub session { |
9a9252c2 |
283 | my $c = shift; |
9e447f9d |
284 | |
29d15411 |
285 | $c->_session || $c->_load_session || do { |
78476ce0 |
286 | $c->create_session_id; |
9e447f9d |
287 | |
29d15411 |
288 | $c->initialize_session_data; |
4207ce8d |
289 | }; |
9e447f9d |
290 | } |
291 | |
f4d79f85 |
292 | sub keep_flash { |
293 | my ( $c, @keys ) = @_; |
2e412459 |
294 | my $href = $c->_flash_keep_keys || $c->_flash_keep_keys({}); |
295 | (@{$href}{@keys}) = ((undef) x @keys); |
f4d79f85 |
296 | } |
297 | |
873f7011 |
298 | sub flash { |
299 | my $c = shift; |
78476ce0 |
300 | $c->_flash || $c->_load_flash || do { |
301 | $c->create_session_id; |
302 | $c->_flash( {} ); |
4207ce8d |
303 | } |
873f7011 |
304 | } |
305 | |
b7acf64e |
306 | sub session_expire_key { |
307 | my ( $c, %keys ) = @_; |
308 | |
309 | my $now = time; |
4207ce8d |
310 | @{ $c->session->{__expire_keys} }{ keys %keys } = |
311 | map { $now + $_ } values %keys; |
b7acf64e |
312 | } |
313 | |
9e447f9d |
314 | sub initialize_session_data { |
9a9252c2 |
315 | my $c = shift; |
9e447f9d |
316 | |
9a9252c2 |
317 | my $now = time; |
9e447f9d |
318 | |
4207ce8d |
319 | return $c->_session( |
320 | { |
321 | __created => $now, |
322 | __updated => $now, |
323 | |
324 | ( |
325 | $c->config->{session}{verify_address} |
326 | ? ( __address => $c->request->address ) |
327 | : () |
328 | ), |
329 | } |
330 | ); |
9e447f9d |
331 | } |
332 | |
9e447f9d |
333 | sub generate_session_id { |
334 | my $c = shift; |
335 | |
336 | my $digest = $c->_find_digest(); |
337 | $digest->add( $c->session_hash_seed() ); |
338 | return $digest->hexdigest; |
339 | } |
340 | |
78476ce0 |
341 | sub create_session_id { |
342 | my $c = shift; |
343 | |
344 | if ( !$c->_sessionid ) { |
345 | my $sid = $c->generate_session_id; |
346 | |
347 | $c->log->debug(qq/Created session "$sid"/) if $c->debug; |
348 | |
349 | $c->sessionid($sid); |
6687905d |
350 | $c->session_expires(1); |
78476ce0 |
351 | } |
352 | } |
353 | |
9e447f9d |
354 | my $counter; |
9a9252c2 |
355 | |
9e447f9d |
356 | sub session_hash_seed { |
9a9252c2 |
357 | my $c = shift; |
358 | |
359 | return join( "", ++$counter, time, rand, $$, {}, overload::StrVal($c), ); |
9e447f9d |
360 | } |
361 | |
362 | my $usable; |
9a9252c2 |
363 | |
9e447f9d |
364 | sub _find_digest () { |
9a9252c2 |
365 | unless ($usable) { |
d44bc687 |
366 | foreach my $alg (qw/SHA-1 SHA-256 MD5/) { |
4207ce8d |
367 | if ( eval { Digest->new($alg) } ) { |
5faaa4b0 |
368 | $usable = $alg; |
369 | last; |
370 | } |
7d139eeb |
371 | } |
4207ce8d |
372 | Catalyst::Exception->throw( |
9a9252c2 |
373 | "Could not find a suitable Digest module. Please install " |
4207ce8d |
374 | . "Digest::SHA1, Digest::SHA, or Digest::MD5" ) |
375 | unless $usable; |
9a9252c2 |
376 | } |
9e447f9d |
377 | |
378 | return Digest->new($usable); |
379 | } |
380 | |
99b2191e |
381 | sub dump_these { |
382 | my $c = shift; |
383 | |
384 | ( |
385 | $c->NEXT::dump_these(), |
386 | |
387 | $c->sessionid |
388 | ? ( [ "Session ID" => $c->sessionid ], [ Session => $c->session ], ) |
389 | : () |
390 | ); |
391 | } |
392 | |
9e447f9d |
393 | __PACKAGE__; |
394 | |
395 | __END__ |
396 | |
397 | =pod |
398 | |
399 | =head1 NAME |
400 | |
401 | Catalyst::Plugin::Session - Generic Session plugin - ties together server side |
fb1a4ac3 |
402 | storage and client side state required to maintain session data. |
9e447f9d |
403 | |
404 | =head1 SYNOPSIS |
405 | |
8f0b4c16 |
406 | # To get sessions to "just work", all you need to do is use these plugins: |
407 | |
408 | use Catalyst qw/ |
409 | Session |
410 | Session::Store::FastMmap |
411 | Session::State::Cookie |
412 | /; |
413 | |
414 | # you can replace Store::FastMmap with Store::File - both have sensible |
415 | # default configurations (see their docs for details) |
416 | |
417 | # more complicated backends are available for other scenarios (DBI storage, |
418 | # etc) |
419 | |
420 | |
421 | # after you've loaded the plugins you can save session data |
422 | # For example, if you are writing a shopping cart, it could be implemented |
423 | # like this: |
9e447f9d |
424 | |
229a5b53 |
425 | sub add_item : Local { |
426 | my ( $self, $c ) = @_; |
427 | |
428 | my $item_id = $c->req->param("item"); |
429 | |
8f0b4c16 |
430 | # $c->session is a hash ref, a bit like $c->stash |
431 | # the difference is that it' preserved across requests |
229a5b53 |
432 | |
433 | push @{ $c->session->{items} }, $item_id; |
434 | |
435 | $c->forward("MyView"); |
436 | } |
437 | |
438 | sub display_items : Local { |
439 | my ( $self, $c ) = @_; |
440 | |
441 | # values in $c->session are restored |
442 | $c->stash->{items_to_display} = |
8f0b4c16 |
443 | [ map { MyModel->retrieve($_) } @{ $c->session->{items} } ]; |
229a5b53 |
444 | |
445 | $c->forward("MyView"); |
446 | } |
447 | |
9e447f9d |
448 | =head1 DESCRIPTION |
449 | |
450 | The Session plugin is the base of two related parts of functionality required |
451 | for session management in web applications. |
452 | |
453 | The first part, the State, is getting the browser to repeat back a session key, |
454 | so that the web application can identify the client and logically string |
455 | several requests together into a session. |
456 | |
457 | The second part, the Store, deals with the actual storage of information about |
458 | the client. This data is stored so that the it may be revived for every request |
459 | made by the same client. |
460 | |
461 | This plugin links the two pieces together. |
462 | |
8f0b4c16 |
463 | =head1 RECCOMENDED BACKENDS |
464 | |
465 | =over 4 |
466 | |
467 | =item Session::State::Cookie |
468 | |
469 | The only really sane way to do state is using cookies. |
470 | |
471 | =item Session::Store::File |
472 | |
473 | A portable backend, based on Cache::File. |
474 | |
475 | =item Session::Store::FastMmap |
476 | |
477 | A fast and flexible backend, based on Cache::FastMmap. |
478 | |
479 | =back |
480 | |
9e447f9d |
481 | =head1 METHODS |
482 | |
483 | =over 4 |
484 | |
485 | =item sessionid |
486 | |
487 | An accessor for the session ID value. |
488 | |
489 | =item session |
490 | |
491 | Returns a hash reference that might contain unserialized values from previous |
492 | requests in the same session, and whose modified value will be saved for future |
493 | requests. |
494 | |
495 | This method will automatically create a new session and session ID if none |
496 | exists. |
497 | |
ab634fee |
498 | =item session_expires |
499 | |
500 | =item session_expires $reset |
501 | |
502 | This method returns the time when the current session will expire, or 0 if |
503 | there is no current session. If there is a session and it already expired, it |
504 | will delete the session and return 0 as well. |
505 | |
506 | If the C<$reset> parameter is true, and there is a session ID the expiry time |
507 | will be reset to the current time plus the time to live (see |
508 | L</CONFIGURATION>). This is used when creating a new session. |
509 | |
07e714d2 |
510 | =item flash |
511 | |
512 | This is like Ruby on Rails' flash data structure. Think of it as a stash that |
44ab6d1c |
513 | lasts for longer than one request, letting you redirect instead of forward. |
514 | |
515 | The flash data will be cleaned up only on requests on which actually use |
516 | $c->flash (thus allowing multiple redirections), and the policy is to delete |
bf6bd311 |
517 | all the keys which haven't changed since the flash data was loaded at the end |
518 | of every request. |
07e714d2 |
519 | |
520 | sub moose : Local { |
521 | my ( $self, $c ) = @_; |
522 | |
523 | $c->flash->{beans} = 10; |
524 | $c->response->redirect( $c->uri_for("foo") ); |
525 | } |
526 | |
527 | sub foo : Local { |
528 | my ( $self, $c ) = @_; |
529 | |
530 | my $value = $c->flash->{beans}; |
531 | |
532 | # ... |
533 | |
534 | $c->response->redirect( $c->uri_for("bar") ); |
535 | } |
536 | |
537 | sub bar : Local { |
538 | my ( $self, $c ) = @_; |
539 | |
540 | if ( exists $c->flash->{beans} ) { # false |
541 | |
542 | } |
543 | } |
544 | |
bf6bd311 |
545 | =item keep_flash @keys |
546 | |
547 | If you wawnt to keep a flash key for the next request too, even if it hasn't |
548 | changed, call C<keep_flash> and pass in the keys as arguments. |
549 | |
9e447f9d |
550 | =item session_delete_reason |
551 | |
552 | This accessor contains a string with the reason a session was deleted. Possible |
553 | values include: |
554 | |
555 | =over 4 |
556 | |
557 | =item * |
558 | |
559 | C<address mismatch> |
560 | |
561 | =item * |
562 | |
563 | C<session expired> |
564 | |
565 | =back |
566 | |
b7acf64e |
567 | =item session_expire_key $key, $ttl |
568 | |
569 | Mark a key to expire at a certain time (only useful when shorter than the |
570 | expiry time for the whole session). |
571 | |
572 | For example: |
573 | |
574 | __PACKAGE__->config->{session}{expires} = 1000000000000; # forever |
575 | |
576 | # later |
577 | |
578 | $c->session_expire_key( __user => 3600 ); |
579 | |
580 | Will make the session data survive, but the user will still be logged out after |
581 | an hour. |
582 | |
583 | Note that these values are not auto extended. |
584 | |
8f0b4c16 |
585 | =back |
586 | |
10c72079 |
587 | =head1 INTERNAL METHODS |
8f0b4c16 |
588 | |
589 | =over 4 |
590 | |
9e447f9d |
591 | =item setup |
592 | |
593 | This method is extended to also make calls to |
594 | C<check_session_plugin_requirements> and C<setup_session>. |
595 | |
596 | =item check_session_plugin_requirements |
597 | |
598 | This method ensures that a State and a Store plugin are also in use by the |
599 | application. |
600 | |
601 | =item setup_session |
602 | |
603 | This method populates C<< $c->config->{session} >> with the default values |
604 | listed in L</CONFIGURATION>. |
605 | |
606 | =item prepare_action |
607 | |
68fd02ae |
608 | This methoid is extended. |
609 | |
610 | It's only effect is if the (off by default) C<flash_to_stash> configuration |
611 | parameter is on - then it will copy the contents of the flash to the stash at |
612 | prepare time. |
9e447f9d |
613 | |
614 | =item finalize |
615 | |
616 | This method is extended and will extend the expiry time, as well as persist the |
617 | session data if a session exists. |
618 | |
619 | =item delete_session REASON |
620 | |
621 | This method is used to invalidate a session. It takes an optional parameter |
622 | which will be saved in C<session_delete_reason> if provided. |
623 | |
624 | =item initialize_session_data |
625 | |
626 | This method will initialize the internal structure of the session, and is |
627 | called by the C<session> method if appropriate. |
628 | |
68fd02ae |
629 | =item create_session_id |
630 | |
631 | Creates a new session id using C<generate_session_id> if there is no session ID |
632 | yet. |
633 | |
ab634fee |
634 | =item validate_session_id SID |
635 | |
636 | Make sure a session ID is of the right format. |
637 | |
638 | This currently ensures that the session ID string is any amount of case |
639 | insensitive hexadecimal characters. |
640 | |
229a5b53 |
641 | =item generate_session_id |
642 | |
643 | This method will return a string that can be used as a session ID. It is |
644 | supposed to be a reasonably random string with enough bits to prevent |
645 | collision. It basically takes C<session_hash_seed> and hashes it using SHA-1, |
646 | MD5 or SHA-256, depending on the availibility of these modules. |
647 | |
648 | =item session_hash_seed |
649 | |
650 | This method is actually rather internal to generate_session_id, but should be |
651 | overridable in case you want to provide more random data. |
652 | |
653 | Currently it returns a concatenated string which contains: |
654 | |
655 | =over 4 |
656 | |
657 | =item * |
658 | |
659 | A counter |
660 | |
661 | =item * |
662 | |
663 | The current time |
664 | |
665 | =item * |
666 | |
667 | One value from C<rand>. |
668 | |
669 | =item * |
670 | |
671 | The stringified value of a newly allocated hash reference |
672 | |
673 | =item * |
674 | |
675 | The stringified value of the Catalyst context object |
676 | |
677 | =back |
678 | |
679 | In the hopes that those combined values are entropic enough for most uses. If |
680 | this is not the case you can replace C<session_hash_seed> with e.g. |
681 | |
682 | sub session_hash_seed { |
683 | open my $fh, "<", "/dev/random"; |
684 | read $fh, my $bytes, 20; |
685 | close $fh; |
686 | return $bytes; |
687 | } |
688 | |
689 | Or even more directly, replace C<generate_session_id>: |
690 | |
691 | sub generate_session_id { |
692 | open my $fh, "<", "/dev/random"; |
693 | read $fh, my $bytes, 20; |
694 | close $fh; |
695 | return unpack("H*", $bytes); |
696 | } |
697 | |
698 | Also have a look at L<Crypt::Random> and the various openssl bindings - these |
699 | modules provide APIs for cryptographically secure random data. |
700 | |
99b2191e |
701 | =item dump_these |
702 | |
703 | See L<Catalyst/dump_these> - ammends the session data structure to the list of |
704 | dumped objects if session ID is defined. |
705 | |
9e447f9d |
706 | =back |
707 | |
a92c8aeb |
708 | =head1 USING SESSIONS DURING PREPARE |
709 | |
710 | The earliest point in time at which you may use the session data is after |
711 | L<Catalyst::Plugin::Session>'s C<prepare_action> has finished. |
712 | |
713 | State plugins must set $c->session ID before C<prepare_action>, and during |
714 | C<prepare_action> L<Catalyst::Plugin::Session> will actually load the data from |
715 | the store. |
716 | |
717 | sub prepare_action { |
718 | my $c = shift; |
719 | |
720 | # don't touch $c->session yet! |
b1cd7d77 |
721 | |
a92c8aeb |
722 | $c->NEXT::prepare_action( @_ ); |
723 | |
724 | $c->session; # this is OK |
725 | $c->sessionid; # this is also OK |
726 | } |
727 | |
9e447f9d |
728 | =head1 CONFIGURATION |
729 | |
229a5b53 |
730 | $c->config->{session} = { |
731 | expires => 1234, |
732 | }; |
9e447f9d |
733 | |
734 | All configuation parameters are provided in a hash reference under the |
735 | C<session> key in the configuration hash. |
736 | |
737 | =over 4 |
738 | |
739 | =item expires |
740 | |
741 | The time-to-live of each session, expressed in seconds. Defaults to 7200 (two |
742 | hours). |
743 | |
744 | =item verify_address |
745 | |
8c7e922c |
746 | When true, C<<$c->request->address>> will be checked at prepare time. If it is |
747 | not the same as the address that initiated the session, the session is deleted. |
9e447f9d |
748 | |
68fd02ae |
749 | =item flash_to_stash |
750 | |
751 | This option makes it easier to have actions behave the same whether they were |
752 | forwarded to or redirected to. On prepare time it copies the contents of |
753 | C<flash> (if any) to the stash. |
754 | |
9e447f9d |
755 | =back |
756 | |
757 | =head1 SPECIAL KEYS |
758 | |
759 | The hash reference returned by C<< $c->session >> contains several keys which |
760 | are automatically set: |
761 | |
762 | =over 4 |
763 | |
764 | =item __expires |
765 | |
ab634fee |
766 | This key no longer exists. Use C<session_expires> instead. |
9e447f9d |
767 | |
768 | =item __updated |
769 | |
d44bc687 |
770 | The last time a session was saved to the store. |
9e447f9d |
771 | |
772 | =item __created |
773 | |
774 | The time when the session was first created. |
775 | |
776 | =item __address |
777 | |
778 | The value of C<< $c->request->address >> at the time the session was created. |
8c7e922c |
779 | This value is only populated if C<verify_address> is true in the configuration. |
9e447f9d |
780 | |
781 | =back |
782 | |
c80e9f04 |
783 | =head1 CAVEATS |
784 | |
a552e4b5 |
785 | =head2 Round the Robin Proxies |
786 | |
c80e9f04 |
787 | C<verify_address> could make your site inaccessible to users who are behind |
788 | load balanced proxies. Some ISPs may give a different IP to each request by the |
789 | same client due to this type of proxying. If addresses are verified these |
790 | users' sessions cannot persist. |
791 | |
792 | To let these users access your site you can either disable address verification |
793 | as a whole, or provide a checkbox in the login dialog that tells the server |
794 | that it's OK for the address of the client to change. When the server sees that |
795 | this box is checked it should delete the C<__address> sepcial key from the |
796 | session hash when the hash is first created. |
797 | |
a552e4b5 |
798 | =head2 Race Conditions |
799 | |
800 | In this day and age where cleaning detergents and dutch football (not the |
801 | american kind) teams roam the plains in great numbers, requests may happen |
802 | simultaneously. This means that there is some risk of session data being |
803 | overwritten, like this: |
804 | |
805 | =over 4 |
806 | |
807 | =item 1. |
808 | |
809 | request a starts, request b starts, with the same session id |
810 | |
811 | =item 2. |
812 | |
813 | session data is loaded in request a |
814 | |
815 | =item 3. |
816 | |
817 | session data is loaded in request b |
818 | |
819 | =item 4. |
820 | |
821 | session data is changed in request a |
822 | |
823 | =item 5. |
824 | |
825 | request a finishes, session data is updated and written to store |
826 | |
827 | =item 6. |
828 | |
829 | request b finishes, session data is updated and written to store, overwriting |
830 | changes by request a |
831 | |
832 | =back |
833 | |
834 | If this is a concern in your application, a soon to be developed locking |
835 | solution is the only safe way to go. This will have a bigger overhead. |
836 | |
837 | For applications where any given user is only making one request at a time this |
838 | plugin should be safe enough. |
839 | |
d45028d6 |
840 | =head1 AUTHORS |
841 | |
baa9db9c |
842 | =over 4 |
843 | |
844 | =item Andy Grundman |
845 | |
846 | =item Christian Hansen |
847 | |
848 | =item Yuval Kogman, C<nothingmuch@woobling.org> (current maintainer) |
849 | |
850 | =item Sebastian Riedel |
851 | |
852 | =back |
853 | |
854 | And countless other contributers from #catalyst. Thanks guys! |
d45028d6 |
855 | |
cc40ae4b |
856 | =head1 COPYRIGHT & LICENSE |
d45028d6 |
857 | |
858 | Copyright (c) 2005 the aforementioned authors. All rights |
859 | reserved. This program is free software; you can redistribute |
860 | it and/or modify it under the same terms as Perl itself. |
861 | |
9e447f9d |
862 | =cut |
863 | |
864 | |