Ensure that secretbox can accept any bytes-like object as parameter

pyproject.toml

@@ -40,6 +40,8 @@ dependencies = [
 tests = [
     "pytest>=3.2.1,!=3.3.0",
     "hypothesis>=3.27.0",
+    "mypy>=1.4.1",
+    "flake8>=5.0.4",
 ]
 docs = [
     "sphinx<7",

src/nacl/bindings/crypto_secretbox.py

@@ -44,6 +44,9 @@ def crypto_secretbox(message: bytes, nonce: bytes, key: bytes) -> bytes:
     if len(nonce) != crypto_secretbox_NONCEBYTES:
         raise exc.ValueError("Invalid nonce")
 
+    nonce = ffi.from_buffer(nonce)
+    key = ffi.from_buffer(key)
+
     padded = b"\x00" * crypto_secretbox_ZEROBYTES + message
     ciphertext = ffi.new("unsigned char[]", len(padded))
 
@@ -72,6 +75,9 @@ def crypto_secretbox_open(
     if len(nonce) != crypto_secretbox_NONCEBYTES:
         raise exc.ValueError("Invalid nonce")
 
+    nonce = ffi.from_buffer(nonce)
+    key = ffi.from_buffer(key)
+
     padded = b"\x00" * crypto_secretbox_BOXZEROBYTES + ciphertext
     plaintext = ffi.new("unsigned char[]", len(padded))
 

tests/test_bindings.py

@@ -14,8 +14,9 @@
 
 
 import hashlib
+import itertools
 from binascii import hexlify, unhexlify
-from typing import List, Tuple
+from typing import Callable, List, Tuple
 
 from hypothesis import given, settings
 from hypothesis.strategies import binary, integers
@@ -94,6 +95,26 @@ def test_secretbox_easy():
         )
 
 
+@pytest.mark.parametrize(
+    ("encoder", "decoder"),
+    itertools.product(
+        [bytes, bytearray, memoryview],
+        [bytes, bytearray, memoryview],
+    ),
+)
+def test_secretbox_byteslike(
+    encoder: Callable[[bytes], bytes], decoder: Callable[[bytes], bytes]
+):
+    key = b"\x00" * c.crypto_secretbox_KEYBYTES
+    msg = b"message"
+    nonce = b"\x01" * c.crypto_secretbox_NONCEBYTES
+    ct = c.crypto_secretbox(encoder(msg), encoder(nonce), encoder(key))
+    assert len(ct) == len(msg) + c.crypto_secretbox_BOXZEROBYTES
+    assert tohex(ct) == "3ae84dfb89728737bd6e2c8cacbaf8af3d34cc1666533a"
+    msg2 = c.crypto_secretbox_open(decoder(ct), decoder(nonce), decoder(key))
+    assert msg2 == msg
+
+
 def test_secretbox_wrong_length():
     with pytest.raises(ValueError):
         c.crypto_secretbox(b"", b"", b"")