refactor: use pynostr/coincurve instead of secp256k1 (#18)

---------

Co-authored-by: Riccardo Balbo <os@rblb.it>
Co-authored-by: Vlad Stan <stan.v.vlad@gmail.com>

tests/integration/start.sh

@@ -19,8 +19,8 @@ fi
 docker run --name=lnbits_nwcprovider_ext_nostr_test \
 -d \
 --rm \
--v $PWD/strfry.conf:/etc/strfry.conf \
--v $PWD/strfry-data:/app/strfry-db \
+-v $PWD/strfry.conf:/etc/strfry.conf:Z \
+-v $PWD/strfry-data:/app/strfry-db:Z \
 -p 7777:7777 \
 ghcr.io/hoytech/strfry:latest
 

tests/integration/strfry.conf

@@ -47,7 +47,7 @@ relay {
     port = 7777
 
     # Set OS-limit on maximum number of open files/sockets (if 0, don't attempt to set) (restart required)
-    nofiles = 1000000
+    nofiles = 0
 
     # HTTP header that contains the client's real IP, before reverse proxying (ie x-real-ip) (MUST be all lower-case)
     realIpHeader = ""

tests/integration/test_all.py

@@ -1,5 +1,4 @@
 import asyncio
-import base64
 import hashlib
 import json
 import random
@@ -9,11 +8,8 @@ from typing import Union
 import bolt11
 import httpx
 import pytest
-import secp256k1
-from Cryptodome import Random
-from Cryptodome.Cipher import AES
-from Cryptodome.Util.Padding import pad, unpad
 from loguru import logger
+from pynostr.key import PrivateKey
 from websockets.legacy.client import connect
 
 wallets = {
@@ -95,12 +91,12 @@ async def refresh_wallet_balances():
 
 
 def gen_keypair():
-    private_key_hex = bytes.hex(secp256k1._gen_private_key())
-    private_key = secp256k1.PrivateKey(bytes.fromhex(private_key_hex))
-    public_key = private_key.pubkey
+    private_key = PrivateKey()
+    private_key_hex = private_key.hex()
+    public_key = private_key.public_key
     if not public_key:
         raise Exception("Error generating pubkey")
-    public_key_hex = public_key.serialize().hex()[2:]
+    public_key_hex = public_key.hex()
     return {"priv": private_key_hex, "pub": public_key_hex}
 
 
@@ -164,12 +160,12 @@ class NWCWallet:
         self.event_queue = []
         self.subscriptions_count = 0
         self.sub_id = ""
-        self.private_key = secp256k1.PrivateKey(bytes.fromhex(self.secret))
+        self.private_key = PrivateKey.from_hex(self.secret)
         self.private_key_hex = self.secret
-        self.public_key = self.private_key.pubkey
+        self.public_key = self.private_key.public_key
         if not self.public_key:
             raise Exception("Error generating pubkey")
-        self.public_key_hex = self.public_key.serialize().hex()[2:]
+        self.public_key_hex = self.public_key.hex()
         self.task = None
 
     async def close(self):
@@ -243,43 +239,13 @@ class NWCWallet:
             else:
                 break
 
-    def _encrypt_content(
-        self, content: str, pubkey_hex: str, iv_seed: int | None = None
-    ) -> str:
-        pubkey = secp256k1.PublicKey(bytes.fromhex("02" + pubkey_hex), True)
-        shared = pubkey.tweak_mul(bytes.fromhex(self.private_key_hex)).serialize()[1:]
-        if not iv_seed:
-            iv = Random.new().read(AES.block_size)
-        else:
-            iv = hashlib.sha256(iv_seed.to_bytes(32, byteorder="big")).digest()
-            iv = iv[: AES.block_size]
-        aes = AES.new(shared, AES.MODE_CBC, iv)
-        content_bytes = content.encode("utf-8")
-        content_bytes = pad(content_bytes, AES.block_size)
-        encrypted_b64 = base64.b64encode(aes.encrypt(content_bytes)).decode("ascii")
-        iv_b64 = base64.b64encode(iv).decode("ascii")
-        encrypted_content = encrypted_b64 + "?iv=" + iv_b64
-        return encrypted_content
-
-    def _decrypt_content(self, content: str, pubkey_hex: str) -> str:
-        pubkey = secp256k1.PublicKey(bytes.fromhex("02" + pubkey_hex), True)
-        shared = pubkey.tweak_mul(bytes.fromhex(self.private_key_hex)).serialize()[1:]
-        (encrypted_content_b64, iv_b64) = content.split("?iv=")
-        encrypted_content = base64.b64decode(encrypted_content_b64.encode("ascii"))
-        iv = base64.b64decode(iv_b64.encode("ascii"))
-        aes = AES.new(shared, AES.MODE_CBC, iv)
-        decrypted_bytes = aes.decrypt(encrypted_content)
-        decrypted_bytes = unpad(decrypted_bytes, AES.block_size)
-        decrypted = decrypted_bytes.decode("utf-8")
-        return decrypted
-
     async def _on_message(self, _, message: str):
         logger.debug("Received message: " + message)
         msg = json.loads(message)
         if msg[0] == "EVENT":  # Event message
             event = msg[2]
             nwc_pubkey = event["pubkey"]
-            content = self._decrypt_content(event["content"], nwc_pubkey)
+            content = self.private_key.decrypt_message(event["content"], nwc_pubkey)
             content = json.loads(content)
             self.event_queue.append(
                 {
@@ -312,10 +278,9 @@ class NWCWallet:
         event_id = hashlib.sha256(signature_data.encode()).hexdigest()
         event["id"] = event_id
         event["pubkey"] = self.public_key_hex
-        signature = (
-            self.private_key.schnorr_sign(bytes.fromhex(event_id), None, raw=True)
-        ).hex()
-        event["sig"] = signature
+        signature = self.private_key.sign(bytes.fromhex(event_id))
+        # type error? returns str but is bytes
+        event["sig"] = signature.hex()  # type: ignore
         return event
 
     async def send_event(self, method, params):
@@ -331,7 +296,7 @@ class NWCWallet:
             "content": json.dumps({"method": method, "params": params}),
         }
         logger.debug("Sending event: " + str(event))
-        event["content"] = self._encrypt_content(
+        event["content"] = self.private_key.encrypt_message(
             event["content"], self.provider_pub_hex
         )
         self._sign_event(event)
@@ -888,7 +853,7 @@ async def test_idor_vulnerability():
             f"http://localhost:5002/nwcprovider/api/v1/nwc/{nwc_wallet1['pubkey']}",
             headers={"X-Api-Key": wallets["wallet2"]["admin_key"]},
         )
-        assert resp.status_code == 500
+        assert resp.status_code == 400
         assert "Pubkey has no associated wallet" in resp.text