1 /*
2 * SPDX-License-Identifier: ISC
3 *
4 * Copyright (c) 2020 Todd C. Miller <Todd.Miller@sudo.ws>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 /*
20 * This is an open source non-commercial project. Dear PVS-Studio, please check it.
21 * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
22 */
23
24 #include <config.h>
25
26 #include <stdlib.h>
27 #if defined(HAVE_STDINT_H)
28 # include <stdint.h>
29 #elif defined(HAVE_INTTYPES_H)
30 # include <inttypes.h>
31 #endif
32 #include <string.h>
33 #include <arpa/inet.h>
34
35 #include "sudo_compat.h"
36 #include "sudo_util.h"
37 #include "sudo_rand.h"
38
39 struct uuid {
40 uint32_t time_low;
41 uint16_t time_mid;
42 uint16_t time_hi_and_version;
43 uint8_t clock_seq_hi_and_reserved;
44 uint8_t clock_seq_low;
45 uint8_t node[6];
46 };
47
48 /*
49 * Create a type 4 (random), variant 1 universally unique identifier (UUID).
50 * As per RFC 4122 section 4.4.
51 */
52 void
sudo_uuid_create_v1(unsigned char uuid_out[16])53 sudo_uuid_create_v1(unsigned char uuid_out[16])
54 {
55 union {
56 struct uuid id;
57 unsigned char u8[16];
58 } uuid;
59
60 arc4random_buf(&uuid, sizeof(uuid));
61
62 /* Set version to 4 (random), 4 most significant bits (12-15) are 0010. */
63 uuid.id.time_hi_and_version &= 0x0fff;
64 uuid.id.time_hi_and_version |= 0x4000;
65
66 /* Set variant to 1: two most significant bits (6 and 7) are 01. */
67 uuid.id.clock_seq_hi_and_reserved &= 0x3f;
68 uuid.id.clock_seq_hi_and_reserved |= 0x80;
69
70 memcpy(uuid_out, &uuid, 16);
71 }
72
73 /*
74 * Format a uuid as a 36-byte string (plus one for the NUL).
75 */
76 char *
sudo_uuid_to_string_v1(unsigned char uuid[16],char * dst,size_t dstsiz)77 sudo_uuid_to_string_v1(unsigned char uuid[16], char *dst, size_t dstsiz)
78 {
79 const char hex[] = "0123456789abcdef";
80 char *cp = dst;
81 int i;
82
83 if (dstsiz < sizeof("123e4567-e89b-12d3-a456-426655440000"))
84 return NULL;
85
86 for (i = 0; i < 16; i++) {
87 *cp++ = hex[uuid[i] >> 4];
88 *cp++ = hex[uuid[i] & 0x0f];
89
90 switch (i) {
91 case 4:
92 case 6:
93 case 8:
94 case 10:
95 *cp++ = '-';
96 break;
97 }
98 }
99 *cp = '\0';
100
101 return dst;
102 }
103