void hasher::reset()

in src/native/hashing/hasher.cpp [155:215]

• 55 lines of code
• 7 McCabe index (conditional complexity)

void hasher::reset()
{
#ifdef USE_BCRYPT
	#ifndef STATUS_SUCCESS
		#define STATUS_SUCCESS ((NTSTATUS)0x00000000)
	#endif

	BCRYPT_HASH_HANDLE hash_handle;
	NTSTATUS ntstatus = BCryptCreateHash(
		m_algorithm_provider_handle.get(), &hash_handle, nullptr, 0, nullptr, 0, BCRYPT_HASH_REUSABLE_FLAG);
	if (ntstatus != STATUS_SUCCESS)
	{
		std::string msg = "BCryptCreateHash() returned: " + std::to_string(ntstatus);
		throw errors::user_exception(errors::error_code::hash_initialization_failure, msg);
	}
	m_hash_handle.reset(hash_handle);
#endif

#ifdef USE_LIBGCRYPT
	if (m_hd)
	{
		gcry_md_reset(m_hd);
	}
	else
	{
		auto algo = alg_to_gcrypt_algo(m_alg);

		auto open_err = gcry_md_open(&m_hd, algo, 0);
		if (open_err)
		{
			std::string msg = "gcry_md_open(" + gcrypt_algo_to_string(algo) + ") failed: ";
			msg += get_libgcrypt_err_message(open_err);
			throw errors::user_exception(errors::error_code::hash_initialization_failure, msg);
		}
	}
#endif

#ifdef USE_OPENSSL
	auto evp_mp = algorithm_to_EVP_MP(m_alg);
	if (evp_mp == nullptr)
	{
		std::string msg = "Couldn't get evp_mp for algorithm: " + std::to_string(static_cast<int>(m_alg));
	 	throw errors::user_exception(errors::error_code::hash_initialization_failure, msg);
	}

	if (m_md_ctx == nullptr)
	{
		m_md_ctx = EVP_MD_CTX_new();
	}
	else
	{
	 	EVP_MD_CTX_reset(m_md_ctx);
	}

	if (!EVP_DigestInit_ex(m_md_ctx, evp_mp, NULL)) 
	{
		std::string msg = "EVP_DigestInit_ex() failed with err = " + std::to_string(static_cast<int>(ERR_get_error()));
		throw errors::user_exception(errors::error_code::hash_initialization_failure, msg);
	}
#endif
}