defconquals2018 ELF-Crumble

sol.py

import itertools

f = open("broken")
brokendata = f.read()
f.close()

head = 0x5ad
tail = 0x8d4

brokenhead = brokendata[0:head]
mid        = brokendata[head:tail]
brokentail = brokendata[tail:]

fragments = []

for i in range(1,9):
    s = "fragment_" + str(i) + ".dat"
    print "Reading " + s
    t = open(s,"r")
    data = t.read()
    fragments.append(data)
    t.close()

print fragments     


x = [1,2,3,4,5,6,7,8]

perms = list(itertools.permutations(x,8))

print "Perms created size : " + str(len(perms))

dat = ""


c = 0
for idx,i in enumerate(perms):
    dat = brokenhead
    for k in i:
        dat += fragments[k-1]
    dat += brokentail
    j = open("bin_"+str(c),"w")
    j.write(dat)
    j.close()
    c += 1
    if(c%100):
        print "bin_" + str(c) +" created"
        
""" 
bash script to run all of them , correct binary is 39690 so it will take time
for i in {1..40260}
do
NAME="bin_$i"
./$NAME
done
"""