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 //kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_LUKS) += luks.o
  22
  23 //config:config FEATURE_VOLUMEID_LUKS
  24 //config:       bool "luks filesystem"
  25 //config:       default y
  26 //config:       depends on VOLUMEID
  27
  28 #include "volume_id_internal.h"
  29
  30 #define LUKS_MAGIC_L             6
  31 #define UUID_STRING_L           40
  32 #define LUKS_CIPHERNAME_L       32
  33 #define LUKS_CIPHERMODE_L       32
  34 #define LUKS_HASHSPEC_L         32
  35 #define LUKS_DIGESTSIZE         20
  36 #define LUKS_SALTSIZE           32
  37 #define LUKS_NUMKEYS             8
  38
  39 static const uint8_t LUKS_MAGIC[] ALIGN1 = { 'L','U','K','S', 0xba, 0xbe };
  40
  41 struct luks_phdr {
  42         uint8_t         magic[LUKS_MAGIC_L];
  43         uint16_t        version;
  44         uint8_t         cipherName[LUKS_CIPHERNAME_L];
  45         uint8_t         cipherMode[LUKS_CIPHERMODE_L];
  46         uint8_t         hashSpec[LUKS_HASHSPEC_L];
  47         uint32_t        payloadOffset;
  48         uint32_t        keyBytes;
  49         uint8_t         mkDigest[LUKS_DIGESTSIZE];
  50         uint8_t         mkDigestSalt[LUKS_SALTSIZE];
  51         uint32_t        mkDigestIterations;
  52         uint8_t         uuid[UUID_STRING_L];
  53         struct {
  54                 uint32_t        active;
  55                 uint32_t        passwordIterations;
  56                 uint8_t         passwordSalt[LUKS_SALTSIZE];
  57                 uint32_t        keyMaterialOffset;
  58                 uint32_t        stripes;
  59         } keyblock[LUKS_NUMKEYS];
  60 };
  61
  62 enum {
  63         EXPECTED_SIZE_luks_phdr = 0
  64                 + 1 * LUKS_MAGIC_L
  65                 + 2
  66                 + 1 * LUKS_CIPHERNAME_L
  67                 + 1 * LUKS_CIPHERMODE_L
  68                 + 1 * LUKS_HASHSPEC_L
  69                 + 4
  70                 + 4
  71                 + 1 * LUKS_DIGESTSIZE
  72                 + 1 * LUKS_SALTSIZE
  73                 + 4
  74                 + 1 * UUID_STRING_L
  75                 + LUKS_NUMKEYS * (0
  76                   + 4
  77                   + 4
  78                   + 1 * LUKS_SALTSIZE
  79                   + 4
  80                   + 4
  81                   )
  82 };
  83
  84 struct BUG_bad_size_luks_phdr {
  85         char BUG_bad_size_luks_phdr[
  86                 sizeof(struct luks_phdr) == EXPECTED_SIZE_luks_phdr ?
  87                 1 : -1];
  88 };
  89
  90 int FAST_FUNC volume_id_probe_luks(struct volume_id *id /*,uint64_t off*/)
  91 {
  92 #define off ((uint64_t)0)
  93         struct luks_phdr *header;
  94
  95         header = volume_id_get_buffer(id, off, sizeof(*header));
  96         if (header == NULL)
  97                 return -1;
  98
  99         if (memcmp(header->magic, LUKS_MAGIC, LUKS_MAGIC_L))
 100                 return -1;
 101
 102 //      volume_id_set_usage(id, VOLUME_ID_CRYPTO);
 103         volume_id_set_uuid(id, header->uuid, UUID_DCE_STRING);
 104         IF_FEATURE_BLKID_TYPE(id->type = "crypto_LUKS";)
 105
 106         return 0;
 107 }