BIOS keyboard buffer

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helloABW
Posts: 2
Joined: Sat Apr 11, 2020 11:40 pm

BIOS keyboard buffer

Post by helloABW »

bootloader for UEFI clearing BIOS keyboard buffer to prevent password leakage ?
Keystrokes are saved in a 32-byte circular buffer in the BIOS Data Area, located at address
0040:001Eh. Each keystroke being stored on 2 bytes, the first one being the ASCII code and
the second one the BIOS scan code, 16 inputs can be saved.
Once the system is started, if this buffer has not been cleared, it is possible to retrieve
the user password. VeraCrypt prevents this potential leak by zeroing the buffer with the
ClearBiosKeystrokeBuffer function.

http://www.ouah.org/Bios_Information_Leakage.txt

DavidXanatos
Posts: 44
Joined: Mon Jan 27, 2020 8:05 pm

Re: BIOS keyboard buffer

Post by DavidXanatos »

Given that the new DCrypt bootloader is based on the veracrypt one the issue should not be present.

smile
Posts: 4
Joined: Tue Jul 14, 2020 9:40 pm

Re: BIOS keyboard buffer

Post by smile »

DavidXanatos wrote:
Tue Apr 28, 2020 9:24 am
Given that the new DCrypt bootloader is based on the veracrypt one the issue should not be present.
Could you elaborate, new DiskCryptor does not use the same bootloader that was bullet proof, now it uses crappy Veracrypt one?

DavidXanatos
Posts: 44
Joined: Mon Jan 27, 2020 8:05 pm

Re: BIOS keyboard buffer

Post by DavidXanatos »

New DiskCryptor uses its own old bullet proof bootlaoder when installed on a MBR boot system,
and a new one that is based on Veracrypt's one when installed on a EFI boot system.

Whats so crappy about Veracrypt's one?

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