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+--- Thread: [Solved] Invalid LUKS filesize (/thread-7198.html)
[Solved] Invalid LUKS filesize - Fitap - 01-14-2018
Hi,
I have this output when I try to bruteforce luks header of my pendrive
Code:
hashcat@gentoo.org ~/Luks $ hashcat -a 3 -m 14600 4G-header dict.txt
hashcat (v4.0.1) starting...
* Device #1: WARNING! Kernel exec timeout is not disabled.
This may cause "CL_OUT_OF_RESOURCES" or related errors.
To disable the timeout, see: https://hashcat.net/q/timeoutpatch
nvmlDeviceGetFanSpeed(): Not Supported
OpenCL Platform #1: NVIDIA Corporation
======================================
* Device #1: GeForce 940M, 500/2002 MB allocatable, 3MCU
Hashfile '4G-header': Invalid LUKS filesize
No hashes loaded.
Started: Sun Jan 14 15:31:57 2018
Stopped: Sun Jan 14 15:31:57 2018What's wrong?
Time ago could run successfully but now doesn't work for me.
Regards.
RE: Invalid LUKS filesize - philsmd - 01-14-2018
How large is the file called 4G-header ? as you can see here https://hashcat.net/forum/thread-6225-post-33187.html#pid33187 it should be 4097 sectors large (each sector is 512 bytes, therefore a total of 512 * 4097 bytes which is about 2MB).
RE: Invalid LUKS filesize - Fitap - 01-15-2018
Thanks for response @philsmd
Code:
sudo cryptsetup luksHeaderBackup --header-backup-file 4G-header /dev/sdc2
-r-------- 1 root root 1052672 ene 14 14:28 4G-headerRE: Invalid LUKS filesize - philsmd - 01-15-2018
That's not how you can extract the data. You need to provide to hashcat not only the header/metadata but also some part of the encrypted data. If you reduce it to only the first bytes (metadata), hashcat can't verify if the decryption worked correctly.
I'm not sure where you read that the "luksHeaderBackup" method of cryptsetup is able to extract the data that hashcat needs. It's definitely not correct.
The guide is very clear: you need the whole header + some data from the disk/volume: https://hashcat.net/forum/thread-6225-post-33187.html#pid33187 (otherwise, as said, hashcat can't verify if the password was correct).
RE: Invalid LUKS filesize - undeath - 01-15-2018
(01-15-2018, 09:15 AM)philsmd Wrote: The guide is very clear: you need the whole header + some data from the disk/volume: https://hashcat.net/forum/thread-6225-post-33187.html#pid33187
this needs to be on the wiki
RE: [Solved] Invalid LUKS filesize - Fitap - 01-15-2018
Damm, I'm a bit confused.
Sorry.