3 Catalyst::Manual::Tutorial::Authentication - Catalyst Tutorial - Part 4: Authentication
8 This is B<Part 4 of 9> for the Catalyst tutorial.
10 L<Tutorial Overview|Catalyst::Manual::Tutorial>
16 L<Introduction|Catalyst::Manual::Tutorial::Intro>
20 L<Catalyst Basics|Catalyst::Manual::Tutorial::CatalystBasics>
24 L<Basic CRUD|Catalyst::Manual::Tutorial_BasicCRUD>
32 L<Authorization|Catalyst::Manual::Tutorial::Authorization>
36 L<Debugging|Catalyst::Manual::Tutorial::Debugging>
40 L<Testing|Catalyst::Manual::Tutorial::Testing>
44 L<AdvancedCRUD|Catalyst::Manual::Tutorial::AdvancedCRUD>
48 L<Appendices|Catalyst::Manual::Tutorial::Appendicies>
55 Now that we finally have a simple yet functional application, we can
56 focus on providing authentication (with authorization coming next in
59 This part of the tutorial is divided into two main sections: 1) basic,
60 cleartext authentication and 2) hash-based authentication.
62 B<TIP>: Note that all of the code for this part of the tutorial can be
63 pulled from the Catalyst Subversion repository in one step with the
66 svn checkout http://dev.catalyst.perl.org/repos/Catalyst/trunk/examples/Tutorial@4612 .
67 IMPORTANT: Does not work yet. Will be completed for final version.
70 =head1 BASIC AUTHENTICATION
72 This section explores how to add authentication logic to a Catalyst
76 =head2 Add Users and Roles to the Database
78 First, we add both user and role information to the database (we will
79 add the role information here although it will not be used until the
80 authorization section, Part 5). Create a new SQL script file by opening
81 C<myapp02.sql> in your editor and insert:
84 -- Add users and roles tables, along with a many-to-many join table
87 id INTEGER PRIMARY KEY,
96 id INTEGER PRIMARY KEY,
99 CREATE TABLE user_roles (
102 PRIMARY KEY (user_id, role_id)
105 -- Load up some initial test data
107 INSERT INTO users VALUES (1, 'test01', 'mypass', 't01@na.com', 'Joe', 'Blow', 1);
108 INSERT INTO users VALUES (2, 'test02', 'mypass', 't02@na.com', 'Jane', 'Doe', 1);
109 INSERT INTO users VALUES (3, 'test03', 'mypass', 't03@na.com', 'No', 'Go', 0);
110 INSERT INTO roles VALUES (1, 'user');
111 INSERT INTO roles VALUES (2, 'admin');
112 INSERT INTO user_roles VALUES (1, 1);
113 INSERT INTO user_roles VALUES (1, 2);
114 INSERT INTO user_roles VALUES (2, 1);
115 INSERT INTO user_roles VALUES (3, 1);
117 Then load this into the C<myapp.db> database with the following command:
119 $ sqlite3 myapp.db < myapp02.sql
122 =head2 Add User and Role Information to DBIC Schema
124 This step adds DBIC-based classes for the user-related database tables
125 (the role information will not be used until Part 5):
127 Edit C<lib/MyAppDB.pm> and update the contents to match (only the
128 C<MyAppDB =E<gt> [qw/Book BookAuthor Author User UserRole Role/]> line
135 MyAppDB -- DBIC Schema Class
139 # Our schema needs to inherit from 'DBIx::Class::Schema'
140 use base qw/DBIx::Class::Schema/;
142 # Need to load the DB Model classes here.
143 # You can use this syntax if you want:
144 # __PACKAGE__->load_classes(qw/Book BookAuthor Author User UserRole Role/);
145 # Also, if you simply want to load all of the classes in a directory
146 # of the same name as your schema class (as we do here) you can use:
147 # __PACKAGE__->load_classes(qw//);
148 # But the variation below is more flexible in that it can be used to
149 # load from multiple namespaces.
150 __PACKAGE__->load_classes({
151 MyAppDB => [qw/Book BookAuthor Author User UserRole Role/]
157 =head2 Create New "Result Source Objects"
159 Create the following three files with the content shown below.
161 C<lib/MyAppDB/User.pm>:
163 package MyAppDB::User;
165 use base qw/DBIx::Class/;
167 # Load required DBIC stuff
168 __PACKAGE__->load_components(qw/PK::Auto Core/);
170 __PACKAGE__->table('users');
171 # Set columns in table
172 __PACKAGE__->add_columns(qw/id username password email_address first_name last_name/);
173 # Set the primary key for the table
174 __PACKAGE__->set_primary_key('id');
182 # 1) Name of relationship, DBIC will create accessor with this name
183 # 2) Name of the model class referenced by this relationship
184 # 3) Column name in *foreign* table
185 __PACKAGE__->has_many(map_user_role => 'MyAppDB::UserRole', 'user_id');
190 MyAppDB::User - A model object representing a person with access to the system.
194 This is an object that represents a row in the 'users' table of your application
195 database. It uses DBIx::Class (aka, DBIC) to do ORM.
197 For Catalyst, this is designed to be used through MyApp::Model::MyAppDB.
198 Offline utilities may wish to use this class directly.
205 C<lib/MyAppDB/Role.pm>:
207 package MyAppDB::Role;
209 use base qw/DBIx::Class/;
211 # Load required DBIC stuff
212 __PACKAGE__->load_components(qw/PK::Auto Core/);
214 __PACKAGE__->table('roles');
215 # Set columns in table
216 __PACKAGE__->add_columns(qw/id role/);
217 # Set the primary key for the table
218 __PACKAGE__->set_primary_key('id');
226 # 1) Name of relationship, DBIC will create accessor with this name
227 # 2) Name of the model class referenced by this relationship
228 # 3) Column name in *foreign* table
229 __PACKAGE__->has_many(map_user_role => 'MyAppDB::UserRole', 'role_id');
234 MyAppDB::Role - A model object representing a class of access permissions to
239 This is an object that represents a row in the 'roles' table of your
240 application database. It uses DBIx::Class (aka, DBIC) to do ORM.
242 For Catalyst, this is designed to be used through MyApp::Model::MyAppDB.
243 "Offline" utilities may wish to use this class directly.
250 C<lib/MyAppDB/UserRole.pm>:
252 package MyAppDB::UserRole;
254 use base qw/DBIx::Class/;
256 # Load required DBIC stuff
257 __PACKAGE__->load_components(qw/PK::Auto Core/);
259 __PACKAGE__->table('user_roles');
260 # Set columns in table
261 __PACKAGE__->add_columns(qw/user_id role_id/);
262 # Set the primary key for the table
263 __PACKAGE__->set_primary_key(qw/user_id role_id/);
271 # 1) Name of relationship, DBIC will create accessor with this name
272 # 2) Name of the model class referenced by this relationship
273 # 3) Column name in *this* table
274 __PACKAGE__->belongs_to(user => 'MyAppDB::User', 'user_id');
278 # 1) Name of relationship, DBIC will create accessor with this name
279 # 2) Name of the model class referenced by this relationship
280 # 3) Column name in *this* table
281 __PACKAGE__->belongs_to(role => 'MyAppDB::Role', 'role_id');
286 MyAppDB::UserRole - A model object representing the JOIN between Users and Roles.
290 This is an object that represents a row in the 'user_roles' table of your application
291 database. It uses DBIx::Class (aka, DBIC) to do ORM.
293 You probably won't need to use this class directly -- it will be automatically
294 used by DBIC where joins are needed.
296 For Catalyst, this is designed to be used through MyApp::Model::MyAppDB.
297 Offline utilities may wish to use this class directly.
303 The code for these three result source classes is obviously very familiar to the C<Book>, C<Author>, and C<BookAuthor> classes created in Part 2.
306 =head2 Sanity-Check Reload of Development Server
308 We aren't ready to try out the authentication just yet; we only want to do a quick check to be sure our model loads correctly. Press C<Ctrl-C> to kill the previous server instance (if it's still running) and restart it:
310 $ script/myapp_server.pl
312 Look for the three new model objects in the startup debug output:
315 .-------------------------------------------------------------------+----------.
317 +-------------------------------------------------------------------+----------+
318 | MyApp::Controller::Books | instance |
319 | MyApp::Controller::Root | instance |
320 | MyApp::Model::MyAppDB | instance |
321 | MyApp::Model::MyAppDB::Author | class |
322 | MyApp::Model::MyAppDB::Book | class |
323 | MyApp::Model::MyAppDB::BookAuthor | class |
324 | MyApp::Model::MyAppDB::Role | class |
325 | MyApp::Model::MyAppDB::User | class |
326 | MyApp::Model::MyAppDB::UserRole | class |
327 | MyApp::View::TT | instance |
328 '-------------------------------------------------------------------+----------'
331 Again, notice that your "result source" classes have been "re-loaded" by Catalyst under C<MyApp::Model>.
334 =head2 Include Authentication and Session Plugins
336 Edit C<lib/MyApp.pm> and update it as follows (everything below C<StackTrace> is new):
346 Authentication::Store::DBIC
347 Authentication::Credential::Password
350 Session::Store::FastMmap
351 Session::State::Cookie
354 The three C<Authentication> plugins work together to support
355 Authentication while the C<Session> plugins are required to maintain
356 state across multiple HTTP requests. Note that there are several
357 options for L<Session::Store|Catalyst::Plugin::Session::Store>
358 (L<Session::Store::FastMmap|Catalyst::Plugin::Session::Store::FastMmap>
359 is generally a good choice if you are on Unix; try
360 L<Cache::FileCache|Catalyst::Plugin::Cache::FileCache> if you are on
361 Win32) -- consult L<Session::Store|Catalyst::Plugin::Session::Store> and
362 its subclasses for additional information.
365 =head2 Configure Authentication
367 Although C<__PACKAGE__-E<gt>config(name =E<gt> 'value');> is still
368 supported, newer Catalyst applications tend to place all configuration
369 information in C<myapp.yml> and automatically load this information into
370 C<MyApp-E<gt>config> using the
371 L<ConfigLoader|Catalyst::Plugin::ConfigLoader> plugin. Here, we need
372 to load several parameters that tell
373 L<Catalyst::Plugin::Authentication|Catalyst::Plugin::Authentication>
374 where to locate information in your database. To do this, edit the
375 C<myapp.yml> YAML and update it to match:
381 # Note this first definition would be the same as setting
382 # __PACKAGE__->config->{authentication}->{dbic}->{user_class} = 'MyAppDB::User'
383 # in lib/MyApp.pm (IOW, each hash key becomes a "name:" in the YAML file).
385 # This is the model object created by Catalyst::Model::DBIC from your
386 # schema (you created 'MyAppDB::User' but as the Catalyst startup
387 # debug messages show, it was loaded as 'MyApp::Model::MyAppDB::User').
388 # NOTE: Omit 'MyApp::Model' to avoid a component lookup issue in Catalyst 5.66
389 user_class: MyAppDB::User
390 # This is the name of the field in your 'users' table that contains the user's name
392 # This is the name of the field in your 'users' table that contains the password
393 password_field: password
394 # Other options can go here for hashed passwords
396 Inline comments in the code above explain how each field is being used.
398 B<TIP>: Although YAML uses a very simple and easy-to-ready format, it
399 does require the use of a consistent level of indenting. Be sure you
400 line up everything on a given 'level' with the same number of indents.
401 Also, be sure not to use C<tab> characters (YAML does not support them
402 because they are handled inconsistently across editors).
405 =head2 Add Login and Logout Controllers
407 Use the Catalyst create script to create two stub controller files:
409 $ script/myapp_create.pl controller Login
410 $ script/myapp_create.pl controller Logout
412 B<NOTE>: You could easily use a single controller here. For example,
413 you could have a C<User> controller with both C<login> and C<logout>
414 actions. Remember, Catalyst is designed to be very flexible, and leaves
415 such matters up to you, the designer and programmer.
417 Then open C<lib/MyApp/Controller/Login.pm>, locate the C<sub index :
418 Private> method (this was automatically inserted by the helpers when we
419 created the Login controller above), and delete this line:
421 $c->response->body('Matched MyApp::Controller::Login in Login.');
423 Then update it to match:
431 sub index : Private {
434 # Get the username and password from form
435 my $username = $c->request->params->{username} || "";
436 my $password = $c->request->params->{password} || "";
438 # If the username and password values were found in form
439 if ($username && $password) {
440 # Attempt to log the user in
441 if ($c->login($username, $password)) {
442 # If successful, then let them use the application
443 $c->response->redirect($c->uri_for('/books/list'));
446 # Set an error message
447 $c->stash->{error_msg} = "Bad username or password.";
451 # If either of above don't work out, send to the login page
452 $c->stash->{template} = 'login.tt2';
455 This controller fetches the C<username> and C<password> values from the
456 login form and attempts to perform a login. If successful, it redirects
457 the user to the book list page. If the login fails, the user will stay
458 at the login page but receive an error message. If the C<username> and
459 C<password> values are not present in the form, the user will be taken
460 to the empty login form.
462 Note that we could have used something like C<sub default :Private>;
463 however, the use of C<default> actions is discouraged because it does
464 not receive path args as with other actions. The recommended practice
465 is to only use C<default> in C<MyApp::Controller::Root>.
467 Another options would be to use something like
468 C<sub base :Path :Args(0) {...}> (where the C<...> refers to the login
469 code shown in C<sub index : Private> above). We are using C<sub base
470 :Path :Args(0) {...}> here to specifically match the URL C</login>.
471 C<Path> actions (aka, "literal actions") create URI matches relative to
472 the namespace of the controller where they are defined. Although
473 C<Path> supports arguments that allow relative and absolute paths to be
474 defined, here we use an empty C<Path> definition to match on just the
475 name of the controller itself. The method name, C<base>, is arbitrary.
476 We make the match even more specific with the C<:Args(0)> action
477 modifier -- this forces the match on I<only> C</login>, not
478 C</login/somethingelse>.
480 Next, create a corresponding method in C<lib/MyApp/Controller/Logout.pm>:
488 sub index : Private {
491 # Clear the user's state
494 # Send the user to the starting point
495 $c->response->redirect($c->uri_for('/'));
498 As with the login controller, be sure to delete the
499 C<$c->response->body('Matched MyApp::Controller::Logout in Logout.');>
500 line of the C<sub index>.
503 =head2 Add a Login Form TT Template Page
505 Create a login form by opening C<root/src/login.tt2> and inserting:
507 [% META title = 'Login' %]
510 <form method="post" action=" [% Catalyst.uri_for('/login') %] ">
514 <td><input type="text" name="username" size="40" /></td>
518 <td><input type="password" name="password" size="40" /></td>
521 <td colspan="2"><input type="submit" name="submit" value="Submit" /></td>
527 =head2 Add Valid User Check
529 We need something that provides enforcement for the authentication
530 mechanism -- a I<global> mechanism that prevents users who have not
531 passed authentication from reaching any pages except the login page.
532 This is generally done via an C<auto> action/method (prior to Catalyst
533 v5.66, this sort of thing would go in C<MyApp.pm>, but starting in
534 v5.66, the preferred location is C<lib/MyApp/Controller/Root.pm>).
536 Edit the existing C<lib/MyApp/Controller/Root.pm> class file and insert
537 the following method:
541 Check if there is a user and, if not, forward to login page
545 # Note that 'auto' runs after 'begin' but before your actions and that
546 # 'auto' "chain" (all from application path to most specific class are run)
550 # Allow unauthenticated users to reach the login page
551 if ($c->request->path =~ /login/) {
555 # If a user doesn't exist, force login
556 if (!$c->user_exists) {
557 # Dump a log message to the development server debug output
558 $c->log->debug('***Root::auto User not found, forwarding to /login');
559 # Redirect the user to the login page
560 $c->response->redirect($c->uri_for('/login'));
561 # Return 0 to cancel 'post-auto' processing and prevent use of application
565 # User found, so return 1 to continue with processing after this 'auto'
569 B<Note:> Catalyst provides a number of different types of actions, such
570 as C<Local>, C<Regex>, and C<Private>. You should refer to
571 L<Catalyst::Manual::Intro> for a more detailed explanation, but the
572 following bullet points provide a quick introduction:
578 The majority of application use C<Local> actions for items that respond
579 to user requests and C<Private> actions for those that do not directly
580 respond to user input.
584 There are five types of C<Private> actions: C<begin>, C<end>,
585 C<default>, C<index>, and C<auto>.
589 Unlike the other actions where only a single method is called for each
590 request, I<every> auto action along the chain of namespaces will be
595 By placing the authentication enforcement code inside the C<auto> method
596 of C<lib/MyApp/Controller/Root.pm> (or C<lib/MyApp.pm>), it will be
597 called for I<every> request that is received by the entire application.
600 =head2 Displaying Content Only to Authenticated Users
602 Let's say you want to provide some information on the login page that
603 changes depending on whether the user has authenticated yet. To do
604 this, open C<root/src/login.tt2> in your editor and add the following
605 lines to the bottom of the file:
609 # This code illustrates how certain parts of the TT
610 # template will only be shown to users who have logged in
612 [% IF Catalyst.user %]
613 Please Note: You are already logged in as '[% Catalyst.user.username %]'.
614 You can <a href="[% Catalyst.uri_for('/logout') %]">logout</a> here.
616 You need to log in to use this application.
619 Note that this whole block is a comment because the "#" appears
620 immediate after the "[%" (with no spaces in between). Although it
621 can be a handy way to temporarily "comment out" a whole block of
622 TT code, it's probably a little too subtle for use in "normal"
626 Although most of the code is comments, the middle few lines provide a
627 "you are already logged in" reminder if the user returns to the login
628 page after they have already authenticated. For users who have not yet
629 authenticated, a "You need to log in..." message is displayed (note the
630 use of an IF-THEN-ELSE construct in TT).
633 =head2 Try Out Authentication
635 Press C<Ctrl-C> to kill the previous server instance (if it's still
636 running) and restart it:
638 $ script/myapp_server.pl
640 B<IMPORTANT NOTE>: If you happen to be using Internet Explorer, you may
641 need to use the command C<script/myapp_server.pl -k> to enable the
642 keepalive feature in the development server. Otherwise, the HTTP
643 redirect on successful login may not work correctly with IE (it seems to
644 work without -k if you are running the web browser and development
645 server on the same machine). If you are using browser a browser other
646 than IE, it should work either way. If you want to make keepalive the
647 default, you can edit C<script/myapp_server.pl> and change the
648 initialization value for C<$keepalive> to C<1>. (You will need to do
649 this every time you create a new Catalyst application or rebuild the
650 C<myapp_server.pl> script.)
652 Now trying going to L<http://localhost:3000/books/list> and you should
653 be redirected to the login page, hitting Shift+Reload if necessary (the
654 "You are already logged in" message should I<not> appear -- if it does,
655 click the C<logout> button and try again). Note the C<***Root::auto User
656 not found...> debug message in the development server output. Enter
657 username C<test01> and password C<mypass>, and you should be taken to
660 Open C<root/src/books/list.tt2> and add the following lines to the
664 <a href="[% Catalyst.uri_for('/login') %]">Login</a>
665 <a href="[% Catalyst.uri_for('form_create') %]">Create</a>
668 Reload your browser and you should now see a "Login" and "Create" links
669 at the bottom of the page (as mentioned earlier, you can update template
670 files without reloading the development server). Click the first link
671 to return to the login page. This time you I<should> see the "You are
672 already logged in" message.
674 Finally, click the C<You can logout here> link on the C</login> page.
675 You should stay at the login page, but the message should change to "You
676 need to log in to use this application."
679 =head1 USING PASSWORD HASHES
681 In this section we increase the security of our system by converting
682 from cleartext passwords to SHA-1 password hashes.
684 B<Note:> This section is optional. You can skip it and the rest of the
685 tutorial will function normally.
687 Note that even with the techniques shown in this section, the browser
688 still transmits the passwords in cleartext to your application. We are
689 just avoiding the I<storage> of cleartext passwords in the database by
690 using a SHA-1 hash. If you are concerned about cleartext passwords
691 between the browser and your application, consider using SSL/TLS, made
692 easy with the Catalyst plugin
693 L<Catalyst::Plugin:RequireSSL|Catalyst::Plugin:RequireSSL>.
696 =head2 Get a SHA-1 Hash for the Password
698 Catalyst uses the C<Digest> module to support a variety of hashing
699 algorithms. Here we will use SHA-1 (SHA = Secure Hash Algorithm).
700 First, we should compute the SHA-1 hash for the "mypass" password we are
701 using. The following command-line Perl script provides a "quick and
702 dirty" way to do this:
704 $ perl -MDigest::SHA -e 'print Digest::SHA::sha1_hex("mypass"), "\n"'
705 e727d1464ae12436e899a726da5b2f11d8381b26
708 B<Note:> You should probably modify this code for production use to
709 not read the password from the command line. By having the script
710 prompt for the cleartext password, it avoids having the password linger
711 in forms such as your C<.bash_history> files (assuming you are using
712 BASH as your shell). An example of such a script can be found in
716 =head2 Switch to SHA-1 Password Hashes in the Database
718 Next, we need to change the C<password> column of our C<users> table to
719 store this hash value vs. the existing cleartext password. Open
720 C<myapp03.sql> in your editor and enter:
723 -- Convert passwords to SHA-1 hashes
725 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 1;
726 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 2;
727 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 3;
729 Then use the following command to update the SQLite database:
731 $ sqlite3 myapp.db < myapp03.sql
733 B<Note:> We are using SHA-1 hashes here, but many other hashing
734 algorithms are supported. See C<Digest> for more information.
737 =head2 Enable SHA-1 Hash Passwords in
738 C<Catalyst::Plugin::Authentication::Store::DBIC>
740 Edit C<myapp.yml> and update it to match (the C<password_type> and
741 C<password_hash_type> are new, everything else is the same):
747 # Note this first definition would be the same as setting
748 # __PACKAGE__->config->{authentication}->{dbic}->{user_class} = 'MyAppDB::User'
749 # in lib/MyApp.pm (IOW, each hash key becomes a "name:" in the YAML file).
751 # This is the model object created by Catalyst::Model::DBIC from your
752 # schema (you created 'MyAppDB::User' but as the Catalyst startup
753 # debug messages show, it was loaded as 'MyApp::Model::MyAppDB::User').
754 # NOTE: Omit 'MyApp::Model' to avoid a component lookup issue in Catalyst 5.66
755 user_class: MyAppDB::User
756 # This is the name of the field in your 'users' table that contains the user's name
758 # This is the name of the field in your 'users' table that contains the password
759 password_field: password
760 # Other options can go here for hashed passwords
761 # Enabled hashed passwords
762 password_type: hashed
763 # Use the SHA-1 hashing algorithm
764 password_hash_type: SHA-1
767 =head2 Try Out the Hashed Passwords
769 Press C<Ctrl-C> to kill the previous server instance (if it's still
770 running) and restart it:
772 $ script/myapp_server.pl
774 You should now be able to go to L<http://localhost:3000/books/list> and
775 login as before. When done, click the "Logout" link on the login page
776 (or point your browser at L<http://localhost:3000/logout>).
778 B<Note:> If you receive the debug screen in your browser with a
779 C<Can't call method "stash" on an undefined value...> error message,
780 make sure that you are using v0.07 of
781 L<Catalyst::Plugin::Authorization::ACL|Catalyst::Plugin::Authorization::ACL>.
782 The following command can be a useful way to quickly dump the version number
783 of this module on your system:
785 perl -MCatalyst::Plugin::Authorization::ACL -e 'print $Catalyst::Plugin::Authorization::ACL::VERSION, "\n";'
790 Kennedy Clark, C<hkclark@gmail.com>
792 Please report any errors, issues or suggestions to the author. The
793 most recent version of the Catlayst Tutorial can be found at
794 L<http://dev.catalyst.perl.org/repos/Catalyst/trunk/Catalyst-Runtime/lib/Catalyst/Manual/Tutorial/>.
796 Copyright 2006, Kennedy Clark, under Creative Commons License
797 (L<http://creativecommons.org/licenses/by-nc-sa/2.5/>).