platypush/platypush/user/__init__.py

324 lines
10 KiB
Python

import base64
import datetime
import hashlib
import json
import random
import time
from typing import Optional, Dict
import bcrypt
import rsa
from sqlalchemy import Column, Integer, String, DateTime, ForeignKey
from sqlalchemy.orm import make_transient
from platypush.common.db import 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
class UserManager:
"""
Main class for managing platform users
"""
def __init__(self):
db_plugin = get_plugin('db')
assert db_plugin, 'Database plugin not configured'
self.db = db_plugin
self.db.create_all(self.db.get_engine(), Base)
@staticmethod
def _mask_password(user):
make_transient(user)
user.password = None
return user
def _get_session(self, *args, **kwargs):
return self.db.get_session(self.db.get_engine(), *args, **kwargs)
def get_user(self, username):
with self._get_session() as session:
user = self._get_user(session, username)
if not user:
return None
session.expunge(user)
return self._mask_password(user)
def get_user_count(self):
with self._get_session() as session:
return session.query(User).count()
def get_users(self):
with self._get_session() as session:
return session.query(User).all()
def create_user(self, username, password, **kwargs):
if not username:
raise ValueError('Invalid or empty username')
if not password:
raise ValueError('Please provide a password for the user')
with self._get_session(locked=True) as session:
user = self._get_user(session, username)
if user:
raise NameError('The user {} already exists'.format(username))
record = User(
username=username,
password=self._encrypt_password(password),
created_at=datetime.datetime.utcnow(),
**kwargs,
)
session.add(record)
session.commit()
user = self._get_user(session, username)
return self._mask_password(user)
def update_password(self, username, old_password, new_password):
with self._get_session(locked=True) as session:
if not self._authenticate_user(session, username, old_password):
return False
user = self._get_user(session, username)
user.password = self._encrypt_password(new_password)
session.commit()
return True
def authenticate_user(self, username, password):
with self._get_session() as session:
return self._authenticate_user(session, username, password)
def authenticate_user_session(self, session_token):
with self._get_session() as session:
user_session = (
session.query(UserSession)
.filter_by(session_token=session_token)
.first()
)
if not user_session or (
user_session.expires_at
and user_session.expires_at < datetime.datetime.utcnow()
):
return None, None
user = session.query(User).filter_by(user_id=user_session.user_id).first()
return self._mask_password(user), user_session
def delete_user(self, username):
with self._get_session(locked=True) as session:
user = self._get_user(session, username)
if not user:
raise NameError('No such user: {}'.format(username))
user_sessions = (
session.query(UserSession).filter_by(user_id=user.user_id).all()
)
for user_session in user_sessions:
session.delete(user_session)
session.delete(user)
session.commit()
return True
def delete_user_session(self, session_token):
with self._get_session(locked=True) as session:
user_session = (
session.query(UserSession)
.filter_by(session_token=session_token)
.first()
)
if not user_session:
return False
session.delete(user_session)
session.commit()
return True
def create_user_session(self, username, password, expires_at=None):
with self._get_session(locked=True) as session:
user = self._authenticate_user(session, username, password)
if not user:
return None
if expires_at:
if isinstance(expires_at, (int, float)):
expires_at = datetime.datetime.fromtimestamp(expires_at)
elif isinstance(expires_at, str):
expires_at = datetime.datetime.fromisoformat(expires_at)
user_session = UserSession(
user_id=user.user_id,
session_token=self.generate_session_token(),
csrf_token=self.generate_session_token(),
created_at=datetime.datetime.utcnow(),
expires_at=expires_at,
)
session.add(user_session)
session.commit()
return user_session
@staticmethod
def _get_user(session, username):
return session.query(User).filter_by(username=username).first()
@staticmethod
def _encrypt_password(pwd):
if isinstance(pwd, str):
pwd = pwd.encode()
return bcrypt.hashpw(pwd, bcrypt.gensalt(12)).decode()
@classmethod
def _check_password(cls, pwd, hashed_pwd):
return bcrypt.checkpw(cls._to_bytes(pwd), cls._to_bytes(hashed_pwd))
@staticmethod
def _to_bytes(data) -> bytes:
if isinstance(data, str):
data = data.encode()
return data
@staticmethod
def generate_session_token():
rand = bytes(random.randint(0, 255) for _ in range(0, 255))
return hashlib.sha256(rand).hexdigest()
def get_user_by_session(self, session_token: str):
"""
Get a user associated to a session token.
:param session_token: Session token.
"""
with self._get_session() as session:
return (
session.query(User)
.join(UserSession)
.filter_by(session_token=session_token)
.first()
)
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, _ = get_or_generate_jwt_rsa_key_pair()
payload = json.dumps(
{
'username': username,
'password': password,
'created_at': datetime.datetime.now().timestamp(),
'expires_at': expires_at.timestamp() if expires_at else None,
},
sort_keys=True,
indent=None,
)
return base64.b64encode(rsa.encrypt(payload.encode('ascii'), pub_key)).decode()
def validate_jwt_token(self, 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.
"""
_, priv_key = get_or_generate_jwt_rsa_key_pair()
try:
payload = json.loads(
rsa.decrypt(base64.b64decode(token.encode('ascii')), priv_key).decode(
'ascii'
)
)
except (TypeError, ValueError) as e:
raise InvalidJWTTokenException(f'Could not decode JWT token: {e}') from e
expires_at = payload.get('expires_at')
if expires_at and time.time() > expires_at:
raise InvalidJWTTokenException('Expired JWT token')
user = self.authenticate_user(
payload.get('username', ''), payload.get('password', '')
)
if not user:
raise InvalidCredentialsException()
return payload
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 None
if not self._check_password(password, user.password):
return None
return user
class User(Base):
"""Models the User table"""
__tablename__ = 'user'
__table_args__ = {'sqlite_autoincrement': True}
user_id = Column(Integer, primary_key=True)
username = Column(String, unique=True, nullable=False)
password = Column(String)
created_at = Column(DateTime)
class UserSession(Base):
"""Models the UserSession table"""
__tablename__ = 'user_session'
__table_args__ = {'sqlite_autoincrement': True}
session_id = Column(Integer, primary_key=True)
session_token = Column(String, unique=True, nullable=False)
csrf_token = Column(String, unique=True)
user_id = Column(Integer, ForeignKey('user.user_id'), nullable=False)
created_at = Column(DateTime)
expires_at = Column(DateTime)
# vim:sw=4:ts=4:et: