Django rest framework（1）----认证

今天药忘吃喽~ 2021-12-10 13:13 301阅读 0赞

*  [Django组件库之(一) APIView源码][Django_ APIView][  
    ][Link 1]
 *  [Django restframework   (1)  ----认证][Link 1]
 *  [Django rest framework（2）----权限][Django rest framework_2_----]
 *  [Django rest framework（3）----节流][Django rest framework_3_----]
 *  [Django rest framework（4）----版本][Django rest framework_4_----]
 *  [Django rest framework（5）----解析器][Django rest framework_5_----]
 *  [Django rest framework（6）----序列化][Django rest framework_6_----]
 *  [Django rest framework（7）----分页][Django rest framework_7_----]

## 一、基础    ##

### 1.1.安装 ###

两种方式：

*  [github][]
 *  pip直接安装

pip install djangorestframework

### 1.2.需要先了解的一些知识 ###

理解下面两个知识点非常重要，django-rest-framework源码中到处都是基于CBV和面向对象的封装

（1）面向对象封装的两大特性

把同一类方法封装到类中
    
    将数据封装到对象中

（2）CBV

基于反射实现根据请求方式不同，执行不同的方法

原理：url-->view方法-->dispatch方法（反射执行其它方法：GET/POST/PUT/DELETE等等）

## 二、简单实例 ##

### 2.1.settings ###

先创建一个project和一个app(我这里命名为API)

首先要在settings的app中添加

INSTALLED_APPS = [
        'rest_framework',
    ]

### 2.2.url ###

from django.contrib import admin
    from django.urls import path
    from API.views import AuthView
    
    urlpatterns = [
        path('admin/', admin.site.urls),
        path('api/v1/auth/',AuthView.as_view()),
    ]

### 2.3.models ###

一个保存用户的信息

一个保存用户登录成功后的token

from django.db import models
    
    class UserInfo(models.Model):
        USER_TYPE = (
            (1,'普通用户'),
            (2,'VIP'),
            (3,'SVIP')
        )
    
        user_type = models.IntegerField(choices=USER_TYPE)
        username = models.CharField(max_length=32)
        password = models.CharField(max_length=64)
    
    class UserToken(models.Model):
        user = models.OneToOneField(UserInfo,on_delete=models.CASCADE)
        token = models.CharField(max_length=64)

### 2.4.views ###

用户登录（返回token并保存到数据库）

from django.shortcuts import render
    from django.http import JsonResponse
    from rest_framework.views import APIView
    from API import models
    
    def md5(user):
        import hashlib
        import time
        #当前时间，相当于生成一个随机的字符串
        ctime = str(time.time())
        m = hashlib.md5(bytes(user,encoding='utf-8'))
        m.update(bytes(ctime,encoding='utf-8'))
        return m.hexdigest()
    
    class AuthView(object):
        def post(self,request,*args,**kwargs):
            ret = {
         'code':1000,'msg':None}
            try:
                user = request._request.POST.get('username')
                pwd = request._request.POST.get('password')
                obj = models.UserInfo.objects.filter(username=user,password=pwd).first()
                if not obj:
                    ret['code'] = 1001
                    ret['msg'] = '用户名或密码错误'
                #为用户创建token
                token = md5(user)
                #存在就更新，不存在就创建
                models.UserToken.objects.update_or_create(user=obj,defaults={
         'token':token})
                ret['token'] = token
            except Exception as e:
                ret['code'] = 1002
                ret['msg'] = '请求异常'
            return JsonResponse(ret)

### 2.5.利用postman发请求 ###

![1299879-20180404001519020-215358301.png][]

如果用户名和密码正确的话  会生成token值，下次该用户再登录时，token的值就会更新

数据库中可以看到token的值

![1299879-20180404002038848-380615159.png][]

当用户名或密码错误时，抛出异常

![1299879-20180404001749628-1201051594.png][]

##  三、添加认证 ##

基于上面的例子，添加一个认证的类

### 3.1.url ###

path('api/v1/order/',OrderView.as_view()),

### 3.2.views ###

from django.shortcuts import render,HttpResponse
    from django.http import JsonResponse
    from rest_framework.views import APIView
    from API import models
    from rest_framework.request import Request
    from rest_framework import exceptions
    from rest_framework.authentication import BasicAuthentication
    
    ORDER_DICT = {
        1:{
            'name':'apple',
            'price':15
        },
        2:{
            'name':'dog',
            'price':100
        }
    }
    
    def md5(user):
        import hashlib
        import time
        #当前时间，相当于生成一个随机的字符串
        ctime = str(time.time())
        m = hashlib.md5(bytes(user,encoding='utf-8'))
        m.update(bytes(ctime,encoding='utf-8'))
        return m.hexdigest()
    
    class AuthView(object):
        '''用于用户登录验证'''
        def post(self,request,*args,**kwargs):
            ret = {
         'code':1000,'msg':None}
            try:
                user = request._request.POST.get('username')
                pwd = request._request.POST.get('password')
                obj = models.UserInfo.objects.filter(username=user,password=pwd).first()
                if not obj:
                    ret['code'] = 1001
                    ret['msg'] = '用户名或密码错误'
                #为用户创建token
                token = md5(user)
                #存在就更新，不存在就创建
                models.UserToken.objects.update_or_create(user=obj,defaults={
         'token':token})
                ret['token'] = token
            except Exception as e:
                ret['code'] = 1002
                ret['msg'] = '请求异常'
            return JsonResponse(ret)
    
    
    class Authentication(APIView):
        '''认证'''
        def authenticate(self,request):
            token = request._request.GET.get('token')
            token_obj = models.UserToken.objects.filter(token=token).first()
            if not token_obj:
                raise exceptions.AuthenticationFailed('用户认证失败')
            #在rest framework内部会将这两个字段赋值给request，以供后续操作使用
            return (token_obj.user,token_obj)
    
        def authenticate_header(self, request):
            pass
    
    class OrderView(APIView):
        '''订单相关业务'''
    
        authentication_classes = [Authentication,]    #添加认证 def get(self,request,*args,**kwargs):
            #request.user
            #request.auth
            ret = {
         'code':1000,'msg':None,'data':None}
            try:
                ret['data'] = ORDER_DICT
            except Exception as e:
                pass
            return JsonResponse(ret)

### 3.3用postman发get请求 ###

请求的时候没有带token，可以看到会显示“用户认证失败”

![1299879-20180404003946030-804624762.png][]

这样就达到了认证的效果，django-rest-framework的认证是怎么实现的呢，下面基于这个例子来剖析drf的源码。

## 四、drf的认证源码分析 ##

**源码流程图**

![1299879-20180404015121036-251664296.png][]

**请求先到dispatch**

dispatch()主要做了两件事

*  封装request
 *  认证

具体看我写的代码里面的注释

def dispatch(self, request, *args, **kwargs):
            """
            `.dispatch()` is pretty much the same as Django's regular dispatch,
            but with extra hooks for startup, finalize, and exception handling.
            """
            self.args = args
            self.kwargs = kwargs
            #对原始request进行加工，丰富了一些功能
            #Request(
            #     request,
            #     parsers=self.get_parsers(),
            #     authenticators=self.get_authenticators(),
            #     negotiator=self.get_content_negotiator(),
            #     parser_context=parser_context
            # )
            #request(原始request,[BasicAuthentications对象，])
            #获取原生request,request._request
            #获取认证类的对象，request.authticators
            #1.封装request
            request = self.initialize_request(request, *args, **kwargs)
            self.request = request
            self.headers = self.default_response_headers  # deprecate?
    
            try:
                #2.认证
                self.initial(request, *args, **kwargs)
    
                # Get the appropriate handler method
                if request.method.lower() in self.http_method_names:
                    handler = getattr(self, request.method.lower(),
                                      self.http_method_not_allowed)
                else:
                    handler = self.http_method_not_allowed
    
                response = handler(request, *args, **kwargs)
    
            except Exception as exc:
                response = self.handle_exception(exc)
    
            self.response = self.finalize_response(request, response, *args, **kwargs)
            return self.response

### 4.1.reuqest ###

（1）initialize\_request()

可以看到initialize()就是封装原始request

def initialize_request(self, request, *args, **kwargs):
            """
            Returns the initial request object.
            """
            parser_context = self.get_parser_context(request)
    
            return Request(
                request,
                parsers=self.get_parsers(),
                authenticators=self.get_authenticators(),    #[BasicAuthentication(),],把对象封装到request里面了

negotiator=self.get_content_negotiator(), parser_context=parser_context )

（2）get\_authenticators()

通过列表生成式，返回对象的列表

def get_authenticators(self):
            """
            Instantiates and returns the list of authenticators that this view can use.
            """
            return [auth() for auth in self.authentication_classes]

（3）authentication\_classes

APIView里面有个  **authentication\_classes   **字段

可以看到默认是去全局的配置文件找（api\_settings）

class APIView(View):
    
        # The following policies may be set at either globally, or per-view.
        renderer_classes = api_settings.DEFAULT_RENDERER_CLASSES
        parser_classes = api_settings.DEFAULT_PARSER_CLASSES
       authentication_classes = api_settings.DEFAULT_AUTHENTICATION_CLASSES
        throttle_classes = api_settings.DEFAULT_THROTTLE_CLASSES
        permission_classes = api_settings.DEFAULT_PERMISSION_CLASSES
        content_negotiation_class = api_settings.DEFAULT_CONTENT_NEGOTIATION_CLASS
        metadata_class = api_settings.DEFAULT_METADATA_CLASS
        versioning_class = api_settings.DEFAULT_VERSIONING_CLASS

### **4.2.认证** ###

self.initial(request, \*args, \*\*kwargs)

（1）initial()

主要看 self.perform\_authentication(request),实现认证

def initial(self, request, *args, **kwargs):
            """
            Runs anything that needs to occur prior to calling the method handler.
            """
            self.format_kwarg = self.get_format_suffix(**kwargs)
    
            # Perform content negotiation and store the accepted info on the request
            neg = self.perform_content_negotiation(request)
            request.accepted_renderer, request.accepted_media_type = neg
    
            # Determine the API version, if versioning is in use.
            version, scheme = self.determine_version(request, *args, **kwargs)
            request.version, request.versioning_scheme = version, scheme
    
            # Ensure that the incoming request is permitted
            #3.实现认证
            self.perform_authentication(request)
            self.check_permissions(request)
            self.check_throttles(request)

（2）perform\_authentication()

调用了request.user

def perform_authentication(self, request):
            """
            Perform authentication on the incoming request.
    
            Note that if you override this and simply 'pass', then authentication
            will instead be performed lazily, the first time either
            `request.user` or `request.auth` is accessed.
            """
            request.user

（3）user

request.user的request的位置

![1299879-20180404165305715-1382488629.png][]

点进去可以看到Request有个user方法,加 @property 表示调用user方法的时候不需要加括号“user()”，可以直接调用：request.user

@property
        def user(self):
            """
            Returns the user associated with the current request, as authenticated
            by the authentication classes provided to the request.
            """
            if not hasattr(self, '_user'):
                with wrap_attributeerrors():
                    #获取认证对象，进行一步步的认证
                    self._authenticate()
            return self._user

（4）\_authenticate()

循环所有authenticator对象

def _authenticate(self):
            """
            Attempt to authenticate the request using each authentication instance
            in turn.
            """
            #循环认证类的所有对象
            #执行对象的authenticate方法
            for authenticator in self.authenticators:
                try:
                    #执行认证类的authenticate方法
                    #这里分三种情况
                    #1.如果authenticate方法抛出异常，self._not_authenticated()执行
                    #2.有返回值，必须是元组：（request.user,request.auth）
                    #3.返回None，表示当前认证不处理，等下一个认证来处理
                    user_auth_tuple = authenticator.authenticate(self)
                except exceptions.APIException:
                    self._not_authenticated()
                    raise
    
                if user_auth_tuple is not None:
                    self._authenticator = authenticator
                    self.user, self.auth = user_auth_tuple
                    return
    
            self._not_authenticated()

返回值就是例子中的：

token_obj.user-->>request.user

token_obj-->>request.auth

#在rest framework内部会将这两个字段赋值给request，以供后续操作使用
    return (token_obj.user,token_obj)     #例子中的return

当都没有返回值，就执行self.\_not\_authenticated(),相当于匿名用户，没有通过认证

def _not_authenticated(self):
            """
            Set authenticator, user & authtoken representing an unauthenticated request.
    
            Defaults are None, AnonymousUser & None.
            """
            self._authenticator = None
    
            if api_settings.UNAUTHENTICATED_USER:
                self.user = api_settings.UNAUTHENTICATED_USER()   #AnonymousUser匿名用户
            else:
                self.user = None
    
            if api_settings.UNAUTHENTICATED_TOKEN:
                self.auth = api_settings.UNAUTHENTICATED_TOKEN()  #None
            else:
                self.auth = None

**面向对象知识：**

子类继承 父类，调用方法的时候：

*  优先去自己里面找有没有这个方法，有就执行自己的
 *  只有当自己里面没有这个方法的时候才会去父类找

因为authenticate方法我们自己写，所以当执行authenticate()的时候就是执行我们自己写的认证

父类中的authenticate方法

def authenticate(self, request):
            return (self.force_user, self.force_token)

我们自己写的

class Authentication(APIView):
        '''用于用户登录验证'''
        def authenticate(self,request):
            token = request._request.GET.get('token')
            token_obj = models.UserToken.objects.filter(token=token).first()
            if not token_obj:
                raise exceptions.AuthenticationFailed('用户认证失败')
            #在rest framework内部会将这两个字段赋值给request，以供后续操作使用
            return (token_obj.user,token_obj)

认证的流程就是上面写的，弄懂了原理，再写代码就更容易理解为什么了。

### 4.3.配置文件 ###

继续解读源码

![1299879-20180404015623713-1707054504.png][]

默认是去全局配置文件中找，所以我们应该在settings.py中配置好路径

api\_settings源码

api_settings = APISettings(None, DEFAULTS, IMPORT_STRINGS)
    
    
    def reload_api_settings(*args, **kwargs):
        setting = kwargs['setting']
        if setting == 'REST_FRAMEWORK':
            api_settings.reload()

setting中‘REST\_FRAMEWORK’中找

全局配置方法：

API文件夹下面新建文件夹utils,再新建auth.py文件，里面写上认证的类

settings.py

#设置全局认证
    REST_FRAMEWORK = {
        "DEFAULT_AUTHENTICATION_CLASSES":['API.utils.auth.Authentication',]   #里面写你的认证的类的路径
    }

auth.py

# API/utils/auth.py
    
    from rest_framework import exceptions
    from API import models
    
    
    class Authentication(object):
        '''用于用户登录验证'''
        def authenticate(self,request):
            token = request._request.GET.get('token')
            token_obj = models.UserToken.objects.filter(token=token).first()
            if not token_obj:
                raise exceptions.AuthenticationFailed('用户认证失败')
            #在rest framework内部会将这两个字段赋值给request，以供后续操作使用
            return (token_obj.user,token_obj)
    
        def authenticate_header(self, request):
            pass

在settings里面设置的全局认证，所有业务都需要经过认证，如果想让某个不需要认证，只需要在其中添加下面的代码：

authentication_classes = []    #里面为空，代表不需要认证

![ContractedBlock.gif][] ![ExpandedBlockStart.gif][]

from django.shortcuts import render,HttpResponse
    from django.http import JsonResponse
    from rest_framework.views import APIView
    from API import models
    from rest_framework.request import Request
    from rest_framework import exceptions
    from rest_framework.authentication import BasicAuthentication
    
    ORDER_DICT = {
        1:{
            'name':'apple',
            'price':15
        },
        2:{
            'name':'dog',
            'price':100
        }
    }
    
    def md5(user):
        import hashlib
        import time
        #当前时间，相当于生成一个随机的字符串
        ctime = str(time.time())
        m = hashlib.md5(bytes(user,encoding='utf-8'))
        m.update(bytes(ctime,encoding='utf-8'))
        return m.hexdigest()
    
    class AuthView(APIView):
        '''用于用户登录验证'''
    
        authentication_classes = []    #里面为空，代表不需要认证
    
        def post(self,request,*args,**kwargs):
            ret = {
          'code':1000,'msg':None}
            try:
                user = request._request.POST.get('username')
                pwd = request._request.POST.get('password')
                obj = models.UserInfo.objects.filter(username=user,password=pwd).first()
                if not obj:
                    ret['code'] = 1001
                    ret['msg'] = '用户名或密码错误'
                #为用户创建token
                token = md5(user)
                #存在就更新，不存在就创建
                models.UserToken.objects.update_or_create(user=obj,defaults={
          'token':token})
                ret['token'] = token
            except Exception as e:
                ret['code'] = 1002
                ret['msg'] = '请求异常'
            return JsonResponse(ret)
    
    
    
    
    class OrderView(APIView):
        '''订单相关业务'''
    
    
        def get(self,request,*args,**kwargs):
            # self.dispatch
            #request.user
            #request.auth
            ret = {
          'code':1000,'msg':None,'data':None}
            try:
                ret['data'] = ORDER_DICT
            except Exception as e:
                pass
            return JsonResponse(ret)

API/view.py代码

再测试一下我们的代码

不带token发请求

![1299879-20180404022319722-1860740291.png][]

带token发请求

![1299879-20180404022226996-802309711.png][]

## 五、drf的内置认证 ##

rest\_framework里面内置了一些认证，我们自己写的认证类都要继承内置认证类 "BaseAuthentication"

### 4.1.BaseAuthentication源码： ###

class BaseAuthentication(object):
        """
        All authentication classes should extend BaseAuthentication.
        """
    
        def authenticate(self, request):
            """
            Authenticate the request and return a two-tuple of (user, token).
            """
            #内置的认证类，authenticate方法，如果不自己写，默认则抛出异常
            raise NotImplementedError(".authenticate() must be overridden.")
    
        def authenticate_header(self, request):
            """
            Return a string to be used as the value of the `WWW-Authenticate`
            header in a `401 Unauthenticated` response, or `None` if the
            authentication scheme should return `403 Permission Denied` responses.
            """
            #authenticate_header方法，作用是当认证失败的时候，返回的响应头
            pass

### 4.2.修改自己写的认证类 ###

自己写的Authentication必须继承内置认证类BaseAuthentication

# API/utils/auth/py
    
    from rest_framework import exceptions
    from API import models
    from rest_framework.authentication import BaseAuthentication
    
    
    class Authentication(BaseAuthentication):
        '''用于用户登录验证'''
        def authenticate(self,request):
            token = request._request.GET.get('token')
            token_obj = models.UserToken.objects.filter(token=token).first()
            if not token_obj:
                raise exceptions.AuthenticationFailed('用户认证失败')
            #在rest framework内部会将这两个字段赋值给request，以供后续操作使用
            return (token_obj.user,token_obj)
    
        def authenticate_header(self, request):
            pass

### 4.3.其它内置认证类 ###

rest\_framework里面还内置了其它认证类，我们主要用到的就是BaseAuthentication，剩下的很少用到

![1299879-20180405110038137-843873057.png][]

## 六、总结 ##

**自己写认证类方法梳理**

（1）创建认证类

*  继承BaseAuthentication    --->>1.重写authenticate方法；2.authenticate\_header方法直接写pass就可以（这个方法必须写）

（2）authenticate()返回值（三种）

*  None ----->>>当前认证不管，等下一个认证来执行
 *  raise exceptions.AuthenticationFailed('用户认证失败')       \# from rest\_framework import exceptions
 *   有返回值元祖形式：（元素1，元素2）      \#元素1复制给request.user;  元素2复制给request.auth

（3）局部使用

*  authentication\_classes = \[BaseAuthentication,\]

（4）全局使用

#设置全局认证
    REST_FRAMEWORK = {
        "DEFAULT_AUTHENTICATION_CLASSES":['API.utils.auth.Authentication',]
    }

**源码流程**

\--->>dispatch

--封装request

---获取定义的认证类（全局/局部），通过列表生成式创建对象

---initial

----peform\_authentication

-----request.user   （每部循环创建的对象）

转载于:https://www.cnblogs.com/liqianglog/p/11133572.html

[Django_ APIView]: https://www.cnblogs.com/liqianglog/p/11117755.html
[Link 1]: https://www.cnblogs.com/liqianglog/p/11133572.html
[Django rest framework_2_----]: https://www.cnblogs.com/liqianglog/p/11133614.html
[Django rest framework_3_----]: https://www.cnblogs.com/liqianglog/p/11133589.html
[Django rest framework_4_----]: https://www.cnblogs.com/liqianglog/p/11133615.html
[Django rest framework_5_----]: https://www.cnblogs.com/liqianglog/p/11133595.html
[Django rest framework_6_----]: https://www.cnblogs.com/liqianglog/p/11133596.html
[Django rest framework_7_----]: https://www.cnblogs.com/liqianglog/p/11133624.html
[github]: https://github.com/encode/django-rest-framework
[1299879-20180404001519020-215358301.png]: /images/20211210/8163dbd8c50741f4879b847227f3ca80.png
[1299879-20180404002038848-380615159.png]: /images/20211210/a9b6a8bdb5dc4392afbfa2d299aa7d29.png
[1299879-20180404001749628-1201051594.png]: /images/20211210/ea056cb5b8d041f69a52b3b76e7524eb.png
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