UserIdentity.php

<?php

/**
 * UserIdentity represents the data needed to identity a user.
 * It contains the authentication method that checks if the provided
 * data can identity the user.
 */
class UserIdentity extends CUserIdentity
{
private $_id;
/**
* Authenticates a user using the User data model.
* @return boolean whether authentication succeeds.
*/
public function authenticate()
{
    $user=User::model()->findByAttributes(array('username'=>$this->username));
         $pass1=$user->password;
         $pass2=$this->password;
         $n=strlen($pass1);

    if($user===null)
    {
        $this->errorCode=self::ERROR_USERNAME_INVALID;
    }
    else
    {

        if(strncmp($pass1,$pass2,$n)!==0)
        {

                $this->errorCode=self::ERROR_PASSWORD_INVALID;
        }
        else
        {   Yii::log('length: '.$n,'trace');
            $this->_id = $user->id;
            Yii::log('id: '.$this->_id,'trace');
            $this->errorCode == self::ERROR_NONE;
                        Yii::log('errorCode: '.$this->errorCode,'trace');
        }
    }
              Yii::log('errorCode: '.$this->errorCode,'trace');
    return !$this->errorCode;

}

public function getId()
{
    return $this->_id;
}
}