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