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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176// 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);