/*

 * SPDX-License-Identifier: ISC

 *

 * Copyright (c) 2020-2021, 2025 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 <stdlib.h>

#if defined(HAVE_STDINT_H)

# include <stdint.h>

#elif defined(HAVE_INTTYPES_H)

# include <inttypes.h>

#endif

#include <string.h>

#include <arpa/inet.h>

#include <sudo_compat.h>

#include <sudo_util.h>

#include <sudo_rand.h>

struct uuid {

    uint32_t time_low;

    uint16_t time_mid;

    uint16_t time_hi_and_version;

    uint8_t clock_seq_hi_and_reserved;

    uint8_t clock_seq_low;

    uint8_t node[6];

};

/*

 * Create a type 4 (random), variant 1 universally unique identifier (UUID).

 * As per RFC 4122 section 4.4.

 */

void

sudo_uuid_create_v1(unsigned char uuid_out[restrict static 16])

{

    struct uuid uuid;

    arc4random_buf(&uuid, sizeof(uuid));

    /* Set version to 4 (random), 4 most significant bits (12-15) are 0010. */

    uuid.time_hi_and_version &= 0x0fff;

    uuid.time_hi_and_version |= 0x4000;

    /* Set variant to 1: two most significant bits (6 and 7) are 01. */

    uuid.clock_seq_hi_and_reserved &= 0x3f;

    uuid.clock_seq_hi_and_reserved |= 0x80;

    /* Convert 16 and 32-bit fields to network byte order. */

    uuid.time_low = ntohl(uuid.time_low);

    uuid.time_mid = ntohs(uuid.time_mid);

    uuid.time_hi_and_version = ntohs(uuid.time_hi_and_version);

    memcpy(uuid_out, &uuid, 16);

}

/*

 * Format a uuid as a 36-byte string (plus one for the NUL).

 */

char *

sudo_uuid_to_string_v1(const unsigned char uuid[restrict static 16], char * restrict dst, size_t dstsiz)

{

    const char hex[] = "0123456789abcdef";

    char *cp = dst;

    unsigned int i;

    if (dstsiz < sizeof("123e4567-e89b-12d3-a456-426655440000"))

  return NULL;

    for (i = 0; i < 16; i++) {

  *cp++ = hex[uuid[i] >> 4];

  *cp++ = hex[uuid[i] & 0x0f];

  switch (i) {

  case 3: case 5: case 7: case 9:

      *cp++ = '-';

      break;

  }

    }

    *cp = '\0';

    return dst;

}

/*

 * Parse 36-byte uuid string into a 16-byte binary uuid.

 * Returns 0 on success, -1 if str is not a valid uuid.

 */

int

sudo_uuid_from_string_v1(const char *str, unsigned char uuid[static 16])

{

    unsigned int i = 0, j = 0;

    int ch;

    if (strlen(str) != 36)

  return -1;

    /* Parse a uuid in the format 123e4567-e89b-12d3-a456-426655440000 */

    while (i < 36) {

  switch (i) {

  case 8: case 13: case 18: case 23:

      if (str[i] != '-')

    return -1;

      i++;

      FALLTHROUGH;

  default:

      ch = sudo_hexchar(str + i);

      if (ch == -1)

    return -1;

      uuid[j++] = ch;

      i += 2;

  }

    }

    return 0;

}