Cypris
6th June 2004 06:29 UTC

Installation file repair help
Hello,
I downloaded a file from the net, the exe file seemed to be corrupted. after researhcing the contents of the file, i discovered it was a NSIS Installer. So, I downloaded NSIS and created an installation to compare it against. Of course i tried several download sites, and contacting the author, all bad files, no response from author. after comparing to serveral NSIS installs, i came down to the conclusion that the actual compressed data is not damaged, and fully intact. the only missing information is about 2k of data, maybe less. i cant complete this file because i am unable to find the compression style the author used. its not LZMA, BZip2, or ZLib, here is the beginning of the file in TEXT format as HexWorkshop dispays:


...;.t.W.u..u.S.u.P."......W.u..u.S.
u.j...W.u..u.S.u.j..u..-..._^[......
@...@...@.?.@.~.@.u.@.f.@.Q.@...@...
@...@.[.@...@.%.@.j.@.{.@.3.@.o.@.U.
..E..M..H..M.. ..H..M..H..M..H.]...U
..SV.u.W.............N.;..M.v.......
+....F.;.v.....t..}..u..e..W+.SQ.F..
VK.........}...;.uG9...........u....
..........F.+.;.v.....t..}..u..e..WS
.u.+..F...K...}....E._.F..E.......^[


If you need the hex:
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


the odd part is, and i dont know if it is on puprose, but within the first 20 bytes of data, it says "W.u..u.S.u.P"

Anyways, if anyone can help me find the compression method, or has the data to complete mine, that would be great.

kichik
10th June 2004 18:06 UTC

How can you tell the compressed data is intact without knowing the original data or the compression format used?

If you know the NSIS version and just don't know the compression used, you only need to try tacking the compressed data to the three different exeheads. If you're lucky and the author didn't recompile NSIS with some source code changes, you'd have your installer, assuming the compressed data is indeed intact.