diff options
| -rw-r--r-- | src/_cffi_src/openssl/err.py | 2 | ||||
| -rw-r--r-- | src/cryptography/hazmat/backends/openssl/backend.py | 19 | ||||
| -rw-r--r-- | tests/hazmat/primitives/test_scrypt.py | 14 |
3 files changed, 34 insertions, 1 deletions
diff --git a/src/_cffi_src/openssl/err.py b/src/_cffi_src/openssl/err.py index 59751355..b4d053c6 100644 --- a/src/_cffi_src/openssl/err.py +++ b/src/_cffi_src/openssl/err.py @@ -22,6 +22,8 @@ static const int ERR_LIB_PKCS12; static const int ERR_LIB_SSL; static const int ERR_LIB_X509; +static const int ERR_R_MALLOC_FAILURE; + static const int ASN1_R_BOOLEAN_IS_WRONG_LENGTH; static const int ASN1_R_BUFFER_TOO_SMALL; static const int ASN1_R_CIPHER_HAS_NO_OBJECT_IDENTIFIER; diff --git a/src/cryptography/hazmat/backends/openssl/backend.py b/src/cryptography/hazmat/backends/openssl/backend.py index ae966cd0..fda6293c 100644 --- a/src/cryptography/hazmat/backends/openssl/backend.py +++ b/src/cryptography/hazmat/backends/openssl/backend.py @@ -2120,7 +2120,24 @@ class Backend(object): key_material, len(key_material), salt, len(salt), n, r, p, scrypt._MEM_LIMIT, buf, length ) - self.openssl_assert(res == 1) + if res != 1: + errors = self._consume_errors() + if not self._lib.CRYPTOGRAPHY_OPENSSL_LESS_THAN_111: + # This error is only added to the stack in 1.1.1+ + self.openssl_assert( + errors[0]._lib_reason_match( + self._lib.ERR_LIB_EVP, + self._lib.ERR_R_MALLOC_FAILURE + ) + ) + + # memory required formula explained here: + # https://blog.filippo.io/the-scrypt-parameters/ + min_memory = 128 * n * r // (1024**2) + raise MemoryError( + "Not enough memory to derive key. These parameters require" + " {} MB of memory.".format(min_memory) + ) return self._ffi.buffer(buf)[:] def aead_cipher_supported(self, cipher): diff --git a/tests/hazmat/primitives/test_scrypt.py b/tests/hazmat/primitives/test_scrypt.py index 64abfe79..25d2c615 100644 --- a/tests/hazmat/primitives/test_scrypt.py +++ b/tests/hazmat/primitives/test_scrypt.py @@ -80,6 +80,20 @@ class TestScrypt(object): Scrypt(salt, length, work_factor, block_size, parallelization_factor, backend) + def test_scrypt_malloc_failure(self, backend): + password = b"NaCl" + work_factor = 1024 ** 3 + block_size = 589824 + parallelization_factor = 16 + length = 64 + salt = b"NaCl" + + scrypt = Scrypt(salt, length, work_factor, block_size, + parallelization_factor, backend) + + with pytest.raises(MemoryError): + scrypt.derive(password) + def test_password_not_bytes(self, backend): password = 1 work_factor = 1024 |