add authenticaiton to api

addtoken  endpoint, add me endpoint
add token management and verification

apiserver/main.py

 from typing import Optional
 from typing import Dict
 
-from fastapi import FastAPI
-from fastapi import HTTPException
+from fastapi import FastAPI, HTTPException, status
+from fastapi.param_functions import Depends
+from fastapi.security import OAuth2PasswordRequestForm, OAuth2PasswordBearer
 
-from pydantic import BaseModel
+from datetime import timedelta
 
 from .storage import JsonFileStorageAdapter
 from .storage import AbstractLocationDataStorageAdapter
@@ -13,16 +14,26 @@ from .storage import LocationDataType
 
 from .config import ApiserverSettings
 
+from .security import User, AbstractDBInterface, JsonDBInterface, get_current_user, authenticate_user, create_access_token, Token, ACCESS_TOKEN_EXPIRES_MINUTES
+
 from enum import Enum
 
+class ReservedPaths(Enum):
+    TOKEN: str = 'token'
+    HASH: str = 'hash'
+    AUTH: str = "auth"
+    ME: str = "me"
 
-settings = ApiserverSettings()
 
 app = FastAPI(
     title="API-Server for the Data Catalog"
 )
 
+
+settings: ApiserverSettings = ApiserverSettings()
 adapter: AbstractLocationDataStorageAdapter = JsonFileStorageAdapter(settings)
+userdb: AbstractDBInterface = JsonDBInterface(settings)
+oauth2_scheme: OAuth2PasswordBearer = OAuth2PasswordBearer(tokenUrl="token")
 
 #### A NOTE ON IDS
 # the id of a dataset is not yet defined, it could be simply generated, it could be based on some hash of the metadata or simple be the name, which would then need to be enforced to be unique
@@ -31,24 +42,44 @@ adapter: AbstractLocationDataStorageAdapter = JsonFileStorageAdapter(settings)
 
 # list types of data locations, currently datasets (will be provided by the pillars) and targets (possible storage locations for worklfow results or similar)
 @app.get("/")
-def get_types():
+async def get_types():
     return [{element.value : "/" + element.value} for element in LocationDataType]
-    
+
+# return information about the currently logged in user
+@app.get("/me", response_model=User)
+async def read_users_me(token: str = Depends(oauth2_scheme)):
+    user = get_current_user(token, userdb)
+    return user
+# authenticate with username/ password, return an auth-token
+@app.post("/token", response_model=Token)
+async def login_for_access_token(form_data: OAuth2PasswordRequestForm = Depends()):
+    user = authenticate_user(userdb, form_data.username, form_data.password)
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Incorrect username or password",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRES_MINUTES)
+    access_token = create_access_token(
+        data={"sub": user.username}, expires_delta=access_token_expires
+    )
+    return {"access_token": access_token, "token_type": "bearer"}
 
 # list id and name of every registered dataset for the specified type
 @app.get("/{location_data_type}")
-def list_datasets(location_data_type : LocationDataType):
+async def list_datasets(location_data_type : LocationDataType):
     return adapter.getList(location_data_type)
 
 # register a new dataset, the response will contain the new dataset and its id
 @app.put("/{location_data_type}")
-def add_dataset(location_data_type : LocationDataType, dataset : LocationData):
+async def add_dataset(location_data_type : LocationDataType, dataset : LocationData, token: str = Depends(oauth2_scheme)):
     usr: str = "testuser"
     return adapter.addNew(location_data_type, dataset, usr)
 
 # returns all information about a specific dataset, identified by id
 @app.get("/{location_data_type}/{dataset_id}")
-def get_specific_dataset(location_data_type : LocationDataType, dataset_id: str):
+async def get_specific_dataset(location_data_type : LocationDataType, dataset_id: str):
     try:
         return adapter.getDetails(location_data_type, dataset_id)
     except FileNotFoundError:
@@ -56,7 +87,7 @@ def get_specific_dataset(location_data_type : LocationDataType, dataset_id: str)
 
 # update the information about a specific dataset, identified by id
 @app.put("/{location_data_type}/{dataset_id}")
-def update_specific_dataset(location_data_type : LocationDataType, dataset_id: str, dataset : LocationData):
+async def update_specific_dataset(location_data_type : LocationDataType, dataset_id: str, dataset : LocationData, token: str = Depends(oauth2_scheme)):
     usr: str = "testuser"
     try:
         return adapter.updateDetails(location_data_type, dataset_id, dataset, usr)
@@ -65,7 +96,7 @@ def update_specific_dataset(location_data_type : LocationDataType, dataset_id: s
 
 # delete a specific dataset
 @app.delete("/{location_data_type}/{dataset_id}")
-def delete_specific_dataset(location_data_type : LocationDataType, dataset_id: str):
+async def delete_specific_dataset(location_data_type : LocationDataType, dataset_id: str, token: str = Depends(oauth2_scheme)):
     usr: str = "testuser"
     try:
         return adapter.delete(location_data_type, dataset_id, usr)