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@pawlos pawlos/solv.py Secret
Created Apr 7, 2019

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Full solution script for Confidence 2019 Teaser
import sys
original = [0,0,0,0,0,0,0,0,2 ,0,3,2,1,1,0, 0,
0,0,0,0,0,0,0,1,0 ,3,4,2,3,0,0xff,0,
0,0,0,0,0,0,1,0,2 ,2,1,3,0,1,0 ,0,
0,0,0,0,0,0,0,2,0 ,1,0,0,0,0,0 ,0,
0,0,0,0,0,0,0,0,0xfe,0,0,0,0,0,0 ,0]
import importlib
a=importlib.import_module(sys.argv[1])
import string
def solve():
print('#'+str(len(a.solution)))
new_sol = []
sol_len = len(a.solution)
while sol_len > 0:
partial = a.solution[0]
if partial in a.solution:
a.solution.remove(partial)
sol_len = len(a.solution)
for c in xrange(0x30,0x7d+1):
if chr(c) not in string.digits and chr(c) not in string.ascii_lowercase and chr(c) != '}':
continue
idx = 72
if original[idx] != 0xfe:
break
flag = original[:]
correct = True
p = (c << a.shifts) + partial
clone = p
for k in range(a.bit_len):
b = p & 3
if b == 0:
idx -= 17
elif b == 1:
idx -= 15
elif b == 2:
idx += 15
elif b == 3:
idx += 17
if idx < 0:
idx += 16
if idx < 0 or idx > len(flag):
correct = False
if flag[idx] == 0 or flag[idx] == 0xfe:
correct = False
break #we can't step on zero's
flag[idx] -= 1
p >>= 2
if correct:# and idx==30:
#print("#[+] Potential successful num: {0:x}".format(clone))
new_sol.append(clone)
return new_sol
print("bit_len={0}".format(a.bit_len+4))
print("shifts={0}".format(a.shifts+8))
print("solution=["+','.join('{:#04x}'.format(x) for x in solve())+"]")
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