<com:TContent ID="body" > <h1 id="5501">Authentication and Authorization</h1> <p id="720549" class="block-content"> Authentication is a process of verifying whether someone is who he claims he is. It usually involves a username and a password, but may include any other methods of demonstrating identity, such as a smart card, fingerprints, etc. </p> <p id="720550" class="block-content"> Authorization is finding out if the person, once identified, is permitted to manipulate specific resources. This is usually determined by finding out if that person is of a particular role that has access to the resources. </p> <h2 id="5502">How PRADO Auth Framework Works</h2> <p id="720551" class="block-content"> PRADO provides an extensible authentication/authorization framework. As described in <a href="?page=Fundamentals.Applications">application lifecycles</a>, <tt>TApplication</tt> reserves several lifecycles for modules responsible for authentication and authorization. PRADO provides the <tt>TAuthManager</tt> module for such purposes. Developers can plug in their own auth modules easily. <tt>TAuthManager</tt> is designed to be used together with <tt>TUserManager</tt> module, which implements a read-only user database. </p> <p id="720552" class="block-content"> When a page request occurs, <tt>TAuthManager</tt> will try to restore user information from session. If no user information is found, the user is considered as an anonymous or guest user. To facilitate user identity verification, <tt>TAuthManager</tt> provides two commonly used methods: <tt>login()</tt> and <tt>logout()</tt>. A user is logged in (verified) if his username and password entries match a record in the user database managed by <tt>TUserManager</tt>. A user is logged out if his user information is cleared from session and he needs to re-login if he makes new page requests. </p> <p id="720553" class="block-content"> During <tt>Authorization</tt> application lifecycle, which occurs after <tt>Authentication</tt> lifecycle, <tt>TAuthManager</tt> will verify if the current user has access to the requested page according to a set of authorization rules. The authorization is role-based, i.e., a user has access to a page if 1) the page explicitly states that the user has access; 2) or the user is of a particular role that has access to the page. If the user does not have access to the page, <tt>TAuthManager</tt> will redirect user browser to the login page which is specified by <tt>LoginPage</tt> property. </p> <h2 id="5503">Using PRADO Auth Framework</h2> <p id="720554" class="block-content"> To enable PRADO auth framework, add the <tt>TAuthManager</tt> module and <tt>TUserManager</tt> module to <a href="?page=Configurations.AppConfig">application configuration</a>, </p> <com:TTextHighlighter Language="xml" CssClass="source block-content" id="code1"> <service id="page" class="TPageService"> <modules> <module id="auth" class="System.Security.TAuthManager" UserManager="users" LoginPage="UserLogin" /> <module id="users" class="System.Security.TUserManager" PasswordMode="Clear"> <user name="demo" password="demo" /> <user name="admin" password="admin" /> </module> </modules> </service> </com:TTextHighlighter> <p id="720555" class="block-content"> In the above, the <tt>UserManager</tt> property of <tt>TAuthManager</tt> is set to the <tt>users</tt> module which is <tt>TUserManager</tt>. Developers may replace it with a different user management module that is derived from <tt>TUserManager</tt>. </p> <p id="720556" class="block-content"> Authorization rules for pages are specified in <a href="?page=Configurations.PageConfig">page configurations</a> as follows, </p> <com:TTextHighlighter Language="xml" CssClass="source block-content" id="code2"> <authorization> <allow pages="PageID1,PageID2" users="User1,User2" roles="Role1" /> <deny pages="PageID1,PageID2" users="?" verb="post" /> </authorization> </com:TTextHighlighter> <p id="720557" class="block-content"> An authorization rule can be either an <tt>allow</tt> rule or a <tt>deny</tt> rule. Each rule consists of four optional properties: </p> <ul id="u1" class="block-content"> <li><tt>pages</tt> - list of comma-separated page names that this rule applies to. If empty, not set or wildcard '*', this rule will apply to all pages under the current directory and all its subdirectories recursively.</li> <li><tt>users</tt> - list of comma-separated user names that this rule applies to. If empty, not set or wildcard '*', this rule will apply to all users including anonymous/guest user. A character ? refers to anonymous/guest user. And a character @ refers to authenticated users (available since v3.1).</li> <li><tt>roles</tt> - list of comma-separated user roles that this rule applies to. If empty, not set or wildcard '*', this rule will apply to all user roles.</li> <li><tt>verb</tt> - page access method that this rule applies to. It can be either <tt>get</tt> or <tt>post</tt>. If empty, not set or wildcard '*', the rule will apply to both methods.</li> </ul> <p id="720558" class="block-content"> When a page request is being processed, a list of authorization rules may be available. However, only the <i>first effective</i> rule <i>matching</i> the current user will render the authorization result. </p> <ul id="u2" class="block-content"> <li>Rules are ordered bottom-up, i.e., the rules contained in the configuration of current page folder go first. Rules in configurations of parent page folders go after.</li> <li>A rule is effective if the current page is in the listed pages of the rule AND the current user action (<tt>get</tt> or <tt>post</tt>) is in the listed actions.</li> <li>A rule matching occurs if the current user name is in the listed user names of an <i>effective</i> rule OR if the user's role is in the listed roles of that rule.</li> <li>If no rule matches, the user is authorized.</li> </ul> <p id="720559" class="block-content"> In the above example, anonymous users will be denied from posting to <tt>PageID1</tt> and <tt>PageID2</tt>, while <tt>User1</tt> and <tt>User2</tt> and all users of role <tt>Role1</tt> can access the two pages (in both <tt>get</tt> and <tt>post</tt> methods). </p> <com:SinceVersion Version="3.1.1" /> <p class="block-content"> Since version 3.1.1, the <tt>pages</tt> attribute in the authorization rules can take relative page paths with wildcard '*'. For example, <tt>pages="admin.Home"</tt> refers to the <tt>Home</tt> page under the <tt>admin</tt> directory, and <tt>pages="admin.*"</tt> would refer to all pages under the <tt>admin</tt> directory and subdirectories. </p> <p class="block-content"> Also introduced in version 3.1.1 are IP rules. They are specified by a new attribute <tt>ips</tt> in authorization rules. The IP rules are used to determine if an authorization rule aplies to an end-user according to his IP address. One can list a few IPs together, separated by comma ','. Wildcard '*' can be used in the rules. For example, <tt>ips="192.168.0.2, 192.168.1.*"</tt> means the rule applies to users whose IP address is 192.168.0.2 or 192.168.1.*. The latter matches any host in the subnet 192.168.1. If the attribute 'ips' is empty, not set or wildcard '*', the corresponding rule will apply to requests coming from any host address. </p> <h2 id="5504">Using <tt>TUserManager</tt></h2> <p id="720560" class="block-content"> As aforementioned, <tt>TUserManager</tt> implements a read-only user database. The user information are specified in either application configuration or an external XML file. </p> <p id="720561" class="block-content"> We have seen in the above example that two users are specified in the application configuration. Complete syntax of specifying the user and role information is as follows, </p> <com:TTextHighlighter Language="xml" CssClass="source block-content" id="code3"> <user name="demo" password="demo" roles="demo,admin" /> <role name="admin" users="demo,demo2" /> </com:TTextHighlighter> <p id="720562" class="block-content"> where the <tt>roles</tt> attribute in <tt>user</tt> element is optional. User roles can be specified in either the <tt>user</tt> element or in a separate <tt>role</tt> element. </p> <h2 id="5505">Using <tt>TDbUserManager</tt></h2> <p id="720563" class="block-content"> <tt>TDbUserManager</tt> is introduced in v3.1.0. Its main purpose is to simplify the task of managing user accounts that are stored in a database. It requires developers to write a user class that represents the necessary information for a user account. The user class must extend from <tt>TDbUser</tt>. </p> <p id="720564" class="block-content"> To use <tt>TDbUserManager</tt>, configure it in the application configuration like following: </p> <com:TTextHighlighter Language="xml" CssClass="source block-content" id="code4"> <module id="db" class="System.Data.TDataSourceConfig" ..../> <module id="users" class="System.Security.TDbUserManager" UserClass="Path.To.MyUserClass" ConnectionID="db" /> <module id="auth" class="System.Security.TAuthManager" UserManager="users" LoginPage="Path.To.LoginPage" /> </com:TTextHighlighter> </p> <p id="720565" class="block-content"> In the above, <tt>UserClass</tt> specifies what class will be used to create user instance. The class must extend from <tt>TDbUser</tt>. <tt>ConnectionID</tt> refers to the ID of a <tt>TDataSourceConfig</tt> module which specifies how to establish database connection to retrieve user information. </p> <p id="720566" class="block-content"> The user class has to implement the two abstract methods in <tt>TDbUser</tt>: <tt>validateUser()</tt> and <tt>createUser()</tt>. Since user account information is stored in a database, the user class may make use of its <tt>DbConnection</tt> property to reach the database. </p> <com:SinceVersion Version="3.1.1" /> <p id="720567" class="block-content"> Since 3.1.1, <tt>TAuthManager</tt> provides support to allow remembering login by setting <tt>AllowAutoLogin</tt> to true. Accordingly, <tt>TDbUser</tt> adds two methods to facilitate the implementation of this feature. In particular, two new methods are introduced: <tt>createUserFromCookie()</tt> and <tt>saveUserToCookie()</tt>. Developers should implement these two methods if remembering login is needed. Below is a sample implementation: </p> <com:TTextHighlighter Language="php" CssClass="source block-content" id="code5"> public function createUserFromCookie($cookie) { if(($data=$cookie->Value)!=='') { $application=Prado::getApplication(); if(($data=$application->SecurityManager->validateData($data))!==false) { $data=unserialize($data); if(is_array($data) && count($data)===3) { list($username,$address,$token)=$data; $sql='SELECT passcode FROM user WHERE LOWER(username)=:username'; $command=$this->DbConnection->createCommand($sql); $command->bindValue(':username',strtolower($username)); if($token===$command->queryScalar() && $token!==false && $address=$application->Request->UserHostAddress) return $this->createUser($username); } } } return null; } public function saveUserToCookie($cookie) { $application=Prado::getApplication(); $username=strtolower($this->Name); $address=$application->Request->UserHostAddress; $sql='SELECT passcode FROM user WHERE LOWER(username)=:username'; $command=$this->DbConnection->createCommand($sql); $command->bindValue(':username',strtolower($username)); $token=$command->queryScalar(); $data=array($username,$address,$token); $data=serialize($data); $data=$application->SecurityManager->hashData($data); $cookie->setValue($data); } </com:TTextHighlighter> </com:TContent>