/*

 * SPDX-License-Identifier: ISC

 *

 * Copyright (c) 2013-2015, 2023 Todd C. Miller <Todd.Miller@sudo.ws>

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

#include <config.h>

#include <sudo_compat.h>

#include <sudo_debug.h>

#include <sudo_util.h>

/*

 * Converts a two-byte hex string to decimal.

 * Returns a value 0-255 on success or -1 for invalid input.

 */

int

sudo_hexchar_v1(const char s[restrict static 2])

{

    unsigned char result[2];

    unsigned int i;

    debug_decl(sudo_hexchar, SUDO_DEBUG_UTIL);

    for (i = 0; i < 2; i++) {

  switch (s[i]) {

  case '0':

      result[i] = 0;

      break;

  case '1':

      result[i] = 1;

      break;

  case '2':

      result[i] = 2;

      break;

  case '3':

      result[i] = 3;

      break;

  case '4':

      result[i] = 4;

      break;

  case '5':

      result[i] = 5;

      break;

  case '6':

      result[i] = 6;

      break;

  case '7':

      result[i] = 7;

      break;

  case '8':

      result[i] = 8;

      break;

  case '9':

      result[i] = 9;

      break;

  case 'A':

  case 'a':

      result[i] = 10;

      break;

  case 'B':

  case 'b':

      result[i] = 11;

      break;

  case 'C':

  case 'c':

      result[i] = 12;

      break;

  case 'D':

  case 'd':

      result[i] = 13;

      break;

  case 'E':

  case 'e':

      result[i] = 14;

      break;

  case 'F':

  case 'f':

      result[i] = 15;

      break;

  default:

      /* Invalid input. */

      debug_return_int(-1);

  }

    }

    debug_return_int((result[0] << 4) | result[1]);

}