JWT认证

优势

"""
1) 服务器不要存储token,token交给每个客户端本身存储,服务器压力小
2)服务器存储的是 签发和校验token 两段算法,签发认证的效率高
3)算法完成各集群服务器同步成本低,路由项目完成集群部署(适应高并发)
"""

 

格式

"""
1) jwt token采用三段式:头部.载荷.签名
2)每一部分都是一个json字典加密形参的字符串
3)头部和载荷采用的是base64可逆加密(前台后台均可以解密)
4)签名采用hash256不可逆加密(后台校验采用碰撞校验)
5)各部分字典的内容:
    头部:基础信息 - 公司信息、项目组信息、可逆加密采用的算法
    载荷:有用但非私密的信息 - 用户可公开信息、过时时间
    签名:头部+载荷+秘钥 不可逆加密后的结果
    注:服务器jwt签名加密秘钥必定不能泄露
    
签发token:固定的头部信息加密.当前的登录用户与过时时间加密.头部+载荷+秘钥生成不可逆加密
校验token:头部可校验也能够不校验,载荷校验出用户与过时时间,头部+载荷+秘钥完成碰撞检测校验token是否被篡改
"""

 

 

drf-jwt插件

官网

https://github.com/jpadilla/django-rest-framework-jwt

 

安装

>: pip3 install djangorestframework-jwt

 

登陆-签发token:api/urls.py

# ObtainJSONWebToken视图类就是经过username和password获得user对象而后签发token
from rest_framework_jwt.views import ObtainJSONWebToken, obtain_jwt_token
urlpatterns = [
    # url(r'^jogin/$', ObtainJSONWebToken.as_view()),
    url(r'^jogin/$', obtain_jwt_token),
]

认证 - 校验token:全局或局部配置drf-jwt的认证类 JSONWebTokenAuthentication

from rest_framework.views import APIView
from utils.response import APIResponse
# 必须登陆后才能访问 - 经过了认证权限组件
from rest_framework.permissions import IsAuthenticated
from rest_framework_jwt.authentication import JSONWebTokenAuthentication
class UserDetail(APIView):
    authentication_classes = [JSONWebTokenAuthentication]  # jwt-token校验request.user
    permission_classes = [IsAuthenticated]  # 结合权限组件筛选掉游客
    def get(self, request, *args, **kwargs):
        return APIResponse(results={'username': request.user.username})

 

路由与接口测试

# 路由
url(r'^user/detail/$', views.UserDetail.as_view()),

# 接口:/api/user/detail/
# 认证信息:必须在请求头的 Authorization 中携带 "jwt 后台签发的token" 格式的认证字符串

 

 

 

签发token

源码入口

# 前提:给一个局部禁用了全部 认证与权限 的视图类发送用户信息获得token,其实就是登陆接口

# 1)rest_framework_jwt.views.ObtainJSONWebToken 的 父类 JSONWebTokenAPIView 的 post 方法
#        接受有username、password的post请求
# 2)post方法将请求数据交给 rest_framework_jwt.serializer.JSONWebTokenSerializer 处理
#        完成数据的校验,会走序列化类的 全局钩子校验规则,校验获得登陆用户并签发token存储在序列化对象中

核心源码:rest_framework_jwt.serializer.JSONWebTokenSerializer的validate(self, attrs)方法

def validate(self, attrs):
    # 帐号密码字典
    credentials = {
        self.username_field: attrs.get(self.username_field),
        'password': attrs.get('password')
    }
    if all(credentials.values()):
        # 签发token第1步:用帐号密码获得user对象
        user = authenticate(**credentials)
        if user:
            if not user.is_active:
                msg = _('User account is disabled.')
                raise serializers.ValidationError(msg)
            # 签发token第2步:经过user获得payload,payload包含着用户信息与过时时间
            payload = jwt_payload_handler(user)
            # 在视图类中,能够经过 序列化对象.object.get('user'或者'token') 拿到user和token 
            return {
                # 签发token第3步:经过payload签发出token
                'token': jwt_encode_handler(payload),
                'user': user
            }
        else:
            msg = _('Unable to log in with provided credentials.')
            raise serializers.ValidationError(msg)
    else:
        msg = _('Must include "{username_field}" and "password".')
        msg = msg.format(username_field=self.username_field)
        raise serializers.ValidationError(msg)

手动签发token逻辑

# 1)经过username、password获得user对象
# 2)经过user对象生成payload:jwt_payload_handler(user) => payload
#        from rest_framework_jwt.serializers import jwt_payload_handler
# 3)经过payload签发token:jwt_encode_handler(payload) => token
#        from rest_framework_jwt.serializers import jwt_encode_handler

 

 

校验token

源码入口

# 前提:访问一个配置了jwt认证规则的视图类,就须要提交认证字符串token,在认证类中完成token的校验

# 1)rest_framework_jwt.authentication.JSONWebTokenAuthentication 的 父类 BaseJSONWebTokenAuthentication 的 authenticate 方法
#        请求头拿认证信息jwt-token => 经过反爬小规则肯定有用的token => payload => user

核心源码:rest_framework_jwt.authentication.BaseJSONWebTokenAuthentication的authenticate(self, request)方法

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`.
    """
    # 带有反爬小规则的获取token:前台必须按 "jwt token字符串" 方式提交
    # 校验user第1步:从请求头 HTTP_AUTHORIZATION 中拿token,并提取
    jwt_value = self.get_jwt_value(request)
    # 游客
    if jwt_value is None:
        return None
    # 校验
    try:
        # 校验user第2步:token => payload
        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()
    # 校验user第3步:token => payload
    user = self.authenticate_credentials(payload)

    return (user, jwt_value)

手动校验token逻辑

# 1)从请求头中获取token
# 2)根据token解析出payload:jwt_decode_handler(token) => payloay
#        from rest_framework_jwt.authentication import jwt_decode_handler
# 3)根据payload解析出user:self.authenticate_credentials(payload) => user
#        继承drf-jwt的BaseJSONWebTokenAuthentication,拿到父级的authenticate_credentials方法

 

 

案例:实现多方式登录签发token

models.py

from django.db import models​from django.contrib.auth.models import AbstractUserclass User(AbstractUser):    mobile = models.CharField(max_length=11, unique=True)​    class Meta:        db_table = 'api_user'        verbose_name = '用户表'        verbose_name_plural = verbose_name​    def __str__(self):        return self.username
View Code

serializers.py

from rest_framework import serializers
from . import models
import re

# 拿到前台token的两个函数: user => payload => token
# from rest_framework_jwt.settings import api_settings
# jwt_payload_handler = api_settings.JWT_PAYLOAD_HANDLER
# jwt_encode_handler = api_settings.JWT_ENCODE_HANDLER
from rest_framework_jwt.serializers import jwt_payload_handler
from rest_framework_jwt.serializers import jwt_encode_handler


# 1) 前台提交多种登陆信息都采用一个key,因此后台能够自定义反序列化字段进行对应
# 2) 序列化类要处理序列化与反序列化,要在fields中设置model绑定的Model类全部使用到的字段
# 3) 区分序列化字段与反序列化字段 read_only | write_only
# 4) 在自定义校验规则中(局部钩子、全局钩子)校验数据是否合法、肯定登陆的用户、根据用户签发token
# 5) 将登陆的用户与签发的token保存在序列化类对象中
class UserModelSerializer(serializers.ModelSerializer):
    # 自定义反序列字段:必定要设置write_only,只参与反序列化,不会与model类字段映射
    usr = serializers.CharField(write_only=True)
    pwd = serializers.CharField(write_only=True)
    class Meta:
        model = models.User
        fields = ['usr', 'pwd', 'username', 'mobile', 'email']
        # 系统校验规则
        extra_kwargs = {
            'username': {
                'read_only': True
            },
            'mobile': {
                'read_only': True
            },
            'email': {
                'read_only': True
            },
        }

    def validate(self, attrs):
        usr = attrs.get('usr')
        pwd = attrs.get('pwd')

        # 多方式登陆:各分支处理获得该方式下对应的用户
        if re.match(r'.+@.+', usr):
            user_query = models.User.objects.filter(email=usr)
        elif re.match(r'1[3-9][0-9]{9}', usr):
            user_query = models.User.objects.filter(mobile=usr)
        else:
            user_query = models.User.objects.filter(username=usr)
        user_obj = user_query.first()

        # 签发:获得登陆用户,签发token并存储在实例化对象中
        if user_obj and user_obj.check_password(pwd):
            # 签发token,将token存放到 实例化类对象的token 名字中
            payload = jwt_payload_handler(user_obj)
            token = jwt_encode_handler(payload)
            # 将当前用户与签发的token都保存在序列化对象中
            self.user = user_obj
            self.token = token
            return attrs

        raise serializers.ValidationError({'data': '数据有误'})
View Code

 

views.py

#实现多方式登录签发token:帐号、手机号、邮箱等登录
# 1) 禁用认证与权限组件
# 2) 拿到前台登陆信息,交给序列化类
# 3) 序列化类校验获得登陆用户与token存放在序列化对象中
# 4) 取出登陆用户与token返回给前台
import re
from . import serializers, models
from utils.response import APIResponse

from rest_framework_jwt.serializers import jwt_payload_handler
from rest_framework_jwt.serializers import jwt_encode_handler

class LoginAPIView(APIView):
    # 1) 禁用认证与权限组件
    authentication_classes = []
    permission_classes = []
    def post(self, request, *args, **kwargs):
        # 2) 拿到前台登陆信息,交给序列化类,规则:帐号用usr传,密码用pwd传
        user_ser = serializers.UserModelSerializer(data=request.data)
        # 3) 序列化类校验获得登陆用户与token存放在序列化对象中
        user_ser.is_valid(raise_exception=True)
        # 4) 取出登陆用户与token返回给前台
        return APIResponse(token=user_ser.token, results=serializers.UserModelSerializer(user_ser.user).data)
View Code

 

 

案例:自定义认证反爬规则的认证类

authentications.py

import jwt
from rest_framework_jwt.authentication import BaseJSONWebTokenAuthentication
from rest_framework_jwt.authentication import jwt_decode_handler
from rest_framework.exceptions import AuthenticationFailed
class JWTAuthentication(BaseJSONWebTokenAuthentication):
    def authenticate(self, request):
        jwt_token = request.META.get('HTTP_AUTHORIZATION')

        # 自定义校验规则:auth token jwt
        token = self.parse_jwt_token(jwt_token)

        if token is None:
            return None

        try:
            # token => payload
            payload = jwt_decode_handler(token)
        except jwt.ExpiredSignature:
            raise AuthenticationFailed('token已过时')
        except:
            raise AuthenticationFailed('非法用户')
        # payload => user
        user = self.authenticate_credentials(payload)

        return (user, token)

    # 自定义校验规则:auth token jwt,auth为前盐,jwt为后盐
    def parse_jwt_token(self, jwt_token):
        tokens = jwt_token.split()
        if len(tokens) != 3 or tokens[0].lower() != 'auth' or tokens[2].lower() != 'jwt':
            return None
        return tokens[1]
View Code

views.py

from rest_framework.views import APIView
from utils.response import APIResponse
# 必须登陆后才能访问 - 经过了认证权限组件
from rest_framework.permissions import IsAuthenticated
# 自定义jwt校验规则
from .authentications import JWTAuthentication
class UserDetail(APIView):
    authentication_classes = [JWTAuthentication]
    permission_classes = [IsAuthenticated]
    def get(self, request, *args, **kwargs):
        return APIResponse(results={'username': request.user.username})
View Code