diff options
| author | Mounir IDRASSI <mounir.idrassi@idrix.fr> | 2018-06-22 14:51:18 +0200 |
|---|---|---|
| committer | Mounir IDRASSI <mounir.idrassi@idrix.fr> | 2018-06-23 00:33:43 +0200 |
| commit | 0342ec53dea13d16115fdb44ddc74724d82519c3 (patch) | |
| tree | 784a321c550166ca556e83bdef29c44c3a77e681 /DcsCfg | |
| parent | 6db4cbaaffefd284f0ac056313a619594a5cbd04 (diff) | |
| download | VeraCrypt-DCS-0342ec53dea13d16115fdb44ddc74724d82519c3.tar.gz VeraCrypt-DCS-0342ec53dea13d16115fdb44ddc74724d82519c3.zip | |
Handle case of first sector unencrypted (e.g. because of Windows Repair) when performing decryption of system using rescue disk.
Diffstat (limited to 'DcsCfg')
| -rw-r--r-- | DcsCfg/DcsCfgCrypt.c | 211 |
1 files changed, 123 insertions, 88 deletions
diff --git a/DcsCfg/DcsCfgCrypt.c b/DcsCfg/DcsCfgCrypt.c index 0ca45ec..390f5ca 100644 --- a/DcsCfg/DcsCfgCrypt.c +++ b/DcsCfg/DcsCfgCrypt.c @@ -417,6 +417,10 @@ RangeCrypt( UINT64 remainsOnStart;
UINT64 pos;
UINTN rd;
+ BOOL bIsSystemEncyption = FALSE;
+
+ if (info->noIterations == get_pkcs5_iteration_count (info->pkcs5, info->volumePim, FALSE, TRUE))
+ bIsSystemEncyption = TRUE;
io = EfiGetBlockIO(disk);
if (!io) {
@@ -478,6 +482,13 @@ RangeCrypt( if (encrypt) {
EncryptDataUnits(buf, (UINT64_STRUCT*)&pos, (UINT32)(rd), info);
} else {
+ if (bIsSystemEncyption && (pos == start) && (0xEB52904E54465320 == BE64 (*(uint64 *) buf)))
+ {
+ // first sector is not encrypted (e.g. because of Windows repair).
+ // So we encrypt it so that decryption will lead to correct result
+ EncryptDataUnits(buf, (UINT64_STRUCT*)&pos, 1, info);
+ }
+
DecryptDataUnits(buf, (UINT64_STRUCT*)&pos, (UINT32)(rd), info);
}
@@ -560,90 +571,96 @@ RangeCrypt( RangeCryptProgress(size, remains, pos, remainsOnStart);
}
else if (!encrypt)
- {
- BOOL bIsSystemEncyption = FALSE;
- if (info->noIterations == get_pkcs5_iteration_count (info->pkcs5, info->volumePim, FALSE, TRUE))
- bIsSystemEncyption = TRUE;
-
+ {
if (bIsSystemEncyption)
{
- /*
- * Case of OS decryption by Rescue Disk
- * Check if NTFS marker exists. If not, then probably disk affected by
- * bug in 1.19 Rescue Disk which caused the first 50 MB of disk to be
- * decrypted in a wrong way. In this case, try to reverse the faulty decryption
- * and then perform correct decryption
- */
- remains = size % CRYPT_BUF_SECTORS;
- if (remains > 0)
- {
- /* 1.19 bug appears only when size not multiple of 50 MB */
- res = io->ReadBlocks(io, io->Media->MediaId, start, 512, buf);
- if (!EFI_ERROR(res)) {
- if (0xEB52904E54465320 != BE64 (*(uint64 *) buf)) /* NTFS */
+ res = io->ReadBlocks(io, io->Media->MediaId, start, 512, buf);
+ if (!EFI_ERROR(res)) {
+ /*
+ * Case of OS decryption by Rescue Disk
+ * Check if NTFS marker exists. If not, then probably disk affected by
+ * either Windows Repair overwriting first sector or the bug in 1.19
+ * Rescue Disk which caused the first 50 MB of disk to be
+ * decrypted in a wrong way. In this case, try to reverse the faulty decryption
+ * and then perform correct decryption
+ */
+ if (0xEB52904E54465320 != BE64 (*(uint64 *) buf)) /* NTFS */
+ {
+ /* encrypt it to see if the first sector was unencrypted before decrypt done */
+ EncryptDataUnits(buf, (UINT64_STRUCT*)&start, 1, info);
+
+ if (0xEB52904E54465320 == BE64 (*(uint64 *) buf)) /* NTFS */
{
- if (AskConfirm("\r\nSystem already decrypted but partition can't be recognized.\r\nDid you use 1.19 Rescue Disk previously to decrypt OS?", 1)) {
- OUT_PRINT(L"\r\nTrying to recover data corrupted by 1.19 Rescue Disk bug.");
-
- pos = start + remains - CRYPT_BUF_SECTORS;
- // Read
- do {
- res = io->ReadBlocks(io, io->Media->MediaId, pos, CRYPT_BUF_SECTORS << 9, buf);
- if (EFI_ERROR(res)) {
- UINT8 ar;
- ERR_PRINT(L"Read error: %r\n", res);
- ar = AskAR();
- if (ar != 'R' && ar != 'r')
- break;
- }
- } while (EFI_ERROR(res));
-
- if (EFI_ERROR(res))
- {
- OUT_PRINT(L"\r\nNo corrective action performed.");
+ // Write corrected first sector
+ do {
+ res = io->WriteBlocks(io, io->Media->MediaId, start, 512, buf);
+ if (EFI_ERROR(res)) {
+ UINT8 ar;
+ ERR_PRINT(L"Write error: %r\n", res);
+ ar = AskAR();
+ if (ar != 'R' && ar != 'r')
+ break;
}
- else
- {
- UINT8* realEncryptedData = buf + ((CRYPT_BUF_SECTORS - remains) << 9);
- BOOL bPerformWrite = FALSE;
+ } while (EFI_ERROR(res));
+
+ if (EFI_ERROR(res))
+ {
+ OUT_PRINT(L"\r\nThe corrected first sector could not be written.");
+ }
+ }
+ else
+ {
+ /* restore original value */
+ DecryptDataUnits(buf, (UINT64_STRUCT*)&start, 1, info);
- // reverse faulty decryption
- EncryptDataUnits(buf, (UINT64_STRUCT*)&pos, (UINT32)(remains), info);
+ remains = size % CRYPT_BUF_SECTORS;
+ if (remains > 0)
+ {
+ /* 1.19 bug appears only when size not multiple of 50 MB */
+ if (AskConfirm("\r\nSystem already decrypted but partition can't be recognized.\r\nDid you use 1.19 Rescue Disk previously to decrypt OS?", 1)) {
+ OUT_PRINT(L"\r\nTrying to recover data corrupted by 1.19 Rescue Disk bug.");
+
+ pos = start + remains - CRYPT_BUF_SECTORS;
+ // Read
+ do {
+ res = io->ReadBlocks(io, io->Media->MediaId, pos, CRYPT_BUF_SECTORS << 9, buf);
+ if (EFI_ERROR(res)) {
+ UINT8 ar;
+ ERR_PRINT(L"Read error: %r\n", res);
+ ar = AskAR();
+ if (ar != 'R' && ar != 'r')
+ break;
+ }
+ } while (EFI_ERROR(res));
- // decrypt the correct data
- DecryptDataUnits(realEncryptedData, (UINT64_STRUCT*)&start, (UINT32)(remains), info);
-
- if (0xEB52904E54465320 == BE64 (*(uint64 *) realEncryptedData)) /* NTFS */
- bPerformWrite = TRUE;
- else
+ if (EFI_ERROR(res))
{
- if (AskConfirm("\r\nDecrypted data don't contain valid partition information. Proceeed anyway?", 1))
- bPerformWrite = TRUE;
+ OUT_PRINT(L"\r\nNo corrective action performed.");
}
-
- if (bPerformWrite)
+ else
{
- // Write original encrypted data
- do {
- res = io->WriteBlocks(io, io->Media->MediaId, pos, (UINTN)((CRYPT_BUF_SECTORS - remains) << 9), buf);
- if (EFI_ERROR(res)) {
- UINT8 ar;
- ERR_PRINT(L"Write error: %r\n", res);
- ar = AskAR();
- if (ar != 'R' && ar != 'r')
- break;
- }
- } while (EFI_ERROR(res));
+ UINT8* realEncryptedData = buf + ((CRYPT_BUF_SECTORS - remains) << 9);
+ BOOL bPerformWrite = FALSE;
+
+ // reverse faulty decryption
+ EncryptDataUnits(buf, (UINT64_STRUCT*)&pos, (UINT32)(remains), info);
- if (EFI_ERROR(res))
+ // decrypt the correct data
+ DecryptDataUnits(realEncryptedData, (UINT64_STRUCT*)&start, (UINT32)(remains), info);
+
+ if (0xEB52904E54465320 == BE64 (*(uint64 *) realEncryptedData)) /* NTFS */
+ bPerformWrite = TRUE;
+ else
{
- OUT_PRINT(L"\r\nNo corrective action performed.");
+ if (AskConfirm("\r\nDecrypted data don't contain valid partition information. Proceeed anyway?", 1))
+ bPerformWrite = TRUE;
}
- else
- {
- // Write correctly decrypted data
+
+ if (bPerformWrite)
+ {
+ // Write original encrypted data
do {
- res = io->WriteBlocks(io, io->Media->MediaId, start, (UINTN) (remains << 9), realEncryptedData);
+ res = io->WriteBlocks(io, io->Media->MediaId, pos, (UINTN)((CRYPT_BUF_SECTORS - remains) << 9), buf);
if (EFI_ERROR(res)) {
UINT8 ar;
ERR_PRINT(L"Write error: %r\n", res);
@@ -652,30 +669,48 @@ RangeCrypt( break;
}
} while (EFI_ERROR(res));
-
+
if (EFI_ERROR(res))
{
- OUT_PRINT(L"\r\nFailed to write decrypted data.");
+ OUT_PRINT(L"\r\nNo corrective action performed.");
}
else
- {
- OUT_PRINT(L"\r\nData recovered successfully!");
+ {
+ // Write correctly decrypted data
+ do {
+ res = io->WriteBlocks(io, io->Media->MediaId, start, (UINTN) (remains << 9), realEncryptedData);
+ if (EFI_ERROR(res)) {
+ UINT8 ar;
+ ERR_PRINT(L"Write error: %r\n", res);
+ ar = AskAR();
+ if (ar != 'R' && ar != 'r')
+ break;
+ }
+ } while (EFI_ERROR(res));
+
+ if (EFI_ERROR(res))
+ {
+ OUT_PRINT(L"\r\nFailed to write decrypted data.");
+ }
+ else
+ {
+ OUT_PRINT(L"\r\nData recovered successfully!");
+ }
}
}
- }
- else
- {
- OUT_PRINT(L"\r\nNo corrective action performed.");
- }
- }
- }
- else
- {
- OUT_PRINT(L"\n\rNo corrective action attempted.");
+ else
+ {
+ OUT_PRINT(L"\r\nNo corrective action performed.");
+ }
+ }
+ }
+ else
+ {
+ OUT_PRINT(L"\n\rNo corrective action attempted.");
+ }
+
}
-
- }
-
+ }
}
}
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