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