91 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			91 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
"""passbook multi-factor authentication engine"""
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from inspect import Signature
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from typing import Optional
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from django.contrib.auth import _clean_credentials
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from django.contrib.auth.signals import user_login_failed
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from django.core.exceptions import PermissionDenied
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from django.forms.utils import ErrorList
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from django.utils.translation import gettext as _
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from django.views.generic import FormView
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from structlog import get_logger
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from passbook.core.models import User
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from passbook.factors.base import AuthenticationFactor
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from passbook.factors.password.forms import PasswordForm
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from passbook.factors.view import AuthenticationView
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from passbook.lib.config import CONFIG
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from passbook.lib.utils.reflection import path_to_class
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LOGGER = get_logger()
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def authenticate(request, backends, **credentials) -> Optional[User]:
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    """If the given credentials are valid, return a User object.
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    Customized version of django's authenticate, which accepts a list of backends"""
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    for backend_path in backends:
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        backend = path_to_class(backend_path)()
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        try:
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            signature = Signature.from_callable(backend.authenticate)
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            signature.bind(request, **credentials)
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        except TypeError:
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            LOGGER.warning("Backend doesn't accept our arguments", backend=backend)
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            # This backend doesn't accept these credentials as arguments. Try the next one.
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            continue
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        LOGGER.debug("Attempting authentication...", backend=backend)
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        try:
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            user = backend.authenticate(request, **credentials)
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        except PermissionDenied:
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            LOGGER.debug("Backend threw PermissionDenied", backend=backend)
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            # This backend says to stop in our tracks - this user should not be allowed in at all.
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            break
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        if user is None:
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            continue
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        # Annotate the user object with the path of the backend.
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        user.backend = backend_path
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        return user
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    # The credentials supplied are invalid to all backends, fire signal
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    user_login_failed.send(
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        sender=__name__, credentials=_clean_credentials(credentials), request=request
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    )
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class PasswordFactor(FormView, AuthenticationFactor):
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    """Authentication factor which authenticates against django's AuthBackend"""
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    form_class = PasswordForm
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    template_name = "login/factors/backend.html"
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    def form_valid(self, form):
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        """Authenticate against django's authentication backend"""
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        uid_fields = CONFIG.y("passbook.uid_fields")
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        kwargs = {
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            "password": form.cleaned_data.get("password"),
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        }
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        for uid_field in uid_fields:
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            kwargs[uid_field] = getattr(self.authenticator.pending_user, uid_field)
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        try:
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            user = authenticate(
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                self.request, self.authenticator.current_factor.backends, **kwargs
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            )
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            if user:
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                # User instance returned from authenticate() has .backend property set
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                self.authenticator.pending_user = user
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                self.request.session[
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                    AuthenticationView.SESSION_USER_BACKEND
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                ] = user.backend
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                return self.authenticator.user_ok()
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            # No user was found -> invalid credentials
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            LOGGER.debug("Invalid credentials")
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            # Manually inject error into form
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            # pylint: disable=protected-access
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            errors = form._errors.setdefault("password", ErrorList())
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            errors.append(_("Invalid password"))
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            return self.form_invalid(form)
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        except PermissionDenied:
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            # User was found, but permission was denied (i.e. user is not active)
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            LOGGER.debug("Denied access", **kwargs)
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            return self.authenticator.user_invalid()
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