DRF(六)

    # 登录
    url(r‘^v1/login/$‘, views.LoginSessionAPIView.as_view()),

from rest_framework.views import APIView
from django.contrib import auth
class LoginSessionAPIView(APIView):
    # 登录要禁用认证与权限
    authentication_classes = []
    permission_classes = []
    def post(self, request, *args, **kwargs):
        username = request.data.get(‘username‘)
        password = request.data.get(‘password‘)
        if not (username and password):
            return Response(‘信息有误‘)
        # user = models.User.objects.filter(username=username).first()  # type: models.User
        # user.check_password(password)
        user = auth.authenticate(request, username=username, password=password)
        if not user:
            return Response(‘登录失败‘)
        auth.login(request, user=user)
        return Response(‘登录成功‘)

系统：session认证
rest_framework.authentication.SessionAuthentication
ajax请求通过认证：
cookie中要携带 sessionid、csrftoken，请求头中要携带 x-csrftoken,后台从META字典中获取

from rest_framework.authentication import BaseAuthentication
def authenticate(self, request):
    auth = 从request中得到
    user = 从auth中得到 (session校验中user是由sessionid解析出来的,而jwt校验user是由token字符串解析出来的)
    if not user:
        return None
    return user, auth

jwt：json web tokens 采用json格式在web上传输的 认证字符串

jwt字符串：头.载荷.签名

头：公司基本信息、项目组基本信息、常规加密算法名
载荷：用户信息、过期时间
签名：头、载荷、秘钥

{头信息字典，采用base64加密算法}.{载荷信息字典，采用base64加密算法}.{头加密串、载荷加密串、服务器秘钥，采用hs256加密算法}

base64是可逆加密
hash256是不可逆加密

pip install djangorestframework-jwt

   from rest_framework_jwt.views import ObtainJSONWebToken, obtain_jwt_token

    # url(r‘^v2/login/$‘, ObtainJSONWebToken.as_view()),
    url(r‘^v2/login/$‘, obtain_jwt_token),

 def post(self, request, *args, **kwargs):
        serializer = self.get_serializer(data=request.data)

        if serializer.is_valid():
            user = serializer.object.get(‘user‘) or request.user
            token = serializer.object.get(‘token‘)
            response_data = jwt_response_payload_handler(token, user, request)
            response = Response(response_data)
            if api_settings.JWT_AUTH_COOKIE:
                expiration = (datetime.utcnow() +
                              api_settings.JWT_EXPIRATION_DELTA)
                response.set_cookie(api_settings.JWT_AUTH_COOKIE,
                                    token,
                                    expires=expiration,
                                    httponly=True)
            return response

        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

url(r‘^v3/login/$‘, views.LoginJWTAPIView.as_view()),

import re
from utils.response import APIResponse
from rest_framework_jwt.serializers import jwt_encode_handler, jwt_payload_handler
class LoginJWTAPIView(APIView):
    authentication_classes = ()
    permission_classes = ()
    def post(self, request, *args, **kwargs):
        # username可能携带的不止是用户名，可能还是用户的其它唯一标识 手机号 邮箱
        username = request.data.get(‘username‘)
        password = request.data.get(‘password‘)

        # 如果username匹配上手机号正则 => 可能是手机登录
        if re.match(r‘1[3-9][0-9]{9}‘, username):
            try:
                # 手动通过 user 签发 jwt-token
                user = models.User.objects.get(mobile=username)
            except:
                return APIResponse(1, ‘该手机未注册‘)

        # 邮箱登录 等

        # 账号登录
        else:
            try:
                # 手动通过 user 签发 jwt-token
                user = models.User.objects.get(username=username)
            except:
                return APIResponse(1, ‘该账号未注册‘)

        # 获得用户后，校验密码并签发token
        if not user.check_password(password):
            return APIResponse(1, ‘密码错误‘)
        payload = jwt_payload_handler(user)
        token = jwt_encode_handler(payload)
        return APIResponse(0, ‘ok‘, results={
            ‘username‘: user.username,
            ‘mobile‘: user.mobile,
            ‘token‘: token
        })

rest_framework_jwt.authentication.JSONWebTokenAuthentication
ajax请求通过认证：
请求头中要携带 authorization，值为 jwt+空格+token

  url(r‘^v3/cars/$‘, views.CarV3ModelViewSet.as_view({
        ‘get‘: ‘list‘,
        ‘post‘: ‘create‘
    })),
    url(r‘^v3/cars/(?P<pk>.*)/$‘, views.CarV3ModelViewSet.as_view({
        ‘get‘: ‘retrieve‘,
        ‘put‘: ‘update‘,
        ‘patch‘: ‘partial_update‘,
        ‘delete‘: ‘destroy‘,
    })),

from rest_framework_jwt.authentication import JSONWebTokenAuthentication
class CarV3ModelViewSet(ModelViewSet):
    authentication_classes = [JSONWebTokenAuthentication]
    permission_classes = [IsAuthenticatedOrReadOnly]
    queryset = models.Car.objects.filter(is_delete=False)
    serializer_class = serializers.CarModelSerializer
    def destroy(self, request, *args, **kwargs):
        obj = self.get_object()
        obj.is_delete = True
        obj.save()
        return Response(‘删除成功‘)

 def authenticate(self, request):
        """
        Returns a two-tuple of `User` and token if a valid signature has been
        supplied using JWT-based authentication.  Otherwise returns `None`.
        """
        jwt_value = self.get_jwt_value(request)
        if jwt_value is None:
            return None

        try:
            payload = jwt_decode_handler(jwt_value)
        except jwt.ExpiredSignature:
            msg = _(‘Signature has expired.‘)
            raise exceptions.AuthenticationFailed(msg)
        except jwt.DecodeError:
            msg = _(‘Error decoding signature.‘)
            raise exceptions.AuthenticationFailed(msg)
        except jwt.InvalidTokenError:
            raise exceptions.AuthenticationFailed()

        user = self.authenticate_credentials(payload)

        return (user, jwt_value)

 def get_jwt_value(self, request):
        auth = get_authorization_header(request).split()
        auth_header_prefix = api_settings.JWT_AUTH_HEADER_PREFIX.lower()

        if not auth:
            if api_settings.JWT_AUTH_COOKIE:
                return request.COOKIES.get(api_settings.JWT_AUTH_COOKIE)
            return None

        if smart_text(auth[0].lower()) != auth_header_prefix:
            return None

        if len(auth) == 1:
            msg = _(‘Invalid Authorization header. No credentials provided.‘)
            raise exceptions.AuthenticationFailed(msg)
        elif len(auth) > 2:
            msg = _(‘Invalid Authorization header. Credentials string ‘
                    ‘should not contain spaces.‘)
            raise exceptions.AuthenticationFailed(msg)

        return auth[1]

def get_authorization_header(request):
    """
    Return request‘s ‘Authorization:‘ header, as a bytestring.

    Hide some test client ickyness where the header can be unicode.
    """
    auth = request.META.get(‘HTTP_AUTHORIZATION‘, b‘‘)
    if isinstance(auth, str):
        # Work around django test client oddness
        auth = auth.encode(HTTP_HEADER_ENCODING)
    return auth

   payload = {
        ‘user_id‘: user.pk,
        ‘username‘: username,
        ‘exp‘: datetime.utcnow() + api_settings.JWT_EXPIRATION_DELTA
    }

    ‘JWT_EXPIRATION_DELTA‘: datetime.timedelta(seconds=300),

自定义：基于jwt、其它
1）自定义认证类，继承BaseAuthentication(或其子类)，重写authenticate
2）authenticate中完成
    拿到认证标识 auth
    反解析出用户 user
    前两步操作失败 返回None => 游客
    前两步操作成功 返回user，auth => 登录用户
    注：如果在某个分支抛出异常，直接定义失败 => 非法用户

# jwt配置
import datetime
JWT_AUTH = {
    ‘JWT_EXPIRATION_DELTA‘: datetime.timedelta(seconds=30000),
    ‘JWT_AUTH_HEADER_PREFIX‘: ‘TOKEN‘,
}

REST_FRAMEWORK = {
    ‘DEFAULT_AUTHENTICATION_CLASSES‘: [
        # django默认session校验：校验规则 游客 及 登录用户
        # ‘rest_framework.authentication.SessionAuthentication‘,
        # ‘rest_framework.authentication.BasicAuthentication‘,
        # ‘rest_framework_jwt.authentication.JSONWebTokenAuthentication‘,
        ‘api.authentications.JWTAuthentication‘,
    ],
}

from rest_framework.authentication import BaseAuthentication
from rest_framework.exceptions import AuthenticationFailed
import jwt
from rest_framework_jwt.authentication import BaseJSONWebTokenAuthentication
from rest_framework_jwt.authentication import jwt_decode_handler

class JWTAuthentication(BaseJSONWebTokenAuthentication):
    # 自定义认证类，重写authenticate方法
    def authenticate(self, request):
        # 认证通过，返回user，auth
        # 认证失败，返回None
        auth = request.META.get(‘HTTP_AUTH‘)  # 前台用auth携带token
        if not auth:
            return None

        try:
            payload = jwt_decode_handler(auth)

        # 出现jwt解析异常，直接抛出异常，代表非法用户，也可以返回None，作为游客处理
        except jwt.ExpiredSignature:
            raise AuthenticationFailed(‘token已过期‘)
        except:
            raise AuthenticationFailed(‘token非法‘)


        user = self.authenticate_credentials(payload)
        return (user, auth)

from rest_framework_jwt.authentication import JSONWebTokenAuthentication
class CarV3ModelViewSet(ModelViewSet):
    #authentication_classes = [JSONWebTokenAuthentication]
    permission_classes = [IsAuthenticatedOrReadOnly]
    queryset = models.Car.objects.filter(is_delete=False)
    serializer_class = serializers.CarModelSerializer
    def destroy(self, request, *args, **kwargs):
        obj = self.get_object()
        obj.is_delete = True
        obj.save()
        return Response(‘删除成功‘)

系统：
1）AllowAny：允许所有用户，校验方法直接返回True
2）IsAuthenticated：只允许登录用户
    必须request.user和request.user.is_authenticated都通过
3）IsAuthenticatedOrReadOnly：游客只读，登录用户无限制
    get、option、head 请求无限制
    前台请求必须校验 request.user和request.user.is_authenticated
4）IsAdminUser：是否是后台用户
    校验 request.user和request.user.is_staff    is_staff(可以登录后台管理系统的用户)
    

自定义：基于auth的Group与Permission表
1）自定义权限类，继承BasePermission，重写has_permission
2）has_permission中完成
    拿到登录用户 user <= request.user
    校验user的分组或是权限
    前两步操作失败 返回False => 无权限
    前两步操作成功 返回True => 有权限

    # 权限: 只有管理员分组成员才可以查看所以用户信息
    url(r‘^users/$‘, views.UserListAPIView.as_view()),

from rest_framework.generics import ListAPIView
from .permissions import AdminPermission

class UserListAPIView(ListAPIView):
    queryset = models.User.objects.filter(is_active=True)
    serializer_class = serializers.UserModelSerializer
    # 登录的用户必须是自定义管理员分组成员
    permission_classes = [AdminPermission]

from rest_framework.permissions import BasePermission

class AdminPermission(BasePermission):
    # 继承BasePermission，重写has_permission
    def has_permission(self, request, view):
        # 有权限，返回True
        # 无权限，返回False
        user = request.user
        if not user:
            return False
        # 用户是 管理员 分组 (管理员分组是Group表中的一条自定义记录)
        if not user.groups.filter(name=‘管理员‘):
            return False
        # 登录的用户必须是自定义管理员分组成员
        return True

系统：
1）AnonRateThrottle：对同一IP游客的限制
2）UserRateThrottle：对同一IP登录用户的限制
必须在settings.py中
‘DEFAULT_THROTTLE_RATES‘: {
    ‘user‘: ‘10/min‘,  # 登录的用户一分钟可以访问10次
    ‘anon‘: ‘3/min‘,  # 游客一分钟可以访问3次
}
在视图类中：
class TempAPIView(APIView):
    ...
    throttle_classes = [AnonRateThrottle, UserRateThrottle]
    
    

自定义：基于auth的Group与Permission表
1）自定义频率类，继承SimpleRateThrottle，重写get_cache_key，明确scope
    SimpleRateThrottle已经帮我们实现了 allow_request、wait
2）scope与settings.py的DEFAULT_THROTTLE_RATES配合使用
3）get_cache_key中完成
    拿到限制信息 ident <= request中获取
    没有限制信息 返回None => 不限制
    有限制信息 返回限制信息字符串 => 有限制

 def check_throttles(self, request):
        """
        Check if request should be throttled.
        Raises an appropriate exception if the request is throttled.
        """
        throttle_durations = []
        for throttle in self.get_throttles():
            if not throttle.allow_request(request, self):
                throttle_durations.append(throttle.wait())

        if throttle_durations:
            self.throttled(request, max(throttle_durations))

    def allow_request(self, request, view):
        """
        Implement the check to see if the request should be throttled.

        On success calls `throttle_success`.
        On failure calls `throttle_failure`.
        """
        if self.rate is None:
            return True

        self.key = self.get_cache_key(request, view)
        if self.key is None:
            return True

        self.history = self.cache.get(self.key, [])
        self.now = self.timer()

        # Drop any requests from the history which have now passed the
        # throttle duration
        while self.history and self.history[-1] <= self.now - self.duration:
            self.history.pop()
        if len(self.history) >= self.num_requests:
            return self.throttle_failure()
        return self.throttle_success()