/*
 * otpcli - command-line interface for HOTP and TOTP
 * Written in 2020-2021 by Lucas
 *
 * To the extent possible under law, the author(s) have dedicated all
 * copyright and related and neighboring rights to this software to the
 * public domain worldwide. This software is distributed without any
 * warranty.
 *
 * You should have received a copy of the CC0 Public Domain Dedication
 * along with this software. If not, see
 * <http://creativecommons.org/publicdomain/zero/1.0/>.
 */

#include <stdint.h>

enum otp_type {
	OTP_HOTP,
	OTP_TOTP,
};

enum otp_hmac {
	OTP_HMAC_SHA1,
	OTP_HMAC_SHA256,
	OTP_HMAC_SHA512,
};

struct otpcfg {
	enum otp_type type;
	enum otp_hmac algorithm;
	unsigned int digits;
	const void *secret;
	size_t secretlen;

	union {
		struct {
			uint64_t counter;
		} hotp;
		struct {
			uint64_t time;
			unsigned int period;
		} totp;
	} u;
};

int32_t otp(const struct otpcfg *);