sudo/lib/util/uuid.c

100 lines
2.6 KiB
C

/*
* SPDX-License-Identifier: ISC
*
* Copyright (c) 2020 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.
*/
/*
* This is an open source non-commercial project. Dear PVS-Studio, please check it.
* PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
*/
#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;
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 4:
case 6:
case 8:
case 10:
*cp++ = '-';
break;
}
}
*cp = '\0';
return dst;
}