/*
 * uuid.c
 * ------
 * UUID support for keystore database.
 *
 * Copyright (c) 2016, NORDUnet A/S All rights reserved.
 * Copyright: 2020, The Commons Conservancy Cryptech Project
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the copyright holder nor the names of its
 *   contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>

#include "hal.h"
#include "hal_internal.h"

hal_error_t hal_uuid_gen(hal_uuid_t *uuid)
{
  hal_error_t err;

  if (uuid == NULL)
    return HAL_ERROR_BAD_ARGUMENTS;

  /*
   * Generate a version 4 UUID as specified in RFC 4122.
   * This is basically a 122-bit random number.
   */

  if ((err = hal_rpc_get_random(uuid->uuid, sizeof(uuid->uuid))) != HAL_OK)
    return err;

  /*
   * Set high order bits of clock_seq_hi_and_reserved and
   * time_hi_and_version fields to magic values as specified by RFC
   * 4122 section 4.4.
   *
   * Not recommended reading if you've eaten recently.
   */

  uuid->uuid[6] &= 0x0f;
  uuid->uuid[6] |= 0x40;
  uuid->uuid[8] &= 0x3f;
  uuid->uuid[8] |= 0x80;

  return HAL_OK;
}

hal_error_t hal_uuid_parse(hal_uuid_t *uuid, const char * const string)
{
  static const char fmt[]
    = "%2hx%2hx%2hx%2hx-%2hx%2hx-%2hx%2hx-%2hx%2hx-%2hx%2hx%2hx%2hx%2hx%2hx";
  uint16_t tmp[16];

   if (uuid == NULL || string == NULL ||
       sscanf(string, fmt,
	     tmp +  0, tmp +  1, tmp +  2, tmp +  3,
	     tmp +  4, tmp +  5, tmp +  6, tmp +  7,
	     tmp +  8, tmp +  9, tmp + 10, tmp + 11,
	     tmp + 12, tmp + 13, tmp + 14, tmp + 15) != 16)
     return HAL_ERROR_BAD_ARGUMENTS;

   for (unsigned i = 0; i < 16; ++i)
     uuid->uuid[i] = tmp[i] & 0xff;

  return HAL_OK;
}

hal_error_t hal_uuid_format(const hal_uuid_t * const uuid, char *buffer, const size_t buffer_len)
{
  static const char fmt[]
    = "%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx";

  if (uuid == NULL || buffer == NULL || buffer_len < HAL_UUID_TEXT_SIZE)
    return HAL_ERROR_BAD_ARGUMENTS;

  if (snprintf(buffer, buffer_len, fmt,
               uuid->uuid[ 0], uuid->uuid[ 1], uuid->uuid[ 2], uuid->uuid[ 3],
               uuid->uuid[ 4], uuid->uuid[ 5], uuid->uuid[ 6], uuid->uuid[ 7],
               uuid->uuid[ 8], uuid->uuid[ 9], uuid->uuid[10], uuid->uuid[11],
               uuid->uuid[12], uuid->uuid[13], uuid->uuid[14], uuid->uuid[15]) != HAL_UUID_TEXT_SIZE - 1)
    return HAL_ERROR_RESULT_TOO_LONG;

  return HAL_OK;
}


/*
 * Local variables:
 * indent-tabs-mode: nil
 * End:
 */