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:
  24 //config:config FEATURE_VOLUMEID_LUKS
  25 //config:       bool "luks filesystem"
  26 //config:       default y
  27 //config:       depends on VOLUMEID
  28 //config:       help
  29 //config:         TODO
  30 //config:
  31
  32 #include "volume_id_internal.h"
  33
  34 #define LUKS_MAGIC_L             6
  35 #define UUID_STRING_L           40
  36 #define LUKS_CIPHERNAME_L       32
  37 #define LUKS_CIPHERMODE_L       32
  38 #define LUKS_HASHSPEC_L         32
  39 #define LUKS_DIGESTSIZE         20
  40 #define LUKS_SALTSIZE           32
  41 #define LUKS_NUMKEYS             8
  42
  43 static const uint8_t LUKS_MAGIC[] = { 'L','U','K','S', 0xba, 0xbe };
  44
  45 struct luks_phdr {
  46         uint8_t         magic[LUKS_MAGIC_L];
  47         uint16_t        version;
  48         uint8_t         cipherName[LUKS_CIPHERNAME_L];
  49         uint8_t         cipherMode[LUKS_CIPHERMODE_L];
  50         uint8_t         hashSpec[LUKS_HASHSPEC_L];
  51         uint32_t        payloadOffset;
  52         uint32_t        keyBytes;
  53         uint8_t         mkDigest[LUKS_DIGESTSIZE];
  54         uint8_t         mkDigestSalt[LUKS_SALTSIZE];
  55         uint32_t        mkDigestIterations;
  56         uint8_t         uuid[UUID_STRING_L];
  57         struct {
  58                 uint32_t        active;
  59                 uint32_t        passwordIterations;
  60                 uint8_t         passwordSalt[LUKS_SALTSIZE];
  61                 uint32_t        keyMaterialOffset;
  62                 uint32_t        stripes;
  63         } keyblock[LUKS_NUMKEYS];
  64 };
  65
  66 enum {
  67         EXPECTED_SIZE_luks_phdr = 0
  68                 + 1 * LUKS_MAGIC_L
  69                 + 2
  70                 + 1 * LUKS_CIPHERNAME_L
  71                 + 1 * LUKS_CIPHERMODE_L
  72                 + 1 * LUKS_HASHSPEC_L
  73                 + 4
  74                 + 4
  75                 + 1 * LUKS_DIGESTSIZE
  76                 + 1 * LUKS_SALTSIZE
  77                 + 4
  78                 + 1 * UUID_STRING_L
  79                 + LUKS_NUMKEYS * (0
  80                   + 4
  81                   + 4
  82                   + 1 * LUKS_SALTSIZE
  83                   + 4
  84                   + 4
  85                   )
  86 };
  87
  88 struct BUG_bad_size_luks_phdr {
  89         char BUG_bad_size_luks_phdr[
  90                 sizeof(struct luks_phdr) == EXPECTED_SIZE_luks_phdr ?
  91                 1 : -1];
  92 };
  93
  94 int FAST_FUNC volume_id_probe_luks(struct volume_id *id /*,uint64_t off*/)
  95 {
  96 #define off ((uint64_t)0)
  97         struct luks_phdr *header;
  98
  99         header = volume_id_get_buffer(id, off, sizeof(*header));
 100         if (header == NULL)
 101                 return -1;
 102
 103         if (memcmp(header->magic, LUKS_MAGIC, LUKS_MAGIC_L))
 104                 return -1;
 105
 106 //      volume_id_set_usage(id, VOLUME_ID_CRYPTO);
 107         volume_id_set_uuid(id, header->uuid, UUID_DCE_STRING);
 108         IF_FEATURE_BLKID_TYPE(id->type = "crypto_LUKS";)
 109
 110         return 0;
 111 }