0e48bc0f90
Some OIDC identity providers may provide a random value in the "sub" field instead of an identifying ID. In this case, it may be a good idea to fallback to matching the user on its email field.
137 lines
4.8 KiB
Python
137 lines
4.8 KiB
Python
"""Authentication Backends for the People core app."""
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from django.conf import settings
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from django.contrib.auth import get_user_model
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from django.core.exceptions import SuspiciousOperation
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from django.utils.translation import gettext_lazy as _
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import requests
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from mozilla_django_oidc.auth import (
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OIDCAuthenticationBackend as MozillaOIDCAuthenticationBackend,
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)
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User = get_user_model()
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class OIDCAuthenticationBackend(MozillaOIDCAuthenticationBackend):
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"""Custom OpenID Connect (OIDC) Authentication Backend.
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This class overrides the default OIDC Authentication Backend to accommodate differences
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in the User model, and handles signed and/or encrypted UserInfo response.
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"""
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def get_userinfo(self, access_token, id_token, payload):
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"""Return user details dictionary.
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Parameters:
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- access_token (str): The access token.
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- id_token (str): The id token (unused).
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- payload (dict): The token payload (unused).
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Note: The id_token and payload parameters are unused in this implementation,
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but were kept to preserve base method signature.
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Note: It handles signed and/or encrypted UserInfo Response. It is required by
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Agent Connect, which follows the OIDC standard. It forces us to override the
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base method, which deal with 'application/json' response.
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Returns:
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- dict: User details dictionary obtained from the OpenID Connect user endpoint.
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"""
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user_response = requests.get(
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self.OIDC_OP_USER_ENDPOINT,
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headers={"Authorization": f"Bearer {access_token}"},
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verify=self.get_settings("OIDC_VERIFY_SSL", True),
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timeout=self.get_settings("OIDC_TIMEOUT", None),
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proxies=self.get_settings("OIDC_PROXY", None),
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)
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user_response.raise_for_status()
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userinfo = self.verify_token(user_response.text)
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return userinfo
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def get_or_create_user(self, access_token, id_token, payload):
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"""Return a User based on userinfo. Create a new user if no match is found.
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Parameters:
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- access_token (str): The access token.
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- id_token (str): The ID token.
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- payload (dict): The user payload.
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Returns:
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- User: An existing or newly created User instance.
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Raises:
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- Exception: Raised when user creation is not allowed and no existing user is found.
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"""
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user_info = self.get_userinfo(access_token, id_token, payload)
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# Get user's full name from OIDC fields defined in settings
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full_name = self.compute_full_name(user_info)
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email = user_info.get("email")
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claims = {
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"email": email,
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"name": full_name,
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}
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sub = user_info.get("sub")
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if not sub:
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raise SuspiciousOperation(
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_("User info contained no recognizable user identification")
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)
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# if sub is absent, try matching on email
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user = self.get_existing_user(sub, email)
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if user:
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self.update_user_if_needed(user, claims)
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elif self.get_settings("OIDC_CREATE_USER", True):
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user = User.objects.create(sub=sub, password="!", **claims) # noqa: S106
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return user
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def create_user(self, claims):
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"""Return a newly created User instance."""
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sub = claims.get("sub")
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if sub is None:
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raise SuspiciousOperation(
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_("Claims contained no recognizable user identification")
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)
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return self.UserModel.objects.create(
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password="!", # noqa: S106
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sub=sub,
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email=claims.get("email"),
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name=claims.get("name"),
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)
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def compute_full_name(self, user_info):
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"""Compute user's full name based on OIDC fields in settings."""
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name_fields = settings.USER_OIDC_FIELDS_TO_NAME
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full_name = " ".join(
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user_info[field] for field in name_fields if user_info.get(field)
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)
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return full_name or None
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def get_existing_user(self, sub, email):
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"""Fetch existing user by sub or email."""
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try:
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return User.objects.get(sub=sub, is_active=True)
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except User.DoesNotExist:
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if email and settings.OIDC_FALLBACK_TO_EMAIL_FOR_IDENTIFICATION:
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try:
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return User.objects.get(email=email, is_active=True)
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except User.DoesNotExist:
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pass
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return None
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def update_user_if_needed(self, user, claims):
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"""Update user claims if they have changed."""
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has_changed = any(
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value and value != getattr(user, key) for key, value in claims.items()
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)
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if has_changed:
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updated_claims = {key: value for key, value in claims.items() if value}
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self.UserModel.objects.filter(sub=user.sub).update(**updated_claims)
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