[oclug] CIM file format.

[Ross Jordan]

I've been doing some work reverse engineering some Linux based
access points, and I'm wondering if anyone has heard of .cim files.
(The firmware for one particular AP is distributed in a file 
 called Model_Firmware_version.cim)

I am presuming it is some type of compressed image. They are
not cramfs as many of the other linux access points are. Strings
doesn't show anything useful. Attempting to uncompress (using
unzip, gunzip, bunzip2, ar, uncompress and others) doesn't seem
to work. Running the file command only gives data:

# file CN3000_Firmware_v.1.21.cim
CN3000_Firmware_v.1.21.cim: data

(Does anyone know where to get a really comprehensive magic file
 for file?)

vgrepping the file gives a few interesting bits, such as:

0000170: ab59 7028 b598 31b6 8b3c 2f7f 8b45 ed3b  .Yp(..1..</..E.;
0000180: 0606 feea fa9f ff43 f8fe 7a90 7e69 70f2  .......C..z.~ip.
0000190: 89db 60da 626b dae4 6933 cfe3 f546 7341  ..`.bk..i3...FsA

Which almost seems to be Czip (second line).

Anyways, I thought I'd throw this out, and if anyone has heard of 
cim, give me a shout.

-Ross