It is required that you pass in a value for the "algorithms" argument when calling decode()

Question

The following pages are the code of projects: If i am using token = jwt.encode(payload,'secret', algorithm='HS256').decode('utf-8') statement then

'str' object has no attribute 'decode'

error is occuring. Also, when I am removing and using it without .decode('utf-8') and proceeding with the further code. it is working fine. But when I am applying payload = jwt.decode(token, 'secret', algorithm=['HS256'])

then

It is required that you pass in a value for the "algorithms" argument when calling decode()"

This above-mentioned error is occurring. Please Help me to rectify this error. This is the mentioned error that saying algorithms argument when calling decode() error should be rectified.

View Page:

from django.http import request, response
from django.shortcuts import render
from rest_framework import serializers
from rest_framework.views import APIView
from myusers.serializers import UserSerializer
from rest_framework.exceptions import AuthenticationFailed
from rest_framework.response import Response
from .models import User
import jwt, datetime
# Create your views here.
class RegisterView(APIView):
    def post(self,request):
        serializer = UserSerializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        serializer.save()
        return Response(serializer.data)

class LoginView(APIView):
       def post(self,request):
           email=request.data['email']
           password = request.data['password']

           user = User.objects.filter(email=email).first()

           if user is None:
               raise AuthenticationFailed('User Not Found!!!')
            
           if not user.check_password(password):
               raise AuthenticationFailed('Incorrect Password!!!')
           
           payload={
               'id':user.id,
               'exp':datetime.datetime.utcnow() + datetime.timedelta(minutes=60),
               'iat':datetime.datetime.utcnow()
           }

           token = jwt.encode(payload,'secret', algorithm='HS256').decode('utf-8')

           response = Response()
           
           response.data={
                   "jwt":token
               }
             
           response.set_cookie(key='jwt', value=token, httponly=True)
           return response

class Userview(APIView):
    def get(self,request):
        token = request.COOKIES.get('jwt')
        
        if not token:
            raise AuthenticationFailed('User Authentication Failed!!!')
        
        try:
            payload = jwt.decode(token, 'secret', algorithm=['HS256'])
        except jwt.ExpiredSignatureError:
            raise AuthenticationFailed('Unauthenticated!')
        
        user = User.objects.filter(id = payload['id']).first()
        serializer = UserSerializer(user)
        return Response(serializer.data)


class LogoutView(APIView):
    def post(self, request):
        response = Response()
        response.delete_cookie('jwt')
        response.data = {
            'message': 'success'
        }
        return response


Serializer Page:
from django.db.models import fields
from rest_framework import serializers
from .models import User
class UserSerializer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = ['id', 'name','email','password']
        extra_kwargs={
            'password' : {'write_only':True}
        }
    
    def create(self, validated_data):
        password = validated_data.pop('password',None)
        instance = self.Meta.model(**validated_data)

        if password is not None:
            instance.set_password(password)
        instance.save()
        return instance

Model Page: 
from django.db import models
from django.contrib.auth.models import AbstractUser

# Create your models here.
class User(AbstractUser):
    name = models.CharField(max_length=255)
    email = models.CharField(max_length=250, unique=True)
    password = models.CharField(max_length=255)
    username = None

    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = []

    
Urls page:
from django.urls import path
from .views import RegisterView, LoginView, Userview

urlpatterns = [
    path('register',RegisterView.as_view()),
    path('login',LoginView.as_view()),
    path('user',Userview.as_view()),
    path('logout',Userview.as_view()),
]


Setting Page:
"""
Django settings for login project.

Generated by 'django-admin startproject' using Django 4.0.1.

For more information on this file, see
https://docs.djangoproject.com/en/4.0/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/4.0/ref/settings/
"""

from pathlib import Path

# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/4.0/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'django-insecure-k02ug7k7bm-q0cgy4uini(mol=__ye-cm)$c1q+utmhg86ds$7'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = []


# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'myusers',
    'rest_framework',
    'corsheaders'
]

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'login.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'login.wsgi.application'


# Database
# https://docs.djangoproject.com/en/4.0/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': BASE_DIR / 'db.sqlite3',
    }
}


# Password validation
# https://docs.djangoproject.com/en/4.0/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/4.0/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/4.0/howto/static-files/

STATIC_URL = 'static/'
AUTH_USER_MODEL = 'myusers.User'

# Default primary key field type
# https://docs.djangoproject.com/en/4.0/ref/settings/#default-auto-field

DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'


CORS_ORIGIN_ALLOW_ALL = True
CORS_ALLOW_CREDENTIALS = True

Answer 1

You're missing an 's', the parameter is called "algorithms" in the decode function:

payload = jwt.decode(token, 'secret', algorithms=['HS256'])

and you're also passing an array of possible values.

When you call encode, the parameter is "algorithm" and only takes a single value.

The reason is that during encoding (i.e signing), you have to use explicitly one algorithm, because a token can only be signed using one algorithm. But during decoding (verifying), you tell the function which algorithms you accept.