source: MondoRescue/branches/3.3/mindi-busybox/util-linux/volume_id/luks.c@ 3621

/*
 * volume_id - reads filesystem label and uuid
 *
 * Copyright (C) 2005 W. Michael Petullo <mike@flyn.org>
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

//kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_LUKS) += luks.o

//config:
//config:config FEATURE_VOLUMEID_LUKS
//config:   bool "luks filesystem"
//config:   default y
//config:   depends on VOLUMEID
//config:   help
//config:     TODO
//config:

#include "volume_id_internal.h"

#define LUKS_MAGIC_L             6
#define UUID_STRING_L           40
#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

static const uint8_t LUKS_MAGIC[] ALIGN1 = { '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];
};

enum {
    EXPECTED_SIZE_luks_phdr = 0
        + 1 * LUKS_MAGIC_L
        + 2
        + 1 * LUKS_CIPHERNAME_L
        + 1 * LUKS_CIPHERMODE_L
        + 1 * LUKS_HASHSPEC_L
        + 4
        + 4
        + 1 * LUKS_DIGESTSIZE
        + 1 * LUKS_SALTSIZE
        + 4
        + 1 * UUID_STRING_L
        + LUKS_NUMKEYS * (0
          + 4
          + 4
          + 1 * LUKS_SALTSIZE
          + 4
          + 4
          )
};

struct BUG_bad_size_luks_phdr {
    char BUG_bad_size_luks_phdr[
        sizeof(struct luks_phdr) == EXPECTED_SIZE_luks_phdr ?
        1 : -1];
};

int FAST_FUNC volume_id_probe_luks(struct volume_id *id /*,uint64_t off*/)
{
#define off ((uint64_t)0)
    struct luks_phdr *header;

    header = volume_id_get_buffer(id, off, sizeof(*header));
    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, UUID_DCE_STRING);
    IF_FEATURE_BLKID_TYPE(id->type = "crypto_LUKS";)

    return 0;
}