Latest revision as of 11:24, 22 October 2012

Ghost in the Shellcode 2012 Teasers writeups

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.

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