Added support for JWT token-based authentication

platypush/backend/http/app/routes/auth.py

@@ -0,0 +1,69 @@
+import datetime
+import json
+import logging
+from typing import Dict, Optional
+
+from flask import Blueprint, request, abort, jsonify
+
+from platypush.exceptions.user import UserException
+from platypush.user import UserManager
+
+auth = Blueprint('auth', __name__)
+log = logging.getLogger(__name__)
+
+# Declare routes list
+__routes__ = [
+    auth,
+]
+
+
+@auth.route('/auth', methods=['POST'])
+def auth_endpoint() -> Dict[str, Optional[str]]:
+    """
+    Authentication endpoint. It validates the user credentials provided over a JSON payload with the following
+    structure:
+
+        .. code-block:: json
+
+            {
+                "username": "USERNAME",
+                "password": "PASSWORD",
+                "expiry_days": "The generated token should be valid for these many days"
+            }
+
+    ``expiry_days`` is optional, and if omitted or set to zero the token will be valid indefinitely.
+
+    Upon successful validation, a new JWT token will be generated using the service's self-generated RSA key-pair and it
+    will be returned to the user. The token can then be used to authenticate API calls to ``/execute`` by setting the
+    ``Authorization: Bearer <TOKEN_HERE>`` header upon HTTP calls.
+
+    :return: Return structure:
+
+        .. code-block:: json
+
+            {
+                "token": "<generated token here>"
+            }
+    """
+    try:
+        payload = json.loads(request.get_data(as_text=True))
+        username, password = payload['username'], payload['password']
+    except Exception as e:
+        log.warning('Invalid payload passed to the auth endpoint: ' + str(e))
+        abort(400)
+        return jsonify({'token': None})
+
+    expiry_days = payload.get('expiry_days')
+    expires_at = None
+    if expiry_days:
+        expires_at = datetime.datetime.now() + datetime.timedelta(days=expiry_days)
+
+    user_manager = UserManager()
+
+    try:
+        return jsonify({
+            'token': user_manager.generate_jwt_token(username=username, password=password, expires_at=expires_at),
+        })
+    except UserException as e:
+        abort(401, str(e))
+        return jsonify({'token': None})

platypush/backend/http/app/utils.py

@@ -109,6 +109,7 @@ def send_request(action, wait_for_response=True, **kwargs):
 
 def _authenticate_token():
     token = Config.get('token')
+    user_manager = UserManager()
 
     if 'X-Token' in request.headers:
         user_token = request.headers['X-Token']
@@ -119,6 +120,10 @@ def _authenticate_token():
     else:
         return False
 
+    try:
+        user_manager.validate_jwt_token(user_token)
+        return True
+    except:
         return token and user_token == token
 
 
@@ -179,7 +184,6 @@ def authenticate(redirect_page='', skip_auth_methods=None, check_csrf_token=Fals
         def wrapper(*args, **kwargs):
             user_manager = UserManager()
             n_users = user_manager.get_user_count()
-            token = Config.get('token')
             skip_methods = skip_auth_methods or []
 
             # User/pass HTTP authentication
@@ -191,7 +195,7 @@ def authenticate(redirect_page='', skip_auth_methods=None, check_csrf_token=Fals
 
             # Token-based authentication
             token_auth_ok = True
-            if token and 'token' not in skip_methods:
+            if 'token' not in skip_methods:
                 token_auth_ok = _authenticate_token()
                 if token_auth_ok:
                     return f(*args, **kwargs)

platypush/exceptions/__init__.py

@@ -0,0 +1,20 @@
+from typing import Optional, Union
+
+
+class PlatypushException(Exception):
+    """
+    Base class for all Platypush exceptions.
+    """
+    def __init__(self, error: Optional[Union[str, Exception]] = None, *args):
+        super().__init__(*args)
+        self._inner_exception = None
+        self._msg = None
+
+        if isinstance(error, str):
+            self._msg = error
+        elif isinstance(error, Exception):
+            self._inner_exception = error
+            self._msg = str(error)
+
+    def __str__(self):
+        return self._msg

platypush/exceptions/user.py

@@ -0,0 +1,44 @@
+from typing import Optional, Union
+
+from platypush.exceptions import PlatypushException
+
+
+class UserException(PlatypushException):
+    """
+    Base class for all user exceptions.
+    """
+    def __init__(self, *args, user: Optional[Union[str, int]] = None, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.user = user
+
+
+class AuthenticationException(UserException):
+    """
+    Authentication error exception.
+    """
+    def __init__(self, error='Unauthorized', *args, **kwargs):
+        super().__init__(error, *args, **kwargs)
+
+
+class InvalidTokenException(AuthenticationException):
+    """
+    Exception raised in case of wrong user token.
+    """
+    def __init__(self, error='Invalid user token', *args, **kwargs):
+        super().__init__(error, *args, **kwargs)
+
+
+class InvalidCredentialsException(AuthenticationException):
+    """
+    Exception raised in case of wrong user token.
+    """
+    def __init__(self, error='Invalid credentials', *args, **kwargs):
+        super().__init__(error, *args, **kwargs)
+
+
+class InvalidJWTTokenException(InvalidTokenException):
+    """
+    Exception raised in case of wrong/invalid JWT token.
+    """
+    def __init__(self, error='Invalid JWT token', *args, **kwargs):
+        super().__init__(error, *args, **kwargs)

platypush/plugins/user.py

@@ -56,7 +56,7 @@ class UserPlugin(Plugin):
         :return: True if the provided username and password are correct, False otherwise
         """
 
-        return self.user_manager.authenticate_user(username, password)
+        return True if self.user_manager.authenticate_user(username, password) else False
 
     @action
     def update_password(self, username, old_password, new_password):

platypush/user/__init__.py

@@ -1,14 +1,19 @@
 import datetime
 import hashlib
 import random
+import time
+from typing import Optional, Dict
 
 import bcrypt
+import jwt
 
 from sqlalchemy import Column, Integer, String, DateTime, ForeignKey
 from sqlalchemy.orm import sessionmaker, scoped_session
 from sqlalchemy.ext.declarative import declarative_base
 
 from platypush.context import get_plugin
+from platypush.exceptions.user import InvalidJWTTokenException, InvalidCredentialsException
+from platypush.utils import get_or_generate_jwt_rsa_key_pair
 
 Base = declarative_base()
 
@@ -121,7 +126,8 @@ class UserManager:
 
     def create_user_session(self, username, password, expires_at=None):
         session = self._get_db_session()
-        if not self._authenticate_user(session, username, password):
+        user = self._authenticate_user(session, username, password)
+        if not user:
             return None
 
         if expires_at:
@@ -130,9 +136,8 @@ class UserManager:
             elif isinstance(expires_at, str):
                 expires_at = datetime.datetime.fromisoformat(expires_at)
 
-        user = self._get_user(session, username)
+        user_session = UserSession(user_id=user.user_id, session_token=self.generate_session_token(),
-        user_session = UserSession(user_id=user.user_id, session_token=self._generate_token(),
+                                   csrf_token=self.generate_session_token(), created_at=datetime.datetime.utcnow(),
-                                   csrf_token=self._generate_token(), created_at=datetime.datetime.utcnow(),
                                    expires_at=expires_at)
 
         session.add(user_session)
@@ -152,10 +157,64 @@ class UserManager:
         return bcrypt.checkpw(pwd.encode(), hashed_pwd)
 
     @staticmethod
-    def _generate_token():
+    def generate_session_token():
         rand = bytes(random.randint(0, 255) for _ in range(0, 255))
         return hashlib.sha256(rand).hexdigest()
 
+    def generate_jwt_token(self, username: str, password: str, expires_at: Optional[datetime.datetime] = None) -> str:
+        """
+        Create a user JWT token for API usage.
+
+        :param username: User name.
+        :param password: Password.
+        :param expires_at: Expiration datetime of the token.
+        :return: The generated JWT token as a string.
+        :raises: :class:`platypush.exceptions.user.InvalidCredentialsException` in case of invalid credentials.
+        """
+        user = self.authenticate_user(username, password)
+        if not user:
+            raise InvalidCredentialsException()
+
+        pub_key, priv_key = get_or_generate_jwt_rsa_key_pair()
+        payload = {
+            'username': username,
+            'created_at': datetime.datetime.now().timestamp(),
+            'expires_at': expires_at.timestamp() if expires_at else None,
+        }
+
+        return jwt.encode(payload, priv_key, algorithm='RS256').decode()
+
+    @staticmethod
+    def validate_jwt_token(token: str) -> Dict[str, str]:
+        """
+        Validate a JWT token.
+
+        :param token: Token to validate.
+        :return: On success, it returns the JWT payload with the following structure:
+
+            .. code-block:: json
+
+                {
+                    "username": "user ID/name",
+                    "created_at": "token creation timestamp",
+                    "expires_at": "token expiration timestamp"
+                }
+
+        :raises: :class:`platypush.exceptions.user.InvalidJWTTokenException` in case of invalid token.
+        """
+        pub_key, priv_key = get_or_generate_jwt_rsa_key_pair()
+
+        try:
+            payload = jwt.decode(token.encode(), pub_key, algorithms=['RS256'])
+        except jwt.exceptions.PyJWTError as e:
+            raise InvalidJWTTokenException(str(e))
+
+        expires_at = payload.get('expires_at')
+        if expires_at and time.time() > expires_at:
+            raise InvalidJWTTokenException('Expired JWT token')
+
+        return payload
+
     def _get_db_session(self):
         Base.metadata.create_all(self._engine)
         session = scoped_session(sessionmaker())
@@ -163,11 +222,17 @@ class UserManager:
         return session()
 
     def _authenticate_user(self, session, username, password):
+        """
+        :return: :class:`platypush.user.User` instance if the user exists and the password is valid, ``None`` otherwise.
+        """
         user = self._get_user(session, username)
         if not user:
-            return False
+            return None
 
-        return self._check_password(password, user.password)
+        if not self._check_password(password, user.password):
+            return None
+
+        return user
 
 
 class User(Base):

platypush/utils/__init__.py

@@ -4,12 +4,13 @@ import importlib
 import inspect
 import logging
 import os
+import pathlib
 import re
 import signal
 import socket
 import ssl
 import urllib.request
-from typing import Optional
+from typing import Optional, Tuple
 
 logger = logging.getLogger('utils')
 
@@ -351,4 +352,72 @@ def run(action, *args, **kwargs):
     return response.output
 
 
+def generate_rsa_key_pair(key_file: Optional[str] = None, size: int = 2048) -> Tuple[str, str]:
+    """
+    Generate an RSA key pair.
+
+    :param key_file: Target file for the private key (the associated public key will be stored in ``<key_file>.pub``.
+        If no key file is specified then the public and private keys will be returned in ASCII format in a dictionary
+        with the following structure:
+
+            .. code-block:: json
+
+                {
+                    "private": "private key here",
+                    "public": "public key here"
+                }
+
+    :param size: Key size (default: 2048 bits).
+    :return: A tuple with the generated ``(priv_key_str, pub_key_str)``.
+    """
+    from cryptography.hazmat.primitives import serialization
+    from cryptography.hazmat.primitives.asymmetric import rsa
+    from cryptography.hazmat.backends import default_backend
+
+    public_exp = 65537
+    private_key = rsa.generate_private_key(
+        public_exponent=public_exp,
+        key_size=size,
+        backend=default_backend()
+    )
+
+    logger.info('Generating RSA {} key pair'.format(size))
+    private_key_str = private_key.private_bytes(
+        encoding=serialization.Encoding.PEM,
+        format=serialization.PrivateFormat.TraditionalOpenSSL,
+        encryption_algorithm=serialization.NoEncryption()
+    ).decode()
+
+    public_key_str = private_key.public_key().public_bytes(
+        encoding=serialization.Encoding.PEM,
+        format=serialization.PublicFormat.PKCS1,
+    ).decode()
+
+    if key_file:
+        logger.info('Saving private key to {}'.format(key_file))
+        with open(os.path.expanduser(key_file), 'w') as f1, \
+                open(os.path.expanduser(key_file) + '.pub', 'w') as f2:
+            f1.write(private_key_str)
+            f2.write(public_key_str)
+            os.chmod(key_file, 0o600)
+
+    return public_key_str, private_key_str
+
+
+def get_or_generate_jwt_rsa_key_pair():
+    from platypush.config import Config
+
+    key_dir = os.path.join(Config.get('workdir'), 'jwt')
+    priv_key_file = os.path.join(key_dir, 'id_rsa')
+    pub_key_file = priv_key_file + '.pub'
+
+    if os.path.isfile(priv_key_file) and os.path.isfile(pub_key_file):
+        with open(pub_key_file, 'r') as f1, \
+                open(priv_key_file, 'r') as f2:
+            return f1.read(), f2.read()
+
+    pathlib.Path(key_dir).mkdir(parents=True, exist_ok=True, mode=0o755)
+    return generate_rsa_key_pair(priv_key_file, size=2048)
+
+
 # vim:sw=4:ts=4:et:

requirements.txt

@@ -34,6 +34,8 @@ sqlalchemy
 
 # Support for multi-users and password authentication
 bcrypt
+cryptography
+pyjwt
 
 # Support for Zeroconf/Bonjour
 zeroconf

setup.py

@@ -65,6 +65,8 @@ setup(
         'zeroconf>=0.27.0',
         'tz',
         'python-dateutil',
+        'cryptography',
+        'pyjwt',
     ],
 
     extras_require={