一、什么是认证
只有认证通过的用户才能访问指定的url地址，比如：查询课程信息，需要登录之后才能查看，没有登录，就不能查看，这时候需要用到认证组件
二、利用token记录认证过的用户
1、什么是token
token是服务端生成的一串字符串，以作客户端进行请求的一个令牌，当第一次登录后，服务器生成一个Token便将此Token返回给客户端，以后客户端只需带上这个Token前来请求数据即可，无需再次带上用户名和密码。session的存储是需要空间的，session的传输一般都是通过cookie来传输，或url重写的方式。
token在服务器时可以不用存储用户信息的，token传递的方式也不限于cookie传递，token也可以保存起来
2、token的原理
当第一次登录认证过后，就会返回一个token到前台，前台之后发送请求，就会带上这个token字符串，
3、cookie、session、token的区别
cookie是保存在浏览器，以key:value的形式传递到服务器认证用户，用户名密码可能裸露，不安全
session是保存在服务器，产生随机字符串与用户信息对应，将随机字符串放在cookie中。服务器会保存一份，可能保存到缓存/数据库/文件
token发送请求的对象可以是浏览器，也可以是移动端。服务器不需要记录任何东西，每次都是一个无状态的请求，每次都是通过解密来验证是否合法
三、drf的认证组件
# 用户信息表
class UserInfo(models.Model):
name = models.CharField(max_length=32)
pwd = models.CharField(max_length=32) # 用户token
class UserToken(models.Model):
token = models.CharField(max_length=64)
user = models.OneToOneField(to=UserInfo)
1、基本使用
from rest_framework.authentication import BaseAuthentication
from rest_framework.exceptions import APIException
from app01 import models # 定义一个认证类
class LoginAuth(BaseAuthentication):
# 重写authenticate方法
def authenticate(self, request):
# 从路由中获取token，从request对象中获取，如果token放在header中
# query_params 是Request封装的原生request.GET
token = request.query_params.get('token')
ret = models.UserToken.objects.filter(token=token).first()
if ret:
# 能查到,说明认证通过,返回空，或者返回当前的用户对象
# ret.user就是当前登录用户对象,一旦retrun了,后面的认证类都不执行了
return ret.user,ret
# 如果查不到，抛出异常
raise APIException('用户认证失败')
# view 层
from rest_framework.views import APIView
# 获取随机字符串——token
def get_token(name):
md = hashlib.md5()
md.update(str(name).encode('utf-8'))
return md.hexdigest()
# 用户登录
class Login(APIView):
def post(self, request, *args, **kwargs):
response = {'status': 100, 'msg': '登录成功'}
name = request.data.get('name')
pwd = request.data.get('pwd')
ret = models.UserInfo.objects.filter(name=name, pwd=pwd).first()
if ret:
token = get_token(name)
# 一旦用户信息校验通过，就产生一个token保存在Token表中
models.UserToken.objects.create(token=token, user=ret)
response['token'] = token
else:
response['status'] = 101
response['msg'] = '用户名或密码错误'
return JsonResponse(response, safe=False) # 查看所有图书信息
class Book(APIView):
# 指定authentication_classes，会循环列表实例化，进行认证
# 该方法是局部使用认证
authentication_classes = [UserAuth.UserAuth, ] def get(self, request, *args, **kwargs):
response = {'status': 100, 'msg': '查询成功'}
ret = models.Book.objects.all()
ser = MySerializer.BookSerializer(instance=ret, many=True)
response['data'] = ser.data
return JsonResponse(response, safe=False)
2、全局使用、局部使用、局部禁用认证
（1）全局使用
- 在settings文件中配置，配置完以后，就无需在视图类中写，已经是所有视图类都需要认证
- 必须为
REST_FRAMEWORK，key值必须为DEFAULT_AUTHENTICATION_CLASSES
REST_FRAMEWORK={
'DEFAULT_AUTHENTICATION_CLASSES':['app01.MyAuth.LoginAuth',],
}
（2）局部使用
在需要使用的视图类中写，只对当前视图类起认证作用，重新定义authentication_classes
class Book(APIView):
# 该方法是局部使用认证
authentication_classes = [UserAuth.UserAuth, ] def get(self, request, *args, **kwargs):
response = {'status': 100, 'msg': '查询成功'}
ret = models.Book.objects.all()
ser = MySerializer.BookSerializer(instance=ret, many=True)
response['data'] = ser.data
return JsonResponse(response, safe=False)
（3）局部禁用
在配置过全局认证以后，有些视图类不需要认证，可以局部禁用认证，只需将authentication_classes定义为空列表即可。例如：登录视图，不应该有认证，就可以局部禁用
# settings中
REST_FRAMEWORK={
'DEFAULT_AUTHENTICATION_CLASSES':['app01.MyAuth.LoginAuth',],
} # view的视图类中
class Book(APIView):
# 该方法是局部使用认证
authentication_classes = [] def get(self, request, *args, **kwargs):
response = {'status': 100, 'msg': '查询成功'}
ret = models.Book.objects.all()
ser = MySerializer.BookSerializer(instance=ret, many=True)
response['data'] = ser.data
return JsonResponse(response, safe=False)
3、不存数据库的token实现认证
# 登录以后，会产生一个随机字符串，返回到移动端/PC端，下一次发送请求，就在后面拼上 ?token=asdfasdgasdg|{"id":1}，这样只要将后面的id通过加密获取随机字符串，与原字符串比较是否一致即可，不用再讲token存到数据库
def check_token(token):
user = None
ret = True
try:
# token 拿到的是 ‘fsdfasdfasd|{\"name\": \"lqz\", \"id\": 1}’
ll = token.split('|')
md = haslib.md5()
md.update(ll[1].encode('utf-8'))
md5.update(settings.password.encode('utf-8'))
hex = md.hexdigest()
if hex == ll[0]:
user = ll[1]
else:
ret = False
except Exception as e:
ret = False
return ret,user
class LoginAuth(BaseAuthentication):
# 重写authenticate方法
def authenticate(self, request):
token = request.query_params.get('token')
ret, user_info = check_token(token)
if ret:
return user_info, None
# 如果查不到,抛异常
raise exceptions.APIException('您认证失败')
def create_token(user_id):
md5 = hashlib.md5()
md5.update(user_id.encode('utf-8'))
# 加盐加密
md5.update(settings.password.encode('utf-8'))
hex = md5.hexdigest()
# 加密完以后，直接在后面拼上id，用于认证，传过来的id加密以后是否和原token一致
token = hex + '|' + user_id
print(token)
return token # 登录
# 产生随机字符串的时候就不需要存到数据库中
class Login(APIView):
authentication_classes = [] def post(self, request, *args, **kwargs):
response = {'status': 100, 'msg': '登录成功'}
name = request.data.get('name')
pwd = request.data.get('pwd')
try:
user = models.UserInfo.objects.get(name=name, pwd=pwd)
user_info_json = json.dumps({'name': user.name, 'id': user.pk})
# 生产dafgasdewf|{'name':user.name,'id':user.pk}的token
token = create_token(str(user.pk))
response['token'] = token
except ObjectDoesNotExist as e:
response['status'] = 101
response['msg'] = '用户名或密码错误'
except Exception as e:
response['status'] = 102
# response['msg']='未知错误'
response['msg'] = str(e)
return JsonResponse(response, safe=False)
四、源码分析
as_view ----------> view -------------> dispatch -------> Request包装新的request ------> 认证、权限、频率 --------> 根据请求方式分发到不同的方法
url(r'books/',views.Book.as_view())
1、Book中没有as_view
2、APIView的as_view
class APIView(View):
@classmethod
# cls 是 Book类
def as_view(cls, **initkwargs):
# view = super(APIView, Book).as_view(**initkwargs)
view = super(APIView, cls).as_view(**initkwargs)
view.cls = cls
view.initkwargs = initkwargs
# Note: session based authentication is explicitly CSRF validated,
# all other authentication is CSRF exempt.
return csrf_exempt(view)
3、view = super(APIView, cls).as_view(**initkwargs) ---------------------> View中的as_view
class View(object):
@classonlymethod
# cls====> Book
def as_view(cls, **initkwargs):
def view(request, *args, **kwargs):
# 实例化产生一个book对象
self = cls(**initkwargs)
if hasattr(self, 'get') and not hasattr(self, 'head'):
self.head = self.get
self.request = request
self.args = args
self.kwargs = kwargs
# 调dispatch方法
return self.dispatch(request, *args, **kwargs)
view.view_class = cls
view.view_initkwargs = initkwargs
# take name and docstring from class
update_wrapper(view, cls, updated=())
# and possible attributes set by decorators
# like csrf_exempt from dispatch
update_wrapper(view, cls.dispatch, assigned=())
return view
4、return self.dispatch(request, *args, **kwargs) ----------------> dispatch
self====> Book对象，一层层找dispatch
APIView中找到dispatch
class APIView(View):
def dispatch(self, request, *args, **kwargs):
self.args = args
self.kwargs = kwargs
# (a)初始化request，就是通过Request类来包装原生request，得到包装后的request
request = self.initialize_request(request, *args, **kwargs)
# 从现在开始request就是包装后的request
self.request = request
self.headers = self.default_response_headers # deprecate?
try:
# (b) 认证、权限、频率
self.initial(request, *args, **kwargs)
# Get the appropriate handler method
# http_method_names表示列表['get', 'post', 'put', 'patch', 'delete', 'head', 'options', 'trace']
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
（a）request = self.initialize_request(request, *args, **kwargs) 包装 request
self 是Book对象
class APIView(View):
# 默认的认证列表类
authentication_classes = api_settings.DEFAULT_AUTHENTICATION_CLASSES
def initialize_request(self, request, *args, **kwargs):
"""
Returns the initial request object.
"""
parser_context = self.get_parser_context(request)
# (a-b)实例化初始化产生新的request对象
return Request(
request,
parsers=self.get_parsers(),
authenticators=self.get_authenticators(), # 认证类实例化产生的对象的列表
negotiator=self.get_content_negotiator(),
parser_context=parser_context
)
def get_authenticators(self):
"""
Instantiates and returns the list of authenticators that this view can use.
"""
return [auth() for auth in self.authentication_classes]
（a------1）return Request( ··· ) ----------> Request类初始化
def __init__(self, request, parsers=None, authenticators=None,
negotiator=None, parser_context=None):
assert isinstance(request, HttpRequest), (
'The `request` argument must be an instance of '
'`django.http.HttpRequest`, not `{}.{}`.'
.format(request.__class__.__module__, request.__class__.__name__)
) self._request = request
self.parsers = parsers or ()
self.authenticators = authenticators or ()
self.negotiator = negotiator or self._default_negotiator()
self.parser_context = parser_context
self._data = Empty
self._files = Empty
self._full_data = Empty
self._content_type = Empty
self._stream = Empty if self.parser_context is None:
self.parser_context = {}
self.parser_context['request'] = self
self.parser_context['encoding'] = request.encoding or settings.DEFAULT_CHARSET force_user = getattr(request, '_force_auth_user', None)
force_token = getattr(request, '_force_auth_token', None)
if force_user is not None or force_token is not None:
forced_auth = ForcedAuthentication(force_user, force_token)
self.authenticators = (forced_auth,)
（b）self.initial(request, *args, **kwargs) -----> 认证、权限、频率
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
# （b------1) 认证
self.perform_authentication(request)
# （b------2)权限
self.check_permissions(request)
# 频率
self.check_throttles(request)
（b------1) self.perform_authentication(request) -------> 认证
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
（b------1------1) 调用request的user方法，request是Request实例化产生的对象
class Request(object):
@property
def user(self): # 这里的self是request
if not hasattr(self, '_user'):
with wrap_attributeerrors():
self._authenticate() # 具体方法如下
return self._user
（b------1------1-------1) self._authenticate()
class Request(object):
def _authenticate(self):
# 这里的self是request
# self.authenticators就是在Request实例化的时候，传过来的认证类的对象的列表
# 即：[auth() for auth in self.authentication_classes]
for authenticator in self.authenticators:
try:
# 重写的就是这个authenticate()方法,
# 两个参数，第一个是对象本身（自动传）；第二个是这里的self，就是request
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()