header

Torsten Curdt’s weblog

What compression is this?

Dear lazyweb, I have come across a set of compressed data. I am trying to decompress it. It’s no inflate, it’s not bzip2 and it’s not gzip. Anyone recognizing what this could be?

000  2a 1f 8d 24 65 11 59 37  c8 47 91 a2 7d 5d 1d 5a  |*..$e.Y7ÈG.¢}].Z|
010  0d 1c 95 6b 7c 1b f9 f9  fa e0 56 8a 54 cd 0f ba  |...k|.ùùúà V.TÃ.º|
020  37 18 73 01 cc c5 20 23  63 9c 29 38 5d 50 3c fc  |7.s.ÌÅ #c.)8]P<ü|
030  9e 31 9b 49 5b 17 82 25  d5 91 a4 a9 62 40 10 ca  |.1.I[..%Õ.¤©b@.Ê|
040  54 4a 7c 7b 8a 07 95 71  2f 2d 22 bb 74 a2 e2 56  |TJ|{...q/-"»t¢âV|
050  f8 94 8d 62 a1 f7 6d 7c  a8 c2 78 1d f9 a6 04 16  |ø..b¡÷m|¨Âx.ù¦..|
060  f3 e3 08 7e 52 b9 90 57  aa 8c d4 e9 e6 ec cb 76  |óã.~R¹.Wª.ÔéæìËv|
070  24 4d d7 c2 2f 43 09 b1  09 12 68 cb b0 0e b9 b8  |$M×Â/C.±..hË°.¹¸|
080  5a 48 b3 b7 77 e3 5c 0b  ad cf 40 ce 00 b5 e4 62  |ZH³·wã\.-Ã@ÃŽ.µäb|
090  44 0e ad c4 ce bd 87 44  1e 15 40 0f 07 53 0f 0a  |D.-Äν.D..@..S..|
...

Update: Turns out this is still deflate - but DES enrypted. Boy I so hate this proprietary limbo. A new release of uif2iso4mac is out that supports the new format.

  • Hey, Brett. It's part of the UIF image format (which is like an ISO) This part was zlib compressed before (inflate/deflate) in version 1 but no longer is in format version 2. The format still suggests the output size - so I am pretty sure it is compressed. I just don't know with what algorithm ...or whether they used some sort of encryption to keep their format closed.

    I hope to extract the full compressed and uncompressed data on the weekend. (Need to get access to the original software on Windows)
  • Brett
    Is that the whole file? How do you know it's compressed and not just some gibberish caused by solar flares or a hash function?
blog comments powered by Disqus