/*
 * Copyright (c) 2020, Arm Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#ifndef UUID_H
#define UUID_H

#include <stddef.h>
#include <stdint.h>

#define UUID_OCTETS_LEN			        (16)
#define UUID_CANONICAL_FORM_LEN			(36)


#ifdef __cplusplus
extern "C" {
#endif

/*
 * Structure for holding an octet representation of a UUID.
 */
struct uuid_octets
{
    uint8_t octets[UUID_OCTETS_LEN];
};

/*
 * Structure for holding an canonical string representation of a UUID.
 */
struct uuid_canonical
{
    char characters[UUID_CANONICAL_FORM_LEN + 1];
};

/*
 * Check if uuid string in canonical form is valid. Returns the number of
 * valid characters. This will either be UUID_CANONICAL_FORM_LEN or zero
 * if the string is invalid in some way.
 */
size_t uuid_is_valid(const char *canonical_form);

/*
 * Parses a uuid string in canonical string form, outputting as an array of bytes
 * in the standard big endian byte order. Returns the number of characters parsed
 * from the input string. Returns zero if there is a parsing error.
 */
size_t uuid_parse_to_octets(const char *canonical_form,
    uint8_t *buf, size_t buf_size);

/*
 * Parses a uuid string in canonical string form but instead of outputting octets
 * in standard byte order, octets from each section of the canonical uuid are
 * reversed.
 */
size_t uuid_parse_to_octets_reversed(const char *canonical_form,
    uint8_t *buf, size_t buf_size);

/*
 * Reverses bytes from the normal big endian binary encoding to the reversed encoding used
 * by tf-a and optee (same byte order as uuid_parse_to_octets_reversed()).
 */
void uuid_reverse_octets(const struct uuid_octets *standard_encoding,
    uint8_t *buf, size_t buf_size);


#ifdef __cplusplus
}
#endif

#endif /* UUID_H */