Fix bug 713
[osm/NBI.git] / osm_nbi / auth.py
index 4bc4628..bb65738 100644 (file)
@@ -1,17 +1,23 @@
 # -*- coding: utf-8 -*-
 
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
+# Copyright 2018 Whitestack, LLC
+# Copyright 2018 Telefonica S.A.
 #
-#    http://www.apache.org/licenses/LICENSE-2.0
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
-# implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: esousa@whitestack.com or alfonso.tiernosepulveda@telefonica.com
+##
 
 
 """
@@ -25,6 +31,7 @@ __date__ = "$27-jul-2018 23:59:59$"
 
 import cherrypy
 import logging
+import yaml
 from base64 import standard_b64decode
 from copy import deepcopy
 from functools import reduce
@@ -32,6 +39,8 @@ from hashlib import sha256
 from http import HTTPStatus
 from random import choice as random_choice
 from time import time
+from os import path
+from base_topic import BaseTopic    # To allow project names in project_id
 
 from authconn import AuthException
 from authconn_keystone import AuthconnKeystone
@@ -46,9 +55,10 @@ class Authenticator:
     Authorization. Initially it should support Openstack Keystone as a
     backend through a plugin model where more backends can be added and a
     RBAC model to manage permissions on operations.
+    This class must be threading safe
     """
 
-    periodin_db_pruning = 60*30  # for the internal backend only. every 30 minutes expired tokens will be pruned
+    periodin_db_pruning = 60 * 30  # for the internal backend only. every 30 minutes expired tokens will be pruned
 
     def __init__(self):
         """
@@ -60,7 +70,10 @@ class Authenticator:
         self.db = None
         self.tokens_cache = dict()
         self.next_db_prune_time = 0  # time when next cleaning of expired tokens must be done
-
+        self.resources_to_operations_file = None
+        self.roles_to_operations_file = None
+        self.resources_to_operations_mapping = {}
+        self.operation_to_allowed_roles = {}
         self.logger = logging.getLogger("nbi.authenticator")
 
     def start(self, config):
@@ -92,6 +105,34 @@ class Authenticator:
                 else:
                     raise AuthException("Unknown authentication backend: {}"
                                         .format(config["authentication"]["backend"]))
+            if not self.resources_to_operations_file:
+                if "resources_to_operations" in config["rbac"]:
+                    self.resources_to_operations_file = config["rbac"]["resources_to_operations"]
+                else:
+                    possible_paths = (
+                        __file__[:__file__.rfind("auth.py")] + "resources_to_operations.yml",
+                        "./resources_to_operations.yml"
+                    )
+                    for config_file in possible_paths:
+                        if path.isfile(config_file):
+                            self.resources_to_operations_file = config_file
+                            break
+                    if not self.resources_to_operations_file:
+                        raise AuthException("Invalid permission configuration: resources_to_operations file missing")
+            if not self.roles_to_operations_file:
+                if "roles_to_operations" in config["rbac"]:
+                    self.roles_to_operations_file = config["rbac"]["roles_to_operations"]
+                else:
+                    possible_paths = (
+                        __file__[:__file__.rfind("auth.py")] + "roles_to_operations.yml",
+                        "./roles_to_operations.yml"
+                    )
+                    for config_file in possible_paths:
+                        if path.isfile(config_file):
+                            self.roles_to_operations_file = config_file
+                            break
+                    if not self.roles_to_operations_file:
+                        raise AuthException("Invalid permission configuration: roles_to_operations file missing")
         except Exception as e:
             raise AuthException(str(e))
 
@@ -102,15 +143,129 @@ class Authenticator:
         except DbException as e:
             raise AuthException(str(e), http_code=e.http_code)
 
-    def init_db(self, target_version='1.1'):
+    def init_db(self, target_version='1.0'):
         """
-        Check if the database has been initialized, with at least one user. If not, create an adthe required tables
+        Check if the database has been initialized, with at least one user. If not, create the required tables
         and insert the predefined mappings between roles and permissions.
 
         :param target_version: schema version that should be present in the database.
         :return: None if OK, exception if error or version is different.
         """
-        pass
+        # Always reads operation to resource mapping from file (this is static, no need to store it in MongoDB)
+        # Operations encoding: "<METHOD> <URL>"
+        # Note: it is faster to rewrite the value than to check if it is already there or not
+        if self.config["authentication"]["backend"] == "internal":
+            return
+
+        operations = []
+        with open(self.resources_to_operations_file, "r") as stream:
+            resources_to_operations_yaml = yaml.load(stream)
+
+        for resource, operation in resources_to_operations_yaml["resources_to_operations"].items():
+            operation_key = operation.replace(".", ":")
+            if operation_key not in operations:
+                operations.append(operation_key)
+            self.resources_to_operations_mapping[resource] = operation_key
+
+        records = self.db.get_list("roles_operations")
+
+        # Loading permissions to MongoDB. If there are permissions already in MongoDB, do nothing.
+        if len(records) == 0:
+            with open(self.roles_to_operations_file, "r") as stream:
+                roles_to_operations_yaml = yaml.load(stream)
+
+            roles = []
+            for role_with_operations in roles_to_operations_yaml["roles_to_operations"]:
+                # Verifying if role already exists. If it does, send warning to log and ignore it.
+                if role_with_operations["role"] not in roles:
+                    roles.append(role_with_operations["role"])
+                else:
+                    self.logger.warning("Duplicated role with name: {0}. Role definition is ignored."
+                                        .format(role_with_operations["role"]))
+                    continue
+
+                role_ops = {}
+                root = None
+
+                if not role_with_operations["operations"]:
+                    continue
+
+                for operation, is_allowed in role_with_operations["operations"].items():
+                    if not isinstance(is_allowed, bool):
+                        continue
+
+                    if operation == ".":
+                        root = is_allowed
+                        continue
+
+                    if len(operation) != 1 and operation[-1] == ".":
+                        self.logger.warning("Invalid operation {0} terminated in '.'. "
+                                            "Operation will be discarded"
+                                            .format(operation))
+                        continue
+
+                    operation_key = operation.replace(".", ":")
+                    if operation_key not in role_ops.keys():
+                        role_ops[operation_key] = is_allowed
+                    else:
+                        self.logger.info("In role {0}, the operation {1} with the value {2} was discarded due to "
+                                         "repetition.".format(role_with_operations["role"], operation, is_allowed))
+
+                if not root:
+                    root = False
+                    self.logger.info("Root for role {0} not defined. Default value 'False' applied."
+                                     .format(role_with_operations["role"]))
+
+                now = time()
+                operation_to_roles_item = {
+                    "_admin": {
+                        "created": now,
+                        "modified": now,
+                    },
+                    "name": role_with_operations["role"],
+                    "root": root
+                }
+
+                for operation, value in role_ops.items():
+                    operation_to_roles_item[operation] = value
+
+                if self.config["authentication"]["backend"] != "internal" and \
+                        role_with_operations["role"] != "anonymous":
+                    keystone_id = [role for role in self.backend.get_role_list() 
+                                   if role["name"] == role_with_operations["role"]]
+                    if keystone_id:
+                        keystone_id = keystone_id[0]
+                    else:
+                        keystone_id = self.backend.create_role(role_with_operations["role"])
+                    operation_to_roles_item["_id"] = keystone_id["_id"]
+
+                self.db.create("roles_operations", operation_to_roles_item)
+
+        permissions = {oper: [] for oper in operations}
+        records = self.db.get_list("roles_operations")
+
+        ignore_fields = ["_id", "_admin", "name", "root"]
+        for record in records:
+            record_permissions = {oper: record["root"] for oper in operations}
+            operations_joined = [(oper, value) for oper, value in record.items() if oper not in ignore_fields]
+            operations_joined.sort(key=lambda x: x[0].count(":"))
+
+            for oper in operations_joined:
+                match = list(filter(lambda x: x.find(oper[0]) == 0, record_permissions.keys()))
+
+                for m in match:
+                    record_permissions[m] = oper[1]
+
+            allowed_operations = [k for k, v in record_permissions.items() if v is True]
+
+            for allowed_op in allowed_operations:
+                permissions[allowed_op].append(record["name"])
+
+        for oper, role_list in permissions.items():
+            self.operation_to_allowed_roles[oper] = role_list
+
+        if self.config["authentication"]["backend"] != "internal":
+            self.backend.assign_role_to_user("admin", "admin", "system_admin")
 
     def authorize(self):
         token = None
@@ -145,10 +300,15 @@ class Authenticator:
             if self.config["authentication"]["backend"] == "internal":
                 return self._internal_authorize(token)
             else:
+                if not token:
+                    raise AuthException("Needed a token or Authorization http header",
+                                        http_code=HTTPStatus.UNAUTHORIZED)
                 try:
                     self.backend.validate_token(token)
+                    self.check_permissions(self.tokens_cache[token], cherrypy.request.path_info,
+                                           cherrypy.request.method)
                     # TODO: check if this can be avoided. Backend may provide enough information
-                    return self.tokens_cache[token]
+                    return deepcopy(self.tokens_cache[token])
                 except AuthException:
                     self.del_token(token)
                     raise
@@ -180,6 +340,9 @@ class Authenticator:
             else:
                 project_id = projects[0]
 
+            if not session:
+                token, projects = self.backend.authenticate_with_token(token, project_id)
+
             if project_id == "admin":
                 session_admin = True
             else:
@@ -239,6 +402,82 @@ class Authenticator:
             except KeyError:
                 raise AuthException("Token '{}' not found".format(token), http_code=HTTPStatus.NOT_FOUND)
 
+    def check_permissions(self, session, url, method):
+        self.logger.info("Session: {}".format(session))
+        self.logger.info("URL: {}".format(url))
+        self.logger.info("Method: {}".format(method))
+
+        key, parameters = self._normalize_url(url, method)
+
+        # TODO: Check if parameters might be useful for the decision
+
+        operation = self.resources_to_operations_mapping[key]
+        roles_required = self.operation_to_allowed_roles[operation]
+        roles_allowed = self.backend.get_user_role_list(session["id"])
+
+        if "anonymous" in roles_required:
+            return
+
+        for role in roles_allowed:
+            if role in roles_required:
+                return
+
+        raise AuthException("Access denied: lack of permissions.")
+
+    def get_user_list(self):
+        return self.backend.get_user_list()
+
+    def _normalize_url(self, url, method):
+        # Removing query strings
+        normalized_url = url if '?' not in url else url[:url.find("?")]
+        normalized_url_splitted = normalized_url.split("/")
+        parameters = {}
+
+        filtered_keys = [key for key in self.resources_to_operations_mapping.keys()
+                         if method in key.split()[0]]
+
+        for idx, path_part in enumerate(normalized_url_splitted):
+            tmp_keys = []
+            for tmp_key in filtered_keys:
+                splitted = tmp_key.split()[1].split("/")
+                if idx >= len(splitted):
+                    continue
+                elif "<" in splitted[idx] and ">" in splitted[idx]:
+                    if splitted[idx] == "<artifactPath>":
+                        tmp_keys.append(tmp_key)
+                        continue
+                    elif idx == len(normalized_url_splitted) - 1 and \
+                            len(normalized_url_splitted) != len(splitted):
+                        continue
+                    else:
+                        tmp_keys.append(tmp_key)
+                elif splitted[idx] == path_part:
+                    if idx == len(normalized_url_splitted) - 1 and \
+                            len(normalized_url_splitted) != len(splitted):
+                        continue
+                    else:
+                        tmp_keys.append(tmp_key)
+            filtered_keys = tmp_keys
+            if len(filtered_keys) == 1 and \
+                    filtered_keys[0].split("/")[-1] == "<artifactPath>":
+                break
+
+        if len(filtered_keys) == 0:
+            raise AuthException("Cannot make an authorization decision. URL not found. URL: {0}".format(url))
+        elif len(filtered_keys) > 1:
+            raise AuthException("Cannot make an authorization decision. Multiple URLs found. URL: {0}".format(url))
+
+        filtered_key = filtered_keys[0]
+
+        for idx, path_part in enumerate(filtered_key.split()[1].split("/")):
+            if "<" in path_part and ">" in path_part:
+                if path_part == "<artifactPath>":
+                    parameters[path_part[1:-1]] = "/".join(normalized_url_splitted[idx:])
+                else:
+                    parameters[path_part[1:-1]] = normalized_url_splitted[idx]
+
+        return filtered_key, parameters
+
     def _internal_authorize(self, token_id):
         try:
             if not token_id:
@@ -247,7 +486,8 @@ class Authenticator:
             now = time()
             session = self.tokens_cache.get(token_id)
             if session and session["expires"] < now:
-                del self.tokens_cache[token_id]
+                # delete token. MUST be done with care, as another thread maybe already delete it. Do not use del
+                self.tokens_cache.pop(token_id, None)
                 session = None
             if session:
                 return session
@@ -268,7 +508,7 @@ class Authenticator:
             if self.config["global"].get("test.user_not_authorized"):
                 return {"id": "fake-token-id-for-test",
                         "project_id": self.config["global"].get("test.project_not_authorized", "admin"),
-                        "username": self.config["global"]["test.user_not_authorized"]}
+                        "username": self.config["global"]["test.user_not_authorized"], "admin": True}
             else:
                 raise
 
@@ -299,17 +539,21 @@ class Authenticator:
 
         token_id = ''.join(random_choice('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789')
                            for _ in range(0, 32))
-        if indata.get("project_id"):
-            project_id = indata.get("project_id")
-            if project_id not in user_content["projects"]:
-                raise AuthException("project {} not allowed for this user"
-                                    .format(project_id), http_code=HTTPStatus.UNAUTHORIZED)
+        project_id = indata.get("project_id")
+        if project_id:
+            if project_id != "admin":
+                # To allow project names in project_id
+                proj = self.db.get_one("projects", {BaseTopic.id_field("projects", project_id): project_id})
+                if proj["_id"] not in user_content["projects"] and proj["name"] not in user_content["projects"]:
+                    raise AuthException("project {} not allowed for this user"
+                                        .format(project_id), http_code=HTTPStatus.UNAUTHORIZED)
         else:
             project_id = user_content["projects"][0]
         if project_id == "admin":
             session_admin = True
         else:
-            project = self.db.get_one("projects", {"_id": project_id})
+            # To allow project names in project_id
+            project = self.db.get_one("projects", {BaseTopic.id_field("projects", project_id): project_id})
             session_admin = project.get("admin", False)
         new_session = {"issued_at": now, "expires": now + 3600,
                        "_id": token_id, "id": token_id, "project_id": project_id, "username": user_content["username"],
@@ -354,4 +598,4 @@ class Authenticator:
         if not self.next_db_prune_time or self.next_db_prune_time >= now:
             self.db.del_list("tokens", {"expires.lt": now})
             self.next_db_prune_time = self.periodin_db_pruning + now
-            self.tokens_cache.clear()   # force to reload tokens from database
+            self.tokens_cache.clear()  # force to reload tokens from database