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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* ASN.1 Object identifier (OID) registry
3 *
4 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#include <linux/module.h>
9#include <linux/export.h>
10#include <linux/oid_registry.h>
11#include <linux/kernel.h>
12#include <linux/errno.h>
13#include <linux/bug.h>
14#include "oid_registry_data.c"
15
16MODULE_DESCRIPTION("OID Registry");
17MODULE_AUTHOR("Red Hat, Inc.");
18MODULE_LICENSE("GPL");
19
20/**
21 * look_up_OID - Find an OID registration for the specified data
22 * @data: Binary representation of the OID
23 * @datasize: Size of the binary representation
24 */
25enum OID look_up_OID(const void *data, size_t datasize)
26{
27 const unsigned char *octets = data;
28 enum OID oid;
29 unsigned char xhash;
30 unsigned i, j, k, hash;
31 size_t len;
32
33 /* Hash the OID data */
34 hash = datasize - 1;
35
36 for (i = 0; i < datasize; i++)
37 hash += octets[i] * 33;
38 hash = (hash >> 24) ^ (hash >> 16) ^ (hash >> 8) ^ hash;
39 hash &= 0xff;
40
41 /* Binary search the OID registry. OIDs are stored in ascending order
42 * of hash value then ascending order of size and then in ascending
43 * order of reverse value.
44 */
45 i = 0;
46 k = OID__NR;
47 while (i < k) {
48 j = (i + k) / 2;
49
50 xhash = oid_search_table[j].hash;
51 if (xhash > hash) {
52 k = j;
53 continue;
54 }
55 if (xhash < hash) {
56 i = j + 1;
57 continue;
58 }
59
60 oid = oid_search_table[j].oid;
61 len = oid_index[oid + 1] - oid_index[oid];
62 if (len > datasize) {
63 k = j;
64 continue;
65 }
66 if (len < datasize) {
67 i = j + 1;
68 continue;
69 }
70
71 /* Variation is most likely to be at the tail end of the
72 * OID, so do the comparison in reverse.
73 */
74 while (len > 0) {
75 unsigned char a = oid_data[oid_index[oid] + --len];
76 unsigned char b = octets[len];
77 if (a > b) {
78 k = j;
79 goto next;
80 }
81 if (a < b) {
82 i = j + 1;
83 goto next;
84 }
85 }
86 return oid;
87 next:
88 ;
89 }
90
91 return OID__NR;
92}
93EXPORT_SYMBOL_GPL(look_up_OID);
94
95/*
96 * sprint_OID - Print an Object Identifier into a buffer
97 * @data: The encoded OID to print
98 * @datasize: The size of the encoded OID
99 * @buffer: The buffer to render into
100 * @bufsize: The size of the buffer
101 *
102 * The OID is rendered into the buffer in "a.b.c.d" format and the number of
103 * bytes is returned. -EBADMSG is returned if the data could not be intepreted
104 * and -ENOBUFS if the buffer was too small.
105 */
106int sprint_oid(const void *data, size_t datasize, char *buffer, size_t bufsize)
107{
108 const unsigned char *v = data, *end = v + datasize;
109 unsigned long num;
110 unsigned char n;
111 size_t ret;
112 int count;
113
114 if (v >= end)
115 goto bad;
116
117 n = *v++;
118 ret = count = snprintf(buffer, bufsize, "%u.%u", n / 40, n % 40);
119 if (count >= bufsize)
120 return -ENOBUFS;
121 buffer += count;
122 bufsize -= count;
123
124 while (v < end) {
125 num = 0;
126 n = *v++;
127 if (!(n & 0x80)) {
128 num = n;
129 } else {
130 num = n & 0x7f;
131 do {
132 if (v >= end)
133 goto bad;
134 n = *v++;
135 num <<= 7;
136 num |= n & 0x7f;
137 } while (n & 0x80);
138 }
139 ret += count = snprintf(buffer, bufsize, ".%lu", num);
140 if (count >= bufsize)
141 return -ENOBUFS;
142 buffer += count;
143 bufsize -= count;
144 }
145
146 return ret;
147
148bad:
149 snprintf(buffer, bufsize, "(bad)");
150 return -EBADMSG;
151}
152EXPORT_SYMBOL_GPL(sprint_oid);
153
154/**
155 * sprint_OID - Print an Object Identifier into a buffer
156 * @oid: The OID to print
157 * @buffer: The buffer to render into
158 * @bufsize: The size of the buffer
159 *
160 * The OID is rendered into the buffer in "a.b.c.d" format and the number of
161 * bytes is returned.
162 */
163int sprint_OID(enum OID oid, char *buffer, size_t bufsize)
164{
165 int ret;
166
167 BUG_ON(oid >= OID__NR);
168
169 ret = sprint_oid(oid_data + oid_index[oid],
170 oid_index[oid + 1] - oid_index[oid],
171 buffer, bufsize);
172 BUG_ON(ret == -EBADMSG);
173 return ret;
174}
175EXPORT_SYMBOL_GPL(sprint_OID);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* ASN.1 Object identifier (OID) registry
3 *
4 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#include <linux/module.h>
9#include <linux/export.h>
10#include <linux/oid_registry.h>
11#include <linux/kernel.h>
12#include <linux/errno.h>
13#include <linux/bug.h>
14#include <linux/asn1.h>
15#include "oid_registry_data.c"
16
17MODULE_DESCRIPTION("OID Registry");
18MODULE_AUTHOR("Red Hat, Inc.");
19MODULE_LICENSE("GPL");
20
21/**
22 * look_up_OID - Find an OID registration for the specified data
23 * @data: Binary representation of the OID
24 * @datasize: Size of the binary representation
25 */
26enum OID look_up_OID(const void *data, size_t datasize)
27{
28 const unsigned char *octets = data;
29 enum OID oid;
30 unsigned char xhash;
31 unsigned i, j, k, hash;
32 size_t len;
33
34 /* Hash the OID data */
35 hash = datasize - 1;
36
37 for (i = 0; i < datasize; i++)
38 hash += octets[i] * 33;
39 hash = (hash >> 24) ^ (hash >> 16) ^ (hash >> 8) ^ hash;
40 hash &= 0xff;
41
42 /* Binary search the OID registry. OIDs are stored in ascending order
43 * of hash value then ascending order of size and then in ascending
44 * order of reverse value.
45 */
46 i = 0;
47 k = OID__NR;
48 while (i < k) {
49 j = (i + k) / 2;
50
51 xhash = oid_search_table[j].hash;
52 if (xhash > hash) {
53 k = j;
54 continue;
55 }
56 if (xhash < hash) {
57 i = j + 1;
58 continue;
59 }
60
61 oid = oid_search_table[j].oid;
62 len = oid_index[oid + 1] - oid_index[oid];
63 if (len > datasize) {
64 k = j;
65 continue;
66 }
67 if (len < datasize) {
68 i = j + 1;
69 continue;
70 }
71
72 /* Variation is most likely to be at the tail end of the
73 * OID, so do the comparison in reverse.
74 */
75 while (len > 0) {
76 unsigned char a = oid_data[oid_index[oid] + --len];
77 unsigned char b = octets[len];
78 if (a > b) {
79 k = j;
80 goto next;
81 }
82 if (a < b) {
83 i = j + 1;
84 goto next;
85 }
86 }
87 return oid;
88 next:
89 ;
90 }
91
92 return OID__NR;
93}
94EXPORT_SYMBOL_GPL(look_up_OID);
95
96/**
97 * parse_OID - Parse an OID from a bytestream
98 * @data: Binary representation of the header + OID
99 * @datasize: Size of the binary representation
100 * @oid: Pointer to oid to return result
101 *
102 * Parse an OID from a bytestream that holds the OID in the format
103 * ASN1_OID | length | oid. The length indicator must equal to datasize - 2.
104 * -EBADMSG is returned if the bytestream is too short.
105 */
106int parse_OID(const void *data, size_t datasize, enum OID *oid)
107{
108 const unsigned char *v = data;
109
110 /* we need 2 bytes of header and at least 1 byte for oid */
111 if (datasize < 3 || v[0] != ASN1_OID || v[1] != datasize - 2)
112 return -EBADMSG;
113
114 *oid = look_up_OID(data + 2, datasize - 2);
115 return 0;
116}
117EXPORT_SYMBOL_GPL(parse_OID);
118
119/*
120 * sprint_OID - Print an Object Identifier into a buffer
121 * @data: The encoded OID to print
122 * @datasize: The size of the encoded OID
123 * @buffer: The buffer to render into
124 * @bufsize: The size of the buffer
125 *
126 * The OID is rendered into the buffer in "a.b.c.d" format and the number of
127 * bytes is returned. -EBADMSG is returned if the data could not be interpreted
128 * and -ENOBUFS if the buffer was too small.
129 */
130int sprint_oid(const void *data, size_t datasize, char *buffer, size_t bufsize)
131{
132 const unsigned char *v = data, *end = v + datasize;
133 unsigned long num;
134 unsigned char n;
135 size_t ret;
136 int count;
137
138 if (v >= end)
139 goto bad;
140
141 n = *v++;
142 ret = count = snprintf(buffer, bufsize, "%u.%u", n / 40, n % 40);
143 if (count >= bufsize)
144 return -ENOBUFS;
145 buffer += count;
146 bufsize -= count;
147
148 while (v < end) {
149 n = *v++;
150 if (!(n & 0x80)) {
151 num = n;
152 } else {
153 num = n & 0x7f;
154 do {
155 if (v >= end)
156 goto bad;
157 n = *v++;
158 num <<= 7;
159 num |= n & 0x7f;
160 } while (n & 0x80);
161 }
162 ret += count = snprintf(buffer, bufsize, ".%lu", num);
163 if (count >= bufsize)
164 return -ENOBUFS;
165 buffer += count;
166 bufsize -= count;
167 }
168
169 return ret;
170
171bad:
172 snprintf(buffer, bufsize, "(bad)");
173 return -EBADMSG;
174}
175EXPORT_SYMBOL_GPL(sprint_oid);
176
177/**
178 * sprint_OID - Print an Object Identifier into a buffer
179 * @oid: The OID to print
180 * @buffer: The buffer to render into
181 * @bufsize: The size of the buffer
182 *
183 * The OID is rendered into the buffer in "a.b.c.d" format and the number of
184 * bytes is returned.
185 */
186int sprint_OID(enum OID oid, char *buffer, size_t bufsize)
187{
188 int ret;
189
190 BUG_ON(oid >= OID__NR);
191
192 ret = sprint_oid(oid_data + oid_index[oid],
193 oid_index[oid + 1] - oid_index[oid],
194 buffer, bufsize);
195 BUG_ON(ret == -EBADMSG);
196 return ret;
197}
198EXPORT_SYMBOL_GPL(sprint_OID);