Application Security with Yii Framework
                    Authentication and Authorization




Ilko Kacharov | kachar136@gmail.com
Advantages of the framework
 1.   Very good documentation and many examples
 2.   Yii community is growing rapidly, has many free extensions
 3.   Easy approach to develop modules and components
 4.   Model, Controller, Module code generation tool may be used with custom code templates.
 5.   Abstract(static) component/module access Yii::app()->getComponent('db'); Yii::app()->getModule('ocstats');
 6.   It gives great power with strong code controlling, 100% true OOP framework, push-pull MVC
 7.   It is super fast because of the usage of autoloading functions
 8.   Easy configuration in php array, application may be started with different configs.
 9.   Easy to extend / customize, simple code structure
10.   Yii Authentication API for multi-channel login, easy to extend, SOAP support
11.   User Access Control using different schemes like RBAC, ACL
12.   Web services and console applications can be build as easy as web apps.
13.   Easy form creation and form validation (client and server side), built-in ajax support
14.   Easy to setup database connections and database migrations. Query builder or plain queries
15.   Easy to use CRUD functions (create,read,update,delete) Article::model()->findByPk()
16.   Many ready to use web widgets and tools like menus, action tables, calendars, etc.
17.   Integration with twitter bootstrap css layouts and js widgets (http://yii-booster.clevertech.biz/)
18.   Multiple plain PHP layouts, templates and partial templates.
19.   Automatic javascript/css registering and including in the main layout from anywhere
20.   Friendly with third-party code
21.   Internationalisation and translations module by module in php arrays, string extraction tool
22.   Error handling and logging
Performance




RPS (requests per second) means how many requests an
application written in a framework can process per second and
APC stands for Alternative PHP Cache, a caching component used
for increase of application performance (in comparison to the
same metering with this extension turned off).
http://www.yiiframework.com/performance/
Core Application Components
Yii predefines a set of core application components to provide features common among Web applications.
For example, the request component is used to resolve user requests and provide information such as URL, cookies.
By configuring the properties of these core components, we can change the default behaviors of Yii in nearly every aspect.

Below we list the core components that are pre-declared by CWebApplication.

assetManager:         CAssetManager - manages the publishing of private asset files.
authManager:          CAuthManager - manages role-based access control (RBAC).
cache:                CCache - provides data caching functionality.
clientScript:         CClientScript - manages client scripts (javascripts and CSS).
coreMessages:         CPhpMessageSource - provides translated core messages used by Yii framework.
db:                   CDbConnection - provides the database connection.
errorHandler:         CErrorHandler - handles uncaught PHP errors and exceptions.
messages:             CPhpMessageSource - provides translated messaged used by Yii application.
request:              CHttpRequest - provides information related with user requests.
securityManager:      CSecurityManager - provides security-related services, such as hashing, encryption.
session:              CHttpSession - provides session-related functionalities.
statePersister:       CStatePersister - provides global state persistence method.
urlManager:           CUrlManager - provides URL parsing and creation functionality.
user:                 CWebUser - represents the identity information of the current user.
themeManager:         CThemeManager - manages themes.

and others...
Application life cycle
                                                                    The following diagram shows a typical workflow of
The following diagram shows the static structure of an Yii          an Yii application when it is handling a user
app:                                                                request:




 1. Pre-initializes the application with CApplication::preinit();
 2. Set up class autoloader and error handling;
 3. Register core application components;
 4. Load application configuration;
 5. Initialize the application with CApplication::init()
    - Register application behaviors;
    - Load static application components;
 6. Raise onBeginRequest event;
 7. Process the user request:
    - Resolve the user request;
    - Create controller;
    - Run controller;
 http://www.hooto.com/media/image/view/?id=919&style=full
Authentication




 Authentication is the mechanism whereby systems
         may securely identify their users.

 Authentication systems provide an answers to the questions:

                    Who is the user?

Is the user really who he/she represents himself to be?
Authorization



Authorization verifies what you have the permissions
            you need to access an object.

 It is the mechanism by which a system determines
 what level of access a particular authenticated user
 should have to secured resources controlled by the
                       system.

● Is user X authorized to access resource R?
● Is user X authorized to perform operation P?
● Is user X authorized to perform operation P on resource R?
Access Control Lists




An access control list (ACL) is a list of permissions
             attached to an object.

An ACL specifies which users or system processes
  are granted access to objects, as well as what
     operations are allowed on given objects
Role-Based Access Control



  Role-based access control (RBAC) is an approach to
     restricting system access to authorized users.
Three primary rules are defined for RBAC:
1. Role assignment: A subject can exercise a permission only if the
    subject has selected or been assigned a role.
2. Role authorization: A subject's active role must be authorized for the
    subject. With rule 1 above, this rule ensures that users can take on
    only roles for which they are authorized.
3. Permission authorization: A subject can exercise a permission only if
    the permission is authorized for the subject's active role.
Role-Based Access Control

When defining an RBAC model, the following conventions are useful:
 ● Subject = A person or automated agent
 ● Role = Job function or title which defines an authority level
 ● Permissions = An approval of a mode of access to a resource
 ● Session = A mapping involving S, R and/or P
 ● Subject Assignment
 ● Permission Assignment
 ● Partially ordered Role Hierarchy
Steps to secure an Yii Application



1. Defining Identity Class
2. Login and Logout
3. Cookie-based Login
4. Access Control Filter
5. Handling Authorization Result
6. Role-Based Access Control
7. Configuring Authorization
   Manager
8. Defining Authorization Hierarchy
9. Using Business Rules
Authenticate method in Yii Application



public function authenticate()
{
  $record=User::model()->findByAttributes(array('username'=>$this->username));
  if($record===null)
     $this->errorCode=self::ERROR_USERNAME_INVALID;
  else if($record->password!==crypt($this->password,$record->password))
     $this->errorCode=self::ERROR_PASSWORD_INVALID;
  else
  {
     $this->_id=$record->id;
     $this->setState('title', $record->title);
     $this->errorCode=self::ERROR_NONE;
  }
  return !$this->errorCode;
}
API, documentation and community
The Definitive     http://www.yiiframework.com/doc/guide/
Guide to Yii

GitHub             https://github.com/yiisoft/yii/commits/master


Forum              http://www.yiiframework.com/forum/

                   Total Posts:                  173,083
                   Total Members:                 61,015
                   Active users at time of visit: 320
                   International treads:          20 Languages (incl. BG)

IRC Channel        http://www.yiiframework.com/chat/
                   Active users at time of visit: 90

Yii Books          http://www.seesawlabs.com/yii-book
                   http://yii.larryullman.com/toc.php
                   http://yiicookbook.org/
                   http://packtlib.packtpub.com/library/9781847199584

IDE integrations   Integrations with code completion, templates testing and debugging:
                   NetBeans
                   Eclipse
                   PhpStorm
                   Nusphere phpEd
Links



        Official website               http://www.yiiframework.com/


  Definitive Guide to Yii En/Ru        http://yiiframework.ru/


  Yii API and Class Reference          http://www.yiiframework.com/doc/api/


  Extensions Library (over 1k)         http://www.yiiframework.com/extensions/


 Yii General Forum (60k users)         http://www.yiiframework.com/forum/


Yii Cheat sheet (quick reference)      http://static.yiiframework.com/files/yii-1.0-cheatsheet.pdf


        Yii Related Sites              http://www.yiiframework.com/wiki/98/yii-related-sites/
References



D.R. Kuhn (1998). "Role Based Access Control on MLS Systems Without Kernel Changes"
        (PDF). Third ACM Workshop on Role Based Access Control. pp. 25–32.

A.C. O'Connor and R.J. Loomis (December 2010) (PDF). Economic Analysis of Role-Based
                      Access Control. Research Triangle Institute.

             John Mitchell. "Access Control and Operating System Security"

                          Michael Clarkson. "Access Control"
License and requirements

Yii is an open source project released under the terms of the BSD License.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
  ●     Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
  ●     Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the
        documentation and/or other materials provided with the distribution.
  ●     Neither the name of Yii Software LLC nor the names of its contributors may be used to endorse or promote products derived from this
        software without specific prior written permission.




Requirement:            PHP 5.1.0 or above
Clevertech are currently actively developing their next major version 2.0. Yii 2.0 will be rebuilt on top of PHP 5.3.0+ and is aimed
to become a state-of-the-art of the new generation of PHP framework.
They advise:
"If you have a new project to develop on Yii, do not wait for 2.0 as it will still take considerable time to reach the production
quality."


Installation:
Installation of Yii mainly involves the following three steps:
 1.     Download Yii Framework from yiiframework.com or github repo (newest)
 2.     Unpack the Yii release file to any directory. (ex. /opt/yii/)
 3.     Link your application with the framework source

Yii Framework Security

  • 1.
    Application Security withYii Framework Authentication and Authorization Ilko Kacharov | [email protected]
  • 2.
    Advantages of theframework 1. Very good documentation and many examples 2. Yii community is growing rapidly, has many free extensions 3. Easy approach to develop modules and components 4. Model, Controller, Module code generation tool may be used with custom code templates. 5. Abstract(static) component/module access Yii::app()->getComponent('db'); Yii::app()->getModule('ocstats'); 6. It gives great power with strong code controlling, 100% true OOP framework, push-pull MVC 7. It is super fast because of the usage of autoloading functions 8. Easy configuration in php array, application may be started with different configs. 9. Easy to extend / customize, simple code structure 10. Yii Authentication API for multi-channel login, easy to extend, SOAP support 11. User Access Control using different schemes like RBAC, ACL 12. Web services and console applications can be build as easy as web apps. 13. Easy form creation and form validation (client and server side), built-in ajax support 14. Easy to setup database connections and database migrations. Query builder or plain queries 15. Easy to use CRUD functions (create,read,update,delete) Article::model()->findByPk() 16. Many ready to use web widgets and tools like menus, action tables, calendars, etc. 17. Integration with twitter bootstrap css layouts and js widgets (http://yii-booster.clevertech.biz/) 18. Multiple plain PHP layouts, templates and partial templates. 19. Automatic javascript/css registering and including in the main layout from anywhere 20. Friendly with third-party code 21. Internationalisation and translations module by module in php arrays, string extraction tool 22. Error handling and logging
  • 3.
    Performance RPS (requests persecond) means how many requests an application written in a framework can process per second and APC stands for Alternative PHP Cache, a caching component used for increase of application performance (in comparison to the same metering with this extension turned off). http://www.yiiframework.com/performance/
  • 4.
    Core Application Components Yiipredefines a set of core application components to provide features common among Web applications. For example, the request component is used to resolve user requests and provide information such as URL, cookies. By configuring the properties of these core components, we can change the default behaviors of Yii in nearly every aspect. Below we list the core components that are pre-declared by CWebApplication. assetManager: CAssetManager - manages the publishing of private asset files. authManager: CAuthManager - manages role-based access control (RBAC). cache: CCache - provides data caching functionality. clientScript: CClientScript - manages client scripts (javascripts and CSS). coreMessages: CPhpMessageSource - provides translated core messages used by Yii framework. db: CDbConnection - provides the database connection. errorHandler: CErrorHandler - handles uncaught PHP errors and exceptions. messages: CPhpMessageSource - provides translated messaged used by Yii application. request: CHttpRequest - provides information related with user requests. securityManager: CSecurityManager - provides security-related services, such as hashing, encryption. session: CHttpSession - provides session-related functionalities. statePersister: CStatePersister - provides global state persistence method. urlManager: CUrlManager - provides URL parsing and creation functionality. user: CWebUser - represents the identity information of the current user. themeManager: CThemeManager - manages themes. and others...
  • 5.
    Application life cycle The following diagram shows a typical workflow of The following diagram shows the static structure of an Yii an Yii application when it is handling a user app: request: 1. Pre-initializes the application with CApplication::preinit(); 2. Set up class autoloader and error handling; 3. Register core application components; 4. Load application configuration; 5. Initialize the application with CApplication::init() - Register application behaviors; - Load static application components; 6. Raise onBeginRequest event; 7. Process the user request: - Resolve the user request; - Create controller; - Run controller; http://www.hooto.com/media/image/view/?id=919&style=full
  • 6.
    Authentication Authentication isthe mechanism whereby systems may securely identify their users. Authentication systems provide an answers to the questions: Who is the user? Is the user really who he/she represents himself to be?
  • 7.
    Authorization Authorization verifies whatyou have the permissions you need to access an object. It is the mechanism by which a system determines what level of access a particular authenticated user should have to secured resources controlled by the system. ● Is user X authorized to access resource R? ● Is user X authorized to perform operation P? ● Is user X authorized to perform operation P on resource R?
  • 8.
    Access Control Lists Anaccess control list (ACL) is a list of permissions attached to an object. An ACL specifies which users or system processes are granted access to objects, as well as what operations are allowed on given objects
  • 9.
    Role-Based Access Control Role-based access control (RBAC) is an approach to restricting system access to authorized users. Three primary rules are defined for RBAC: 1. Role assignment: A subject can exercise a permission only if the subject has selected or been assigned a role. 2. Role authorization: A subject's active role must be authorized for the subject. With rule 1 above, this rule ensures that users can take on only roles for which they are authorized. 3. Permission authorization: A subject can exercise a permission only if the permission is authorized for the subject's active role.
  • 10.
    Role-Based Access Control Whendefining an RBAC model, the following conventions are useful: ● Subject = A person or automated agent ● Role = Job function or title which defines an authority level ● Permissions = An approval of a mode of access to a resource ● Session = A mapping involving S, R and/or P ● Subject Assignment ● Permission Assignment ● Partially ordered Role Hierarchy
  • 11.
    Steps to securean Yii Application 1. Defining Identity Class 2. Login and Logout 3. Cookie-based Login 4. Access Control Filter 5. Handling Authorization Result 6. Role-Based Access Control 7. Configuring Authorization Manager 8. Defining Authorization Hierarchy 9. Using Business Rules
  • 12.
    Authenticate method inYii Application public function authenticate() { $record=User::model()->findByAttributes(array('username'=>$this->username)); if($record===null) $this->errorCode=self::ERROR_USERNAME_INVALID; else if($record->password!==crypt($this->password,$record->password)) $this->errorCode=self::ERROR_PASSWORD_INVALID; else { $this->_id=$record->id; $this->setState('title', $record->title); $this->errorCode=self::ERROR_NONE; } return !$this->errorCode; }
  • 13.
    API, documentation andcommunity The Definitive http://www.yiiframework.com/doc/guide/ Guide to Yii GitHub https://github.com/yiisoft/yii/commits/master Forum http://www.yiiframework.com/forum/ Total Posts: 173,083 Total Members: 61,015 Active users at time of visit: 320 International treads: 20 Languages (incl. BG) IRC Channel http://www.yiiframework.com/chat/ Active users at time of visit: 90 Yii Books http://www.seesawlabs.com/yii-book http://yii.larryullman.com/toc.php http://yiicookbook.org/ http://packtlib.packtpub.com/library/9781847199584 IDE integrations Integrations with code completion, templates testing and debugging: NetBeans Eclipse PhpStorm Nusphere phpEd
  • 14.
    Links Official website http://www.yiiframework.com/ Definitive Guide to Yii En/Ru http://yiiframework.ru/ Yii API and Class Reference http://www.yiiframework.com/doc/api/ Extensions Library (over 1k) http://www.yiiframework.com/extensions/ Yii General Forum (60k users) http://www.yiiframework.com/forum/ Yii Cheat sheet (quick reference) http://static.yiiframework.com/files/yii-1.0-cheatsheet.pdf Yii Related Sites http://www.yiiframework.com/wiki/98/yii-related-sites/
  • 15.
    References D.R. Kuhn (1998)."Role Based Access Control on MLS Systems Without Kernel Changes" (PDF). Third ACM Workshop on Role Based Access Control. pp. 25–32. A.C. O'Connor and R.J. Loomis (December 2010) (PDF). Economic Analysis of Role-Based Access Control. Research Triangle Institute. John Mitchell. "Access Control and Operating System Security" Michael Clarkson. "Access Control"
  • 16.
    License and requirements Yiiis an open source project released under the terms of the BSD License. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: ● Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. ● Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. ● Neither the name of Yii Software LLC nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. Requirement: PHP 5.1.0 or above Clevertech are currently actively developing their next major version 2.0. Yii 2.0 will be rebuilt on top of PHP 5.3.0+ and is aimed to become a state-of-the-art of the new generation of PHP framework. They advise: "If you have a new project to develop on Yii, do not wait for 2.0 as it will still take considerable time to reach the production quality." Installation: Installation of Yii mainly involves the following three steps: 1. Download Yii Framework from yiiframework.com or github repo (newest) 2. Unpack the Yii release file to any directory. (ex. /opt/yii/) 3. Link your application with the framework source