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 -r 4612 .
69 =head1 BASIC AUTHENTICATION
71 This section explores how to add authentication logic to a Catalyst
75 =head2 Add Users and Roles to the Database
77 First, we add both user and role information to the database (we will
78 add the role information here although it will not be used until the
79 authorization section, Part 5). Create a new SQL script file by opening
80 C<myapp02.sql> in your editor and insert:
83 -- Add users and roles tables, along with a many-to-many join table
86 id INTEGER PRIMARY KEY,
95 id INTEGER PRIMARY KEY,
98 CREATE TABLE user_roles (
101 PRIMARY KEY (user_id, role_id)
104 -- Load up some initial test data
106 INSERT INTO users VALUES (1, 'test01', 'mypass', 't01@na.com', 'Joe', 'Blow', 1);
107 INSERT INTO users VALUES (2, 'test02', 'mypass', 't02@na.com', 'Jane', 'Doe', 1);
108 INSERT INTO users VALUES (3, 'test03', 'mypass', 't03@na.com', 'No', 'Go', 0);
109 INSERT INTO roles VALUES (1, 'user');
110 INSERT INTO roles VALUES (2, 'admin');
111 INSERT INTO user_roles VALUES (1, 1);
112 INSERT INTO user_roles VALUES (1, 2);
113 INSERT INTO user_roles VALUES (2, 1);
114 INSERT INTO user_roles VALUES (3, 1);
116 Then load this into the C<myapp.db> database with the following command:
118 $ sqlite3 myapp.db < myapp02.sql
121 =head2 Add User and Role Information to DBIC Schema
123 This step adds DBIC-based classes for the user-related database tables
124 (the role information will not be used until Part 5):
126 Edit C<lib/MyAppDB.pm> and update the contents to match (only the
127 C<MyAppDB =E<gt> [qw/Book BookAuthor Author User UserRole Role/]> line
134 MyAppDB -- DBIC Schema Class
138 # Our schema needs to inherit from 'DBIx::Class::Schema'
139 use base qw/DBIx::Class::Schema/;
141 # Need to load the DB Model classes here.
142 # You can use this syntax if you want:
143 # __PACKAGE__->load_classes(qw/Book BookAuthor Author User UserRole Role/);
144 # Also, if you simply want to load all of the classes in a directory
145 # of the same name as your schema class (as we do here) you can use:
146 # __PACKAGE__->load_classes(qw//);
147 # But the variation below is more flexible in that it can be used to
148 # load from multiple namespaces.
149 __PACKAGE__->load_classes({
150 MyAppDB => [qw/Book BookAuthor Author User UserRole Role/]
156 =head2 Create New "Result Source Objects"
158 Create the following three files with the content shown below.
160 C<lib/MyAppDB/User.pm>:
162 package MyAppDB::User;
164 use base qw/DBIx::Class/;
166 # Load required DBIC stuff
167 __PACKAGE__->load_components(qw/PK::Auto Core/);
169 __PACKAGE__->table('users');
170 # Set columns in table
171 __PACKAGE__->add_columns(qw/id username password email_address first_name last_name/);
172 # Set the primary key for the table
173 __PACKAGE__->set_primary_key('id');
181 # 1) Name of relationship, DBIC will create accessor with this name
182 # 2) Name of the model class referenced by this relationship
183 # 3) Column name in *foreign* table
184 __PACKAGE__->has_many(map_user_role => 'MyAppDB::UserRole', 'user_id');
189 MyAppDB::User - A model object representing a person with access to the system.
193 This is an object that represents a row in the 'users' table of your application
194 database. It uses DBIx::Class (aka, DBIC) to do ORM.
196 For Catalyst, this is designed to be used through MyApp::Model::MyAppDB.
197 Offline utilities may wish to use this class directly.
204 C<lib/MyAppDB/Role.pm>:
206 package MyAppDB::Role;
208 use base qw/DBIx::Class/;
210 # Load required DBIC stuff
211 __PACKAGE__->load_components(qw/PK::Auto Core/);
213 __PACKAGE__->table('roles');
214 # Set columns in table
215 __PACKAGE__->add_columns(qw/id role/);
216 # Set the primary key for the table
217 __PACKAGE__->set_primary_key('id');
225 # 1) Name of relationship, DBIC will create accessor with this name
226 # 2) Name of the model class referenced by this relationship
227 # 3) Column name in *foreign* table
228 __PACKAGE__->has_many(map_user_role => 'MyAppDB::UserRole', 'role_id');
233 MyAppDB::Role - A model object representing a class of access permissions to
238 This is an object that represents a row in the 'roles' table of your
239 application database. It uses DBIx::Class (aka, DBIC) to do ORM.
241 For Catalyst, this is designed to be used through MyApp::Model::MyAppDB.
242 "Offline" utilities may wish to use this class directly.
249 C<lib/MyAppDB/UserRole.pm>:
251 package MyAppDB::UserRole;
253 use base qw/DBIx::Class/;
255 # Load required DBIC stuff
256 __PACKAGE__->load_components(qw/PK::Auto Core/);
258 __PACKAGE__->table('user_roles');
259 # Set columns in table
260 __PACKAGE__->add_columns(qw/user_id role_id/);
261 # Set the primary key for the table
262 __PACKAGE__->set_primary_key(qw/user_id role_id/);
270 # 1) Name of relationship, DBIC will create accessor with this name
271 # 2) Name of the model class referenced by this relationship
272 # 3) Column name in *this* table
273 __PACKAGE__->belongs_to(user => 'MyAppDB::User', 'user_id');
277 # 1) Name of relationship, DBIC will create accessor with this name
278 # 2) Name of the model class referenced by this relationship
279 # 3) Column name in *this* table
280 __PACKAGE__->belongs_to(role => 'MyAppDB::Role', 'role_id');
285 MyAppDB::UserRole - A model object representing the JOIN between Users and Roles.
289 This is an object that represents a row in the 'user_roles' table of your application
290 database. It uses DBIx::Class (aka, DBIC) to do ORM.
292 You probably won't need to use this class directly -- it will be automatically
293 used by DBIC where joins are needed.
295 For Catalyst, this is designed to be used through MyApp::Model::MyAppDB.
296 Offline utilities may wish to use this class directly.
302 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.
305 =head2 Sanity-Check Reload of Development Server
307 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:
309 $ script/myapp_server.pl
311 Look for the three new model objects in the startup debug output:
314 .-------------------------------------------------------------------+----------.
316 +-------------------------------------------------------------------+----------+
317 | MyApp::Controller::Books | instance |
318 | MyApp::Controller::Root | instance |
319 | MyApp::Model::MyAppDB | instance |
320 | MyApp::Model::MyAppDB::Author | class |
321 | MyApp::Model::MyAppDB::Book | class |
322 | MyApp::Model::MyAppDB::BookAuthor | class |
323 | MyApp::Model::MyAppDB::Role | class |
324 | MyApp::Model::MyAppDB::User | class |
325 | MyApp::Model::MyAppDB::UserRole | class |
326 | MyApp::View::TT | instance |
327 '-------------------------------------------------------------------+----------'
330 Again, notice that your "result source" classes have been "re-loaded" by Catalyst under C<MyApp::Model>.
333 =head2 Include Authentication and Session Plugins
335 Edit C<lib/MyApp.pm> and update it as follows (everything below C<StackTrace> is new):
345 Authentication::Store::DBIC
346 Authentication::Credential::Password
349 Session::Store::FastMmap
350 Session::State::Cookie
353 The three C<Authentication> plugins work together to support
354 Authentication while the C<Session> plugins are required to maintain
355 state across multiple HTTP requests. Note that there are several
356 options for L<Session::Store|Catalyst::Plugin::Session::Store>
357 (L<Session::Store::FastMmap|Catalyst::Plugin::Session::Store::FastMmap>
358 is generally a good choice if you are on Unix; try
359 L<Cache::FileCache|Catalyst::Plugin::Cache::FileCache> if you are on
360 Win32) -- consult L<Session::Store|Catalyst::Plugin::Session::Store> and
361 its subclasses for additional information.
364 =head2 Configure Authentication
366 Although C<__PACKAGE__-E<gt>config(name =E<gt> 'value');> is still
367 supported, newer Catalyst applications tend to place all configuration
368 information in C<myapp.yml> and automatically load this information into
369 C<MyApp-E<gt>config> using the
370 L<ConfigLoader|Catalyst::Plugin::ConfigLoader> plugin. Here, we need
371 to load several parameters that tell
372 L<Catalyst::Plugin::Authentication|Catalyst::Plugin::Authentication>
373 where to locate information in your database. To do this, edit the
374 C<myapp.yml> YAML and update it to match:
380 # Note this first definition would be the same as setting
381 # __PACKAGE__->config->{authentication}->{dbic}->{user_class} = 'MyAppDB::User'
382 # in lib/MyApp.pm (IOW, each hash key becomes a "name:" in the YAML file).
384 # This is the model object created by Catalyst::Model::DBIC from your
385 # schema (you created 'MyAppDB::User' but as the Catalyst startup
386 # debug messages show, it was loaded as 'MyApp::Model::MyAppDB::User').
387 # NOTE: Omit 'MyApp::Model' to avoid a component lookup issue in Catalyst 5.66
388 user_class: MyAppDB::User
389 # This is the name of the field in your 'users' table that contains the user's name
391 # This is the name of the field in your 'users' table that contains the password
392 password_field: password
393 # Other options can go here for hashed passwords
395 Inline comments in the code above explain how each field is being used.
397 B<TIP>: Although YAML uses a very simple and easy-to-ready format, it
398 does require the use of a consistent level of indenting. Be sure you
399 line up everything on a given 'level' with the same number of indents.
400 Also, be sure not to use C<tab> characters (YAML does not support them
401 because they are handled inconsistently across editors).
404 =head2 Add Login and Logout Controllers
406 Use the Catalyst create script to create two stub controller files:
408 $ script/myapp_create.pl controller Login
409 $ script/myapp_create.pl controller Logout
411 B<NOTE>: You could easily use a single controller here. For example,
412 you could have a C<User> controller with both C<login> and C<logout>
413 actions. Remember, Catalyst is designed to be very flexible, and leaves
414 such matters up to you, the designer and programmer.
416 Then open C<lib/MyApp/Controller/Login.pm>, locate the C<sub index :
417 Private> method (this was automatically inserted by the helpers when we
418 created the Login controller above), and delete this line:
420 $c->response->body('Matched MyApp::Controller::Login in Login.');
422 Then update it to match:
430 sub index : Private {
433 # Get the username and password from form
434 my $username = $c->request->params->{username} || "";
435 my $password = $c->request->params->{password} || "";
437 # If the username and password values were found in form
438 if ($username && $password) {
439 # Attempt to log the user in
440 if ($c->login($username, $password)) {
441 # If successful, then let them use the application
442 $c->response->redirect($c->uri_for('/books/list'));
445 # Set an error message
446 $c->stash->{error_msg} = "Bad username or password.";
450 # If either of above don't work out, send to the login page
451 $c->stash->{template} = 'login.tt2';
454 This controller fetches the C<username> and C<password> values from the
455 login form and attempts to perform a login. If successful, it redirects
456 the user to the book list page. If the login fails, the user will stay
457 at the login page but receive an error message. If the C<username> and
458 C<password> values are not present in the form, the user will be taken
459 to the empty login form.
461 Note that we could have used something like C<sub default :Private>;
462 however, the use of C<default> actions is discouraged because it does
463 not receive path args as with other actions. The recommended practice
464 is to only use C<default> in C<MyApp::Controller::Root>.
466 Another options would be to use something like
467 C<sub base :Path :Args(0) {...}> (where the C<...> refers to the login
468 code shown in C<sub index : Private> above). We are using C<sub base
469 :Path :Args(0) {...}> here to specifically match the URL C</login>.
470 C<Path> actions (aka, "literal actions") create URI matches relative to
471 the namespace of the controller where they are defined. Although
472 C<Path> supports arguments that allow relative and absolute paths to be
473 defined, here we use an empty C<Path> definition to match on just the
474 name of the controller itself. The method name, C<base>, is arbitrary.
475 We make the match even more specific with the C<:Args(0)> action
476 modifier -- this forces the match on I<only> C</login>, not
477 C</login/somethingelse>.
479 Next, create a corresponding method in C<lib/MyApp/Controller/Logout.pm>:
487 sub index : Private {
490 # Clear the user's state
493 # Send the user to the starting point
494 $c->response->redirect($c->uri_for('/'));
497 As with the login controller, be sure to delete the
498 C<$c->response->body('Matched MyApp::Controller::Logout in Logout.');>
499 line of the C<sub index>.
502 =head2 Add a Login Form TT Template Page
504 Create a login form by opening C<root/src/login.tt2> and inserting:
506 [% META title = 'Login' %]
509 <form method="post" action=" [% Catalyst.uri_for('/login') %] ">
513 <td><input type="text" name="username" size="40" /></td>
517 <td><input type="password" name="password" size="40" /></td>
520 <td colspan="2"><input type="submit" name="submit" value="Submit" /></td>
526 =head2 Add Valid User Check
528 We need something that provides enforcement for the authentication
529 mechanism -- a I<global> mechanism that prevents users who have not
530 passed authentication from reaching any pages except the login page.
531 This is generally done via an C<auto> action/method (prior to Catalyst
532 v5.66, this sort of thing would go in C<MyApp.pm>, but starting in
533 v5.66, the preferred location is C<lib/MyApp/Controller/Root.pm>).
535 Edit the existing C<lib/MyApp/Controller/Root.pm> class file and insert
536 the following method:
540 Check if there is a user and, if not, forward to login page
544 # Note that 'auto' runs after 'begin' but before your actions and that
545 # 'auto' "chain" (all from application path to most specific class are run)
549 # Allow unauthenticated users to reach the login page
550 if ($c->request->path =~ /login/) {
554 # If a user doesn't exist, force login
555 if (!$c->user_exists) {
556 # Dump a log message to the development server debug output
557 $c->log->debug('***Root::auto User not found, forwarding to /login');
558 # Redirect the user to the login page
559 $c->response->redirect($c->uri_for('/login'));
560 # Return 0 to cancel 'post-auto' processing and prevent use of application
564 # User found, so return 1 to continue with processing after this 'auto'
568 B<Note:> Catalyst provides a number of different types of actions, such
569 as C<Local>, C<Regex>, and C<Private>. You should refer to
570 L<Catalyst::Manual::Intro> for a more detailed explanation, but the
571 following bullet points provide a quick introduction:
577 The majority of application use C<Local> actions for items that respond
578 to user requests and C<Private> actions for those that do not directly
579 respond to user input.
583 There are five types of C<Private> actions: C<begin>, C<end>,
584 C<default>, C<index>, and C<auto>.
588 Unlike the other actions where only a single method is called for each
589 request, I<every> auto action along the chain of namespaces will be
594 By placing the authentication enforcement code inside the C<auto> method
595 of C<lib/MyApp/Controller/Root.pm> (or C<lib/MyApp.pm>), it will be
596 called for I<every> request that is received by the entire application.
599 =head2 Displaying Content Only to Authenticated Users
601 Let's say you want to provide some information on the login page that
602 changes depending on whether the user has authenticated yet. To do
603 this, open C<root/src/login.tt2> in your editor and add the following
604 lines to the bottom of the file:
608 # This code illustrates how certain parts of the TT
609 # template will only be shown to users who have logged in
611 [% IF Catalyst.user %]
612 Please Note: You are already logged in as '[% Catalyst.user.username %]'.
613 You can <a href="[% Catalyst.uri_for('/logout') %]">logout</a> here.
615 You need to log in to use this application.
618 Note that this whole block is a comment because the "#" appears
619 immediate after the "[%" (with no spaces in between). Although it
620 can be a handy way to temporarily "comment out" a whole block of
621 TT code, it's probably a little too subtle for use in "normal"
625 Although most of the code is comments, the middle few lines provide a
626 "you are already logged in" reminder if the user returns to the login
627 page after they have already authenticated. For users who have not yet
628 authenticated, a "You need to log in..." message is displayed (note the
629 use of an IF-THEN-ELSE construct in TT).
632 =head2 Try Out Authentication
634 Press C<Ctrl-C> to kill the previous server instance (if it's still
635 running) and restart it:
637 $ script/myapp_server.pl
639 B<IMPORTANT NOTE>: If you happen to be using Internet Explorer, you may
640 need to use the command C<script/myapp_server.pl -k> to enable the
641 keepalive feature in the development server. Otherwise, the HTTP
642 redirect on successful login may not work correctly with IE (it seems to
643 work without -k if you are running the web browser and development
644 server on the same machine). If you are using browser a browser other
645 than IE, it should work either way. If you want to make keepalive the
646 default, you can edit C<script/myapp_server.pl> and change the
647 initialization value for C<$keepalive> to C<1>. (You will need to do
648 this every time you create a new Catalyst application or rebuild the
649 C<myapp_server.pl> script.)
651 Now trying going to L<http://localhost:3000/books/list> and you should
652 be redirected to the login page, hitting Shift+Reload if necessary (the
653 "You are already logged in" message should I<not> appear -- if it does,
654 click the C<logout> button and try again). Note the C<***Root::auto User
655 not found...> debug message in the development server output. Enter
656 username C<test01> and password C<mypass>, and you should be taken to
659 Open C<root/src/books/list.tt2> and add the following lines to the
663 <a href="[% Catalyst.uri_for('/login') %]">Login</a>
664 <a href="[% Catalyst.uri_for('form_create') %]">Create</a>
667 Reload your browser and you should now see a "Login" and "Create" links
668 at the bottom of the page (as mentioned earlier, you can update template
669 files without reloading the development server). Click the first link
670 to return to the login page. This time you I<should> see the "You are
671 already logged in" message.
673 Finally, click the C<You can logout here> link on the C</login> page.
674 You should stay at the login page, but the message should change to "You
675 need to log in to use this application."
678 =head1 USING PASSWORD HASHES
680 In this section we increase the security of our system by converting
681 from cleartext passwords to SHA-1 password hashes.
683 B<Note:> This section is optional. You can skip it and the rest of the
684 tutorial will function normally.
686 Note that even with the techniques shown in this section, the browser
687 still transmits the passwords in cleartext to your application. We are
688 just avoiding the I<storage> of cleartext passwords in the database by
689 using a SHA-1 hash. If you are concerned about cleartext passwords
690 between the browser and your application, consider using SSL/TLS, made
691 easy with the Catalyst plugin
692 L<Catalyst::Plugin:RequireSSL|Catalyst::Plugin:RequireSSL>.
695 =head2 Get a SHA-1 Hash for the Password
697 Catalyst uses the C<Digest> module to support a variety of hashing
698 algorithms. Here we will use SHA-1 (SHA = Secure Hash Algorithm).
699 First, we should compute the SHA-1 hash for the "mypass" password we are
700 using. The following command-line Perl script provides a "quick and
701 dirty" way to do this:
703 $ perl -MDigest::SHA -e 'print Digest::SHA::sha1_hex("mypass"), "\n"'
704 e727d1464ae12436e899a726da5b2f11d8381b26
707 B<Note:> You should probably modify this code for production use to
708 not read the password from the command line. By having the script
709 prompt for the cleartext password, it avoids having the password linger
710 in forms such as your C<.bash_history> files (assuming you are using
711 BASH as your shell). An example of such a script can be found in
715 =head2 Switch to SHA-1 Password Hashes in the Database
717 Next, we need to change the C<password> column of our C<users> table to
718 store this hash value vs. the existing cleartext password. Open
719 C<myapp03.sql> in your editor and enter:
722 -- Convert passwords to SHA-1 hashes
724 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 1;
725 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 2;
726 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 3;
728 Then use the following command to update the SQLite database:
730 $ sqlite3 myapp.db < myapp03.sql
732 B<Note:> We are using SHA-1 hashes here, but many other hashing
733 algorithms are supported. See C<Digest> for more information.
736 =head2 Enable SHA-1 Hash Passwords in
737 C<Catalyst::Plugin::Authentication::Store::DBIC>
739 Edit C<myapp.yml> and update it to match (the C<password_type> and
740 C<password_hash_type> are new, everything else is the same):
746 # Note this first definition would be the same as setting
747 # __PACKAGE__->config->{authentication}->{dbic}->{user_class} = 'MyAppDB::User'
748 # in lib/MyApp.pm (IOW, each hash key becomes a "name:" in the YAML file).
750 # This is the model object created by Catalyst::Model::DBIC from your
751 # schema (you created 'MyAppDB::User' but as the Catalyst startup
752 # debug messages show, it was loaded as 'MyApp::Model::MyAppDB::User').
753 # NOTE: Omit 'MyApp::Model' to avoid a component lookup issue in Catalyst 5.66
754 user_class: MyAppDB::User
755 # This is the name of the field in your 'users' table that contains the user's name
757 # This is the name of the field in your 'users' table that contains the password
758 password_field: password
759 # Other options can go here for hashed passwords
760 # Enabled hashed passwords
761 password_type: hashed
762 # Use the SHA-1 hashing algorithm
763 password_hash_type: SHA-1
766 =head2 Try Out the Hashed Passwords
768 Press C<Ctrl-C> to kill the previous server instance (if it's still
769 running) and restart it:
771 $ script/myapp_server.pl
773 You should now be able to go to L<http://localhost:3000/books/list> and
774 login as before. When done, click the "Logout" link on the login page
775 (or point your browser at L<http://localhost:3000/logout>).
777 B<Note:> If you receive the debug screen in your browser with a
778 C<Can't call method "stash" on an undefined value...> error message,
779 make sure that you are using v0.07 of
780 L<Catalyst::Plugin::Authorization::ACL|Catalyst::Plugin::Authorization::ACL>.
781 The following command can be a useful way to quickly dump the version number
782 of this module on your system:
784 perl -MCatalyst::Plugin::Authorization::ACL -e 'print $Catalyst::Plugin::Authorization::ACL::VERSION, "\n";'
789 Kennedy Clark, C<hkclark@gmail.com>
791 Please report any errors, issues or suggestions to the author. The
792 most recent version of the Catlayst Tutorial can be found at
793 L<http://dev.catalyst.perl.org/repos/Catalyst/trunk/Catalyst-Runtime/lib/Catalyst/Manual/Tutorial/>.
795 Copyright 2006, Kennedy Clark, under Creative Commons License
796 (L<http://creativecommons.org/licenses/by-nc-sa/2.5/>).