added actual jwe decrpytion to fastapi

backend/app/config.py

@@ -6,7 +6,6 @@ class Settings(BaseSettings):
     API_KEY: str
     API_KEY_NAME: str = "X-API-KEY"
     SECRET_KEY: str
-    ALGORITHM: str
     ENVIRONMENT: str
     PLAN_TRIGGER_BUCKET: str
 

backend/app/dependencies.py

@@ -1,6 +1,10 @@
 from fastapi import Depends, HTTPException, status, Request
 from fastapi.security import APIKeyHeader, OAuth2PasswordBearer
-from jose import jwt, JWTError
+from jose import JWTError, jwe
+from Crypto.Protocol.KDF import HKDF
+from Crypto.Hash import SHA256
+from typing import Any
+import json
 from app.config import get_settings
 
 
@@ -29,6 +33,28 @@ def get_user(user_id: str):
         return user
 
 
+def get_derived_encryption_key(secret: str) -> Any:
+    context = str.encode("NextAuth.js Generated Encryption Key")
+    return HKDF(
+        master=secret.encode(),
+        key_len=32,
+        salt="".encode(),
+        hashmod=SHA256,
+        num_keys=1,
+        context=context,
+    )
+
+
+def get_token_payload(token: str, secret: str) -> dict[str, Any]:
+    # This repo: https://github.com/jackrdye/Decrypt-NextAuth-JWE-getToken/tree/main
+    # Contains examples of how to decrypt the JWE token and extract the payload as has been implemented by
+    # next-auth
+    encryption_key = get_derived_encryption_key(secret)
+    payload_str = jwe.decrypt(token, encryption_key).decode()
+    payload: dict[str, Any] = json.loads(payload_str)
+    return payload
+
+
 def validate_jwt_token(token: str = Depends(oauth2_scheme)):
     credentials_exception = HTTPException(
         status_code=status.HTTP_401_UNAUTHORIZED,
@@ -37,8 +63,12 @@ def validate_jwt_token(token: str = Depends(oauth2_scheme)):
     )
     try:
         # The SECRET_KEY should match the NEXTAUTH_SECRET in the front end
-        payload = jwt.decode(token, get_settings().SECRET_KEY, algorithms=[get_settings().ALGORITHM])
-        user_id: str = payload.get("sub")
+        try:
+            payload = get_token_payload(token, get_settings().SECRET_KEY)
+        except Exception as e:
+            print(e)
+            raise credentials_exception
+        user_id: str = payload.get("dbId")
         if user_id is None:
             raise credentials_exception
         user = get_user(user_id=user_id)

backend/app/local/router.py

@@ -1,7 +1,9 @@
 from fastapi import APIRouter, HTTPException, status
-from jose import jwt
+from jose import jwt, jwe
+import json
 import datetime
 from app.config import get_settings
+from app.dependencies import get_derived_encryption_key
 
 router = APIRouter(
     prefix="/local",
@@ -9,14 +11,24 @@ router = APIRouter(
 )
 
 
-def create_dummy_token(secret: str, algorithm: str):
-    data = {
-        "sub": "known_id",
-        "name": "Test User",
-        "iat": datetime.datetime.utcnow(),
-        "exp": datetime.datetime.utcnow() + datetime.timedelta(minutes=30)
+def create_dummy_token(secret: str) -> str:
+    """
+    Create a JWE token using NextAuth.js encryption method
+
+    Arguments:
+    sub -- The subject or identifier for who the token is for (usually a user id)
+    secret -- The secret key to encrypt the token. Should be the same as the key used in NextAuth.js
+    exp -- Optional expiry time for the token. If not provided, token does not expire
+
+    Returns:
+    A string containing the JWE token
+    """
+    claims = {
+        "dbId": "known_id",
     }
-    return jwt.encode(data, secret, algorithm=algorithm)
+
+    token = jwe.encrypt(json.dumps(claims), get_derived_encryption_key(secret), algorithm="dir", encryption="A256GCM")
+    return token
 
 
 @router.get("/dummy-token")
@@ -25,4 +37,4 @@ async def dummy_token():
     if settings.ENVIRONMENT != "local":
         raise HTTPException(status_code=status.HTTP_403_FORBIDDEN,
                             detail="Dummy token can only be generated in local environment")
-    return {"dummy_token": create_dummy_token(settings.SECRET_KEY, settings.ALGORITHM)}
+    return {"dummy_token": create_dummy_token(settings.SECRET_KEY)}

backend/app/main.py

@@ -1,6 +1,7 @@
 from fastapi import FastAPI, Depends
 from mangum import Mangum
 from app.portfolio import router as portfolio_router
+from app.plan import router as plan_router
 from app.dependencies import validate_api_key
 from app.config import get_settings
 
@@ -9,6 +10,7 @@ app = FastAPI(dependencies=[Depends(validate_api_key)])
 
 
 app.include_router(portfolio_router.router, prefix="/v1")
+app.include_router(plan_router.router, prefix="/v1")
 
 if get_settings().ENVIRONMENT == "local":
     from app.local import router as local_router

backend/app/plan/schemas.py

@@ -4,7 +4,7 @@ from pydantic import BaseModel
 class PlanTriggerRequest(BaseModel):
     budget: float | None = None
     goal: str
-    housting_type: str
-    goal_value: float
+    housing_type: str
+    goal_value: str
     portfolio_id: int
     trigger_file_path: str

backend/requirements/base.txt

@@ -25,4 +25,5 @@ uvicorn==0.22.0
 uvloop==0.17.0
 watchfiles==0.19.0
 websockets==11.0.3
-boto3
+boto3
+pycryptodome