Fix bug 731
[osm/NBI.git] / osm_nbi / auth.py
index 4ee9ce2..d916189 100644 (file)
@@ -1,26 +1,52 @@
 # -*- coding: utf-8 -*-
 
+# Copyright 2018 Whitestack, LLC
+# Copyright 2018 Telefonica S.A.
+#
+# 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.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: esousa@whitestack.com or alfonso.tiernosepulveda@telefonica.com
+##
+
+
 """
 Authenticator is responsible for authenticating the users,
 create the tokens unscoped and scoped, retrieve the role
 list inside the projects that they are inserted
 """
 
-__author__ = "Eduardo Sousa <esousa@whitestack.com>"
+__author__ = "Eduardo Sousa <esousa@whitestack.com>; Alfonso Tierno <alfonso.tiernosepulveda@telefonica.com>"
 __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
+from hashlib import sha256
 from http import HTTPStatus
+from random import choice as random_choice
 from time import time
-
-import cherrypy
+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
-from engine import EngineException
+from osm_common import dbmongo
+from osm_common import dbmemory
+from osm_common.dbbase import DbException
 
 
 class Authenticator:
@@ -29,25 +55,25 @@ 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
     """
 
-    def __init__(self, engine):
+    periodin_db_pruning = 60 * 30  # for the internal backend only. every 30 minutes expired tokens will be pruned
+
+    def __init__(self):
         """
         Authenticator initializer. Setup the initial state of the object,
         while it waits for the config dictionary and database initialization.
-
-        Note: engine is only here until all the calls can to it can be replaced.
-
-        :param engine: reference to engine object used.
         """
-        super().__init__()
-
-        self.engine = engine
-
         self.backend = None
         self.config = None
         self.db = None
-        self.tokens = dict()
+        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):
@@ -61,29 +87,183 @@ class Authenticator:
         self.config = config
 
         try:
+            if not self.db:
+                if config["database"]["driver"] == "mongo":
+                    self.db = dbmongo.DbMongo()
+                    self.db.db_connect(config["database"])
+                elif config["database"]["driver"] == "memory":
+                    self.db = dbmemory.DbMemory()
+                    self.db.db_connect(config["database"])
+                else:
+                    raise AuthException("Invalid configuration param '{}' at '[database]':'driver'"
+                                        .format(config["database"]["driver"]))
             if not self.backend:
                 if config["authentication"]["backend"] == "keystone":
                     self.backend = AuthconnKeystone(self.config["authentication"])
                 elif config["authentication"]["backend"] == "internal":
-                    pass
+                    self._internal_tokens_prune()
                 else:
-                    raise Exception("No authentication backend defined")
-            if not self.db:
-                pass
-                # TODO: Implement database initialization
-                # NOTE: Database needed to store the mappings
+                    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))
 
+    def stop(self):
+        try:
+            if self.db:
+                self.db.db_disconnect()
+        except DbException as e:
+            raise AuthException(str(e), http_code=e.http_code)
+
     def init_db(self, target_version='1.0'):
         """
-        Check if the database has been initialized. If not, create the 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():
+            if operation not in operations:
+                operations.append(operation)
+            self.resources_to_operations_mapping[resource] = operation
+
+        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
+
+                    if operation not in role_ops.keys():
+                        role_ops[operation] = 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
@@ -102,7 +282,7 @@ class Authenticator:
                     # 2. Try using session before request a new token. If not, basic authentication will generate
                     token = cherrypy.session.get("Authorization")
                     if token == "logout":
-                        token = None  # force Unauthorized response to insert user pasword again
+                        token = None  # force Unauthorized response to insert user password again
                 elif user_passwd64 and cherrypy.request.config.get("auth.allow_basic_authentication"):
                     # 3. Get new token from user password
                     user = None
@@ -116,15 +296,21 @@ class Authenticator:
                     token = outdata["id"]
                     cherrypy.session['Authorization'] = token
             if self.config["authentication"]["backend"] == "internal":
-                return self.engine.authorize(token)
+                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)
-                    return self.tokens[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 deepcopy(self.tokens_cache[token])
                 except AuthException:
                     self.del_token(token)
                     raise
-        except EngineException as e:
+        except AuthException as e:
             if cherrypy.session.get('Authorization'):
                 del cherrypy.session['Authorization']
             cherrypy.response.headers["WWW-Authenticate"] = 'Bearer realm="{}"'.format(e)
@@ -132,7 +318,7 @@ class Authenticator:
 
     def new_token(self, session, indata, remote):
         if self.config["authentication"]["backend"] == "internal":
-            return self.engine.new_token(session, indata, remote)
+            return self._internal_new_token(session, indata, remote)
         else:
             if indata.get("username"):
                 token, projects = self.backend.authenticate_with_user_password(
@@ -152,6 +338,9 @@ 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:
@@ -163,7 +352,7 @@ class Authenticator:
                 "_id": token,
                 "id": token,
                 "issued_at": now,
-                "expires": now+3600,
+                "expires": now + 3600,
                 "project_id": project_id,
                 "username": indata.get("username") if not session else session.get("username"),
                 "remote_port": remote.port,
@@ -175,35 +364,236 @@ class Authenticator:
             elif remote.ip:
                 new_session["remote_host"] = remote.ip
 
-            self.tokens[token] = new_session
+            # TODO: check if this can be avoided. Backend may provide enough information
+            self.tokens_cache[token] = new_session
 
             return deepcopy(new_session)
 
     def get_token_list(self, session):
         if self.config["authentication"]["backend"] == "internal":
-            return self.engine.get_token_list(session)
+            return self._internal_get_token_list(session)
         else:
-            return [deepcopy(token) for token in self.tokens.values()
+            # TODO: check if this can be avoided. Backend may provide enough information
+            return [deepcopy(token) for token in self.tokens_cache.values()
                     if token["username"] == session["username"]]
 
     def get_token(self, session, token):
         if self.config["authentication"]["backend"] == "internal":
-            return self.engine.get_token(session, token)
+            return self._internal_get_token(session, token)
         else:
-            token_value = self.tokens.get(token)
+            # TODO: check if this can be avoided. Backend may provide enough information
+            token_value = self.tokens_cache.get(token)
             if not token_value:
-                raise EngineException("token not found", http_code=HTTPStatus.NOT_FOUND)
+                raise AuthException("token not found", http_code=HTTPStatus.NOT_FOUND)
             if token_value["username"] != session["username"] and not session["admin"]:
-                raise EngineException("needed admin privileges", http_code=HTTPStatus.UNAUTHORIZED)
+                raise AuthException("needed admin privileges", http_code=HTTPStatus.UNAUTHORIZED)
             return token_value
 
     def del_token(self, token):
         if self.config["authentication"]["backend"] == "internal":
-            return self.engine.del_token(token)
+            return self._internal_del_token(token)
         else:
             try:
                 self.backend.revoke_token(token)
-                del self.tokens[token]
+                del self.tokens_cache[token]
                 return "token '{}' deleted".format(token)
             except KeyError:
-                raise EngineException("Token '{}' not found".format(token), http_code=HTTPStatus.NOT_FOUND)
+                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:
+                raise AuthException("Needed a token or Authorization http header", http_code=HTTPStatus.UNAUTHORIZED)
+            # try to get from cache first
+            now = time()
+            session = self.tokens_cache.get(token_id)
+            if session and session["expires"] < now:
+                # 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
+
+            # get from database if not in cache
+            session = self.db.get_one("tokens", {"_id": token_id})
+            if session["expires"] < now:
+                raise AuthException("Expired Token or Authorization http header", http_code=HTTPStatus.UNAUTHORIZED)
+            self.tokens_cache[token_id] = session
+            return session
+        except DbException as e:
+            if e.http_code == HTTPStatus.NOT_FOUND:
+                raise AuthException("Invalid Token or Authorization http header", http_code=HTTPStatus.UNAUTHORIZED)
+            else:
+                raise
+
+        except AuthException:
+            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"], "admin": True}
+            else:
+                raise
+
+    def _internal_new_token(self, session, indata, remote):
+        now = time()
+        user_content = None
+
+        # Try using username/password
+        if indata.get("username"):
+            user_rows = self.db.get_list("users", {"username": indata.get("username")})
+            if user_rows:
+                user_content = user_rows[0]
+                salt = user_content["_admin"]["salt"]
+                shadow_password = sha256(indata.get("password", "").encode('utf-8') + salt.encode('utf-8')).hexdigest()
+                if shadow_password != user_content["password"]:
+                    user_content = None
+            if not user_content:
+                raise AuthException("Invalid username/password", http_code=HTTPStatus.UNAUTHORIZED)
+        elif session:
+            user_rows = self.db.get_list("users", {"username": session["username"]})
+            if user_rows:
+                user_content = user_rows[0]
+            else:
+                raise AuthException("Invalid token", http_code=HTTPStatus.UNAUTHORIZED)
+        else:
+            raise AuthException("Provide credentials: username/password or Authorization Bearer token",
+                                http_code=HTTPStatus.UNAUTHORIZED)
+
+        token_id = ''.join(random_choice('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789')
+                           for _ in range(0, 32))
+        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:
+            # 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"],
+                       "remote_port": remote.port, "admin": session_admin}
+        if remote.name:
+            new_session["remote_host"] = remote.name
+        elif remote.ip:
+            new_session["remote_host"] = remote.ip
+
+        self.tokens_cache[token_id] = new_session
+        self.db.create("tokens", new_session)
+        # check if database must be prune
+        self._internal_tokens_prune(now)
+        return deepcopy(new_session)
+
+    def _internal_get_token_list(self, session):
+        now = time()
+        token_list = self.db.get_list("tokens", {"username": session["username"], "expires.gt": now})
+        return token_list
+
+    def _internal_get_token(self, session, token_id):
+        token_value = self.db.get_one("tokens", {"_id": token_id}, fail_on_empty=False)
+        if not token_value:
+            raise AuthException("token not found", http_code=HTTPStatus.NOT_FOUND)
+        if token_value["username"] != session["username"] and not session["admin"]:
+            raise AuthException("needed admin privileges", http_code=HTTPStatus.UNAUTHORIZED)
+        return token_value
+
+    def _internal_del_token(self, token_id):
+        try:
+            self.tokens_cache.pop(token_id, None)
+            self.db.del_one("tokens", {"_id": token_id})
+            return "token '{}' deleted".format(token_id)
+        except DbException as e:
+            if e.http_code == HTTPStatus.NOT_FOUND:
+                raise AuthException("Token '{}' not found".format(token_id), http_code=HTTPStatus.NOT_FOUND)
+            else:
+                raise
+
+    def _internal_tokens_prune(self, now=None):
+        now = now or time()
+        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