3 Catalyst::Manual::Tutorial::05_Authentication - Catalyst Tutorial - Chapter 5: Authentication
8 This is B<Chapter 5 of 10> for the Catalyst tutorial.
10 L<Tutorial Overview|Catalyst::Manual::Tutorial>
16 L<Introduction|Catalyst::Manual::Tutorial::01_Intro>
20 L<Catalyst Basics|Catalyst::Manual::Tutorial::02_CatalystBasics>
24 L<More Catalyst Basics|Catalyst::Manual::Tutorial::03_MoreCatalystBasics>
28 L<Basic CRUD|Catalyst::Manual::Tutorial::04_BasicCRUD>
36 L<Authorization|Catalyst::Manual::Tutorial::06_Authorization>
40 L<Debugging|Catalyst::Manual::Tutorial::07_Debugging>
44 L<Testing|Catalyst::Manual::Tutorial::08_Testing>
48 L<Advanced CRUD|Catalyst::Manual::Tutorial::09_AdvancedCRUD>
52 L<Appendices|Catalyst::Manual::Tutorial::10_Appendices>
59 Now that we finally have a simple yet functional application, we can
60 focus on providing authentication (with authorization coming next in
63 This chapter of the tutorial is divided into two main sections: 1) basic,
64 cleartext authentication and 2) hash-based authentication.
66 You can checkout the source code for this example from the catalyst
67 subversion repository as per the instructions in
68 L<Catalyst::Manual::Tutorial::01_Intro|Catalyst::Manual::Tutorial::01_Intro>.
71 =head1 BASIC AUTHENTICATION
73 This section explores how to add authentication logic to a Catalyst
77 =head2 Add Users and Roles to the Database
79 First, we add both user and role information to the database (we will
80 add the role information here although it will not be used until the
81 authorization section, Chapter 6). Create a new SQL script file by opening
82 C<myapp02.sql> in your editor and insert:
85 -- Add users and role tables, along with a many-to-many join table
87 PRAGMA foreign_keys = ON;
89 id INTEGER PRIMARY KEY,
98 id INTEGER PRIMARY KEY,
101 CREATE TABLE user_role (
102 user_id INTEGER REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
103 role_id INTEGER REFERENCES role(id) ON DELETE CASCADE ON UPDATE CASCADE,
104 PRIMARY KEY (user_id, role_id)
107 -- Load up some initial test data
109 INSERT INTO users VALUES (1, 'test01', 'mypass', 't01@na.com', 'Joe', 'Blow', 1);
110 INSERT INTO users VALUES (2, 'test02', 'mypass', 't02@na.com', 'Jane', 'Doe', 1);
111 INSERT INTO users VALUES (3, 'test03', 'mypass', 't03@na.com', 'No', 'Go', 0);
112 INSERT INTO role VALUES (1, 'user');
113 INSERT INTO role VALUES (2, 'admin');
114 INSERT INTO user_role VALUES (1, 1);
115 INSERT INTO user_role VALUES (1, 2);
116 INSERT INTO user_role VALUES (2, 1);
117 INSERT INTO user_role VALUES (3, 1);
119 Then load this into the C<myapp.db> database with the following command:
121 $ sqlite3 myapp.db < myapp02.sql
124 =head2 Add User and Role Information to DBIC Schema
126 Although we could manually edit the DBIC schema information to include
127 the new tables added in the previous step, let's use the C<create=static>
128 option on the DBIC model helper to do most of the work for us:
130 $ script/myapp_create.pl model DB DBIC::Schema MyApp::Schema \
131 create=static components=TimeStamp dbi:SQLite:myapp.db \
132 on_connect_do="PRAGMA foreign_keys = ON"
133 exists "/root/dev/MyApp/script/../lib/MyApp/Model"
134 exists "/root/dev/MyApp/script/../t"
135 Dumping manual schema for MyApp::Schema to directory /root/dev/MyApp/script/../lib ...
136 Schema dump completed.
137 exists "/root/dev/MyApp/script/../lib/MyApp/Model/DB.pm"
139 $ ls lib/MyApp/Schema/Result
140 Author.pm BookAuthor.pm Book.pm Role.pm User.pm UserRole.pm
142 Notice how the helper has added three new table-specific Result Source
143 files to the C<lib/MyApp/Schema/Result> directory. And, more
144 importantly, even if there were changes to the existing result source
145 files, those changes would have only been written above the C<# DO NOT
146 MODIFY THIS OR ANYTHING ABOVE!> comment and your hand-edited
147 enhancements would have been preserved.
149 Speaking of "hand-editted enhancements," we should now add the
150 C<many_to_many> relationship information to the User Result Source file.
151 As with the Book, BookAuthor, and Author files in
152 L<Chapter 3|Catalyst::Manual::Tutorial::03_MoreCatalystBasics>,
153 L<DBIx::Class::Schema::Loader|DBIx::Class::Schema::Loader> has
154 automatically created the C<has_many> and C<belongs_to> relationships
155 for the new User, UserRole, and Role tables. However, as a convenience
156 for mapping Users to their assigned roles (see
157 L<Chapter 6|Catalyst::Manual::Tutorial::06_Authorization>), we will
158 also manually add a C<many_to_many> relationship. Edit
159 C<lib/MyApp/Schema/Result/User.pm> add the following information between
160 the C<# DO NOT MODIFY THIS OR ANYTHING ABOVE!> comment and the closing
165 # 1) Name of relationship, DBIC will create accessor with this name
166 # 2) Name of has_many() relationship this many_to_many() is shortcut for
167 # 3) Name of belongs_to() relationship in model class of has_many() above
168 # You must already have the has_many() defined to use a many_to_many().
169 __PACKAGE__->many_to_many(roles => 'user_roles', 'role_id');
171 The code for this update is obviously very similar to the edits we made
172 to the C<Book> and C<Author> classes created in Chapter 3 with one
173 exception: we only defined the C<many_to_many> relationship in one
174 direction. Whereas we felt that we would want to map Authors to Books
175 B<AND> Books to Authors, here we are only adding the convenience
176 C<many_to_many> in the Users to Roles direction.
178 Note that we do not need to make any change to the
179 C<lib/MyApp/Schema.pm> schema file. It simply tells DBIC to load all
180 of the Result Class and ResultSet Class files it finds in below the
181 C<lib/MyApp/Schema> directory, so it will automatically pick up our
182 new table information.
185 =head2 Sanity-Check of the Development Server Reload
187 We aren't ready to try out the authentication just yet; we only want to
188 do a quick check to be sure our model loads correctly. Assuming that you
189 are following along and using the "-r" option on C<myapp_server.pl>,
190 then the development server should automatically reload (if not, press
191 C<Ctrl-C> to break out of the server if it's running and then enter
192 C<script/myapp_server.pl> to start it). Look for the three new model
193 objects in the startup debug output:
196 .-------------------------------------------------------------------+----------.
198 +-------------------------------------------------------------------+----------+
199 | MyApp::Controller::Books | instance |
200 | MyApp::Controller::Root | instance |
201 | MyApp::Model::DB | instance |
202 | MyApp::Model::DB::Author | class |
203 | MyApp::Model::DB::Book | class |
204 | MyApp::Model::DB::BookAuthor | class |
205 | MyApp::Model::DB::Role | class |
206 | MyApp::Model::DB::User | class |
207 | MyApp::Model::DB::UserRole | class |
208 | MyApp::View::HTML | instance |
209 '-------------------------------------------------------------------+----------'
212 Again, notice that your "Result Class" classes have been "re-loaded"
213 by Catalyst under C<MyApp::Model>.
216 =head2 Include Authentication and Session Plugins
218 Edit C<lib/MyApp.pm> and update it as follows (everything below
219 C<StackTrace> is new):
233 Session::State::Cookie
236 B<Note:> As discussed in MoreCatalystBasics, different versions of
237 C<Catalyst::Devel> have used a variety of methods to load the plugins,
238 but we are going to use the current Catalyst 5.8X practice of putting
239 them on the C<use Catalyst> line.
241 The C<Authentication> plugin supports Authentication while the
242 C<Session> plugins are required to maintain state across multiple HTTP
245 Note that the only required Authentication class is the main one. This
246 is a change that occurred in version 0.09999_01 of the
247 C<Authentication> plugin. You B<do not need> to specify a particular
248 Authentication::Store or Authentication::Credential plugin. Instead,
249 indicate the Store and Credential you want to use in your application
250 configuration (see below).
252 Make sure you include the additional plugins as new dependencies in
253 the Makefile.PL file something like this:
255 requires 'Catalyst::Plugin::Authentication';
256 requires 'Catalyst::Plugin::Session';
257 requires 'Catalyst::Plugin::Session::Store::File';
258 requires 'Catalyst::Plugin::Session::State::Cookie';
260 Note that there are several options for
261 L<Session::Store|Catalyst::Plugin::Session::Store>.
262 L<Session::Store::Memcached|Catalyst::Plugin::Session::Store::Memcached> is
263 generally a good choice if you are on Unix. If you are running on
265 L<Session::Store::File|Catalyst::Plugin::Session::Store::File> is fine. Consult
266 L<Session::Store|Catalyst::Plugin::Session::Store> and its subclasses
267 for additional information and options (for example to use a database-
268 backed session store).
271 =head2 Configure Authentication
273 There are a variety of ways to provide configuration information to
274 L<Catalyst::Plugin::Authentication|Catalyst::Plugin::Authentication>.
276 L<Catalyst::Authentication::Realm::SimpleDB|Catalyst::Authentication::Realm::SimpleDB>
277 because it automatically sets a reasonable set of defaults for us. Open
278 C<lib/MyApp.pm> and place the following text above the call to
279 C<__PACKAGE__-E<gt>setup();>:
281 # Configure SimpleDB Authentication
282 __PACKAGE__->config->{'Plugin::Authentication'} = {
285 user_model => 'DB::User',
286 password_type => 'clear',
290 We could have placed this configuration in C<myapp.conf>, but placing
291 it in C<lib/MyApp.pm> is probably a better place since it's not likely
292 something that users of your application will want to change during
293 deployment (or you could use a mixture: leave C<class> and
294 C<user_model> defined in C<lib/MyApp.pm> as we show above, but place
295 C<password_type> in C<myapp.conf> to allow the type of password to be
296 easily modified during deployment). We will stick with putting
297 all of the authentication-related configuration in C<lib/MyApp.pm>
298 for the tutorial, but if you wish to use C<myapp.conf>, just convert
299 to the following code:
301 <Plugin::Authentication>
307 </Plugin::Authentication>
309 B<TIP:> Here is a short script that will dump the contents of
310 C<MyApp->config> to L<Config::General|Config::General> format in
313 $ CATALYST_DEBUG=0 perl -Ilib -e 'use MyApp; use Config::General;
314 Config::General->new->save_file("myapp.conf", MyApp->config);'
316 B<HOWEVER>, if you try out the command above, be sure to delete the
317 "myapp.conf" command. Otherwise, you will wind up with duplicate
320 B<NOTE:> Because we are using SimpleDB along with a database layout
321 that complies with its default assumptions: we don't need to specify
322 the names of the columns where our username and password information
323 is stored (hence, the "Simple" part of "SimpleDB"). That being said,
324 SimpleDB lets you specify that type of information if you need to.
326 C<Catalyst::Authentication::Realm::SimpleDB|Catalyst::Authentication::Realm::SimpleDB>
330 =head2 Add Login and Logout Controllers
332 Use the Catalyst create script to create two stub controller files:
334 $ script/myapp_create.pl controller Login
335 $ script/myapp_create.pl controller Logout
337 You could easily use a single controller here. For example, you could
338 have a C<User> controller with both C<login> and C<logout> actions.
339 Remember, Catalyst is designed to be very flexible, and leaves such
340 matters up to you, the designer and programmer.
342 Then open C<lib/MyApp/Controller/Login.pm>, locate the
343 C<sub index :Path :Args(0)> method (or C<sub index : Private> if you
344 are using an older version of Catalyst) that was automatically
345 inserted by the helpers when we created the Login controller above,
346 and update the definition of C<sub index> to match:
354 sub index :Path :Args(0) {
357 # Get the username and password from form
358 my $username = $c->request->params->{username};
359 my $password = $c->request->params->{password};
361 # If the username and password values were found in form
362 if ($username && $password) {
363 # Attempt to log the user in
364 if ($c->authenticate({ username => $username,
365 password => $password } )) {
366 # If successful, then let them use the application
367 $c->response->redirect($c->uri_for(
368 $c->controller('Books')->action_for('list')));
371 # Set an error message
372 $c->stash(error_msg => "Bad username or password.");
375 # Set an error message
376 $c->stash(error_msg => "Empty username or password.")
377 unless ($c->user_exists);
380 # If either of above don't work out, send to the login page
381 $c->stash(template => 'login.tt2');
384 Be sure to remove the
385 C<$c-E<gt>response-E<gt>body('Matched MyApp::Controller::Login in Login.');>
386 line of the C<sub index>.
388 This controller fetches the C<username> and C<password> values from the
389 login form and attempts to authenticate the user. If successful, it
390 redirects the user to the book list page. If the login fails, the user
391 will stay at the login page and receive an error message. If the
392 C<username> and C<password> values are not present in the form, the
393 user will be taken to the empty login form.
395 Note that we could have used something like "C<sub default :Path>",
396 however, it is generally recommended (partly for historical reasons,
397 and partly for code clarity) only to use C<default> in
398 C<MyApp::Controller::Root>, and then mainly to generate the 404 not
399 found page for the application.
401 Instead, we are using "C<sub somename :Path :Args(0) {...}>" here to
402 specifically match the URL C</login>. C<Path> actions (aka, "literal
403 actions") create URI matches relative to the namespace of the
404 controller where they are defined. Although C<Path> supports
405 arguments that allow relative and absolute paths to be defined, here
406 we use an empty C<Path> definition to match on just the name of the
407 controller itself. The method name, C<index>, is arbitrary. We make
408 the match even more specific with the C<:Args(0)> action modifier --
409 this forces the match on I<only> C</login>, not
410 C</login/somethingelse>.
412 Next, update the corresponding method in
413 C<lib/MyApp/Controller/Logout.pm> to match:
421 sub index :Path :Args(0) {
424 # Clear the user's state
427 # Send the user to the starting point
428 $c->response->redirect($c->uri_for('/'));
431 As with the login controller, be sure to delete the
432 C<$c-E<gt>response-E<gt>body('Matched MyApp::Controller::Logout in Logout.');>
433 line of the C<sub index>.
436 =head2 Add a Login Form TT Template Page
438 Create a login form by opening C<root/src/login.tt2> and inserting:
440 [% META title = 'Login' %]
443 <form method="post" action="[% c.uri_for('/login') %]">
447 <td><input type="text" name="username" size="40" /></td>
451 <td><input type="password" name="password" size="40" /></td>
454 <td colspan="2"><input type="submit" name="submit" value="Submit" /></td>
460 =head2 Add Valid User Check
462 We need something that provides enforcement for the authentication
463 mechanism -- a I<global> mechanism that prevents users who have not
464 passed authentication from reaching any pages except the login page.
465 This is generally done via an C<auto> action/method in
466 C<lib/MyApp/Controller/Root.pm>.
468 Edit the existing C<lib/MyApp/Controller/Root.pm> class file and insert
469 the following method:
473 Check if there is a user and, if not, forward to login page
477 # Note that 'auto' runs after 'begin' but before your actions and that
478 # 'auto's "chain" (all from application path to most specific class are run)
479 # See the 'Actions' section of 'Catalyst::Manual::Intro' for more info.
483 # Allow unauthenticated users to reach the login page. This
484 # allows unauthenticated users to reach any action in the Login
485 # controller. To lock it down to a single action, we could use:
486 # if ($c->action eq $c->controller('Login')->action_for('index'))
487 # to only allow unauthenticated access to the 'index' action we
489 if ($c->controller eq $c->controller('Login')) {
493 # If a user doesn't exist, force login
494 if (!$c->user_exists) {
495 # Dump a log message to the development server debug output
496 $c->log->debug('***Root::auto User not found, forwarding to /login');
497 # Redirect the user to the login page
498 $c->response->redirect($c->uri_for('/login'));
499 # Return 0 to cancel 'post-auto' processing and prevent use of application
503 # User found, so return 1 to continue with processing after this 'auto'
508 L<Catalyst::Manual::Tutorial::03_MoreCatalystBasics/CREATE A CATALYST CONTROLLER>,
509 every C<auto> method from the application/root controller down to the
510 most specific controller will be called. By placing the
511 authentication enforcement code inside the C<auto> method of
512 C<lib/MyApp/Controller/Root.pm> (or C<lib/MyApp.pm>), it will be
513 called for I<every> request that is received by the entire
517 =head2 Displaying Content Only to Authenticated Users
519 Let's say you want to provide some information on the login page that
520 changes depending on whether the user has authenticated yet. To do
521 this, open C<root/src/login.tt2> in your editor and add the following
522 lines to the bottom of the file:
527 # This code illustrates how certain parts of the TT
528 # template will only be shown to users who have logged in
530 [% IF c.user_exists %]
531 Please Note: You are already logged in as '[% c.user.username %]'.
532 You can <a href="[% c.uri_for('/logout') %]">logout</a> here.
534 You need to log in to use this application.
537 Note that this whole block is a comment because the "#" appears
538 immediate after the "[%" (with no spaces in between). Although it
539 can be a handy way to temporarily "comment out" a whole block of
540 TT code, it's probably a little too subtle for use in "normal"
545 Although most of the code is comments, the middle few lines provide a
546 "you are already logged in" reminder if the user returns to the login
547 page after they have already authenticated. For users who have not yet
548 authenticated, a "You need to log in..." message is displayed (note the
549 use of an IF-THEN-ELSE construct in TT).
552 =head2 Try Out Authentication
554 The development server should have reloaded each time we edited one of
555 the Controllers in the previous section. Now try going to
556 L<http://localhost:3000/books/list> and you should be redirected to the
557 login page, hitting Shift+Reload or Ctrl+Reload if necessary (the "You
558 are already logged in" message should I<not> appear -- if it does, click
559 the C<logout> button and try again). Note the C<***Root::auto User not
560 found...> debug message in the development server output. Enter username
561 C<test01> and password C<mypass>, and you should be taken to the Book
564 B<IMPORTANT NOTE:> If you are having issues with authentication on
565 Internet Explorer, be sure to check the system clocks on both your
566 server and client machines. Internet Explorer is very picky about
567 timestamps for cookies. You can quickly sync a Debian system by
568 installing the "ntpdate" package:
570 sudo aptitude -y install ntpdate
572 And then run the following command:
576 Or, depending on your firewall configuration:
578 sudo ntpdate-debian -u
580 Note: NTP can be a little more finicky about firewalls because it uses
581 UDP vs. the more common TCP that you see with most Internet protocols.
582 Worse case, you might have to manually set the time on your development
583 box instead of using NTP.
585 Open C<root/src/books/list.tt2> and add the following lines to the
586 bottom (below the closing </table> tag):
590 <a href="[% c.uri_for('/login') %]">Login</a>
591 <a href="[% c.uri_for(c.controller.action_for('form_create')) %]">Create</a>
594 Reload your browser and you should now see a "Login" and "Create" links
595 at the bottom of the page (as mentioned earlier, you can update template
596 files without a development server reload). Click the first link
597 to return to the login page. This time you I<should> see the "You are
598 already logged in" message.
600 Finally, click the C<You can logout here> link on the C</login> page.
601 You should stay at the login page, but the message should change to "You
602 need to log in to use this application."
605 =head1 USING PASSWORD HASHES
607 In this section we increase the security of our system by converting
608 from cleartext passwords to SHA-1 password hashes that include a
609 random "salt" value to make them extremely difficult to crack with
610 dictionary and "rainbow table" attacks.
612 B<Note:> This section is optional. You can skip it and the rest of the
613 tutorial will function normally.
615 Be aware that even with the techniques shown in this section, the browser
616 still transmits the passwords in cleartext to your application. We are
617 just avoiding the I<storage> of cleartext passwords in the database by
618 using a salted SHA-1 hash. If you are concerned about cleartext passwords
619 between the browser and your application, consider using SSL/TLS, made
620 easy with the Catalyst plugin Catalyst::Plugin:RequireSSL.
623 =head2 Re-Run the DBIC::Schema Model Helper to Include DBIx::Class::PassphraseColumn
625 Next, we can re-run the model helper to have it include
626 L<DBIx::Class::PassphraseColumn> in all of the Result Classes it generates for
627 us. Simply use the same command we saw in Chapters 3 and 4, but add
628 C<,PassphraseColumn> to the C<components> argument:
630 $ script/myapp_create.pl model DB DBIC::Schema MyApp::Schema \
631 create=static components=TimeStamp,PassphraseColumn dbi:SQLite:myapp.db \
632 on_connect_do="PRAGMA foreign_keys = ON"
634 If you then open one of the Result Classes, you will see that it
635 includes PassphraseColumn in the C<load_components> line. Take a look at
636 C<lib/MyApp/Schema/Result/User.pm> since that's the main class where we
637 want to use hashed and salted passwords:
639 __PACKAGE__->load_components("InflateColumn::DateTime", "TimeStamp", "PassphraseColumn");
642 =head2 Modify the "password" Column to Use PassphraseColumn
644 Open the file C<lib/MyApp/Schema/Result/User.pm> and enter the following
645 text below the "# DO NOT MODIFY THIS OR ANYTHING ABOVE!" line but above
648 # Have the 'password' column use a SHA-1 hash and 20-byte salt
649 # with RFC 2307 encoding; Generate the 'check_password" method
650 __PACKAGE__->add_columns(
652 passphrase => 'rfc2307',
653 passphrase_class => 'SaltedDigest',
655 algorithm => 'SHA-1',
658 passphrase_check_method => 'check_password',
662 This redefines the automatically generated definition for the password fields at
663 the top of the Result Class file to now use PassphraseColumn logic, storing
664 passwords in RFC 2307 format (C<passphrase> is set to C<rfc2307>).
665 C<passphrase_class> can be set to the name of any C<Authen::Passphrase::*>
666 class, such as C<SaltedDigest> to use L<Authen::Passphrase::SaltedDigest>, or
667 C<BlowfishCrypt> to use L<Authen::Passphrase::BlowfishCrypt>.
668 C<passphrase_args> is then used to customize the passphrase class you
669 selected. Here we specified the digest algorithm to use as C<SHA-1> and the size
670 of the salt to use, but we could have also specified any other option the
671 selected passphrase class supports.
673 =head2 Load Hashed Passwords in the Database
675 Next, let's create a quick script to load some hashed and salted passwords
676 into the C<password> column of our C<users> table. Open the file
677 C<set_hashed_passwords.pl> in your editor and enter the following text:
686 my $schema = MyApp::Schema->connect('dbi:SQLite:myapp.db');
688 my @users = $schema->resultset('User')->all;
690 foreach my $user (@users) {
691 $user->password('mypass');
695 PassphraseColumn lets us simply call C<$user->check_password($password)>
696 to see if the user has supplied the correct password, or, as we show
697 above, call C<$user->update($new_password)> to update the hashed
698 password stored for this user.
700 Then run the following command:
702 $ DBIC_TRACE=1 perl -Ilib set_hashed_passwords.pl
704 We had to use the C<-Ilib> argument to tell perl to look under the
705 C<lib> directory for our C<MyApp::Schema> model.
707 The DBIC_TRACE output should show that the update worked:
709 $ DBIC_TRACE=1 perl -Ilib set_hashed_passwords.pl
710 SELECT me.id, me.username, me.password, me.email_address,
711 me.first_name, me.last_name, me.active FROM users me:
712 UPDATE users SET password = ? WHERE ( id = ? ):
713 '{SSHA}esgz64CpHMo8pMfgIIszP13ft23z/zio04aCwNdm0wc6MDeloMUH4g==', '1'
714 UPDATE users SET password = ? WHERE ( id = ? ):
715 '{SSHA}FpGhpCJus+Ea9ne4ww8404HH+hJKW/fW+bAv1v6FuRUy2G7I2aoTRQ==', '2'
716 UPDATE users SET password = ? WHERE ( id = ? ):
717 '{SSHA}ZyGlpiHls8qFBSbHr3r5t/iqcZE602XLMbkSVRRNl6rF8imv1abQVg==', '3'
719 But we can further confirm our actions by dumping the users table:
721 $ sqlite3 myapp.db "select * from users"
722 1|test01|{SSHA}esgz64CpHMo8pMfgIIszP13ft23z/zio04aCwNdm0wc6MDeloMUH4g==|t01@na.com|Joe|Blow|1
723 2|test02|{SSHA}FpGhpCJus+Ea9ne4ww8404HH+hJKW/fW+bAv1v6FuRUy2G7I2aoTRQ==|t02@na.com|Jane|Doe|1
724 3|test03|{SSHA}ZyGlpiHls8qFBSbHr3r5t/iqcZE602XLMbkSVRRNl6rF8imv1abQVg==|t03@na.com|No|Go|0
726 As you can see, the passwords are much harder to steal from the
727 database (not only are the hashes stored, but every hash is different
728 even though the passwords are the same because of the added "salt"
729 value). Also note that this demonstrates how to use a DBIx::Class
730 model outside of your web application -- a very useful feature in many
734 =head2 Enable Hashed and Salted Passwords
736 Edit C<lib/MyApp.pm> and update it to match the following text (the
737 only change is to the C<password_type> field):
739 # Configure SimpleDB Authentication
740 __PACKAGE__->config->{'Plugin::Authentication'} = {
743 user_model => 'DB::User',
744 password_type => 'self_check',
748 The use of C<self_check> will cause
749 Catalyst::Plugin::Authentication::Store::DBIC to call the
750 C<check_password> method we enabled on our C<password> columns.
753 =head2 Try Out the Hashed Passwords
755 The development server should restart as soon as your save the
756 C<lib/MyApp.pm> file in the previous section. You should now be able to
757 go to L<http://localhost:3000/books/list> and login as before. When
758 done, click the "logout" link on the login page (or point your browser
759 at L<http://localhost:3000/logout>).
762 =head1 USING THE SESSION FOR FLASH
764 As discussed in the previous chapter of the tutorial, C<flash> allows
765 you to set variables in a way that is very similar to C<stash>, but it
766 will remain set across multiple requests. Once the value is read, it
767 is cleared (unless reset). Although C<flash> has nothing to do with
768 authentication, it does leverage the same session plugins. Now that
769 those plugins are enabled, let's go back and update the "delete and
770 redirect with query parameters" code seen at the end of the L<Basic
771 CRUD|Catalyst::Manual::Tutorial::04_BasicCRUD> chapter of the tutorial to
772 take advantage of C<flash>.
774 First, open C<lib/MyApp/Controller/Books.pm> and modify C<sub delete>
775 to match the following (everything after the model search line of code
784 sub delete :Chained('object') :PathPart('delete') :Args(0) {
787 # Use the book object saved by 'object' and delete it along
788 # with related 'book_authors' entries
789 $c->stash->{object}->delete;
791 # Use 'flash' to save information across requests until it's read
792 $c->flash->{status_msg} = "Book deleted";
794 # Redirect the user back to the list page
795 $c->response->redirect($c->uri_for($self->action_for('list')));
798 Next, open C<root/src/wrapper.tt2> and update the TT code to pull from
799 flash vs. the C<status_msg> query parameter:
803 [%# Status and error messages %]
804 <span class="message">[% status_msg || c.flash.status_msg %]</span>
805 <span class="error">[% error_msg %]</span>
806 [%# This is where TT will stick all of your template's contents. -%]
808 </div><!-- end content -->
811 Although the sample above only shows the C<content> div, leave the
812 rest of the file intact -- the only change we made to replace
813 "|| c.request.params.status_msg" with "c.flash.status_msg" in the
814 C<< <span class="message"> >> line.
819 Authenticate using the login screen and then point your browser to
820 L<http://localhost:3000/books/url_create/Test/1/4> to create an extra
821 several books. Click the "Return to list" link and delete one of the
822 "Test" books you just added. The C<flash> mechanism should retain our
823 "Book deleted" status message across the redirect.
825 B<NOTE:> While C<flash> will save information across multiple requests,
826 I<it does get cleared the first time it is read>. In general, this is
827 exactly what you want -- the C<flash> message will get displayed on
828 the next screen where it's appropriate, but it won't "keep showing up"
829 after that first time (unless you reset it). Please refer to
830 L<Catalyst::Plugin::Session|Catalyst::Plugin::Session> for additional
834 =head2 Switch To Flash-To-Stash
836 Although the a use of flash above works well, the
837 C<status_msg || c.flash.status_msg> statement is a little ugly. A nice
838 alternative is to use the C<flash_to_stash> feature that automatically
839 copies the content of flash to stash. This makes your controller
840 and template code work regardless of where it was directly access, a
841 forward, or a redirect. To enable C<flash_to_stash>, you can either
842 set the value in C<lib/MyApp.pm> by changing the default
843 C<__PACKAGE__-E<gt>config> setting to something like:
847 # Disable deprecated behavior needed by old applications
848 disable_component_resolution_regex_fallback => 1,
849 session => { flash_to_stash => 1 },
852 B<or> add the following to C<myapp.conf>:
858 The C<__PACKAGE__-E<gt>config> option is probably preferable here
859 since it's not something you will want to change at runtime without it
860 possibly breaking some of your code.
862 Then edit C<root/src/wrapper.tt2> and change the C<status_msg> line
863 to match the following:
865 <span class="message">[% status_msg %]</span>
867 Now go to L<http://localhost:3000/books/list> in your browser. Delete
868 another of the "Test" books you added in the previous step. Flash should
869 still maintain the status message across the redirect even though you
870 are no longer explicitly accessing C<c.flash>.
875 Kennedy Clark, C<hkclark@gmail.com>
877 Please report any errors, issues or suggestions to the author. The
878 most recent version of the Catalyst Tutorial can be found at
879 L<http://dev.catalyst.perl.org/repos/Catalyst/Catalyst-Manual/5.80/trunk/lib/Catalyst/Manual/Tutorial/>.
881 Copyright 2006-2010, Kennedy Clark, under the
882 Creative Commons Attribution Share-Alike License Version 3.0
883 (L<http://creativecommons.org/licenses/by-sa/3.0/us/>).