faster scrypt in testing

hushline/crypto.py

@@ -8,9 +8,11 @@
 
 # https://cryptography.io/en/latest/hazmat/primitives/key-derivation-functions/#scrypt
 SCRYPT_LENGTH = 32  # The desired length of the derived key in bytes.
-SCRYPT_N = 2**14  # CPU/Memory cost parameter. It must be larger than 1 and be a power of 2.
-SCRYPT_R = 8  # Block size parameter.
-SCRYPT_P = 1  # Parallelization parameter.
+_SCRYPT_PARAMS = {
+    "n": 2**14,  # CPU/Memory cost parameter. It must be larger than 1 and be a power of 2.
+    "r": 8,  # Block size parameter.
+    "p": 1,  # Parallelization parameter.
+}
 
 
 def generate_salt() -> str:
@@ -41,13 +43,7 @@ def get_encryption_key(scope: bytes | str | None = None, salt: str | None = None
         salt_bytes = urlsafe_b64decode(salt)
 
         # Use Scrypt to derive a unique encryption key based on the scope
-        kdf = Scrypt(
-            salt=salt_bytes,
-            length=SCRYPT_LENGTH,
-            n=SCRYPT_N,
-            r=SCRYPT_R,
-            p=SCRYPT_P,
-        )
+        kdf = Scrypt(salt=salt_bytes, length=SCRYPT_LENGTH, **_SCRYPT_PARAMS)
 
         # Concatenate the encryption key with the scope
         items = (encryption_key_bytes, scope_bytes)

tests/conftest.py

@@ -9,11 +9,13 @@
 import pytest
 from flask import Flask
 from flask.testing import FlaskClient
+from pytest_mock import MockFixture
 from sqlalchemy import create_engine, text
 from sqlalchemy.exc import OperationalError
 from sqlalchemy.orm import Session, sessionmaker
 
 from hushline import create_app
+from hushline.crypto import _SCRYPT_PARAMS
 from hushline.db import db
 from hushline.model import User, Username
 
@@ -103,6 +105,11 @@ def database(_db_template: None) -> str:
     return db_name
 
 
+@pytest.fixture(autouse=True)
+def _insecure_scrypt_params(mocker: MockFixture) -> None:
+    mocker.patch.dict(_SCRYPT_PARAMS, {"n": 2, "r": 1, "p": 1}, clear=True)
+
+
 @pytest.fixture()
 def app(database: str) -> Generator[Flask, None, None]:
     os.environ["REGISTRATION_CODES_REQUIRED"] = "False"