Oops, missing a couple C::M::DBIC::Schema version references
[catagits/Catalyst-Manual.git] / lib / Catalyst / Manual / Tutorial / Authentication.pod
d442cc9f 1=head1 NAME
3533daff 3Catalyst::Manual::Tutorial::Authentication - Catalyst Tutorial - Part 5: Authentication
d442cc9f 4
6=head1 OVERVIEW
3533daff 8This is B<Part 5 of 10> for the Catalyst tutorial.
d442cc9f 9
10L<Tutorial Overview|Catalyst::Manual::Tutorial>
12=over 4
14=item 1
18=item 2
20L<Catalyst Basics|Catalyst::Manual::Tutorial::CatalystBasics>
22=item 3
3533daff 24L<More Catalyst Basics|Catalyst::Manual::Tutorial::MoreCatalystBasics>
d442cc9f 25
26=item 4
3533daff 28L<Basic CRUD|Catalyst::Manual::Tutorial::BasicCRUD>
d442cc9f 29
30=item 5
3533daff 32B<Authentication>
d442cc9f 33
34=item 6
3533daff 36L<Authorization|Catalyst::Manual::Tutorial::Authorization>
d442cc9f 37
38=item 7
3533daff 40L<Debugging|Catalyst::Manual::Tutorial::Debugging>
d442cc9f 41
42=item 8
3533daff 44L<Testing|Catalyst::Manual::Tutorial::Testing>
d442cc9f 45
46=item 9
3533daff 48L<Advanced CRUD|Catalyst::Manual::Tutorial::AdvancedCRUD>
d442cc9f 49
3533daff 50=item 10
d442cc9f 51
3533daff 52L<Appendices|Catalyst::Manual::Tutorial::Appendices>
d442cc9f 53
3533daff 54=back
2d0526d1 55
2d0526d1 56
d442cc9f 57=head1 DESCRIPTION
905a3a26 59Now that we finally have a simple yet functional application, we can
60focus on providing authentication (with authorization coming next in
9ad715b3 61Part 6).
d442cc9f 62
63This part of the tutorial is divided into two main sections: 1) basic,
64cleartext authentication and 2) hash-based authentication.
66You can checkout the source code for this example from the catalyst
67subversion repository as per the instructions in
1390ef0e 68L<Catalyst::Manual::Tutorial::Intro|Catalyst::Manual::Tutorial::Intro>.
d442cc9f 69
fbbb9084 70
d442cc9f 71=head1 BASIC AUTHENTICATION
73This section explores how to add authentication logic to a Catalyst
77=head2 Add Users and Roles to the Database
79First, we add both user and role information to the database (we will
80add the role information here although it will not be used until the
9ad715b3 81authorization section, Part 6). Create a new SQL script file by opening
d442cc9f 82C<myapp02.sql> in your editor and insert:
84 --
85 -- Add users and roles tables, along with a many-to-many join table
86 --
87 CREATE TABLE users (
89 username TEXT,
90 password TEXT,
91 email_address TEXT,
92 first_name TEXT,
93 last_name TEXT,
94 active INTEGER
95 );
96 CREATE TABLE roles (
98 role TEXT
99 );
100 CREATE TABLE user_roles (
101 user_id INTEGER,
102 role_id INTEGER,
103 PRIMARY KEY (user_id, role_id)
104 );
105 --
106 -- Load up some initial test data
107 --
108 INSERT INTO users VALUES (1, 'test01', 'mypass', 't01@na.com', 'Joe', 'Blow', 1);
109 INSERT INTO users VALUES (2, 'test02', 'mypass', 't02@na.com', 'Jane', 'Doe', 1);
110 INSERT INTO users VALUES (3, 'test03', 'mypass', 't03@na.com', 'No', 'Go', 0);
111 INSERT INTO roles VALUES (1, 'user');
112 INSERT INTO roles VALUES (2, 'admin');
113 INSERT INTO user_roles VALUES (1, 1);
114 INSERT INTO user_roles VALUES (1, 2);
115 INSERT INTO user_roles VALUES (2, 1);
116 INSERT INTO user_roles VALUES (3, 1);
118Then load this into the C<myapp.db> database with the following command:
120 $ sqlite3 myapp.db < myapp02.sql
123=head2 Add User and Role Information to DBIC Schema
3533daff 125Although we could manually edit the DBIC schema information to include
126the new tables added in the previous step, let's use the C<create=static>
127option on the DBIC model helper to do most of the work for us:
d442cc9f 128
d0496197 129 $ script/myapp_create.pl model DB DBIC::Schema MyApp::Schema create=static dbi:SQLite:myapp.db
1390ef0e 130 exists "/root/dev/MyApp/script/../lib/MyApp/Model"
131 exists "/root/dev/MyApp/script/../t"
132 Dumping manual schema for MyApp::Schema to directory /root/dev/MyApp/script/../lib ...
133 Schema dump completed.
134 exists "/root/dev/MyApp/script/../lib/MyApp/Model/DB.pm"
135 $
d0496197 136 $ ls lib/MyApp/Schema
3533daff 137 Authors.pm BookAuthors.pm Books.pm Roles.pm UserRoles.pm Users.pm
d442cc9f 138
905a3a26 139Notice how the helper has added three new table-specific result source
140files to the C<lib/MyApp/Schema/MyApp> directory. And, more
141importantly, even if there were changes to the existing result source
142files, those changes would have only been written above the C<# DO NOT
191dee29 143MODIFY THIS OR ANYTHING ABOVE!> comment and your hand-edited
3533daff 144enhancements would have been preserved.
d442cc9f 145
191dee29 146Speaking of "hand-edit ted enhancements," we should now add
905a3a26 147relationship information to the three new result source files. Edit
148each of these files and add the following information between the C<#
3533daff 149DO NOT MODIFY THIS OR ANYTHING ABOVE!> comment and the closing C<1;>:
d442cc9f 150
d0496197 151C<lib/MyApp/Schema/Users.pm>:
d442cc9f 152
d442cc9f 153 #
154 # Set relationships:
155 #
1390ef0e 156
d442cc9f 157 # has_many():
158 # args:
159 # 1) Name of relationship, DBIC will create accessor with this name
160 # 2) Name of the model class referenced by this relationship
1435672d 161 # 3) Column name in *foreign* table (aka, foreign key in peer table)
d0496197 162 __PACKAGE__->has_many(map_user_role => 'MyApp::Schema::UserRoles', 'user_id');
1390ef0e 163
3533daff 164 # many_to_many():
165 # args:
166 # 1) Name of relationship, DBIC will create accessor with this name
905a3a26 167 # 2) Name of has_many() relationship this many_to_many() is shortcut for
168 # 3) Name of belongs_to() relationship in model class of has_many() above
3533daff 169 # You must already have the has_many() defined to use a many_to_many().
170 __PACKAGE__->many_to_many(roles => 'map_user_role', 'role');
d442cc9f 171
d0496197 173C<lib/MyApp/Schema/Roles.pm>:
d442cc9f 174
d442cc9f 175 #
176 # Set relationships:
177 #
1390ef0e 178
d442cc9f 179 # has_many():
180 # args:
181 # 1) Name of relationship, DBIC will create accessor with this name
182 # 2) Name of the model class referenced by this relationship
1435672d 183 # 3) Column name in *foreign* table (aka, foreign key in peer table)
d0496197 184 __PACKAGE__->has_many(map_user_role => 'MyApp::Schema::UserRoles', 'role_id');
d442cc9f 185
d0496197 187C<lib/MyApp/Schema/UserRoles.pm>:
d442cc9f 188
d442cc9f 189 #
190 # Set relationships:
191 #
1390ef0e 192
d442cc9f 193 # belongs_to():
194 # args:
195 # 1) Name of relationship, DBIC will create accessor with this name
196 # 2) Name of the model class referenced by this relationship
197 # 3) Column name in *this* table
d0496197 198 __PACKAGE__->belongs_to(user => 'MyApp::Schema::Users', 'user_id');
1390ef0e 199
d442cc9f 200 # belongs_to():
201 # args:
202 # 1) Name of relationship, DBIC will create accessor with this name
203 # 2) Name of the model class referenced by this relationship
204 # 3) Column name in *this* table
d0496197 205 __PACKAGE__->belongs_to(role => 'MyApp::Schema::Roles', 'role_id');
d442cc9f 206
3533daff 207
905a3a26 208The code for these three sets of updates is obviously very similar to
209the edits we made to the C<Books>, C<Authors>, and C<BookAuthors>
3533daff 210classes created in Part 3.
905a3a26 212Note that we do not need to make any change to the
213C<lib/MyApp/Schema.pm> schema file. It simply tells DBIC to
79a529cc 214load all of the result class files it finds in below the
905a3a26 215C<lib/MyApp/Schema> directory, so it will automatically pick
3533daff 216up our new table information.
d442cc9f 217
219=head2 Sanity-Check Reload of Development Server
905a3a26 221We aren't ready to try out the authentication just yet; we only want
222to do a quick check to be sure our model loads correctly. Press
223C<Ctrl-C> to kill the previous server instance (if it's still running)
3533daff 224and restart it:
d442cc9f 225
226 $ script/myapp_server.pl
228Look for the three new model objects in the startup debug output:
230 ...
231 .-------------------------------------------------------------------+----------.
232 | Class | Type |
233 +-------------------------------------------------------------------+----------+
234 | MyApp::Controller::Books | instance |
235 | MyApp::Controller::Root | instance |
d0496197 236 | MyApp::Model::DB | instance |
237 | MyApp::Model::DB::Author | class |
238 | MyApp::Model::DB::Books | class |
239 | MyApp::Model::DB::BookAuthors | class |
240 | MyApp::Model::DB::Roles | class |
241 | MyApp::Model::DB::Users | class |
242 | MyApp::Model::DB::UserRoles | class |
d442cc9f 243 | MyApp::View::TT | instance |
244 '-------------------------------------------------------------------+----------'
245 ...
79a529cc 247Again, notice that your "result class" classes have been "re-loaded"
3533daff 248by Catalyst under C<MyApp::Model>.
d442cc9f 249
251=head2 Include Authentication and Session Plugins
905a3a26 253Edit C<lib/MyApp.pm> and update it as follows (everything below
3533daff 254C<StackTrace> is new):
d442cc9f 255
1390ef0e 256 __PACKAGE__->setup(qw/
d442cc9f 257 -Debug
258 ConfigLoader
259 Static::Simple
1390ef0e 260
d442cc9f 261 StackTrace
1390ef0e 262
d442cc9f 263 Authentication
1390ef0e 264
d442cc9f 265 Session
266 Session::Store::FastMmap
267 Session::State::Cookie
1390ef0e 268 /);
d442cc9f 269
94d8da41 270B<Note:> As discussed in MoreCatalystBasics, different versions of
271C<Catalyst::Devel> have used a variety of methods to load the plugins.
533fee73 272You can put the plugins in the C<use Catalyst> statement if you prefer.
94d8da41 273
905a3a26 274The C<Authentication> plugin supports Authentication while the
275C<Session> plugins are required to maintain state across multiple HTTP
6d0971ad 277
905a3a26 278Note that the only required Authentication class is the main one. This
279is a change that occurred in version 0.09999_01 of the
280C<Authentication> plugin. You B<do not need> to specify a particular
281Authentication::Store or Authentication::Credential plugin. Instead,
282indicate the Store and Credential you want to use in your application
6d0971ad 283configuration (see below).
905a3a26 285Note that there are several options for
288is generally a good choice if you are on Unix; try
289L<Session::Store::File|Catalyst::Plugin::Session::Store::File> if you
290are on Win32) -- consult
291L<Session::Store|Catalyst::Plugin::Session::Store> and its subclasses
3533daff 292for additional information and options (for example to use a database-
293backed session store).
d442cc9f 294
296=head2 Configure Authentication
fbbb9084 298Although C<__PACKAGE__-E<gt>config(name =E<gt> 'value');> is still
299supported, newer Catalyst applications tend to place all configuration
300information in C<myapp.conf> and automatically load this information
301into C<MyApp-E<gt>config> using the
905a3a26 302L<ConfigLoader|Catalyst::Plugin::ConfigLoader> plugin.
15e1d0b2 303
fbbb9084 304As discussed in Part 3 of the tutorial, Catalyst has recently
305switched from a default config file format of YAML to
306L<Config::General|Config::General> (an apache-like format). In case
307you are using a version of Catalyst earlier than v5.7014, delete the
308C<myapp.yml>, or convert it to .conf format using the TIP in
309L<Catalyst::Manual::MoreCatalystBasics/EDIT THE LIST OF CATALYST PLUGINS>
310then simply follow the directions below to create a new C<myapp.conf>
311file. Although we will use the C<Config::General> format here because
312YAML files can be difficult to cut and paste in certain environments,
313you are free to use any format supported by
314L<Catalyst::Plugin::ConfigLoader|Catalyst::Plugin::ConfigLoader> and
315L<Config::Any|Config::Any> -- Catalyst will transparently handle the
316different formats.
15e1d0b2 317
905a3a26 318Here, we need to load several parameters that tell
320where to locate information in your database. To do this, edit the
c010ae0d 321C<myapp.conf> file and update it to match:
1390ef0e 323 # rename this file to MyApp.yml and put a : in front of "name" if
324 # you want to use yaml like in old versions of Catalyst
c010ae0d 325 name MyApp
326 <authentication>
327 default_realm dbic
328 <realms>
329 <dbic>
330 <credential>
905a3a26 331 # Note: this first definition would be the same as setting
3533daff 332 # __PACKAGE__->config->{authentication}->{realms}->{dbic}
905a3a26 333 # ->{credential} = 'Password' in lib/MyApp.pm
3533daff 334 #
335 # Specify that we are going to do password-based auth
c010ae0d 336 class Password
3533daff 337 # This is the name of the field in the users table with the
338 # password stored in it
c010ae0d 339 password_field password
905a3a26 340 # We are using an unencrypted password for now
c010ae0d 341 password_type clear
342 </credential>
343 <store>
3533daff 344 # Use DBIC to retrieve username, password & role information
c010ae0d 345 class DBIx::Class
905a3a26 346 # This is the model object created by Catalyst::Model::DBIC
d0496197 347 # from your schema (you created 'MyApp::Schema::User' but as
905a3a26 348 # the Catalyst startup debug messages show, it was loaded as
d0496197 349 # 'MyApp::Model::DB::Users').
905a3a26 350 # NOTE: Omit 'MyApp::Model' here just as you would when using
d0496197 351 # '$c->model("DB::Users)'
352 user_class DB::Users
c010ae0d 353 </store>
354 </dbic>
d0496197 355 </realms>
356 </authentication>
d442cc9f 357
358Inline comments in the code above explain how each field is being used.
1390ef0e 360
d442cc9f 361=head2 Add Login and Logout Controllers
363Use the Catalyst create script to create two stub controller files:
365 $ script/myapp_create.pl controller Login
366 $ script/myapp_create.pl controller Logout
fbbb9084 368You could easily use a single controller here. For example, you could
369have a C<User> controller with both C<login> and C<logout> actions.
370Remember, Catalyst is designed to be very flexible, and leaves such
371matters up to you, the designer and programmer.
d442cc9f 372
fbbb9084 373Then open C<lib/MyApp/Controller/Login.pm>, locate the
374C<sub index :Path :Args(0)> method (or C<sub index : Private> if you
375are using an older version of Catalyst) that was automatically
376inserted by the helpers when we created the Login controller above,
377and update the definition of C<sub index> to match:
d442cc9f 378
379 =head2 index
1390ef0e 380
d442cc9f 381 Login logic
1390ef0e 382
d442cc9f 383 =cut
1390ef0e 384
ae492862 385 sub index :Path :Args(0) {
d442cc9f 386 my ($self, $c) = @_;
1390ef0e 387
d442cc9f 388 # Get the username and password from form
389 my $username = $c->request->params->{username} || "";
390 my $password = $c->request->params->{password} || "";
1390ef0e 391
d442cc9f 392 # If the username and password values were found in form
393 if ($username && $password) {
394 # Attempt to log the user in
905a3a26 395 if ($c->authenticate({ username => $username,
5fefca35 396 password => $password } )) {
d442cc9f 397 # If successful, then let them use the application
0416017e 398 $c->response->redirect($c->uri_for(
399 $c->controller('Books')->action_for('list')));
d442cc9f 400 return;
401 } else {
402 # Set an error message
403 $c->stash->{error_msg} = "Bad username or password.";
404 }
405 }
1390ef0e 406
d442cc9f 407 # If either of above don't work out, send to the login page
408 $c->stash->{template} = 'login.tt2';
409 }
411This controller fetches the C<username> and C<password> values from the
905a3a26 412login form and attempts to authenticate the user. If successful, it
413redirects the user to the book list page. If the login fails, the user
414will stay at the login page and receive an error message. If the
415C<username> and C<password> values are not present in the form, the
f632e28b 416user will be taken to the empty login form.
d442cc9f 417
fbbb9084 418Note that we could have used something like "C<sub default :Path>",
1390ef0e 419however, it is generally recommended (partly for historical reasons,
420and partly for code clarity) only to use C<default> in
421C<MyApp::Controller::Root>, and then mainly to generate the 404 not
85d49fb6 422found page for the application.
ae492862 423
fbbb9084 424Instead, we are using "C<sub somename :Path :Args(0) {...}>" here to
905a3a26 425specifically match the URL C</login>. C<Path> actions (aka, "literal
426actions") create URI matches relative to the namespace of the
427controller where they are defined. Although C<Path> supports
428arguments that allow relative and absolute paths to be defined, here
429we use an empty C<Path> definition to match on just the name of the
430controller itself. The method name, C<index>, is arbitrary. We make
ae492862 431the match even more specific with the C<:Args(0)> action modifier --
905a3a26 432this forces the match on I<only> C</login>, not
d442cc9f 433C</login/somethingelse>.
905a3a26 435Next, update the corresponding method in
3533daff 436C<lib/MyApp/Controller/Logout.pm> to match:
d442cc9f 437
438 =head2 index
1390ef0e 439
d442cc9f 440 Logout logic
1390ef0e 441
d442cc9f 442 =cut
1390ef0e 443
ae492862 444 sub index :Path :Args(0) {
d442cc9f 445 my ($self, $c) = @_;
1390ef0e 446
d442cc9f 447 # Clear the user's state
448 $c->logout;
1390ef0e 449
d442cc9f 450 # Send the user to the starting point
451 $c->response->redirect($c->uri_for('/'));
452 }
905a3a26 454As with the login controller, be sure to delete the
14e5ed66 455C<$c-E<gt>response-E<gt>body('Matched MyApp::Controller::Logout in Logout.');>
d442cc9f 456line of the C<sub index>.
459=head2 Add a Login Form TT Template Page
461Create a login form by opening C<root/src/login.tt2> and inserting:
463 [% META title = 'Login' %]
1390ef0e 464
d442cc9f 465 <!-- Login form -->
8a7c5151 466 <form method="post" action="[% c.uri_for('/login') %]">
d442cc9f 467 <table>
468 <tr>
469 <td>Username:</td>
470 <td><input type="text" name="username" size="40" /></td>
471 </tr>
472 <tr>
473 <td>Password:</td>
474 <td><input type="password" name="password" size="40" /></td>
475 </tr>
476 <tr>
477 <td colspan="2"><input type="submit" name="submit" value="Submit" /></td>
478 </tr>
479 </table>
480 </form>
483=head2 Add Valid User Check
485We need something that provides enforcement for the authentication
486mechanism -- a I<global> mechanism that prevents users who have not
487passed authentication from reaching any pages except the login page.
488This is generally done via an C<auto> action/method (prior to Catalyst
489v5.66, this sort of thing would go in C<MyApp.pm>, but starting in
490v5.66, the preferred location is C<lib/MyApp/Controller/Root.pm>).
492Edit the existing C<lib/MyApp/Controller/Root.pm> class file and insert
493the following method:
495 =head2 auto
1390ef0e 496
d442cc9f 497 Check if there is a user and, if not, forward to login page
1390ef0e 498
d442cc9f 499 =cut
1390ef0e 500
d442cc9f 501 # Note that 'auto' runs after 'begin' but before your actions and that
905a3a26 502 # 'auto's "chain" (all from application path to most specific class are run)
d442cc9f 503 # See the 'Actions' section of 'Catalyst::Manual::Intro' for more info.
504 sub auto : Private {
505 my ($self, $c) = @_;
1390ef0e 506
d442cc9f 507 # Allow unauthenticated users to reach the login page. This
191dee29 508 # allows unauthenticated users to reach any action in the Login
d442cc9f 509 # controller. To lock it down to a single action, we could use:
510 # if ($c->action eq $c->controller('Login')->action_for('index'))
905a3a26 511 # to only allow unauthenticated access to the 'index' action we
d442cc9f 512 # added above.
513 if ($c->controller eq $c->controller('Login')) {
514 return 1;
515 }
1390ef0e 516
d442cc9f 517 # If a user doesn't exist, force login
518 if (!$c->user_exists) {
519 # Dump a log message to the development server debug output
520 $c->log->debug('***Root::auto User not found, forwarding to /login');
521 # Redirect the user to the login page
522 $c->response->redirect($c->uri_for('/login'));
523 # Return 0 to cancel 'post-auto' processing and prevent use of application
524 return 0;
525 }
1390ef0e 526
d442cc9f 527 # User found, so return 1 to continue with processing after this 'auto'
528 return 1;
529 }
0416017e 531As discussed in
532L<Catalyst::Manual::Tutorial::MoreCatalystBasics/CREATE A CATALYST CONTROLLER>,
533every C<auto> method from the application/root controller down to the
534most specific controller will be called. By placing the
535authentication enforcement code inside the C<auto> method of
536C<lib/MyApp/Controller/Root.pm> (or C<lib/MyApp.pm>), it will be
537called for I<every> request that is received by the entire
d442cc9f 539
541=head2 Displaying Content Only to Authenticated Users
543Let's say you want to provide some information on the login page that
544changes depending on whether the user has authenticated yet. To do
545this, open C<root/src/login.tt2> in your editor and add the following
546lines to the bottom of the file:
548 <p>
549 [%
905a3a26 550 # This code illustrates how certain parts of the TT
d442cc9f 551 # template will only be shown to users who have logged in
552 %]
8a7c5151 553 [% IF c.user_exists %]
554 Please Note: You are already logged in as '[% c.user.username %]'.
555 You can <a href="[% c.uri_for('/logout') %]">logout</a> here.
d442cc9f 556 [% ELSE %]
557 You need to log in to use this application.
558 [% END %]
559 [%#
560 Note that this whole block is a comment because the "#" appears
905a3a26 561 immediate after the "[%" (with no spaces in between). Although it
562 can be a handy way to temporarily "comment out" a whole block of
563 TT code, it's probably a little too subtle for use in "normal"
d442cc9f 564 comments.
565 %]
3533daff 566 </p>
d442cc9f 567
568Although most of the code is comments, the middle few lines provide a
569"you are already logged in" reminder if the user returns to the login
570page after they have already authenticated. For users who have not yet
571authenticated, a "You need to log in..." message is displayed (note the
572use of an IF-THEN-ELSE construct in TT).
575=head2 Try Out Authentication
577Press C<Ctrl-C> to kill the previous server instance (if it's still
578running) and restart it:
580 $ script/myapp_server.pl
1390ef0e 582B<IMPORTANT NOTE:> If you are having issues with authentication on
583Internet Explorer, be sure to check the system clocks on both your
584server and client machines. Internet Explorer is very picky about
fbbb9084 585timestamps for cookies. You can quickly sync an Ubuntu system with
586the following command:
25ed8f40 587
588 sudo ntpdate ntp.ubuntu.com
d442cc9f 589
1390ef0e 590Or possibly try C<sudo ntpdate -u ntp.ubuntu.com> (to us an
591unpriviledged port) or C<sudo ntpdate pool.ntp.org> (to try a
592different server in case the Ubuntu NTP server is down).
594Now trying going to L<http://localhost:3000/books/list> and you should
595be redirected to the login page, hitting Shift+Reload or Ctrl+Reload
596if necessary (the "You are already logged in" message should I<not>
597appear -- if it does, click the C<logout> button and try again). Note
598the C<***Root::auto User not found...> debug message in the
599development server output. Enter username C<test01> and password
600C<mypass>, and you should be taken to the Book List page.
d442cc9f 601
602Open C<root/src/books/list.tt2> and add the following lines to the
3533daff 603bottom (below the closing </table> tag):
d442cc9f 604
605 <p>
8a7c5151 606 <a href="[% c.uri_for('/login') %]">Login</a>
0416017e 607 <a href="[% c.uri_for(c.controller.action_for('form_create')) %]">Create</a>
d442cc9f 608 </p>
905a3a26 610Reload your browser and you should now see a "Login" and "Create" links
611at the bottom of the page (as mentioned earlier, you can update template
612files without reloading the development server). Click the first link
613to return to the login page. This time you I<should> see the "You are
d442cc9f 614already logged in" message.
616Finally, click the C<You can logout here> link on the C</login> page.
617You should stay at the login page, but the message should change to "You
618need to log in to use this application."
623In this section we increase the security of our system by converting
624from cleartext passwords to SHA-1 password hashes.
626B<Note:> This section is optional. You can skip it and the rest of the
627tutorial will function normally.
fbbb9084 629Be aware that even with the techniques shown in this section, the browser
d442cc9f 630still transmits the passwords in cleartext to your application. We are
631just avoiding the I<storage> of cleartext passwords in the database by
632using a SHA-1 hash. If you are concerned about cleartext passwords
633between the browser and your application, consider using SSL/TLS, made
fbbb9084 634easy with the Catalyst plugin Catalyst::Plugin:RequireSSL. You should
635also consider adding a "salt" mechanism to your hashed passwords to
b0eca006 636mitigate the risk of a "rainbow table" crack against your passwords (see
638for more information on using a salt value).
d442cc9f 639
641=head2 Get a SHA-1 Hash for the Password
643Catalyst uses the C<Digest> module to support a variety of hashing
644algorithms. Here we will use SHA-1 (SHA = Secure Hash Algorithm).
645First, we should compute the SHA-1 hash for the "mypass" password we are
646using. The following command-line Perl script provides a "quick and
647dirty" way to do this:
649 $ perl -MDigest::SHA -e 'print Digest::SHA::sha1_hex("mypass"), "\n"'
650 e727d1464ae12436e899a726da5b2f11d8381b26
651 $
905a3a26 653B<Note:> If you are following along in Ubuntu, you will need to install
d0496197 654C<Digest::SHA> with the following command to run the example code above:
905a3a26 656 sudo aptitude install libdigest-sha-perl
d0496197 657
d442cc9f 658B<Note:> You should probably modify this code for production use to
659not read the password from the command line. By having the script
660prompt for the cleartext password, it avoids having the password linger
661in forms such as your C<.bash_history> files (assuming you are using
662BASH as your shell). An example of such a script can be found in
663Appendix 3.
666=head2 Switch to SHA-1 Password Hashes in the Database
668Next, we need to change the C<password> column of our C<users> table to
669store this hash value vs. the existing cleartext password. Open
670C<myapp03.sql> in your editor and enter:
672 --
673 -- Convert passwords to SHA-1 hashes
674 --
675 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 1;
676 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 2;
677 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 3;
679Then use the following command to update the SQLite database:
681 $ sqlite3 myapp.db < myapp03.sql
1390ef0e 683B<Note:> We are using SHA-1 hashes here, but many other hashing
d442cc9f 684algorithms are supported. See C<Digest> for more information.
687=head2 Enable SHA-1 Hash Passwords in
45d511e0 690Edit C<myapp.conf> and update it to match (the C<password_type> and
d442cc9f 691C<password_hash_type> are new, everything else is the same):
1390ef0e 693 # rename this file to MyApp.yml and put a : in front of "name" if
694 # you want to use yaml like in old versions of Catalyst
c010ae0d 695 name MyApp
696 <authentication>
697 default_realm dbic
698 <realms>
699 <dbic>
700 <credential>
3533daff 701 # Note this first definition would be the same as setting
702 # __PACKAGE__->config->{authentication}->{realms}->{dbic}
905a3a26 703 # ->{credential} = 'Password' in lib/MyApp.pm
3533daff 704 #
705 # Specify that we are going to do password-based auth
c010ae0d 706 class Password
3533daff 707 # This is the name of the field in the users table with the
708 # password stored in it
c010ae0d 709 password_field password
3533daff 710 # Switch to more secure hashed passwords
c010ae0d 711 password_type hashed
3533daff 712 # Use the SHA-1 hashing algorithm
c010ae0d 713 password_hash_type SHA-1
d0496197 714 </credential>
c010ae0d 715 <store>
3533daff 716 # Use DBIC to retrieve username, password & role information
c010ae0d 717 class DBIx::Class
905a3a26 718 # This is the model object created by Catalyst::Model::DBIC
d0496197 719 # from your schema (you created 'MyApp::Schema::User' but as
905a3a26 720 # the Catalyst startup debug messages show, it was loaded as
d0496197 721 # 'MyApp::Model::DB::Users').
905a3a26 722 # NOTE: Omit 'MyApp::Model' here just as you would when using
d0496197 723 # '$c->model("DB::Users)'
724 user_class DB::Users
d0496197 725 </store>
726 </dbic>
727 </realms>
728 </authentication>
d442cc9f 729
1390ef0e 730
d442cc9f 731=head2 Try Out the Hashed Passwords
733Press C<Ctrl-C> to kill the previous server instance (if it's still
734running) and restart it:
736 $ script/myapp_server.pl
738You should now be able to go to L<http://localhost:3000/books/list> and
fbbb9084 739login as before. When done, click the "logout" link on the login page
d442cc9f 740(or point your browser at L<http://localhost:3000/logout>).
d442cc9f 742
745As discussed in Part 3 of the tutorial, C<flash> allows you to set
905a3a26 746variables in a way that is very similar to C<stash>, but it will
d442cc9f 747remain set across multiple requests. Once the value is read, it
748is cleared (unless reset). Although C<flash> has nothing to do with
749authentication, it does leverage the same session plugins. Now that
fbbb9084 750those plugins are enabled, let's go back and update the "delete
d442cc9f 751and redirect with query parameters" code seen at the end of the
905a3a26 752L<Basic CRUD|Catalyst::Manual::Tutorial::BasicCRUD> part of the
fbbb9084 753tutorial to take advantage of C<flash>.
d442cc9f 754
755First, open C<lib/MyApp/Controller/Books.pm> and modify C<sub delete>
3533daff 756to match the following (everything after the model search line of code
757has changed):
d442cc9f 758
905a3a26 759 =head2 delete
1390ef0e 760
d442cc9f 761 Delete a book
1390ef0e 762
d442cc9f 763 =cut
1390ef0e 764
fbbb9084 765 sub delete :Chained('object') :PathPart('delete') :Args(0) {
766 my ($self, $c) = @_;
1390ef0e 767
fbbb9084 768 # Use the book object saved by 'object' and delete it along
769 # with related 'book_authors' entries
770 $c->stash->{object}->delete;
1390ef0e 771
d442cc9f 772 # Use 'flash' to save information across requests until it's read
773 $c->flash->{status_msg} = "Book deleted";
1390ef0e 774
3533daff 775 # Redirect the user back to the list page
0416017e 776 $c->response->redirect($c->uri_for($self->action_for('list')));
d442cc9f 777 }
1390ef0e 779Next, open C<root/src/wrapper.tt2> and update the TT code to pull from
d442cc9f 780flash vs. the C<status_msg> query parameter:
1390ef0e 782 ...
d442cc9f 783 <div id="content">
1390ef0e 784 [%# Status and error messages %]
785 <span class="message">[% status_msg || c.flash.status_msg %]</span>
786 <span class="error">[% error_msg %]</span>
787 [%# This is where TT will stick all of your template's contents. -%]
788 [% content %]
789 </div><!-- end content -->
790 ...
905a3a26 791
1390ef0e 792Although the sample above only shows the C<content> div, leave the
793rest of the file intact -- the only change we made to the C<wrapper.tt2>
794was to add "C<|| c.request.params.status_msg>" to the
795C<E<lt>span class="message"E<gt>> line.
d442cc9f 796
798=head2 Try Out Flash
fbbb9084 800Restart the development server, log in, and then point your browser to
801L<http://localhost:3000/books/url_create/Test/1/4> to create an extra
802several books. Click the "Return to list" link and delete one of the
803"Test" books you just added. The C<flash> mechanism should retain our
3533daff 804"Book deleted" status message across the redirect.
d442cc9f 805
806B<NOTE:> While C<flash> will save information across multiple requests,
807I<it does get cleared the first time it is read>. In general, this is
808exactly what you want -- the C<flash> message will get displayed on
809the next screen where it's appropriate, but it won't "keep showing up"
810after that first time (unless you reset it). Please refer to
811L<Catalyst::Plugin::Session|Catalyst::Plugin::Session> for additional
1390ef0e 814
3533daff 815=head2 Switch To Flash-To-Stash
fbbb9084 817Although the a use of flash above works well, the
1390ef0e 818C<status_msg || c.flash.status_msg> statement is a little ugly. A nice
905a3a26 819alternative is to use the C<flash_to_stash> feature that automatically
1390ef0e 820copies the content of flash to stash. This makes your controller
905a3a26 821and template code work regardless of where it was directly access, a
fbbb9084 822forward, or a redirect. To enable C<flash_to_stash>, you can either
905a3a26 823set the value in C<lib/MyApp.pm> by changing the default
3533daff 824C<__PACKAGE__-E<gt>config> setting to something like:
826 __PACKAGE__->config(
827 name => 'MyApp',
828 session => {flash_to_stash => 1}
829 );
45d511e0 831B<or> add the following to C<myapp.conf>:
3533daff 832
45d511e0 833 <session>
834 flash_to_stash 1
835 </session>
3533daff 836
905a3a26 837The C<__PACKAGE__-E<gt>config> option is probably preferable here
838since it's not something you will want to change at runtime without it
3533daff 839possibly breaking some of your code.
1390ef0e 841Then edit C<root/src/wrapper.tt2> and change the C<status_msg> line
842to match the following:
3533daff 843
844 <span class="message">[% status_msg %]</span>
846Restart the development server and go to
905a3a26 847L<http://localhost:3000/books/list> in your browser. Delete another
3533daff 848of the "Test" books you added in the previous step. Flash should still
849maintain the status message across the redirect even though you are no
8a7c5151 850longer explicitly accessing C<c.flash>.
3533daff 851
d442cc9f 852
853=head1 AUTHOR
855Kennedy Clark, C<hkclark@gmail.com>
857Please report any errors, issues or suggestions to the author. The
858most recent version of the Catalyst Tutorial can be found at
82ab4bbf 859L<http://dev.catalyst.perl.org/repos/Catalyst/Catalyst-Manual/5.70/trunk/lib/Catalyst/Manual/Tutorial/>.
d442cc9f 860
45c7830f 861Copyright 2006-2008, Kennedy Clark, under Creative Commons License
95674086 862(L<http://creativecommons.org/licenses/by-sa/3.0/us/>).