1 /*
2 * Universally Unique IDentifier (UUID)
3 * Copyright (c) 2008, Jouni Malinen <j@w1.fi>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9 #include "includes.h"
10
11 #include "common.h"
12 #include "crypto/sha256.h"
13 #include "uuid.h"
14
uuid_str2bin(const char * str,u8 * bin)15 int uuid_str2bin(const char *str, u8 *bin)
16 {
17 const char *pos;
18 u8 *opos;
19
20 pos = str;
21 opos = bin;
22
23 if (hexstr2bin(pos, opos, 4))
24 return -1;
25 pos += 8;
26 opos += 4;
27
28 if (*pos++ != '-' || hexstr2bin(pos, opos, 2))
29 return -1;
30 pos += 4;
31 opos += 2;
32
33 if (*pos++ != '-' || hexstr2bin(pos, opos, 2))
34 return -1;
35 pos += 4;
36 opos += 2;
37
38 if (*pos++ != '-' || hexstr2bin(pos, opos, 2))
39 return -1;
40 pos += 4;
41 opos += 2;
42
43 if (*pos++ != '-' || hexstr2bin(pos, opos, 6))
44 return -1;
45
46 return 0;
47 }
48
49
uuid_bin2str(const u8 * bin,char * str,size_t max_len)50 int uuid_bin2str(const u8 *bin, char *str, size_t max_len)
51 {
52 int len;
53 len = os_snprintf(str, max_len, "%02x%02x%02x%02x-%02x%02x-%02x%02x-"
54 "%02x%02x-%02x%02x%02x%02x%02x%02x",
55 bin[0], bin[1], bin[2], bin[3],
56 bin[4], bin[5], bin[6], bin[7],
57 bin[8], bin[9], bin[10], bin[11],
58 bin[12], bin[13], bin[14], bin[15]);
59 if (os_snprintf_error(max_len, len))
60 return -1;
61 return 0;
62 }
63
64
is_nil_uuid(const u8 * uuid)65 int is_nil_uuid(const u8 *uuid)
66 {
67 int i;
68 for (i = 0; i < UUID_LEN; i++)
69 if (uuid[i])
70 return 0;
71 return 1;
72 }
73
74
uuid_random(u8 * uuid)75 int uuid_random(u8 *uuid)
76 {
77 struct os_time t;
78 u8 hash[SHA256_MAC_LEN];
79
80 /* Use HMAC-SHA256 and timestamp as context to avoid exposing direct
81 * os_get_random() output in the UUID field. */
82 os_get_time(&t);
83 if (os_get_random(uuid, UUID_LEN) < 0 ||
84 hmac_sha256(uuid, UUID_LEN, (const u8 *) &t, sizeof(t), hash) < 0)
85 return -1;
86
87 os_memcpy(uuid, hash, UUID_LEN);
88
89 /* Version: 4 = random */
90 uuid[6] = (4 << 4) | (uuid[6] & 0x0f);
91
92 /* Variant specified in RFC 4122 */
93 uuid[8] = 0x80 | (uuid[8] & 0x3f);
94
95 return 0;
96 }
97