From ac6eee4f847b16a82eb0f2d06797793192584455 Mon Sep 17 00:00:00 2001 From: Martijn de Milliano Date: Fri, 10 Apr 2026 18:04:13 +0200 Subject: [PATCH] Process Copilot comments - Use constant from ciphers.py - Raise ValueError or TypeError in sign_with_seed instead of assert - Add missing test case --- tests/test_mldsa.py | 27 ++++++++++++++++++++++----- wolfcrypt/ciphers.py | 32 +++++++++++++++++++++++--------- 2 files changed, 45 insertions(+), 14 deletions(-) diff --git a/tests/test_mldsa.py b/tests/test_mldsa.py index 6e06220..5fe8e0d 100644 --- a/tests/test_mldsa.py +++ b/tests/test_mldsa.py @@ -25,11 +25,9 @@ from wolfcrypt._ffi import lib as _lib if _lib.ML_DSA_ENABLED: import pytest - from wolfcrypt.ciphers import MlDsaPrivate, MlDsaPublic, MlDsaType + from wolfcrypt.ciphers import MlDsaPrivate, MlDsaPublic, MlDsaType, ML_DSA_SIGNATURE_SEED_LENGTH from wolfcrypt.random import Random - ML_DSA_SIGNATURE_SEED_LENGTH = 32 - @pytest.fixture def rng(): return Random() @@ -159,8 +157,27 @@ if _lib.ML_DSA_ENABLED: assert signature == signature_from_same_seed # test that the seed size is checked: - with pytest.raises(AssertionError): + with pytest.raises(ValueError): _ = mldsa_priv.sign_with_seed(message, signature_seed[:-1]) - with pytest.raises(AssertionError): + # test that the seed type is checked (should be bytes-like, not string) + with pytest.raises(TypeError): _ = mldsa_priv.sign_with_seed(message, "") + + def test_sign_with_seed_and_context(mldsa_type, rng): + signature_seed = rng.bytes(ML_DSA_SIGNATURE_SEED_LENGTH) + mldsa_priv = MlDsaPrivate.make_key(mldsa_type, rng) + pub_key = mldsa_priv.encode_pub_key() + + # Import public key + mldsa_pub = MlDsaPublic(mldsa_type) + mldsa_pub.decode_key(pub_key) + + # Sign a message + message = b"This is a test message for ML-DSA signature" + context = b"Some context for the signature" + signature = mldsa_priv.sign_with_seed(message, signature_seed, ctx=context) + assert len(signature) == mldsa_priv.sig_size + # test that the context length is checked (more than 255 bytes is invalid): + with pytest.raises(ValueError): + _ = mldsa_priv.sign_with_seed(message, signature_seed[:-1], ctx=bytes(1000)) diff --git a/wolfcrypt/ciphers.py b/wolfcrypt/ciphers.py index 1e24b0f..b64a2db 100644 --- a/wolfcrypt/ciphers.py +++ b/wolfcrypt/ciphers.py @@ -2028,6 +2028,9 @@ if _lib.ML_KEM_ENABLED: if _lib.ML_DSA_ENABLED: + ML_DSA_SIGNATURE_SEED_LENGTH = 32 + """The length of a signature generation seed.""" + class MlDsaType(IntEnum): """ `MlDsaType` specifies supported ML-DSA types. @@ -2149,9 +2152,7 @@ if _lib.ML_DSA_ENABLED: return res[0] == 1 class MlDsaPrivate(_MlDsaBase): - _SIGNATURE_SEED_LENGTH = 32 - """The length of a signature generation seed.""" - + @classmethod def make_key(cls, mldsa_type, rng=Random()): """ @@ -2286,7 +2287,7 @@ if _lib.ML_DSA_ENABLED: :type message: bytes or str :param seed: 32-byte seed for deterministic signature generation. :type seed: bytes - :param ctx: context (optional) + :param ctx: context (optional, maximum 255 bytes) :type ctx: None for no context, str or bytes otherwise :return: signature :rtype: bytes @@ -2297,20 +2298,33 @@ if _lib.ML_DSA_ENABLED: out_size = _ffi.new("word32 *") out_size[0] = in_size - assert isinstance(seed, bytes) and len(seed) == MlDsaPrivate._SIGNATURE_SEED_LENGTH, \ - f"Seed for generating a signature must be {MlDsaPrivate._SIGNATURE_SEED_LENGTH} bytes." + try: + seed_view = memoryview(seed) + except TypeError as exception: + raise TypeError( + "seed must support the buffer protocol, such as `bytes` or `bytearray`" + ) from exception + if len(seed_view) != ML_DSA_SIGNATURE_SEED_LENGTH: + raise ValueError( + f"Seed for generating a signature must be {ML_DSA_SIGNATURE_SEED_LENGTH}" + "bytes." + ) if ctx is not None: ctx_bytestype = t2b(ctx) + if len(ctx_bytestype) > 255: + raise ValueError( + f"context length {len(ctx_bytestype)} too large: must be 255 or less" + ) ret = _lib.wc_dilithium_sign_ctx_msg_with_seed( _ffi.from_buffer(ctx_bytestype), - len(ctx_bytestype), + len(ctx_bytestype), # length must be < 256 bytes _ffi.from_buffer(msg_bytestype), len(msg_bytestype), signature, out_size, self.native_object, - _ffi.from_buffer(seed), + _ffi.from_buffer(seed_view), ) if ret < 0: # pragma: no cover raise WolfCryptError("wc_dilithium_sign_ctx_msg_with_seed() error (%d)" % ret) @@ -2321,7 +2335,7 @@ if _lib.ML_DSA_ENABLED: signature, out_size, self.native_object, - _ffi.from_buffer(seed), + _ffi.from_buffer(seed_view), ) if ret < 0: # pragma: no cover raise WolfCryptError("wc_dilithium_sign_msg_with_seed() error (%d)" % ret)