LZMA files

[trempa92]

Greetings everybody,

I have a question regarding lzma files. Some may be opened and extracted some may not. I am more interested in those that can be.

Ok so i downloaded access control terminal firmware that lack my region localization.

First i tried unlzma and lzma to see if i even get the same output as original. But sadly no. So i even stopped on modifying anything, i am pretty sure this wont work.



Does any of you got method of compressing gui.tar with lzma to correspond the original file?

Kind regards,

 

[alastairstevenson]

First i tried unlzma and lzma to see if i even get the same output as original. But sadly no.

That should work OK - providing the new file has the same compression as the original, and uses the same compressor - xz or legacy lzma.

What were your command lines for the test?

 

[trempa92]

That should work OK - providing the new file has the same compression as the original, and uses the same compressor - xz or legacy lzma.

What were your command lines for the test?

Thanks for reply alastair,

I used simple unlzma within kali and lzma back, original lzma and the one i repacked look like on the image.

 

[trempa92]

Original lzmainfo


The new one lzmainfo


And in HEX they still different alot. Can you try to unlzma and lzma same files to see if u get same result?

gui.tar.lzma

Thanks

 

[Oleglevsha]

these files are encrypted, so they are not decompressed

 

[trempa92]

these files are encrypted, so they are not decompressed

What a bummer, thanks for reply anyway

 

[Oleglevsha]

Original lzmainfo
View attachment 107257

The new one lzmainfo
View attachment 107258

And in HEX they still different alot. Can you try to unlzma and lzma same files to see if u get same result?

gui.tar.lzma

Thanks

I downloaded your gui.tar.lzma file, it unpacked normally 7-zip

 

[trempa92]

I downloaded your gui.tar.lzma file, it unpacked normally 7-zip

I dont have problem with unpacking, i have problem with repacking. Once repacked, the new file is vastly different from original file. The header will be same, but rest of the data is different. Hence the image in my 1st post