Difference between revisions of "Gits2012teaser"

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(#2 AL's Revenge)
 
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== #1 TelAviv ==
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[[Category:CTF]]
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[[Image:gits-scores.png]]
  
== #2 AL's Revenge ==
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= Ghost in the Shellcode 2012 Teasers writeups =
  
* file 49dd327824d5afe9cdf931ea4b13719f.bin says xz compressed file -> xzcat > f
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http://ghostintheshellcode.com/
* file f says LLVM bitcode -> llvm-dis > f.s (only works with LLVM 2.8, not with 3.0)
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* analyze disassembly, extract C representation:
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<pre>
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Thanks to the organizers for those pretty nice teasers!
int
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VerifySerial(uint64_t name, uint64_t serial)
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{
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uint64_t a = 0x8000000000000000LL;
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        uint64_t b = 0xa348fccd93aea5a7LL;
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uint64_t result = 0;
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/* high order bit set? */
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The following writeups have been made by members of the FIXME team during between January 6th and January 8th.
if (name & a)
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a ^= b;
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if (serial & a)
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* Challenge [[CTF/gits2012teaser/1-TelAviv|#1 TelAviv]] by [[User:Francois|Francois]]
serial ^= b;
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* Challenge [[CTF/gits2012teaser/2-ALsRevenge|#2 AL's Revenge]] by [[User:Corecode|Corecode]]
 
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* Challenge [[CTF/gits2012teaser/3-Hackquest|#3 Hackquest]] by [[User:Corecode|Corecode]]
while (serial != 0) {
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if (serial & 1)
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result ^= name;
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serial >>= 1;
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name <<= 1;
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if (name & a)
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name ^= b;
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}
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return (result == 1);
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}
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</pre>
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== #3 Hackquest ==
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Latest revision as of 09:24, 22 October 2012

Gits-scores.png

Ghost in the Shellcode 2012 Teasers writeups

http://ghostintheshellcode.com/

Thanks to the organizers for those pretty nice teasers!

The following writeups have been made by members of the FIXME team during between January 6th and January 8th.