refactor: untangle lnd's macaroon encryption with AESCipher class (#3152)

lnbits/wallets/lndgrpc.py

@@ -12,7 +12,7 @@ import lnbits.wallets.lnd_grpc_files.lightning_pb2_grpc as lnrpc
 import lnbits.wallets.lnd_grpc_files.router_pb2 as router
 import lnbits.wallets.lnd_grpc_files.router_pb2_grpc as routerrpc
 from lnbits.settings import settings
-from lnbits.utils.crypto import AESCipher, random_secret_and_hash
+from lnbits.utils.crypto import random_secret_and_hash
 
 from .base import (
     InvoiceResponse,
@@ -72,6 +72,11 @@ class LndWallet(Wallet):
                 "cannot initialize LndWallet: missing lnd_grpc_cert or lnd_cert"
             )
 
+        self.endpoint = self.normalize_endpoint(
+            settings.lnd_grpc_endpoint, add_proto=False
+        )
+        self.port = int(settings.lnd_grpc_port)
+
         macaroon = (
             settings.lnd_grpc_macaroon
             or settings.lnd_grpc_admin_macaroon
@@ -80,23 +85,11 @@ class LndWallet(Wallet):
             or settings.lnd_invoice_macaroon
         )
         encrypted_macaroon = settings.lnd_grpc_macaroon_encrypted
-        if encrypted_macaroon:
-            macaroon = AESCipher(description="macaroon decryption").decrypt(
-                encrypted_macaroon
-            )
-        if not macaroon:
-            raise ValueError(
-                "cannot initialize LndWallet: "
-                "missing lnd_grpc_macaroon or lnd_grpc_admin_macaroon or "
-                "lnd_admin_macaroon or lnd_grpc_invoice_macaroon or "
-                "lnd_invoice_macaroon or lnd_grpc_macaroon_encrypted"
-            )
+        try:
+            self.macaroon = load_macaroon(macaroon, encrypted_macaroon)
+        except ValueError as exc:
+            raise ValueError(f"cannot load macaroon for LndWallet: {exc!s}") from exc
 
-        self.endpoint = self.normalize_endpoint(
-            settings.lnd_grpc_endpoint, add_proto=False
-        )
-        self.port = int(settings.lnd_grpc_port)
-        self.macaroon = load_macaroon(macaroon)
         cert = open(cert_path, "rb").read()
         creds = grpc.ssl_channel_credentials(cert)
         auth_creds = grpc.metadata_call_credentials(self.metadata_callback)

lnbits/wallets/lndrest.py

@@ -9,7 +9,7 @@ from loguru import logger
 
 from lnbits.nodes.lndrest import LndRestNode
 from lnbits.settings import settings
-from lnbits.utils.crypto import AESCipher, random_secret_and_hash
+from lnbits.utils.crypto import random_secret_and_hash
 
 from .base import (
     InvoiceResponse,
@@ -35,26 +35,6 @@ class LndRestWallet(Wallet):
                 "cannot initialize LndRestWallet: missing lnd_rest_endpoint"
             )
 
-        macaroon = (
-            settings.lnd_rest_macaroon
-            or settings.lnd_admin_macaroon
-            or settings.lnd_rest_admin_macaroon
-            or settings.lnd_invoice_macaroon
-            or settings.lnd_rest_invoice_macaroon
-        )
-        encrypted_macaroon = settings.lnd_rest_macaroon_encrypted
-        if encrypted_macaroon:
-            macaroon = AESCipher(description="macaroon decryption").decrypt(
-                encrypted_macaroon
-            )
-        if not macaroon:
-            raise ValueError(
-                "cannot initialize LndRestWallet: "
-                "missing lnd_rest_macaroon or lnd_admin_macaroon or "
-                "lnd_rest_admin_macaroon or lnd_invoice_macaroon or "
-                "lnd_rest_invoice_macaroon or lnd_rest_macaroon_encrypted"
-            )
-
         if not settings.lnd_rest_cert:
             logger.warning(
                 "No certificate for LndRestWallet provided! "
@@ -68,7 +48,21 @@ class LndRestWallet(Wallet):
         # even on startup
         cert = settings.lnd_rest_cert or True
 
-        macaroon = load_macaroon(macaroon)
+        macaroon = (
+            settings.lnd_rest_macaroon
+            or settings.lnd_admin_macaroon
+            or settings.lnd_rest_admin_macaroon
+            or settings.lnd_invoice_macaroon
+            or settings.lnd_rest_invoice_macaroon
+        )
+        encrypted_macaroon = settings.lnd_rest_macaroon_encrypted
+        try:
+            macaroon = load_macaroon(macaroon, encrypted_macaroon)
+        except ValueError as exc:
+            raise ValueError(
+                f"cannot load macaroon for LndRestWallet: {exc!s}"
+            ) from exc
+
         headers = {
             "Grpc-Metadata-macaroon": macaroon,
             "User-Agent": settings.user_agent,

lnbits/wallets/macaroon/macaroon.py

@@ -1,45 +1,45 @@
 import base64
-
-from loguru import logger
+from getpass import getpass
+from typing import Optional
 
 from lnbits.utils.crypto import AESCipher
 
 
-def load_macaroon(macaroon: str) -> str:
-    """Returns hex version of a macaroon encoded in base64 or the file path.
+def load_macaroon(
+    macaroon: Optional[str] = None,
+    encrypted_macaroon: Optional[str] = None,
+) -> str:
+    """Returns hex version of a macaroon encoded in base64 or the file path."""
 
-    :param macaroon: Macaroon encoded in base64 or file path.
-    :type macaroon: str
-    :return: Hex version of macaroon.
-    :rtype: str
-    """
+    if macaroon is None and encrypted_macaroon is None:
+        raise ValueError("Either macaroon or encrypted_macaroon must be provided.")
+
+    if encrypted_macaroon:
+        # if the macaroon is encrypted, decrypt it and return the hex version
+        key = getpass("Enter the macaroon decryption key: ")
+        aes = AESCipher(key.encode())
+        return aes.decrypt(encrypted_macaroon)
+
+    assert macaroon, "macaroon must be set here"
 
     # if the macaroon is a file path, load it and return hex version
     if macaroon.split(".")[-1] == "macaroon":
         with open(macaroon, "rb") as f:
             macaroon_bytes = f.read()
             return macaroon_bytes.hex()
-    else:
-        # if macaroon is a provided string
-        # check if it is hex, if so, return
-        try:
-            bytes.fromhex(macaroon)
-            return macaroon
-        except ValueError:
-            pass
-        # convert the bas64 macaroon to hex
-        try:
-            macaroon = base64.b64decode(macaroon).hex()
-        except Exception:
-            pass
+
+    # if macaroon is a provided string check if it is hex, if so, return
+    try:
+        bytes.fromhex(macaroon)
+        return macaroon
+    except ValueError:
+        pass
+
+    # convert the base64 macaroon to hex
+    try:
+        macaroon = base64.b64decode(macaroon).hex()
+        return macaroon
+    except Exception:
+        pass
+
     return macaroon
-
-
-# todo: move to its own (crypto.py) file
-# if this file is executed directly, ask for a macaroon and encrypt it
-if __name__ == "__main__":
-    macaroon = input("Enter macaroon: ")
-    macaroon = load_macaroon(macaroon)
-    macaroon = AESCipher(description="encryption").encrypt(macaroon.encode())
-    logger.info("Encrypted macaroon:")
-    logger.info(macaroon)