printf("Encryption/Decryption Gost R 34.12-2015 Kuznyechik CBC mode...\r\n");
	HCRYPTPROV hProv = 0;
	HCRYPTKEY hKey = 0;
	if (CryptAcquireContextW(
		&hProv,
		NULL,
		L"Crypto-Pro GOST R 34.10-2012 Cryptographic Service Provider",
		PROV_GOST_2012_256,
		CRYPT_VERIFYCONTEXT))
	{
		printf("CryptAcquireContext succeeded.\n");
	}
	else printf("Error during CryptAcquireContext! Error: 0x%x \n", GetError);
	if (CryptGetUserKey(hProv, CALG_GR3412_2015_K, &hKey))
		printf("Symmetric key is available.\n");
	else
	{
		printf("No symmetric key is available.\n");
		printf("Creating symmetric key...\n");
		if (!CryptGenKey(hProv, CALG_GR3412_2015_K, CRYPT_EXPORTABLE, &hKey))
		{
			printf("Error occurred creating symmetric key: 0x%x\n", GetError);
			return false;
		}
		printf("Created symmetric key.\n");
	}