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 (); |
9e447f9d |
13 | |
37160715 |
14 | our $VERSION = "0.01"; |
15 | |
9e447f9d |
16 | BEGIN { |
9a9252c2 |
17 | __PACKAGE__->mk_accessors(qw/sessionid session_delete_reason/); |
9e447f9d |
18 | } |
19 | |
20 | sub setup { |
9a9252c2 |
21 | my $c = shift; |
22 | |
23 | $c->NEXT::setup(@_); |
24 | |
25 | $c->check_session_plugin_requirements; |
26 | $c->setup_session; |
27 | |
28 | return $c; |
9e447f9d |
29 | } |
30 | |
31 | sub check_session_plugin_requirements { |
9a9252c2 |
32 | my $c = shift; |
9e447f9d |
33 | |
9a9252c2 |
34 | unless ( $c->isa("Catalyst::Plugin::Session::State") |
35 | && $c->isa("Catalyst::Plugin::Session::Store") ) |
36 | { |
37 | my $err = |
38 | ( "The Session plugin requires both Session::State " |
39 | . "and Session::Store plugins to be used as well." ); |
9e447f9d |
40 | |
9a9252c2 |
41 | $c->log->fatal($err); |
42 | Catalyst::Exception->throw($err); |
43 | } |
9e447f9d |
44 | } |
45 | |
46 | sub setup_session { |
9a9252c2 |
47 | my $c = shift; |
9e447f9d |
48 | |
9a9252c2 |
49 | my $cfg = ( $c->config->{session} ||= {} ); |
9e447f9d |
50 | |
9a9252c2 |
51 | %$cfg = ( |
52 | expires => 7200, |
53 | verify_address => 1, |
54 | %$cfg, |
55 | ); |
9e447f9d |
56 | |
9a9252c2 |
57 | $c->NEXT::setup_session(); |
9e447f9d |
58 | } |
59 | |
60 | sub finalize { |
9a9252c2 |
61 | my $c = shift; |
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62 | |
9a9252c2 |
63 | if ( $c->{session} ) { |
9e447f9d |
64 | |
9a9252c2 |
65 | # all sessions are extended at the end of the request |
66 | my $now = time; |
67 | @{ $c->{session} }{qw/__updated __expires/} = |
68 | ( $now, $c->config->{session}{expires} + $now ); |
69 | $c->store_session_data( $c->sessionid, $c->{session} ); |
70 | } |
71 | |
72 | $c->NEXT::finalize(@_); |
9e447f9d |
73 | } |
74 | |
75 | sub prepare_action { |
76 | my $c = shift; |
77 | |
3f182468 |
78 | if ( my $sid = $c->sessionid ) { |
3f182468 |
79 | my $s = $c->{session} ||= $c->get_session_data($sid); |
80 | if ( !$s or $s->{__expires} < time ) { |
81 | |
82 | # session expired |
83 | $c->log->debug("Deleting session $sid (expired)") if $c->debug; |
84 | $c->delete_session("session expired"); |
85 | } |
29543a62 |
86 | elsif ($c->config->{session}{verify_address} |
3f182468 |
87 | && $c->{session}{__address} |
88 | && $c->{session}{__address} ne $c->request->address ) |
89 | { |
90 | $c->log->warn( |
91 | "Deleting session $sid due to address mismatch (" |
92 | . $c->{session}{__address} . " != " |
93 | . $c->request->address . ")", |
94 | ); |
95 | $c->delete_session("address mismatch"); |
96 | } |
29543a62 |
97 | else { |
98 | $c->log->debug(qq/Restored session "$sid"/) if $c->debug; |
99 | } |
9a9252c2 |
100 | } |
101 | |
3f182468 |
102 | $c->NEXT::prepare_action(@_); |
9e447f9d |
103 | } |
104 | |
105 | sub delete_session { |
9a9252c2 |
106 | my ( $c, $msg ) = @_; |
9e447f9d |
107 | |
9a9252c2 |
108 | # delete the session data |
109 | my $sid = $c->sessionid; |
110 | $c->delete_session_data($sid); |
9e447f9d |
111 | |
9a9252c2 |
112 | # reset the values in the context object |
113 | $c->{session} = undef; |
114 | $c->sessionid(undef); |
115 | $c->session_delete_reason($msg); |
9e447f9d |
116 | } |
117 | |
118 | sub session { |
9a9252c2 |
119 | my $c = shift; |
9e447f9d |
120 | |
121 | return $c->{session} if $c->{session}; |
122 | |
9a9252c2 |
123 | my $sid = $c->generate_session_id; |
124 | $c->sessionid($sid); |
9e447f9d |
125 | |
9a9252c2 |
126 | $c->log->debug(qq/Created session "$sid"/) if $c->debug; |
9e447f9d |
127 | |
9a9252c2 |
128 | return $c->initialize_session_data; |
9e447f9d |
129 | } |
130 | |
131 | sub initialize_session_data { |
9a9252c2 |
132 | my $c = shift; |
9e447f9d |
133 | |
9a9252c2 |
134 | my $now = time; |
9e447f9d |
135 | |
9a9252c2 |
136 | return $c->{session} = { |
137 | __created => $now, |
138 | __updated => $now, |
139 | __expires => $now + $c->config->{session}{expires}, |
9e447f9d |
140 | |
9a9252c2 |
141 | ( |
142 | $c->config->{session}{verify_address} |
143 | ? ( __address => $c->request->address ) |
144 | : () |
145 | ), |
146 | }; |
9e447f9d |
147 | } |
148 | |
9e447f9d |
149 | sub generate_session_id { |
150 | my $c = shift; |
151 | |
152 | my $digest = $c->_find_digest(); |
153 | $digest->add( $c->session_hash_seed() ); |
154 | return $digest->hexdigest; |
155 | } |
156 | |
157 | my $counter; |
9a9252c2 |
158 | |
9e447f9d |
159 | sub session_hash_seed { |
9a9252c2 |
160 | my $c = shift; |
161 | |
162 | return join( "", ++$counter, time, rand, $$, {}, overload::StrVal($c), ); |
9e447f9d |
163 | } |
164 | |
165 | my $usable; |
9a9252c2 |
166 | |
9e447f9d |
167 | sub _find_digest () { |
9a9252c2 |
168 | unless ($usable) { |
7d139eeb |
169 | foreach my $alg (qw/SHA-1 MD5 SHA-256/) { |
170 | eval { |
29543a62 |
171 | my $obj = Digest->new($alg); |
172 | $usable = $alg; |
173 | return $obj; |
174 | }; |
7d139eeb |
175 | } |
176 | $usable |
9a9252c2 |
177 | or Catalyst::Exception->throw( |
178 | "Could not find a suitable Digest module. Please install " |
179 | . "Digest::SHA1, Digest::SHA, or Digest::MD5" ); |
180 | } |
9e447f9d |
181 | |
182 | return Digest->new($usable); |
183 | } |
184 | |
99b2191e |
185 | sub dump_these { |
186 | my $c = shift; |
187 | |
188 | ( |
189 | $c->NEXT::dump_these(), |
190 | |
191 | $c->sessionid |
192 | ? ( [ "Session ID" => $c->sessionid ], [ Session => $c->session ], ) |
193 | : () |
194 | ); |
195 | } |
196 | |
9e447f9d |
197 | __PACKAGE__; |
198 | |
199 | __END__ |
200 | |
201 | =pod |
202 | |
203 | =head1 NAME |
204 | |
205 | Catalyst::Plugin::Session - Generic Session plugin - ties together server side |
206 | storage and client side tickets required to maintain session data. |
207 | |
208 | =head1 SYNOPSIS |
209 | |
210 | use Catalyst qw/Session Session::Store::FastMmap Session::State::Cookie/; |
211 | |
229a5b53 |
212 | sub add_item : Local { |
213 | my ( $self, $c ) = @_; |
214 | |
215 | my $item_id = $c->req->param("item"); |
216 | |
217 | # $c->session is stored across requests, so |
218 | # other actions will see these values |
219 | |
220 | push @{ $c->session->{items} }, $item_id; |
221 | |
222 | $c->forward("MyView"); |
223 | } |
224 | |
225 | sub display_items : Local { |
226 | my ( $self, $c ) = @_; |
227 | |
228 | # values in $c->session are restored |
229 | $c->stash->{items_to_display} = |
230 | [ map { MyModel->retrieve($_) } @{ $c->session->{items} } ]; |
231 | |
232 | $c->forward("MyView"); |
233 | } |
234 | |
9e447f9d |
235 | =head1 DESCRIPTION |
236 | |
237 | The Session plugin is the base of two related parts of functionality required |
238 | for session management in web applications. |
239 | |
240 | The first part, the State, is getting the browser to repeat back a session key, |
241 | so that the web application can identify the client and logically string |
242 | several requests together into a session. |
243 | |
244 | The second part, the Store, deals with the actual storage of information about |
245 | the client. This data is stored so that the it may be revived for every request |
246 | made by the same client. |
247 | |
248 | This plugin links the two pieces together. |
249 | |
250 | =head1 METHODS |
251 | |
252 | =over 4 |
253 | |
254 | =item sessionid |
255 | |
256 | An accessor for the session ID value. |
257 | |
258 | =item session |
259 | |
260 | Returns a hash reference that might contain unserialized values from previous |
261 | requests in the same session, and whose modified value will be saved for future |
262 | requests. |
263 | |
264 | This method will automatically create a new session and session ID if none |
265 | exists. |
266 | |
267 | =item session_delete_reason |
268 | |
269 | This accessor contains a string with the reason a session was deleted. Possible |
270 | values include: |
271 | |
272 | =over 4 |
273 | |
274 | =item * |
275 | |
276 | C<address mismatch> |
277 | |
278 | =item * |
279 | |
280 | C<session expired> |
281 | |
282 | =back |
283 | |
284 | =item setup |
285 | |
286 | This method is extended to also make calls to |
287 | C<check_session_plugin_requirements> and C<setup_session>. |
288 | |
289 | =item check_session_plugin_requirements |
290 | |
291 | This method ensures that a State and a Store plugin are also in use by the |
292 | application. |
293 | |
294 | =item setup_session |
295 | |
296 | This method populates C<< $c->config->{session} >> with the default values |
297 | listed in L</CONFIGURATION>. |
298 | |
299 | =item prepare_action |
300 | |
301 | This methoid is extended, and will restore session data and check it for |
302 | validity if a session id is defined. It assumes that the State plugin will |
303 | populate the C<sessionid> key beforehand. |
304 | |
305 | =item finalize |
306 | |
307 | This method is extended and will extend the expiry time, as well as persist the |
308 | session data if a session exists. |
309 | |
310 | =item delete_session REASON |
311 | |
312 | This method is used to invalidate a session. It takes an optional parameter |
313 | which will be saved in C<session_delete_reason> if provided. |
314 | |
315 | =item initialize_session_data |
316 | |
317 | This method will initialize the internal structure of the session, and is |
318 | called by the C<session> method if appropriate. |
319 | |
229a5b53 |
320 | =item generate_session_id |
321 | |
322 | This method will return a string that can be used as a session ID. It is |
323 | supposed to be a reasonably random string with enough bits to prevent |
324 | collision. It basically takes C<session_hash_seed> and hashes it using SHA-1, |
325 | MD5 or SHA-256, depending on the availibility of these modules. |
326 | |
327 | =item session_hash_seed |
328 | |
329 | This method is actually rather internal to generate_session_id, but should be |
330 | overridable in case you want to provide more random data. |
331 | |
332 | Currently it returns a concatenated string which contains: |
333 | |
334 | =over 4 |
335 | |
336 | =item * |
337 | |
338 | A counter |
339 | |
340 | =item * |
341 | |
342 | The current time |
343 | |
344 | =item * |
345 | |
346 | One value from C<rand>. |
347 | |
348 | =item * |
349 | |
350 | The stringified value of a newly allocated hash reference |
351 | |
352 | =item * |
353 | |
354 | The stringified value of the Catalyst context object |
355 | |
356 | =back |
357 | |
358 | In the hopes that those combined values are entropic enough for most uses. If |
359 | this is not the case you can replace C<session_hash_seed> with e.g. |
360 | |
361 | sub session_hash_seed { |
362 | open my $fh, "<", "/dev/random"; |
363 | read $fh, my $bytes, 20; |
364 | close $fh; |
365 | return $bytes; |
366 | } |
367 | |
368 | Or even more directly, replace C<generate_session_id>: |
369 | |
370 | sub generate_session_id { |
371 | open my $fh, "<", "/dev/random"; |
372 | read $fh, my $bytes, 20; |
373 | close $fh; |
374 | return unpack("H*", $bytes); |
375 | } |
376 | |
377 | Also have a look at L<Crypt::Random> and the various openssl bindings - these |
378 | modules provide APIs for cryptographically secure random data. |
379 | |
99b2191e |
380 | =item dump_these |
381 | |
382 | See L<Catalyst/dump_these> - ammends the session data structure to the list of |
383 | dumped objects if session ID is defined. |
384 | |
9e447f9d |
385 | =back |
386 | |
a92c8aeb |
387 | =head1 USING SESSIONS DURING PREPARE |
388 | |
389 | The earliest point in time at which you may use the session data is after |
390 | L<Catalyst::Plugin::Session>'s C<prepare_action> has finished. |
391 | |
392 | State plugins must set $c->session ID before C<prepare_action>, and during |
393 | C<prepare_action> L<Catalyst::Plugin::Session> will actually load the data from |
394 | the store. |
395 | |
396 | sub prepare_action { |
397 | my $c = shift; |
398 | |
399 | # don't touch $c->session yet! |
400 | |
401 | $c->NEXT::prepare_action( @_ ); |
402 | |
403 | $c->session; # this is OK |
404 | $c->sessionid; # this is also OK |
405 | } |
406 | |
9e447f9d |
407 | =head1 CONFIGURATION |
408 | |
229a5b53 |
409 | $c->config->{session} = { |
410 | expires => 1234, |
411 | }; |
9e447f9d |
412 | |
413 | All configuation parameters are provided in a hash reference under the |
414 | C<session> key in the configuration hash. |
415 | |
416 | =over 4 |
417 | |
418 | =item expires |
419 | |
420 | The time-to-live of each session, expressed in seconds. Defaults to 7200 (two |
421 | hours). |
422 | |
423 | =item verify_address |
424 | |
425 | When false, C<< $c->request->address >> will be checked at prepare time. If it |
426 | is not the same as the address that initiated the session, the session is |
427 | deleted. |
428 | |
429 | =back |
430 | |
431 | =head1 SPECIAL KEYS |
432 | |
433 | The hash reference returned by C<< $c->session >> contains several keys which |
434 | are automatically set: |
435 | |
436 | =over 4 |
437 | |
438 | =item __expires |
439 | |
440 | A timestamp whose value is the last second when the session is still valid. If |
441 | a session is restored, and __expires is less than the current time, the session |
442 | is deleted. |
443 | |
444 | =item __updated |
445 | |
446 | The last time a session was saved. This is the value of |
447 | C<< $c->{session}{__expires} - $c->config->{session}{expires} >>. |
448 | |
449 | =item __created |
450 | |
451 | The time when the session was first created. |
452 | |
453 | =item __address |
454 | |
455 | The value of C<< $c->request->address >> at the time the session was created. |
456 | This value is only populated of C<verify_address> is true in the configuration. |
457 | |
458 | =back |
459 | |
c80e9f04 |
460 | =head1 CAVEATS |
461 | |
462 | C<verify_address> could make your site inaccessible to users who are behind |
463 | load balanced proxies. Some ISPs may give a different IP to each request by the |
464 | same client due to this type of proxying. If addresses are verified these |
465 | users' sessions cannot persist. |
466 | |
467 | To let these users access your site you can either disable address verification |
468 | as a whole, or provide a checkbox in the login dialog that tells the server |
469 | that it's OK for the address of the client to change. When the server sees that |
470 | this box is checked it should delete the C<__address> sepcial key from the |
471 | session hash when the hash is first created. |
472 | |
d45028d6 |
473 | =head1 AUTHORS |
474 | |
475 | |
476 | |
477 | =head1 COPYRIGHT & LICNESE |
478 | |
479 | Copyright (c) 2005 the aforementioned authors. All rights |
480 | reserved. This program is free software; you can redistribute |
481 | it and/or modify it under the same terms as Perl itself. |
482 | |
9e447f9d |
483 | =cut |
484 | |
485 | |