luks.c revision 2603474ff9be2418900581da1af5cccc9f13cae1
/*
* volume_id - reads filesystem label and uuid
*
* Copyright (C) 2005 W. Michael Petullo <mike@flyn.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation version 2 of the License.
*/
#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1
#endif
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include "libvolume_id.h"
#include "libvolume_id-private.h"
#include "util.h"
#define SECTOR_SHIFT 9
#define SECTOR_SIZE (1 << SECTOR_SHIFT)
#define LUKS_CIPHERNAME_L 32
#define LUKS_CIPHERMODE_L 32
#define LUKS_HASHSPEC_L 32
#define LUKS_DIGESTSIZE 20
#define LUKS_SALTSIZE 32
#define LUKS_NUMKEYS 8
#define LUKS_MAGIC_L 6
#define LUKS_PHDR_SIZE (sizeof(struct luks_phdr)/SECTOR_SIZE+1)
#define UUID_STRING_L 40
static const uint8_t LUKS_MAGIC[] = {'L','U','K','S', 0xba, 0xbe};
struct luks_phdr {
uint8_t magic[LUKS_MAGIC_L];
uint16_t version;
uint8_t cipherName[LUKS_CIPHERNAME_L];
uint8_t cipherMode[LUKS_CIPHERMODE_L];
uint8_t hashSpec[LUKS_HASHSPEC_L];
uint32_t payloadOffset;
uint32_t keyBytes;
uint8_t mkDigest[LUKS_DIGESTSIZE];
uint8_t mkDigestSalt[LUKS_SALTSIZE];
uint32_t mkDigestIterations;
uint8_t uuid[UUID_STRING_L];
struct {
uint32_t active;
uint32_t passwordIterations;
uint8_t passwordSalt[LUKS_SALTSIZE];
uint32_t keyMaterialOffset;
uint32_t stripes;
} keyblock[LUKS_NUMKEYS];
};
int volume_id_probe_luks(struct volume_id *id, uint64_t off, uint64_t size)
{
struct luks_phdr *header;
header = (struct luks_phdr*) volume_id_get_buffer(id, off, LUKS_PHDR_SIZE);
if (header == NULL)
return -1;
if (memcmp(header->magic, LUKS_MAGIC, LUKS_MAGIC_L))
return -1;
volume_id_set_usage(id, VOLUME_ID_CRYPTO);
volume_id_set_uuid(id, header->uuid, 36, UUID_HEX_STRING);
snprintf(id->type_version, sizeof(header->version), "%u", le16_to_cpu(header->version));
id->type = "crypto_LUKS";
return 0;
}