util-linux/volume_id/luks.c

   1 /*
   2  * volume_id - reads filesystem label and uuid
   3  *
   4  * Copyright (C) 2005 W. Michael Petullo <mike@flyn.org>
   5  *
   6  *      This library is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU Lesser General Public
   8  *      License as published by the Free Software Foundation; either
   9  *      version 2.1 of the License, or (at your option) any later version.
  10  *
  11  *      This library is distributed in the hope that it will be useful,
  12  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14  *      Lesser General Public License for more details.
  15  *
  16  *      You should have received a copy of the GNU Lesser General Public
  17  *      License along with this library; if not, write to the Free Software
  18  *      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  */
  20
  21 #include "volume_id_internal.h"
  22
  23 #define LUKS_MAGIC_L             6
  24 #define UUID_STRING_L           40
  25 #define LUKS_CIPHERNAME_L       32
  26 #define LUKS_CIPHERMODE_L       32
  27 #define LUKS_HASHSPEC_L         32
  28 #define LUKS_DIGESTSIZE         20
  29 #define LUKS_SALTSIZE           32
  30 #define LUKS_NUMKEYS             8
  31
  32 static const uint8_t LUKS_MAGIC[] = { 'L','U','K','S', 0xba, 0xbe };
  33
  34 struct luks_phdr {
  35         uint8_t         magic[LUKS_MAGIC_L];
  36         uint16_t        version;
  37         uint8_t         cipherName[LUKS_CIPHERNAME_L];
  38         uint8_t         cipherMode[LUKS_CIPHERMODE_L];
  39         uint8_t         hashSpec[LUKS_HASHSPEC_L];
  40         uint32_t        payloadOffset;
  41         uint32_t        keyBytes;
  42         uint8_t         mkDigest[LUKS_DIGESTSIZE];
  43         uint8_t         mkDigestSalt[LUKS_SALTSIZE];
  44         uint32_t        mkDigestIterations;
  45         uint8_t         uuid[UUID_STRING_L];
  46         struct {
  47                 uint32_t        active;
  48                 uint32_t        passwordIterations;
  49                 uint8_t         passwordSalt[LUKS_SALTSIZE];
  50                 uint32_t        keyMaterialOffset;
  51                 uint32_t        stripes;
  52         } keyblock[LUKS_NUMKEYS];
  53 };
  54
  55 enum {
  56         EXPECTED_SIZE_luks_phdr = 0
  57                 + 1 * LUKS_MAGIC_L
  58                 + 2
  59                 + 1 * LUKS_CIPHERNAME_L
  60                 + 1 * LUKS_CIPHERMODE_L
  61                 + 1 * LUKS_HASHSPEC_L
  62                 + 4
  63                 + 4
  64                 + 1 * LUKS_DIGESTSIZE
  65                 + 1 * LUKS_SALTSIZE
  66                 + 4
  67                 + 1 * UUID_STRING_L
  68                 + LUKS_NUMKEYS * (0
  69                   + 4
  70                   + 4
  71                   + 1 * LUKS_SALTSIZE
  72                   + 4
  73                   + 4
  74                   )
  75 };
  76
  77 struct BUG_bad_size_luks_phdr {
  78         char BUG_bad_size_luks_phdr[
  79                 sizeof(struct luks_phdr) == EXPECTED_SIZE_luks_phdr ?
  80                 1 : -1];
  81 };
  82
  83 int volume_id_probe_luks(struct volume_id *id /*,uint64_t off*/)
  84 {
  85 #define off ((uint64_t)0)
  86         struct luks_phdr *header;
  87
  88         header = volume_id_get_buffer(id, off, sizeof(*header));
  89         if (header == NULL)
  90                 return -1;
  91
  92         if (memcmp(header->magic, LUKS_MAGIC, LUKS_MAGIC_L))
  93                 return -1;
  94
  95 //      volume_id_set_usage(id, VOLUME_ID_CRYPTO);
  96         volume_id_set_uuid(id, header->uuid, UUID_DCE_STRING);
  97 //      id->type = "crypto_LUKS";
  98
  99         return 0;
 100 }