/*
 * Copyright (C) 2010 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef BASE16_H_
#define BASE16_H_

#include <stdint.h>
#include <string.h>

/**
 * Calculate length of base16-encoded data
 * @param raw_len Raw data length
 * @return Encoded string length (excluding NUL)
 */
static inline size_t base16_encoded_len(size_t raw_len) {
	return (2 * raw_len);
}

/**
 * Calculate maximum length of base16-decoded string
 * @param encoded Encoded string
 * @return Maximum length of raw data
 */
static inline size_t base16_decoded_max_len(const char *encoded) {
	return ((strlen(encoded) + 1) / 2);
}

/**
 * Base16-encode data
 *
 * The buffer must be the correct length for the encoded string.  Use
 * something like
 *
 *     char buf[ base16_encoded_len ( len ) + 1 ];
 *
 * (the +1 is for the terminating NUL) to provide a buffer of the
 * correct size.
 *
 * @param raw Raw data
 * @param len Length of raw data
 * @param encoded Buffer for encoded string
 */
extern void base16_encode(uint8_t *raw, size_t len, char *encoded);

/**
 * Base16-decode data
 *
 * The buffer must be large enough to contain the decoded data.  Use
 * something like
 *
 *     char buf[ base16_decoded_max_len ( encoded ) ];
 *
 * to provide a buffer of the correct size.
 * @param encoded Encoded string
 * @param raw Raw data
 * @return Length of raw data, or negative error
 */
extern int base16_decode(const char *encoded, uint8_t *raw);

#endif /* BASE16_H_ */