summaryrefslogtreecommitdiff
path: root/Common/Fat.c
diff options
context:
space:
mode:
Diffstat (limited to 'Common/Fat.c')
-rw-r--r--Common/Fat.c445
1 files changed, 445 insertions, 0 deletions
diff --git a/Common/Fat.c b/Common/Fat.c
new file mode 100644
index 0000000..168e471
--- /dev/null
+++ b/Common/Fat.c
@@ -0,0 +1,445 @@
+/*
+ Legal Notice: Some portions of the source code contained in this file were
+ derived from the source code of Encryption for the Masses 2.02a, which is
+ Copyright (c) 1998-2000 Paul Le Roux and which is governed by the 'License
+ Agreement for Encryption for the Masses'. Modifications and additions to
+ the original source code (contained in this file) and all other portions
+ of this file are Copyright (c) 2003-2010 TrueCrypt Developers Association
+ and are governed by the TrueCrypt License 3.0 the full text of which is
+ contained in the file License.txt included in TrueCrypt binary and source
+ code distribution packages. */
+
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include "Tcdefs.h"
+
+#include "Crypto.h"
+#include "Common/Endian.h"
+#include "Format.h"
+#include "Fat.h"
+#include "Progress.h"
+#include "Random.h"
+#include "Volumes.h"
+
+void
+GetFatParams (fatparams * ft)
+{
+ uint64 volumeSize = (uint64) ft->num_sectors * ft->sector_size;
+ unsigned int fatsecs;
+
+ if(ft->cluster_size == 0) // 'Default' cluster size
+ {
+ uint32 clusterSize;
+
+ // Determine optimal cluster size to minimize FAT size (mounting delay), maximize number of files, keep 4 KB alignment, etc.
+ if (volumeSize >= 2 * BYTES_PER_TB)
+ clusterSize = 256 * BYTES_PER_KB;
+ else if (volumeSize >= 512 * BYTES_PER_GB)
+ clusterSize = 128 * BYTES_PER_KB;
+ else if (volumeSize >= 128 * BYTES_PER_GB)
+ clusterSize = 64 * BYTES_PER_KB;
+ else if (volumeSize >= 64 * BYTES_PER_GB)
+ clusterSize = 32 * BYTES_PER_KB;
+ else if (volumeSize >= 32 * BYTES_PER_GB)
+ clusterSize = 16 * BYTES_PER_KB;
+ else if (volumeSize >= 16 * BYTES_PER_GB)
+ clusterSize = 8 * BYTES_PER_KB;
+ else if (volumeSize >= 512 * BYTES_PER_MB)
+ clusterSize = 4 * BYTES_PER_KB;
+ else if (volumeSize >= 256 * BYTES_PER_MB)
+ clusterSize = 2 * BYTES_PER_KB;
+ else if (volumeSize >= 1 * BYTES_PER_MB)
+ clusterSize = 1 * BYTES_PER_KB;
+ else
+ clusterSize = 512;
+
+ ft->cluster_size = clusterSize / ft->sector_size;
+
+ if (ft->cluster_size == 0)
+ ft->cluster_size = 1;
+
+ if (ft->cluster_size * ft->sector_size > TC_MAX_FAT_CLUSTER_SIZE)
+ ft->cluster_size = TC_MAX_FAT_CLUSTER_SIZE / ft->sector_size;
+
+ if (ft->cluster_size > 128)
+ ft->cluster_size = 128;
+ }
+
+ if (volumeSize <= TC_MAX_FAT_CLUSTER_SIZE * 4)
+ ft->cluster_size = 1;
+
+ // Geometry always set to SECTORS/1/1
+ ft->secs_track = 1;
+ ft->heads = 1;
+
+ ft->dir_entries = 512;
+ ft->fats = 2;
+ ft->media = 0xf8;
+ ft->hidden = 0;
+
+ ft->size_root_dir = ft->dir_entries * 32;
+
+ // FAT12
+ ft->size_fat = 12;
+ ft->reserved = 2;
+ fatsecs = ft->num_sectors - (ft->size_root_dir + ft->sector_size - 1) / ft->sector_size - ft->reserved;
+ ft->cluster_count = (int) (((__int64) fatsecs * ft->sector_size) / (ft->cluster_size * ft->sector_size));
+ ft->fat_length = (((ft->cluster_count * 3 + 1) >> 1) + ft->sector_size - 1) / ft->sector_size;
+
+ if (ft->cluster_count >= 4085) // FAT16
+ {
+ ft->size_fat = 16;
+ ft->reserved = 2;
+ fatsecs = ft->num_sectors - (ft->size_root_dir + ft->sector_size - 1) / ft->sector_size - ft->reserved;
+ ft->cluster_count = (int) (((__int64) fatsecs * ft->sector_size) / (ft->cluster_size * ft->sector_size));
+ ft->fat_length = (ft->cluster_count * 2 + ft->sector_size - 1) / ft->sector_size;
+ }
+
+ if(ft->cluster_count >= 65525) // FAT32
+ {
+ ft->size_fat = 32;
+ ft->reserved = 32 - 1;
+
+ do
+ {
+ ft->reserved++;
+
+ fatsecs = ft->num_sectors - ft->reserved;
+ ft->size_root_dir = ft->cluster_size * ft->sector_size;
+ ft->cluster_count = (int) (((__int64) fatsecs * ft->sector_size) / (ft->cluster_size * ft->sector_size));
+ ft->fat_length = (ft->cluster_count * 4 + ft->sector_size - 1) / ft->sector_size;
+
+ // Align data area on TC_MAX_VOLUME_SECTOR_SIZE
+
+ } while (ft->sector_size == TC_SECTOR_SIZE_LEGACY
+ && (ft->reserved * ft->sector_size + ft->fat_length * ft->fats * ft->sector_size) % TC_MAX_VOLUME_SECTOR_SIZE != 0);
+ }
+
+ ft->cluster_count -= ft->fat_length * ft->fats / ft->cluster_size;
+
+ if (ft->num_sectors >= 65536 || ft->size_fat == 32)
+ {
+ ft->sectors = 0;
+ ft->total_sect = ft->num_sectors;
+ }
+ else
+ {
+ ft->sectors = (uint16) ft->num_sectors;
+ ft->total_sect = 0;
+ }
+}
+
+void
+PutBoot (fatparams * ft, unsigned char *boot)
+{
+ int cnt = 0;
+
+ boot[cnt++] = 0xeb; /* boot jump */
+ boot[cnt++] = 0x3c;
+ boot[cnt++] = 0x90;
+ memcpy (boot + cnt, "MSDOS5.0", 8); /* system id */
+ cnt += 8;
+ *(__int16 *)(boot + cnt) = LE16(ft->sector_size); /* bytes per sector */
+ cnt += 2;
+ boot[cnt++] = (__int8) ft->cluster_size; /* sectors per cluster */
+ *(__int16 *)(boot + cnt) = LE16(ft->reserved); /* reserved sectors */
+ cnt += 2;
+ boot[cnt++] = (__int8) ft->fats; /* 2 fats */
+
+ if(ft->size_fat == 32)
+ {
+ boot[cnt++] = 0x00;
+ boot[cnt++] = 0x00;
+ }
+ else
+ {
+ *(__int16 *)(boot + cnt) = LE16(ft->dir_entries); /* 512 root entries */
+ cnt += 2;
+ }
+
+ *(__int16 *)(boot + cnt) = LE16(ft->sectors); /* # sectors */
+ cnt += 2;
+ boot[cnt++] = (__int8) ft->media; /* media byte */
+
+ if(ft->size_fat == 32)
+ {
+ boot[cnt++] = 0x00;
+ boot[cnt++] = 0x00;
+ }
+ else
+ {
+ *(__int16 *)(boot + cnt) = LE16((uint16) ft->fat_length); /* fat size */
+ cnt += 2;
+ }
+
+ *(__int16 *)(boot + cnt) = LE16(ft->secs_track); /* # sectors per track */
+ cnt += 2;
+ *(__int16 *)(boot + cnt) = LE16(ft->heads); /* # heads */
+ cnt += 2;
+ *(__int32 *)(boot + cnt) = LE32(ft->hidden); /* # hidden sectors */
+ cnt += 4;
+ *(__int32 *)(boot + cnt) = LE32(ft->total_sect); /* # huge sectors */
+ cnt += 4;
+
+ if(ft->size_fat == 32)
+ {
+ *(__int32 *)(boot + cnt) = LE32(ft->fat_length); cnt += 4; /* fat size 32 */
+ boot[cnt++] = 0x00; /* ExtFlags */
+ boot[cnt++] = 0x00;
+ boot[cnt++] = 0x00; /* FSVer */
+ boot[cnt++] = 0x00;
+ boot[cnt++] = 0x02; /* RootClus */
+ boot[cnt++] = 0x00;
+ boot[cnt++] = 0x00;
+ boot[cnt++] = 0x00;
+ boot[cnt++] = 0x01; /* FSInfo */
+ boot[cnt++] = 0x00;
+ boot[cnt++] = 0x06; /* BkBootSec */
+ boot[cnt++] = 0x00;
+ memset(boot+cnt, 0, 12); cnt+=12; /* Reserved */
+ }
+
+ boot[cnt++] = 0x00; /* drive number */ // FIXED 80 > 00
+ boot[cnt++] = 0x00; /* reserved */
+ boot[cnt++] = 0x29; /* boot sig */
+
+ memcpy (boot + cnt, ft->volume_id, 4); /* vol id */
+ cnt += 4;
+
+ memcpy (boot + cnt, ft->volume_name, 11); /* vol title */
+ cnt += 11;
+
+ switch(ft->size_fat) /* filesystem type */
+ {
+ case 12: memcpy (boot + cnt, "FAT12 ", 8); break;
+ case 16: memcpy (boot + cnt, "FAT16 ", 8); break;
+ case 32: memcpy (boot + cnt, "FAT32 ", 8); break;
+ }
+ cnt += 8;
+
+ memset (boot + cnt, 0, ft->size_fat==32 ? 420:448); /* boot code */
+ cnt += ft->size_fat==32 ? 420:448;
+ boot[cnt++] = 0x55;
+ boot[cnt++] = 0xaa; /* boot sig */
+}
+
+
+/* FAT32 FSInfo */
+static void PutFSInfo (unsigned char *sector, fatparams *ft)
+{
+ memset (sector, 0, ft->sector_size);
+ sector[3]=0x41; /* LeadSig */
+ sector[2]=0x61;
+ sector[1]=0x52;
+ sector[0]=0x52;
+ sector[484+3]=0x61; /* StrucSig */
+ sector[484+2]=0x41;
+ sector[484+1]=0x72;
+ sector[484+0]=0x72;
+
+ // Free cluster count
+ *(uint32 *)(sector + 488) = LE32 (ft->cluster_count - ft->size_root_dir / ft->sector_size / ft->cluster_size);
+
+ // Next free cluster
+ *(uint32 *)(sector + 492) = LE32 (2);
+
+ sector[508+3]=0xaa; /* TrailSig */
+ sector[508+2]=0x55;
+ sector[508+1]=0x00;
+ sector[508+0]=0x00;
+}
+
+
+int
+FormatFat (unsigned __int64 startSector, fatparams * ft, void * dev, PCRYPTO_INFO cryptoInfo, BOOL quickFormat)
+{
+ int write_buf_cnt = 0;
+ char sector[TC_MAX_VOLUME_SECTOR_SIZE], *write_buf;
+ unsigned __int64 nSecNo = startSector;
+ int x, n;
+ int retVal;
+ char temporaryKey[MASTER_KEYDATA_SIZE];
+
+ LARGE_INTEGER startOffset;
+ LARGE_INTEGER newOffset;
+
+ // Seek to start sector
+ startOffset.QuadPart = startSector * ft->sector_size;
+ if (!SetFilePointerEx ((HANDLE) dev, startOffset, &newOffset, FILE_BEGIN)
+ || newOffset.QuadPart != startOffset.QuadPart)
+ {
+ return ERR_VOL_SEEKING;
+ }
+
+ /* Write the data area */
+
+ write_buf = (char *)TCalloc (FormatWriteBufferSize);
+ if (!write_buf)
+ return ERR_OUTOFMEMORY;
+
+ memset (sector, 0, ft->sector_size);
+
+ RandgetBytes (ft->volume_id, sizeof (ft->volume_id), FALSE);
+
+ PutBoot (ft, (unsigned char *) sector);
+ if (WriteSector (dev, sector, write_buf, &write_buf_cnt, &nSecNo,
+ cryptoInfo) == FALSE)
+ goto fail;
+
+ /* fat32 boot area */
+ if (ft->size_fat == 32)
+ {
+ /* fsinfo */
+ PutFSInfo((unsigned char *) sector, ft);
+ if (WriteSector (dev, sector, write_buf, &write_buf_cnt, &nSecNo,
+ cryptoInfo) == FALSE)
+ goto fail;
+
+ /* reserved */
+ while (nSecNo - startSector < 6)
+ {
+ memset (sector, 0, ft->sector_size);
+ sector[508+3]=0xaa; /* TrailSig */
+ sector[508+2]=0x55;
+ if (WriteSector (dev, sector, write_buf, &write_buf_cnt, &nSecNo,
+ cryptoInfo) == FALSE)
+ goto fail;
+ }
+
+ /* bootsector backup */
+ memset (sector, 0, ft->sector_size);
+ PutBoot (ft, (unsigned char *) sector);
+ if (WriteSector (dev, sector, write_buf, &write_buf_cnt, &nSecNo,
+ cryptoInfo) == FALSE)
+ goto fail;
+
+ PutFSInfo((unsigned char *) sector, ft);
+ if (WriteSector (dev, sector, write_buf, &write_buf_cnt, &nSecNo,
+ cryptoInfo) == FALSE)
+ goto fail;
+ }
+
+ /* reserved */
+ while (nSecNo - startSector < (unsigned int)ft->reserved)
+ {
+ memset (sector, 0, ft->sector_size);
+ if (WriteSector (dev, sector, write_buf, &write_buf_cnt, &nSecNo,
+ cryptoInfo) == FALSE)
+ goto fail;
+ }
+
+ /* write fat */
+ for (x = 1; x <= ft->fats; x++)
+ {
+ for (n = 0; n < ft->fat_length; n++)
+ {
+ memset (sector, 0, ft->sector_size);
+
+ if (n == 0)
+ {
+ unsigned char fat_sig[12];
+ if (ft->size_fat == 32)
+ {
+ fat_sig[0] = (unsigned char) ft->media;
+ fat_sig[1] = fat_sig[2] = 0xff;
+ fat_sig[3] = 0x0f;
+ fat_sig[4] = fat_sig[5] = fat_sig[6] = 0xff;
+ fat_sig[7] = 0x0f;
+ fat_sig[8] = fat_sig[9] = fat_sig[10] = 0xff;
+ fat_sig[11] = 0x0f;
+ memcpy (sector, fat_sig, 12);
+ }
+ else if (ft->size_fat == 16)
+ {
+ fat_sig[0] = (unsigned char) ft->media;
+ fat_sig[1] = 0xff;
+ fat_sig[2] = 0xff;
+ fat_sig[3] = 0xff;
+ memcpy (sector, fat_sig, 4);
+ }
+ else if (ft->size_fat == 12)
+ {
+ fat_sig[0] = (unsigned char) ft->media;
+ fat_sig[1] = 0xff;
+ fat_sig[2] = 0xff;
+ fat_sig[3] = 0x00;
+ memcpy (sector, fat_sig, 4);
+ }
+ }
+
+ if (WriteSector (dev, sector, write_buf, &write_buf_cnt, &nSecNo,
+ cryptoInfo) == FALSE)
+ goto fail;
+ }
+ }
+
+
+ /* write rootdir */
+ for (x = 0; x < ft->size_root_dir / ft->sector_size; x++)
+ {
+ memset (sector, 0, ft->sector_size);
+ if (WriteSector (dev, sector, write_buf, &write_buf_cnt, &nSecNo,
+ cryptoInfo) == FALSE)
+ goto fail;
+
+ }
+
+ /* Fill the rest of the data area with random data */
+
+ if(!quickFormat)
+ {
+ if (!FlushFormatWriteBuffer (dev, write_buf, &write_buf_cnt, &nSecNo, cryptoInfo))
+ goto fail;
+
+ /* Generate a random temporary key set to be used for "dummy" encryption that will fill
+ the free disk space (data area) with random data. This is necessary for plausible
+ deniability of hidden volumes (and also reduces the amount of predictable plaintext
+ within the volume). */
+
+ // Temporary master key
+ if (!RandgetBytes (temporaryKey, EAGetKeySize (cryptoInfo->ea), FALSE))
+ goto fail;
+
+ // Temporary secondary key (XTS mode)
+ if (!RandgetBytes (cryptoInfo->k2, sizeof cryptoInfo->k2, FALSE))
+ goto fail;
+
+ retVal = EAInit (cryptoInfo->ea, temporaryKey, cryptoInfo->ks);
+ if (retVal != ERR_SUCCESS)
+ {
+ burn (temporaryKey, sizeof(temporaryKey));
+ return retVal;
+ }
+ if (!EAInitMode (cryptoInfo))
+ {
+ burn (temporaryKey, sizeof(temporaryKey));
+ return ERR_MODE_INIT_FAILED;
+ }
+
+ x = ft->num_sectors - ft->reserved - ft->size_root_dir / ft->sector_size - ft->fat_length * 2;
+ while (x--)
+ {
+ if (WriteSector (dev, sector, write_buf, &write_buf_cnt, &nSecNo,
+ cryptoInfo) == FALSE)
+ goto fail;
+ }
+ UpdateProgressBar (nSecNo * ft->sector_size);
+ }
+ else
+ UpdateProgressBar ((uint64) ft->num_sectors * ft->sector_size);
+
+ if (!FlushFormatWriteBuffer (dev, write_buf, &write_buf_cnt, &nSecNo, cryptoInfo))
+ goto fail;
+
+ TCfree (write_buf);
+ burn (temporaryKey, sizeof(temporaryKey));
+ return 0;
+
+fail:
+
+ TCfree (write_buf);
+ burn (temporaryKey, sizeof(temporaryKey));
+ return ERR_OS_ERROR;
+}