Fixed menton to "flash" to point to part 4 of the tutorial (no longer mentioned in...
[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', '', 'Joe', 'Blow', 1);
109 INSERT INTO users VALUES (2, 'test02', 'mypass', '', 'Jane', 'Doe', 1);
110 INSERT INTO users VALUES (3, 'test03', 'mypass', '', '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
acbd7bdd 129 $ script/ model DB DBIC::Schema MyApp::Schema \
130 create=static components=TimeStamp dbi:SQLite:myapp.db
1390ef0e 131 exists "/root/dev/MyApp/script/../lib/MyApp/Model"
132 exists "/root/dev/MyApp/script/../t"
133 Dumping manual schema for MyApp::Schema to directory /root/dev/MyApp/script/../lib ...
134 Schema dump completed.
135 exists "/root/dev/MyApp/script/../lib/MyApp/Model/"
136 $
acbd7bdd 137 $ ls lib/MyApp/Schema/Result
3533daff 138
d442cc9f 139
905a3a26 140Notice how the helper has added three new table-specific result source
acbd7bdd 141files to the C<lib/MyApp/Schema/Result> directory. And, more
905a3a26 142importantly, even if there were changes to the existing result source
143files, those changes would have only been written above the C<# DO NOT
191dee29 144MODIFY THIS OR ANYTHING ABOVE!> comment and your hand-edited
3533daff 145enhancements would have been preserved.
d442cc9f 146
191dee29 147Speaking of "hand-edit ted enhancements," we should now add
905a3a26 148relationship information to the three new result source files. Edit
149each of these files and add the following information between the C<#
3533daff 150DO NOT MODIFY THIS OR ANYTHING ABOVE!> comment and the closing C<1;>:
d442cc9f 151
acbd7bdd 152C<lib/MyApp/Schema/Result/>:
d442cc9f 153
d442cc9f 154 #
155 # Set relationships:
156 #
636ba9f7 157
d442cc9f 158 # has_many():
159 # args:
160 # 1) Name of relationship, DBIC will create accessor with this name
161 # 2) Name of the model class referenced by this relationship
1435672d 162 # 3) Column name in *foreign* table (aka, foreign key in peer table)
acbd7bdd 163 __PACKAGE__->has_many(map_user_role => 'MyApp::Schema::Result::UserRoles', 'user_id');
636ba9f7 164
3533daff 165 # many_to_many():
166 # args:
167 # 1) Name of relationship, DBIC will create accessor with this name
905a3a26 168 # 2) Name of has_many() relationship this many_to_many() is shortcut for
169 # 3) Name of belongs_to() relationship in model class of has_many() above
3533daff 170 # You must already have the has_many() defined to use a many_to_many().
171 __PACKAGE__->many_to_many(roles => 'map_user_role', 'role');
d442cc9f 172
acbd7bdd 174C<lib/MyApp/Schema/Result/>:
d442cc9f 175
d442cc9f 176 #
177 # Set relationships:
178 #
636ba9f7 179
d442cc9f 180 # has_many():
181 # args:
182 # 1) Name of relationship, DBIC will create accessor with this name
183 # 2) Name of the model class referenced by this relationship
1435672d 184 # 3) Column name in *foreign* table (aka, foreign key in peer table)
acbd7bdd 185 __PACKAGE__->has_many(map_user_role => 'MyApp::Schema::Result::UserRoles', 'role_id');
d442cc9f 186
acbd7bdd 188C<lib/MyApp/Schema/Result/>:
d442cc9f 189
d442cc9f 190 #
191 # Set relationships:
192 #
636ba9f7 193
d442cc9f 194 # belongs_to():
195 # args:
196 # 1) Name of relationship, DBIC will create accessor with this name
197 # 2) Name of the model class referenced by this relationship
198 # 3) Column name in *this* table
acbd7bdd 199 __PACKAGE__->belongs_to(user => 'MyApp::Schema::Result::Users', 'user_id');
636ba9f7 200
d442cc9f 201 # belongs_to():
202 # args:
203 # 1) Name of relationship, DBIC will create accessor with this name
204 # 2) Name of the model class referenced by this relationship
205 # 3) Column name in *this* table
acbd7bdd 206 __PACKAGE__->belongs_to(role => 'MyApp::Schema::Result::Roles', 'role_id');
d442cc9f 207
3533daff 208
905a3a26 209The code for these three sets of updates is obviously very similar to
210the edits we made to the C<Books>, C<Authors>, and C<BookAuthors>
3533daff 211classes created in Part 3.
636ba9f7 213Note that we do not need to make any change to the
214C<lib/MyApp/> schema file. It simply tells DBIC to load all
215of the Result Class and ResultSet Class files it finds in below the
216C<lib/MyApp/Schema> directory, so it will automatically pick up our
acbd7bdd 217new table information.
d442cc9f 218
220=head2 Sanity-Check Reload of Development Server
905a3a26 222We aren't ready to try out the authentication just yet; we only want
223to do a quick check to be sure our model loads correctly. Press
224C<Ctrl-C> to kill the previous server instance (if it's still running)
3533daff 225and restart it:
d442cc9f 226
227 $ script/
229Look for the three new model objects in the startup debug output:
231 ...
232 .-------------------------------------------------------------------+----------.
233 | Class | Type |
234 +-------------------------------------------------------------------+----------+
235 | MyApp::Controller::Books | instance |
236 | MyApp::Controller::Root | instance |
d0496197 237 | MyApp::Model::DB | instance |
238 | MyApp::Model::DB::Author | class |
239 | MyApp::Model::DB::Books | class |
240 | MyApp::Model::DB::BookAuthors | class |
241 | MyApp::Model::DB::Roles | class |
242 | MyApp::Model::DB::Users | class |
243 | MyApp::Model::DB::UserRoles | class |
d442cc9f 244 | MyApp::View::TT | instance |
245 '-------------------------------------------------------------------+----------'
246 ...
acbd7bdd 248Again, notice that your "Result Class" classes have been "re-loaded"
3533daff 249by Catalyst under C<MyApp::Model>.
d442cc9f 250
252=head2 Include Authentication and Session Plugins
905a3a26 254Edit C<lib/> and update it as follows (everything below
3533daff 255C<StackTrace> is new):
d442cc9f 256
acbd7bdd 257 # Load plugins
258 use Catalyst qw/-Debug
259 ConfigLoader
260 Static::Simple
636ba9f7 261
acbd7bdd 262 StackTrace
636ba9f7 263
acbd7bdd 264 Authentication
636ba9f7 265
acbd7bdd 266 Session
267 Session::Store::FastMmap
268 Session::State::Cookie
269 /;
d442cc9f 270
636ba9f7 271B<Note:> As discussed in MoreCatalystBasics, different versions of
272C<Catalyst::Devel> have used a variety of methods to load the plugins.
533fee73 273You can put the plugins in the C<use Catalyst> statement if you prefer.
94d8da41 274
905a3a26 275The C<Authentication> plugin supports Authentication while the
276C<Session> plugins are required to maintain state across multiple HTTP
6d0971ad 278
905a3a26 279Note that the only required Authentication class is the main one. This
280is a change that occurred in version 0.09999_01 of the
281C<Authentication> plugin. You B<do not need> to specify a particular
282Authentication::Store or Authentication::Credential plugin. Instead,
283indicate the Store and Credential you want to use in your application
6d0971ad 284configuration (see below).
905a3a26 286Note that there are several options for
289is generally a good choice if you are on Unix; try
290L<Session::Store::File|Catalyst::Plugin::Session::Store::File> if you
291are on Win32) -- consult
292L<Session::Store|Catalyst::Plugin::Session::Store> and its subclasses
3533daff 293for additional information and options (for example to use a database-
294backed session store).
d442cc9f 295
297=head2 Configure Authentication
636ba9f7 299Although C<__PACKAGE__-E<gt>config(name =E<gt> 'value');> is still
300supported, newer Catalyst applications tend to place all configuration
301information in C<myapp.conf> and automatically load this information
302into C<MyApp-E<gt>config> using the
905a3a26 303L<ConfigLoader|Catalyst::Plugin::ConfigLoader> plugin.
15e1d0b2 304
636ba9f7 305As discussed in Part 3 of the tutorial, Catalyst has recently
306switched from a default config file format of YAML to
307L<Config::General|Config::General> (an apache-like format). In case
308you are using a version of Catalyst earlier than v5.7014, delete the
309C<myapp.yml>, or convert it to .conf format using the TIP in
310L<Catalyst::Manual::MoreCatalystBasics/EDIT THE LIST OF CATALYST PLUGINS>
311then simply follow the directions below to create a new C<myapp.conf>
fbbb9084 312file. Although we will use the C<Config::General> format here because
636ba9f7 313YAML files can be difficult to cut and paste in certain environments,
314you are free to use any format supported by
fbbb9084 315L<Catalyst::Plugin::ConfigLoader|Catalyst::Plugin::ConfigLoader> and
316L<Config::Any|Config::Any> -- Catalyst will transparently handle the
317different formats.
15e1d0b2 318
905a3a26 319Here, we need to load several parameters that tell
321where to locate information in your database. To do this, edit the
c010ae0d 322C<myapp.conf> file and update it to match:
1390ef0e 324 # rename this file to MyApp.yml and put a : in front of "name" if
325 # you want to use yaml like in old versions of Catalyst
c010ae0d 326 name MyApp
327 <authentication>
328 default_realm dbic
329 <realms>
330 <dbic>
331 <credential>
905a3a26 332 # Note: this first definition would be the same as setting
3533daff 333 # __PACKAGE__->config->{authentication}->{realms}->{dbic}
905a3a26 334 # ->{credential} = 'Password' in lib/
3533daff 335 #
336 # Specify that we are going to do password-based auth
c010ae0d 337 class Password
3533daff 338 # This is the name of the field in the users table with the
339 # password stored in it
c010ae0d 340 password_field password
905a3a26 341 # We are using an unencrypted password for now
c010ae0d 342 password_type clear
343 </credential>
344 <store>
3533daff 345 # Use DBIC to retrieve username, password & role information
c010ae0d 346 class DBIx::Class
905a3a26 347 # This is the model object created by Catalyst::Model::DBIC
acbd7bdd 348 # from your schema (you created 'MyApp::Schema::Result::User'
636ba9f7 349 # but as the Catalyst startup debug messages show, it was
acbd7bdd 350 # loaded as 'MyApp::Model::DB::Users').
905a3a26 351 # NOTE: Omit 'MyApp::Model' here just as you would when using
d0496197 352 # '$c->model("DB::Users)'
353 user_class DB::Users
c010ae0d 354 </store>
355 </dbic>
d0496197 356 </realms>
357 </authentication>
d442cc9f 358
359Inline comments in the code above explain how each field is being used.
1390ef0e 361
d442cc9f 362=head2 Add Login and Logout Controllers
364Use the Catalyst create script to create two stub controller files:
366 $ script/ controller Login
367 $ script/ controller Logout
636ba9f7 369You could easily use a single controller here. For example, you could
370have a C<User> controller with both C<login> and C<logout> actions.
371Remember, Catalyst is designed to be very flexible, and leaves such
fbbb9084 372matters up to you, the designer and programmer.
d442cc9f 373
636ba9f7 374Then open C<lib/MyApp/Controller/>, locate the
375C<sub index :Path :Args(0)> method (or C<sub index : Private> if you
376are using an older version of Catalyst) that was automatically
377inserted by the helpers when we created the Login controller above,
fbbb9084 378and update the definition of C<sub index> to match:
d442cc9f 379
380 =head2 index
636ba9f7 381
d442cc9f 382 Login logic
636ba9f7 383
d442cc9f 384 =cut
636ba9f7 385
ae492862 386 sub index :Path :Args(0) {
d442cc9f 387 my ($self, $c) = @_;
636ba9f7 388
d442cc9f 389 # Get the username and password from form
390 my $username = $c->request->params->{username} || "";
391 my $password = $c->request->params->{password} || "";
636ba9f7 392
d442cc9f 393 # If the username and password values were found in form
394 if ($username && $password) {
395 # Attempt to log the user in
905a3a26 396 if ($c->authenticate({ username => $username,
5fefca35 397 password => $password } )) {
d442cc9f 398 # If successful, then let them use the application
0416017e 399 $c->response->redirect($c->uri_for(
400 $c->controller('Books')->action_for('list')));
d442cc9f 401 return;
402 } else {
403 # Set an error message
404 $c->stash->{error_msg} = "Bad username or password.";
405 }
406 }
636ba9f7 407
d442cc9f 408 # If either of above don't work out, send to the login page
409 $c->stash->{template} = 'login.tt2';
410 }
412This controller fetches the C<username> and C<password> values from the
905a3a26 413login form and attempts to authenticate the user. If successful, it
414redirects the user to the book list page. If the login fails, the user
415will stay at the login page and receive an error message. If the
416C<username> and C<password> values are not present in the form, the
f632e28b 417user will be taken to the empty login form.
d442cc9f 418
636ba9f7 419Note that we could have used something like "C<sub default :Path>",
420however, it is generally recommended (partly for historical reasons,
421and partly for code clarity) only to use C<default> in
422C<MyApp::Controller::Root>, and then mainly to generate the 404 not
85d49fb6 423found page for the application.
ae492862 424
fbbb9084 425Instead, we are using "C<sub somename :Path :Args(0) {...}>" here to
905a3a26 426specifically match the URL C</login>. C<Path> actions (aka, "literal
427actions") create URI matches relative to the namespace of the
428controller where they are defined. Although C<Path> supports
429arguments that allow relative and absolute paths to be defined, here
430we use an empty C<Path> definition to match on just the name of the
431controller itself. The method name, C<index>, is arbitrary. We make
ae492862 432the match even more specific with the C<:Args(0)> action modifier --
905a3a26 433this forces the match on I<only> C</login>, not
d442cc9f 434C</login/somethingelse>.
905a3a26 436Next, update the corresponding method in
3533daff 437C<lib/MyApp/Controller/> to match:
d442cc9f 438
439 =head2 index
636ba9f7 440
d442cc9f 441 Logout logic
636ba9f7 442
d442cc9f 443 =cut
636ba9f7 444
ae492862 445 sub index :Path :Args(0) {
d442cc9f 446 my ($self, $c) = @_;
636ba9f7 447
d442cc9f 448 # Clear the user's state
449 $c->logout;
636ba9f7 450
d442cc9f 451 # Send the user to the starting point
452 $c->response->redirect($c->uri_for('/'));
453 }
905a3a26 455As with the login controller, be sure to delete the
14e5ed66 456C<$c-E<gt>response-E<gt>body('Matched MyApp::Controller::Logout in Logout.');>
d442cc9f 457line of the C<sub index>.
460=head2 Add a Login Form TT Template Page
462Create a login form by opening C<root/src/login.tt2> and inserting:
464 [% META title = 'Login' %]
636ba9f7 465
d442cc9f 466 <!-- Login form -->
8a7c5151 467 <form method="post" action="[% c.uri_for('/login') %]">
d442cc9f 468 <table>
469 <tr>
470 <td>Username:</td>
471 <td><input type="text" name="username" size="40" /></td>
472 </tr>
473 <tr>
474 <td>Password:</td>
475 <td><input type="password" name="password" size="40" /></td>
476 </tr>
477 <tr>
478 <td colspan="2"><input type="submit" name="submit" value="Submit" /></td>
479 </tr>
480 </table>
481 </form>
484=head2 Add Valid User Check
486We need something that provides enforcement for the authentication
487mechanism -- a I<global> mechanism that prevents users who have not
488passed authentication from reaching any pages except the login page.
489This is generally done via an C<auto> action/method (prior to Catalyst
490v5.66, this sort of thing would go in C<>, but starting in
491v5.66, the preferred location is C<lib/MyApp/Controller/>).
493Edit the existing C<lib/MyApp/Controller/> class file and insert
494the following method:
496 =head2 auto
636ba9f7 497
d442cc9f 498 Check if there is a user and, if not, forward to login page
636ba9f7 499
d442cc9f 500 =cut
636ba9f7 501
d442cc9f 502 # Note that 'auto' runs after 'begin' but before your actions and that
905a3a26 503 # 'auto's "chain" (all from application path to most specific class are run)
d442cc9f 504 # See the 'Actions' section of 'Catalyst::Manual::Intro' for more info.
505 sub auto : Private {
506 my ($self, $c) = @_;
636ba9f7 507
d442cc9f 508 # Allow unauthenticated users to reach the login page. This
191dee29 509 # allows unauthenticated users to reach any action in the Login
d442cc9f 510 # controller. To lock it down to a single action, we could use:
511 # if ($c->action eq $c->controller('Login')->action_for('index'))
905a3a26 512 # to only allow unauthenticated access to the 'index' action we
d442cc9f 513 # added above.
514 if ($c->controller eq $c->controller('Login')) {
515 return 1;
516 }
636ba9f7 517
d442cc9f 518 # If a user doesn't exist, force login
519 if (!$c->user_exists) {
520 # Dump a log message to the development server debug output
521 $c->log->debug('***Root::auto User not found, forwarding to /login');
522 # Redirect the user to the login page
523 $c->response->redirect($c->uri_for('/login'));
524 # Return 0 to cancel 'post-auto' processing and prevent use of application
525 return 0;
526 }
636ba9f7 527
d442cc9f 528 # User found, so return 1 to continue with processing after this 'auto'
529 return 1;
530 }
636ba9f7 532As discussed in
533L<Catalyst::Manual::Tutorial::MoreCatalystBasics/CREATE A CATALYST CONTROLLER>,
534every C<auto> method from the application/root controller down to the
535most specific controller will be called. By placing the
536authentication enforcement code inside the C<auto> method of
537C<lib/MyApp/Controller/> (or C<lib/>), it will be
538called for I<every> request that is received by the entire
0416017e 539application.
d442cc9f 540
542=head2 Displaying Content Only to Authenticated Users
544Let's say you want to provide some information on the login page that
545changes depending on whether the user has authenticated yet. To do
546this, open C<root/src/login.tt2> in your editor and add the following
547lines to the bottom of the file:
acbd7bdd 549 ...
d442cc9f 550 <p>
551 [%
905a3a26 552 # This code illustrates how certain parts of the TT
d442cc9f 553 # template will only be shown to users who have logged in
554 %]
8a7c5151 555 [% IF c.user_exists %]
556 Please Note: You are already logged in as '[% c.user.username %]'.
557 You can <a href="[% c.uri_for('/logout') %]">logout</a> here.
d442cc9f 558 [% ELSE %]
559 You need to log in to use this application.
560 [% END %]
561 [%#
562 Note that this whole block is a comment because the "#" appears
905a3a26 563 immediate after the "[%" (with no spaces in between). Although it
564 can be a handy way to temporarily "comment out" a whole block of
565 TT code, it's probably a little too subtle for use in "normal"
d442cc9f 566 comments.
567 %]
3533daff 568 </p>
d442cc9f 569
570Although most of the code is comments, the middle few lines provide a
571"you are already logged in" reminder if the user returns to the login
572page after they have already authenticated. For users who have not yet
573authenticated, a "You need to log in..." message is displayed (note the
574use of an IF-THEN-ELSE construct in TT).
577=head2 Try Out Authentication
579Press C<Ctrl-C> to kill the previous server instance (if it's still
580running) and restart it:
582 $ script/
636ba9f7 584B<IMPORTANT NOTE:> If you are having issues with authentication on
585Internet Explorer, be sure to check the system clocks on both your
586server and client machines. Internet Explorer is very picky about
acbd7bdd 587timestamps for cookies. You can quickly sync a Debian system by
588installing the "ntpdate" package:
590 sudo aptitude -y install ntpdate
592And then run the following command:
25ed8f40 593
acbd7bdd 594 sudo ntpdate-debian
d442cc9f 595
acbd7bdd 596Or, depending on your firewall configuration:
598 sudo ntpdate-debian -u
636ba9f7 600Note: NTP can be a little more finicky about firewalls because it uses
acbd7bdd 601UDP vs. the more common TCP that you see with most Internet protocols.
602Worse case, you might have to manually set the time on your development
603box instead of using NTP.
1390ef0e 604
636ba9f7 605Now trying going to L<http://localhost:3000/books/list> and you should
606be redirected to the login page, hitting Shift+Reload or Ctrl+Reload
607if necessary (the "You are already logged in" message should I<not>
608appear -- if it does, click the C<logout> button and try again). Note
609the C<***Root::auto User not found...> debug message in the
610development server output. Enter username C<test01> and password
1390ef0e 611C<mypass>, and you should be taken to the Book List page.
d442cc9f 612
613Open C<root/src/books/list.tt2> and add the following lines to the
3533daff 614bottom (below the closing </table> tag):
d442cc9f 615
616 <p>
8a7c5151 617 <a href="[% c.uri_for('/login') %]">Login</a>
0416017e 618 <a href="[% c.uri_for(c.controller.action_for('form_create')) %]">Create</a>
d442cc9f 619 </p>
905a3a26 621Reload your browser and you should now see a "Login" and "Create" links
622at the bottom of the page (as mentioned earlier, you can update template
623files without reloading the development server). Click the first link
624to return to the login page. This time you I<should> see the "You are
d442cc9f 625already logged in" message.
627Finally, click the C<You can logout here> link on the C</login> page.
628You should stay at the login page, but the message should change to "You
629need to log in to use this application."
634In this section we increase the security of our system by converting
635from cleartext passwords to SHA-1 password hashes.
637B<Note:> This section is optional. You can skip it and the rest of the
638tutorial will function normally.
fbbb9084 640Be aware that even with the techniques shown in this section, the browser
d442cc9f 641still transmits the passwords in cleartext to your application. We are
642just avoiding the I<storage> of cleartext passwords in the database by
643using a SHA-1 hash. If you are concerned about cleartext passwords
644between the browser and your application, consider using SSL/TLS, made
fbbb9084 645easy with the Catalyst plugin Catalyst::Plugin:RequireSSL. You should
636ba9f7 646also consider adding a "salt" mechanism to your hashed passwords to
b0eca006 647mitigate the risk of a "rainbow table" crack against your passwords (see
649for more information on using a salt value).
d442cc9f 650
652=head2 Get a SHA-1 Hash for the Password
654Catalyst uses the C<Digest> module to support a variety of hashing
655algorithms. Here we will use SHA-1 (SHA = Secure Hash Algorithm).
656First, we should compute the SHA-1 hash for the "mypass" password we are
657using. The following command-line Perl script provides a "quick and
658dirty" way to do this:
660 $ perl -MDigest::SHA -e 'print Digest::SHA::sha1_hex("mypass"), "\n"'
661 e727d1464ae12436e899a726da5b2f11d8381b26
d0496197 662
d442cc9f 663B<Note:> You should probably modify this code for production use to
664not read the password from the command line. By having the script
665prompt for the cleartext password, it avoids having the password linger
666in forms such as your C<.bash_history> files (assuming you are using
667BASH as your shell). An example of such a script can be found in
668Appendix 3.
671=head2 Switch to SHA-1 Password Hashes in the Database
673Next, we need to change the C<password> column of our C<users> table to
674store this hash value vs. the existing cleartext password. Open
675C<myapp03.sql> in your editor and enter:
677 --
678 -- Convert passwords to SHA-1 hashes
679 --
680 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 1;
681 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 2;
682 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 3;
684Then use the following command to update the SQLite database:
686 $ sqlite3 myapp.db < myapp03.sql
636ba9f7 688B<Note:> We are using SHA-1 hashes here, but many other hashing
d442cc9f 689algorithms are supported. See C<Digest> for more information.
692=head2 Enable SHA-1 Hash Passwords in
45d511e0 695Edit C<myapp.conf> and update it to match (the C<password_type> and
d442cc9f 696C<password_hash_type> are new, everything else is the same):
1390ef0e 698 # rename this file to MyApp.yml and put a : in front of "name" if
699 # you want to use yaml like in old versions of Catalyst
c010ae0d 700 name MyApp
701 <authentication>
702 default_realm dbic
703 <realms>
704 <dbic>
705 <credential>
3533daff 706 # Note this first definition would be the same as setting
707 # __PACKAGE__->config->{authentication}->{realms}->{dbic}
905a3a26 708 # ->{credential} = 'Password' in lib/
3533daff 709 #
710 # Specify that we are going to do password-based auth
c010ae0d 711 class Password
3533daff 712 # This is the name of the field in the users table with the
713 # password stored in it
c010ae0d 714 password_field password
3533daff 715 # Switch to more secure hashed passwords
c010ae0d 716 password_type hashed
3533daff 717 # Use the SHA-1 hashing algorithm
c010ae0d 718 password_hash_type SHA-1
d0496197 719 </credential>
c010ae0d 720 <store>
3533daff 721 # Use DBIC to retrieve username, password & role information
c010ae0d 722 class DBIx::Class
905a3a26 723 # This is the model object created by Catalyst::Model::DBIC
acbd7bdd 724 # from your schema (you created 'MyApp::Schema::Result::User'
636ba9f7 725 # but as the Catalyst startup debug messages show, it was
acbd7bdd 726 # loaded as 'MyApp::Model::DB::Users').
905a3a26 727 # NOTE: Omit 'MyApp::Model' here just as you would when using
d0496197 728 # '$c->model("DB::Users)'
729 user_class DB::Users
d0496197 730 </store>
731 </dbic>
732 </realms>
733 </authentication>
d442cc9f 734
1390ef0e 735
d442cc9f 736=head2 Try Out the Hashed Passwords
738Press C<Ctrl-C> to kill the previous server instance (if it's still
739running) and restart it:
741 $ script/
743You should now be able to go to L<http://localhost:3000/books/list> and
fbbb9084 744login as before. When done, click the "logout" link on the login page
d442cc9f 745(or point your browser at L<http://localhost:3000/logout>).
d442cc9f 747
636ba9f7 750As discussed in the previous part of the tutorial, C<flash> allows you to
751set variables in a way that is very similar to C<stash>, but it will
d442cc9f 752remain set across multiple requests. Once the value is read, it
753is cleared (unless reset). Although C<flash> has nothing to do with
754authentication, it does leverage the same session plugins. Now that
fbbb9084 755those plugins are enabled, let's go back and update the "delete
d442cc9f 756and redirect with query parameters" code seen at the end of the
905a3a26 757L<Basic CRUD|Catalyst::Manual::Tutorial::BasicCRUD> part of the
fbbb9084 758tutorial to take advantage of C<flash>.
d442cc9f 759
760First, open C<lib/MyApp/Controller/> and modify C<sub delete>
3533daff 761to match the following (everything after the model search line of code
762has changed):
d442cc9f 763
905a3a26 764 =head2 delete
636ba9f7 765
d442cc9f 766 Delete a book
636ba9f7 767
d442cc9f 768 =cut
636ba9f7 769
fbbb9084 770 sub delete :Chained('object') :PathPart('delete') :Args(0) {
771 my ($self, $c) = @_;
636ba9f7 772
fbbb9084 773 # Use the book object saved by 'object' and delete it along
774 # with related 'book_authors' entries
775 $c->stash->{object}->delete;
636ba9f7 776
d442cc9f 777 # Use 'flash' to save information across requests until it's read
778 $c->flash->{status_msg} = "Book deleted";
636ba9f7 779
3533daff 780 # Redirect the user back to the list page
0416017e 781 $c->response->redirect($c->uri_for($self->action_for('list')));
d442cc9f 782 }
1390ef0e 784Next, open C<root/src/wrapper.tt2> and update the TT code to pull from
d442cc9f 785flash vs. the C<status_msg> query parameter:
1390ef0e 787 ...
d442cc9f 788 <div id="content">
1390ef0e 789 [%# Status and error messages %]
790 <span class="message">[% status_msg || c.flash.status_msg %]</span>
791 <span class="error">[% error_msg %]</span>
792 [%# This is where TT will stick all of your template's contents. -%]
793 [% content %]
794 </div><!-- end content -->
795 ...
905a3a26 796
636ba9f7 797Although the sample above only shows the C<content> div, leave the
1390ef0e 798rest of the file intact -- the only change we made to the C<wrapper.tt2>
636ba9f7 799was to add "C<|| c.request.params.status_msg>" to the
1390ef0e 800C<E<lt>span class="message"E<gt>> line.
d442cc9f 801
803=head2 Try Out Flash
636ba9f7 805Restart the development server, log in, and then point your browser to
806L<http://localhost:3000/books/url_create/Test/1/4> to create an extra
807several books. Click the "Return to list" link and delete one of the
808"Test" books you just added. The C<flash> mechanism should retain our
3533daff 809"Book deleted" status message across the redirect.
d442cc9f 810
811B<NOTE:> While C<flash> will save information across multiple requests,
812I<it does get cleared the first time it is read>. In general, this is
813exactly what you want -- the C<flash> message will get displayed on
814the next screen where it's appropriate, but it won't "keep showing up"
815after that first time (unless you reset it). Please refer to
816L<Catalyst::Plugin::Session|Catalyst::Plugin::Session> for additional
1390ef0e 819
3533daff 820=head2 Switch To Flash-To-Stash
636ba9f7 822Although the a use of flash above works well, the
1390ef0e 823C<status_msg || c.flash.status_msg> statement is a little ugly. A nice
905a3a26 824alternative is to use the C<flash_to_stash> feature that automatically
1390ef0e 825copies the content of flash to stash. This makes your controller
905a3a26 826and template code work regardless of where it was directly access, a
fbbb9084 827forward, or a redirect. To enable C<flash_to_stash>, you can either
905a3a26 828set the value in C<lib/> by changing the default
3533daff 829C<__PACKAGE__-E<gt>config> setting to something like:
831 __PACKAGE__->config(
832 name => 'MyApp',
833 session => {flash_to_stash => 1}
834 );
45d511e0 836B<or> add the following to C<myapp.conf>:
3533daff 837
45d511e0 838 <session>
839 flash_to_stash 1
840 </session>
3533daff 841
905a3a26 842The C<__PACKAGE__-E<gt>config> option is probably preferable here
843since it's not something you will want to change at runtime without it
3533daff 844possibly breaking some of your code.
1390ef0e 846Then edit C<root/src/wrapper.tt2> and change the C<status_msg> line
847to match the following:
3533daff 848
849 <span class="message">[% status_msg %]</span>
851Restart the development server and go to
905a3a26 852L<http://localhost:3000/books/list> in your browser. Delete another
3533daff 853of the "Test" books you added in the previous step. Flash should still
854maintain the status message across the redirect even though you are no
8a7c5151 855longer explicitly accessing C<c.flash>.
3533daff 856
d442cc9f 857
858=head1 AUTHOR
860Kennedy Clark, C<>
862Please report any errors, issues or suggestions to the author. The
863most recent version of the Catalyst Tutorial can be found at
82ab4bbf 864L<>.
d442cc9f 865
45c7830f 866Copyright 2006-2008, Kennedy Clark, under Creative Commons License
95674086 867(L<>).