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| 1 | +# |
| 2 | +# Copyright (c) nexB Inc. and others. All rights reserved. |
| 3 | +# DejaCode is a trademark of nexB Inc. |
| 4 | +# SPDX-License-Identifier: AGPL-3.0-only |
| 5 | +# See https://github.com/aboutcode-org/dejacode for support or download. |
| 6 | +# See https://aboutcode.org for more information about AboutCode FOSS projects. |
| 7 | +# |
| 8 | + |
| 9 | + |
| 10 | +from django.contrib.auth import get_user_model |
| 11 | +from django.contrib.auth.models import Group |
| 12 | +from django.core.exceptions import ObjectDoesNotExist |
| 13 | + |
| 14 | +from guardian.shortcuts import assign_perm |
| 15 | +from guardian.shortcuts import get_groups_with_perms |
| 16 | +from guardian.shortcuts import get_users_with_perms |
| 17 | +from guardian.shortcuts import remove_perm |
| 18 | +from rest_framework import permissions |
| 19 | +from rest_framework import serializers |
| 20 | +from rest_framework import status |
| 21 | +from rest_framework.decorators import action |
| 22 | +from rest_framework.response import Response |
| 23 | + |
| 24 | +from dje.api import DataspacedSlugRelatedField |
| 25 | + |
| 26 | +User = get_user_model() |
| 27 | + |
| 28 | + |
| 29 | +class CanManageObjectPermissions(permissions.BasePermission): |
| 30 | + """ |
| 31 | + Allows managing object-level permissions if the user is: |
| 32 | + - a superuser, or |
| 33 | + - the object's owner (configurable via ``owner_field`` on the View). |
| 34 | + """ |
| 35 | + |
| 36 | + owner_field = "created_by" |
| 37 | + |
| 38 | + def has_object_permission(self, request, view, obj): |
| 39 | + user = request.user |
| 40 | + if not user.is_authenticated: |
| 41 | + return False |
| 42 | + |
| 43 | + if user.is_superuser: |
| 44 | + return True |
| 45 | + |
| 46 | + owner_field = getattr(view, "owner_field", self.owner_field) |
| 47 | + owner = getattr(obj, owner_field, None) |
| 48 | + return owner == user |
| 49 | + |
| 50 | + |
| 51 | +class ObjectPermissionSerializer(serializers.Serializer): |
| 52 | + """ |
| 53 | + Validates POST/DELETE input for the manage_permissions action. |
| 54 | + Exactly one of ``user`` or ``group`` must be provided alongside ``permissions``. |
| 55 | + """ |
| 56 | + |
| 57 | + user = DataspacedSlugRelatedField( |
| 58 | + queryset=User.objects.all(), |
| 59 | + slug_field="username", |
| 60 | + required=False, |
| 61 | + allow_null=True, |
| 62 | + default=None, |
| 63 | + ) |
| 64 | + group = serializers.SlugRelatedField( |
| 65 | + queryset=Group.objects.all(), |
| 66 | + slug_field="name", |
| 67 | + required=False, |
| 68 | + allow_null=True, |
| 69 | + default=None, |
| 70 | + ) |
| 71 | + permissions = serializers.ListField(child=serializers.CharField(), allow_empty=False) |
| 72 | + |
| 73 | + class Meta: |
| 74 | + fields = ("user", "group", "permissions") |
| 75 | + |
| 76 | + def validate(self, data): |
| 77 | + has_user = data.get("user") is not None |
| 78 | + has_group = data.get("group") is not None |
| 79 | + if not has_user and not has_group: |
| 80 | + raise serializers.ValidationError("Either 'user' or 'group' must be provided.") |
| 81 | + if has_user and has_group: |
| 82 | + raise serializers.ValidationError( |
| 83 | + "Only one of 'user' or 'group' can be provided, not both." |
| 84 | + ) |
| 85 | + return data |
| 86 | + |
| 87 | + |
| 88 | +class ObjectPermissionsMixin: |
| 89 | + """ |
| 90 | + Mixin that adds a ``/permissions/`` endpoint for any object-level ViewSet. |
| 91 | + Supports GET (list), POST (assign), and DELETE (remove) operations for |
| 92 | + both individual users and groups. |
| 93 | +
|
| 94 | + GET /api/{model}/{uuid}/permissions/ |
| 95 | + POST /api/{model}/{uuid}/permissions/ |
| 96 | + DELETE /api/{model}/{uuid}/permissions/ |
| 97 | + """ |
| 98 | + |
| 99 | + @action( |
| 100 | + detail=True, |
| 101 | + methods=["get", "post", "delete"], |
| 102 | + url_path="permissions", |
| 103 | + serializer_class=ObjectPermissionSerializer, |
| 104 | + permission_classes=[permissions.IsAuthenticated, CanManageObjectPermissions], |
| 105 | + ) |
| 106 | + def manage_permissions(self, request, *args, **kwargs): |
| 107 | + """ |
| 108 | + Manage object-level permissions for this object. |
| 109 | +
|
| 110 | + - GET: List users and groups with their permissions. |
| 111 | + - POST: Assign permissions. Provide ``user`` or ``group`` and ``permissions`` list. |
| 112 | + - DELETE: Remove permissions. Provide ``user`` or ``group`` and ``permissions`` list. |
| 113 | + """ |
| 114 | + obj = self.get_object() |
| 115 | + serializer_context = {**self.get_serializer_context(), "object": obj} |
| 116 | + |
| 117 | + if request.method == "GET": |
| 118 | + users_with_perms = get_users_with_perms(obj, attach_perms=True) |
| 119 | + groups_with_perms = get_groups_with_perms(obj, attach_perms=True) |
| 120 | + data = { |
| 121 | + "users": [ |
| 122 | + { |
| 123 | + "dataspace": user.dataspace.name, |
| 124 | + "username": user.get_username(), |
| 125 | + "object_permissions": list(perms), |
| 126 | + } |
| 127 | + for user, perms in users_with_perms.items() |
| 128 | + ], |
| 129 | + "groups": [ |
| 130 | + { |
| 131 | + "name": group.name, |
| 132 | + "object_permissions": list(perms), |
| 133 | + } |
| 134 | + for group, perms in groups_with_perms.items() |
| 135 | + ], |
| 136 | + } |
| 137 | + return Response(data, status=status.HTTP_200_OK) |
| 138 | + |
| 139 | + # POST or DELETE |
| 140 | + serializer = self.get_serializer(data=request.data, context=serializer_context) |
| 141 | + if not serializer.is_valid(): |
| 142 | + return Response({"errors": serializer.errors}, status=status.HTTP_400_BAD_REQUEST) |
| 143 | + |
| 144 | + target = serializer.validated_data["user"] or serializer.validated_data["group"] |
| 145 | + perms = serializer.validated_data["permissions"] |
| 146 | + |
| 147 | + if request.method == "POST": |
| 148 | + errors = [] |
| 149 | + for perm in perms: |
| 150 | + try: |
| 151 | + assign_perm(perm, target, obj) |
| 152 | + except ObjectDoesNotExist: |
| 153 | + errors.append(f"Cannot assign permission '{perm}' due to an internal error.") |
| 154 | + |
| 155 | + if errors: |
| 156 | + return Response({"errors": errors}, status=status.HTTP_400_BAD_REQUEST) |
| 157 | + |
| 158 | + return Response({"status": "permissions assigned"}, status=status.HTTP_200_OK) |
| 159 | + |
| 160 | + if request.method == "DELETE": |
| 161 | + errors = [] |
| 162 | + for perm in perms: |
| 163 | + try: |
| 164 | + remove_perm(perm, target, obj) |
| 165 | + except ObjectDoesNotExist: |
| 166 | + errors.append(f"Cannot remove permission '{perm}' due to an internal error.") |
| 167 | + |
| 168 | + if errors: |
| 169 | + return Response({"errors": errors}, status=status.HTTP_400_BAD_REQUEST) |
| 170 | + |
| 171 | + return Response({"status": "permissions removed"}, status=status.HTTP_200_OK) |
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