authentication.md 2.93 KB
Newer Older
1 2 3
Authentication
==============

Larry Ullman committed
4
Authentication is the act of verifying who a user is, and is the basis of the login process. Typically, authentication uses the combination of an identifier--a username or email address--and a password. The user submits these values  through a form, and the application then compares the submitted information against that previously stored (e.g., upon registration).
5

6
In Yii, this entire process is performed semi-automatically, leaving the developer to merely implement [[yii\web\IdentityInterface]], the most important class in the authentication system. Typically, implementation of `IdentityInterface` is accomplished using the `User` model.
Larry Ullman committed
7

Qiang Xue committed
8
You can find a fully featured example of authentication in the
Larry Ullman committed
9
[advanced application template](installation.md). Below, only the interface methods are listed:
10 11 12 13

```php
class User extends ActiveRecord implements IdentityInterface
{
14
    // ...
15

16 17 18 19 20 21 22 23
    /**
     * Finds an identity by the given ID.
     *
     * @param string|integer $id the ID to be looked for
     * @return IdentityInterface|null the identity object that matches the given ID.
     */
    public static function findIdentity($id)
    {
Alexander Makarov committed
24
        return static::findOne($id);
25
    }
26

27 28 29 30 31 32 33 34
    /**
     * Finds an identity by the given token.
     *
     * @param string $token the token to be looked for
     * @return IdentityInterface|null the identity object that matches the given token.
     */
    public static function findIdentityByAccessToken($token)
    {
Alexander Makarov committed
35
        return static::findOne(['access_token' => $token]);
36
    }
Qiang Xue committed
37

38 39 40 41 42 43 44
    /**
     * @return int|string current user ID
     */
    public function getId()
    {
        return $this->id;
    }
45

46 47 48 49 50 51 52
    /**
     * @return string current user auth key
     */
    public function getAuthKey()
    {
        return $this->auth_key;
    }
53

54 55 56 57 58 59 60 61
    /**
     * @param string $authKey
     * @return boolean if auth key is valid for current user
     */
    public function validateAuthKey($authKey)
    {
        return $this->getAuthKey() === $authKey;
    }
62 63 64
}
```

Larry Ullman committed
65 66
Two of the outlined methods are simple: `findIdentity` is provided with an  ID value and returns a model instance associated with that ID. The `getId` method returns the ID itself.
Two of the other methods--`getAuthKey` and `validateAuthKey`--are used to provide extra security to the "remember me" cookie. The `getAuthKey` method should return a string that is unique for each user. You can create reliably create a unique string using `Security::generateRandomKey()`. It's a good idea to also save this as part of the user's record:
67 68 69 70

```php
public function beforeSave($insert)
{
71 72 73 74 75 76 77
    if (parent::beforeSave($insert)) {
        if ($this->isNewRecord) {
            $this->auth_key = Security::generateRandomKey();
        }
        return true;
    }
    return false;
78 79 80
}
```

Larry Ullman committed
81
The `validateAuthKey` method just needs to compare the `$authKey` variable, passed as parameter (itself retrieved from a cookie), with the value fetched from database.