core/homeassistant/auth/mfa_modules/totp.py

214 lines
7.0 KiB
Python

"""Time-based One Time Password auth module."""
import logging
from io import BytesIO
from typing import Any, Dict, Optional, Tuple # noqa: F401
import voluptuous as vol
from homeassistant.auth.models import User
from homeassistant.core import HomeAssistant
from . import MultiFactorAuthModule, MULTI_FACTOR_AUTH_MODULES, \
MULTI_FACTOR_AUTH_MODULE_SCHEMA, SetupFlow
REQUIREMENTS = ['pyotp==2.2.6', 'PyQRCode==1.2.1']
CONFIG_SCHEMA = MULTI_FACTOR_AUTH_MODULE_SCHEMA.extend({
}, extra=vol.PREVENT_EXTRA)
STORAGE_VERSION = 1
STORAGE_KEY = 'auth_module.totp'
STORAGE_USERS = 'users'
STORAGE_USER_ID = 'user_id'
STORAGE_OTA_SECRET = 'ota_secret'
INPUT_FIELD_CODE = 'code'
DUMMY_SECRET = 'FPPTH34D4E3MI2HG'
_LOGGER = logging.getLogger(__name__)
def _generate_qr_code(data: str) -> str:
"""Generate a base64 PNG string represent QR Code image of data."""
import pyqrcode
qr_code = pyqrcode.create(data)
with BytesIO() as buffer:
qr_code.svg(file=buffer, scale=4)
return '{}'.format(
buffer.getvalue().decode("ascii").replace('\n', '')
.replace('<?xml version="1.0" encoding="UTF-8"?>'
'<svg xmlns="http://www.w3.org/2000/svg"', '<svg')
)
def _generate_secret_and_qr_code(username: str) -> Tuple[str, str, str]:
"""Generate a secret, url, and QR code."""
import pyotp
ota_secret = pyotp.random_base32()
url = pyotp.totp.TOTP(ota_secret).provisioning_uri(
username, issuer_name="Home Assistant")
image = _generate_qr_code(url)
return ota_secret, url, image
@MULTI_FACTOR_AUTH_MODULES.register('totp')
class TotpAuthModule(MultiFactorAuthModule):
"""Auth module validate time-based one time password."""
DEFAULT_TITLE = 'Time-based One Time Password'
def __init__(self, hass: HomeAssistant, config: Dict[str, Any]) -> None:
"""Initialize the user data store."""
super().__init__(hass, config)
self._users = None # type: Optional[Dict[str, str]]
self._user_store = hass.helpers.storage.Store(
STORAGE_VERSION, STORAGE_KEY)
@property
def input_schema(self) -> vol.Schema:
"""Validate login flow input data."""
return vol.Schema({INPUT_FIELD_CODE: str})
async def _async_load(self) -> None:
"""Load stored data."""
data = await self._user_store.async_load()
if data is None:
data = {STORAGE_USERS: {}}
self._users = data.get(STORAGE_USERS, {})
async def _async_save(self) -> None:
"""Save data."""
await self._user_store.async_save({STORAGE_USERS: self._users})
def _add_ota_secret(self, user_id: str,
secret: Optional[str] = None) -> str:
"""Create a ota_secret for user."""
import pyotp
ota_secret = secret or pyotp.random_base32() # type: str
self._users[user_id] = ota_secret # type: ignore
return ota_secret
async def async_setup_flow(self, user_id: str) -> SetupFlow:
"""Return a data entry flow handler for setup module.
Mfa module should extend SetupFlow
"""
user = await self.hass.auth.async_get_user(user_id) # type: ignore
return TotpSetupFlow(self, self.input_schema, user)
async def async_setup_user(self, user_id: str, setup_data: Any) -> str:
"""Set up auth module for user."""
if self._users is None:
await self._async_load()
result = await self.hass.async_add_executor_job(
self._add_ota_secret, user_id, setup_data.get('secret'))
await self._async_save()
return result
async def async_depose_user(self, user_id: str) -> None:
"""Depose auth module for user."""
if self._users is None:
await self._async_load()
if self._users.pop(user_id, None): # type: ignore
await self._async_save()
async def async_is_user_setup(self, user_id: str) -> bool:
"""Return whether user is setup."""
if self._users is None:
await self._async_load()
return user_id in self._users # type: ignore
async def async_validation(
self, user_id: str, user_input: Dict[str, Any]) -> bool:
"""Return True if validation passed."""
if self._users is None:
await self._async_load()
# user_input has been validate in caller
# set INPUT_FIELD_CODE as vol.Required is not user friendly
return await self.hass.async_add_executor_job(
self._validate_2fa, user_id, user_input.get(INPUT_FIELD_CODE, ''))
def _validate_2fa(self, user_id: str, code: str) -> bool:
"""Validate two factor authentication code."""
import pyotp
ota_secret = self._users.get(user_id) # type: ignore
if ota_secret is None:
# even we cannot find user, we still do verify
# to make timing the same as if user was found.
pyotp.TOTP(DUMMY_SECRET).verify(code)
return False
return bool(pyotp.TOTP(ota_secret).verify(code))
class TotpSetupFlow(SetupFlow):
"""Handler for the setup flow."""
def __init__(self, auth_module: TotpAuthModule,
setup_schema: vol.Schema,
user: User) -> None:
"""Initialize the setup flow."""
super().__init__(auth_module, setup_schema, user.id)
# to fix typing complaint
self._auth_module = auth_module # type: TotpAuthModule
self._user = user
self._ota_secret = None # type: Optional[str]
self._url = None # type Optional[str]
self._image = None # type Optional[str]
async def async_step_init(
self, user_input: Optional[Dict[str, str]] = None) \
-> Dict[str, Any]:
"""Handle the first step of setup flow.
Return self.async_show_form(step_id='init') if user_input == None.
Return self.async_create_entry(data={'result': result}) if finish.
"""
import pyotp
errors = {} # type: Dict[str, str]
if user_input:
verified = await self.hass.async_add_executor_job( # type: ignore
pyotp.TOTP(self._ota_secret).verify, user_input['code'])
if verified:
result = await self._auth_module.async_setup_user(
self._user_id, {'secret': self._ota_secret})
return self.async_create_entry(
title=self._auth_module.name,
data={'result': result}
)
errors['base'] = 'invalid_code'
else:
hass = self._auth_module.hass
self._ota_secret, self._url, self._image = \
await hass.async_add_executor_job( # type: ignore
_generate_secret_and_qr_code, str(self._user.name))
return self.async_show_form(
step_id='init',
data_schema=self._setup_schema,
description_placeholders={
'code': self._ota_secret,
'url': self._url,
'qr_code': self._image
},
errors=errors
)