xref: /openbmc/u-boot/lib/uuid.c (revision d718ded056eefb6239bd2e0a57b7f6d99c6e9e4b)
1 /*
2  * Copyright 2011 Calxeda, Inc.
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <linux/ctype.h>
8 #include <errno.h>
9 #include <common.h>
10 #include <asm/io.h>
11 #include <part_efi.h>
12 #include <malloc.h>
13 
14 /*
15  * UUID - Universally Unique IDentifier - 128 bits unique number.
16  *        There are 5 versions and one variant of UUID defined by RFC4122
17  *        specification. Depends on version uuid number base on a time,
18  *        host name, MAC address or random data.
19  *
20  * UUID binary format (16 bytes):
21  *
22  * 4B-2B-2B-2B-6B (big endian - network byte order)
23  *
24  * UUID string is 36 length of characters (36 bytes):
25  *
26  * 0        9    14   19   24
27  * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
28  *    be     be   be   be       be
29  *
30  * where x is a hexadecimal character. Fields are separated by '-'s.
31  * When converting to a binary UUID, le means the field should be converted
32  * to little endian and be means it should be converted to big endian.
33  *
34  * UUID is also used as GUID (Globally Unique Identifier) with the same binary
35  * format but it differs in string format like below.
36  *
37  * GUID:
38  * 0        9    14   19   24
39  * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
40  *    le     le   le   be       be
41  *
42  * GUID is used e.g. in GPT (GUID Partition Table) as a partiions unique id.
43  */
44 int uuid_str_valid(const char *uuid)
45 {
46 	int i, valid;
47 
48 	if (uuid == NULL)
49 		return 0;
50 
51 	for (i = 0, valid = 1; uuid[i] && valid; i++) {
52 		switch (i) {
53 		case 8: case 13: case 18: case 23:
54 			valid = (uuid[i] == '-');
55 			break;
56 		default:
57 			valid = isxdigit(uuid[i]);
58 			break;
59 		}
60 	}
61 
62 	if (i != UUID_STR_LEN || !valid)
63 		return 0;
64 
65 	return 1;
66 }
67 
68 /*
69  * uuid_str_to_bin() - convert string UUID or GUID to big endian binary data.
70  *
71  * @param uuid_str - pointer to UUID or GUID string [37B]
72  * @param uuid_bin - pointer to allocated array for big endian output [16B]
73  * @str_format     - UUID string format: 0 - UUID; 1 - GUID
74  */
75 int uuid_str_to_bin(char *uuid_str, unsigned char *uuid_bin, int str_format)
76 {
77 	uint16_t tmp16;
78 	uint32_t tmp32;
79 	uint64_t tmp64;
80 
81 	if (!uuid_str_valid(uuid_str))
82 		return -EINVAL;
83 
84 	if (str_format == UUID_STR_FORMAT_STD) {
85 		tmp32 = cpu_to_be32(simple_strtoul(uuid_str, NULL, 16));
86 		memcpy(uuid_bin, &tmp32, 4);
87 
88 		tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 9, NULL, 16));
89 		memcpy(uuid_bin + 4, &tmp16, 2);
90 
91 		tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 14, NULL, 16));
92 		memcpy(uuid_bin + 6, &tmp16, 2);
93 	} else {
94 		tmp32 = cpu_to_le32(simple_strtoul(uuid_str, NULL, 16));
95 		memcpy(uuid_bin, &tmp32, 4);
96 
97 		tmp16 = cpu_to_le16(simple_strtoul(uuid_str + 9, NULL, 16));
98 		memcpy(uuid_bin + 4, &tmp16, 2);
99 
100 		tmp16 = cpu_to_le16(simple_strtoul(uuid_str + 14, NULL, 16));
101 		memcpy(uuid_bin + 6, &tmp16, 2);
102 	}
103 
104 	tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 19, NULL, 16));
105 	memcpy(uuid_bin + 8, &tmp16, 2);
106 
107 	tmp64 = cpu_to_be64(simple_strtoull(uuid_str + 24, NULL, 16));
108 	memcpy(uuid_bin + 10, (char *)&tmp64 + 2, 6);
109 
110 	return 0;
111 }
112 
113 /*
114  * uuid_bin_to_str() - convert big endian binary data to string UUID or GUID.
115  *
116  * @param uuid_bin - pointer to binary data of UUID (big endian) [16B]
117  * @param uuid_str - pointer to allocated array for output string [37B]
118  * @str_format     - UUID string format: 0 - UUID; 1 - GUID
119  */
120 void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format)
121 {
122 	const u8 uuid_char_order[UUID_BIN_LEN] = {0, 1, 2, 3, 4, 5, 6, 7, 8,
123 						  9, 10, 11, 12, 13, 14, 15};
124 	const u8 guid_char_order[UUID_BIN_LEN] = {3, 2, 1, 0, 5, 4, 7, 6, 8,
125 						  9, 10, 11, 12, 13, 14, 15};
126 	const u8 *char_order;
127 	int i;
128 
129 	/*
130 	 * UUID and GUID bin data - always in big endian:
131 	 * 4B-2B-2B-2B-6B
132 	 * be be be be be
133 	 */
134 	if (str_format == UUID_STR_FORMAT_STD)
135 		char_order = uuid_char_order;
136 	else
137 		char_order = guid_char_order;
138 
139 	for (i = 0; i < 16; i++) {
140 		sprintf(uuid_str, "%02x", uuid_bin[char_order[i]]);
141 		uuid_str += 2;
142 		switch (i) {
143 		case 3:
144 		case 5:
145 		case 7:
146 		case 9:
147 			*uuid_str++ = '-';
148 			break;
149 		}
150 	}
151 }
152