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st98/solve.py Secret

Created May 28, 2017 06:47
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WhiteHat Contest 13 - [Reverse Engineering 100] Tuy Hoa
Raw
solve.py
import re
from z3 import *
funcs = '''
push rbp
mov rbp,rsp
sub rsp,0x10
mov eax,DWORD PTR [rip+0x201823] # 6021c8 <key+0x8>
mov ecx,DWORD PTR [rip+0x201831] # 6021dc <key+0x1c>
mov edx,DWORD PTR [rip+0x201813] # 6021c4 <key+0x4>
add edx,ecx
xor eax,edx
sub eax,0x7cd54cbf
mov eax,eax
mov QWORD PTR [rbp-0x8],rax
mov eax,DWORD PTR [rip+0x2017fa] # 6021c0 <key>
mov edx,DWORD PTR [rip+0x2017fc] # 6021c8 <key+0x8>
mov esi,DWORD PTR [rip+0x20180a] # 6021dc <key+0x1c>
mov ecx,DWORD PTR [rip+0x2017ec] # 6021c4 <key+0x4>
add ecx,esi
xor edx,ecx
sub edx,0x7cd54cbf
cmp eax,edx
je 4009eb <_Z5func0v+0x54>
call 40096d <_Z14wrong_passwordv>
mov rax,QWORD PTR [rbp-0x8]
leave
ret
push rbp
mov rbp,rsp
sub rsp,0x10
mov edx,DWORD PTR [rip+0x2017c1] # 6021c0 <key>
mov eax,DWORD PTR [rip+0x2017df] # 6021e4 <key+0x24>
add edx,eax
mov eax,DWORD PTR [rip+0x2017b3] # 6021c0 <key>
sub edx,eax
mov eax,edx
add eax,0x6102312f
mov eax,eax
mov QWORD PTR [rbp-0x8],rax
mov eax,DWORD PTR [rip+0x2017a2] # 6021c4 <key+0x4>
mov ecx,DWORD PTR [rip+0x201798] # 6021c0 <key>
mov edx,DWORD PTR [rip+0x2017b6] # 6021e4 <key+0x24>
add ecx,edx
mov edx,DWORD PTR [rip+0x20178a] # 6021c0 <key>
sub ecx,edx
mov edx,ecx
add edx,0x6102312f
cmp eax,edx
je 400a49 <_Z5func1v+0x58>
call 40096d <_Z14wrong_passwordv>
mov rax,QWORD PTR [rbp-0x8]
leave
ret
push rbp
mov rbp,rsp
sub rsp,0x10
mov eax,DWORD PTR [rip+0x20176f] # 6021cc <key+0xc>
mov ecx,DWORD PTR [rip+0x20177d] # 6021e0 <key+0x20>
mov edx,DWORD PTR [rip+0x201773] # 6021dc <key+0x1c>
add edx,ecx
sub eax,edx
mov edx,eax
mov eax,DWORD PTR [rip+0x20174f] # 6021c4 <key+0x4>
xor eax,edx
sub eax,0x6d6460c8
mov eax,eax
mov QWORD PTR [rbp-0x8],rax
mov eax,DWORD PTR [rip+0x201740] # 6021c8 <key+0x8>
mov edx,DWORD PTR [rip+0x20173e] # 6021cc <key+0xc>
mov esi,DWORD PTR [rip+0x20174c] # 6021e0 <key+0x20>
mov ecx,DWORD PTR [rip+0x201742] # 6021dc <key+0x1c>
add ecx,esi
sub edx,ecx
mov ecx,edx
mov edx,DWORD PTR [rip+0x20171e] # 6021c4 <key+0x4>
xor edx,ecx
sub edx,0x6d6460c8
cmp eax,edx
je 400ab7 <_Z5func2v+0x68>
call 40096d <_Z14wrong_passwordv>
mov rax,QWORD PTR [rbp-0x8]
leave
ret
push rbp
mov rbp,rsp
sub rsp,0x10
mov edx,DWORD PTR [rip+0x2016f5] # 6021c0 <key>
mov eax,DWORD PTR [rip+0x201707] # 6021d8 <key+0x18>
xor edx,eax
mov eax,DWORD PTR [rip+0x2016f3] # 6021cc <key+0xc>
xor edx,eax
mov eax,DWORD PTR [rip+0x201703] # 6021e4 <key+0x24>
sub edx,eax
mov eax,DWORD PTR [rip+0x2016df] # 6021c8 <key+0x8>
add eax,edx
sub eax,0x37fafffd
mov eax,eax
mov QWORD PTR [rbp-0x8],rax
mov eax,DWORD PTR [rip+0x2016d0] # 6021cc <key+0xc>
mov ecx,DWORD PTR [rip+0x2016be] # 6021c0 <key>
mov edx,DWORD PTR [rip+0x2016d0] # 6021d8 <key+0x18>
xor ecx,edx
mov edx,DWORD PTR [rip+0x2016bc] # 6021cc <key+0xc>
xor ecx,edx
mov edx,DWORD PTR [rip+0x2016cc] # 6021e4 <key+0x24>
sub ecx,edx
mov edx,DWORD PTR [rip+0x2016a8] # 6021c8 <key+0x8>
add edx,ecx
sub edx,0x37fafffd
cmp eax,edx
je 400b31 <_Z5func3v+0x74>
call 40096d <_Z14wrong_passwordv>
mov rax,QWORD PTR [rbp-0x8]
leave
ret
push rbp
mov rbp,rsp
sub rsp,0x10
mov edx,DWORD PTR [rip+0x201693] # 6021d8 <key+0x18>
mov eax,DWORD PTR [rip+0x201681] # 6021cc <key+0xc>
sub edx,eax
mov eax,DWORD PTR [rip+0x201689] # 6021dc <key+0x1c>
add edx,eax
mov eax,DWORD PTR [rip+0x201675] # 6021d0 <key+0x10>
xor eax,edx
add eax,0x2a312dd3
mov eax,eax
mov QWORD PTR [rbp-0x8],rax
mov eax,DWORD PTR [rip+0x201662] # 6021d0 <key+0x10>
mov ecx,DWORD PTR [rip+0x201664] # 6021d8 <key+0x18>
mov edx,DWORD PTR [rip+0x201652] # 6021cc <key+0xc>
sub ecx,edx
mov edx,DWORD PTR [rip+0x20165a] # 6021dc <key+0x1c>
add ecx,edx
mov edx,DWORD PTR [rip+0x201646] # 6021d0 <key+0x10>
xor edx,ecx
add edx,0x2a312dd3
cmp eax,edx
je 400b9b <_Z5func4v+0x64>
call 40096d <_Z14wrong_passwordv>
mov rax,QWORD PTR [rbp-0x8]
leave
ret
push rbp
mov rbp,rsp
sub rsp,0x10
mov edx,DWORD PTR [rip+0x201619] # 6021c8 <key+0x8>
mov eax,DWORD PTR [rip+0x20162b] # 6021e0 <key+0x20>
sub edx,eax
mov eax,DWORD PTR [rip+0x201607] # 6021c4 <key+0x4>
xor edx,eax
mov eax,DWORD PTR [rip+0x20161f] # 6021e4 <key+0x24>
xor eax,edx
sub eax,0x3dea7877
mov eax,eax
mov QWORD PTR [rbp-0x8],rax
mov eax,DWORD PTR [rip+0x2015fc] # 6021d4 <key+0x14>
mov ecx,DWORD PTR [rip+0x2015ea] # 6021c8 <key+0x8>
mov edx,DWORD PTR [rip+0x2015fc] # 6021e0 <key+0x20>
sub ecx,edx
mov edx,DWORD PTR [rip+0x2015d8] # 6021c4 <key+0x4>
xor ecx,edx
mov edx,DWORD PTR [rip+0x2015f0] # 6021e4 <key+0x24>
xor edx,ecx
sub edx,0x3dea7877
cmp eax,edx
je 400c05 <_Z5func5v+0x64>
call 40096d <_Z14wrong_passwordv>
mov rax,QWORD PTR [rbp-0x8]
leave
ret
push rbp
mov rbp,rsp
sub rsp,0x10
mov eax,DWORD PTR [rip+0x2015b3] # 6021cc <key+0xc>
mov edx,DWORD PTR [rip+0x2015c1] # 6021e0 <key+0x20>
mov esi,DWORD PTR [rip+0x2015ab] # 6021d0 <key+0x10>
mov ecx,DWORD PTR [rip+0x201599] # 6021c4 <key+0x4>
add ecx,esi
sub edx,ecx
add edx,eax
mov eax,DWORD PTR [rip+0x20159d] # 6021d4 <key+0x14>
sub edx,eax
mov eax,DWORD PTR [rip+0x20159d] # 6021dc <key+0x1c>
xor edx,eax
mov eax,DWORD PTR [rip+0x201581] # 6021c8 <key+0x8>
add eax,edx
sub eax,0x45bdbb01
mov eax,eax
mov QWORD PTR [rbp-0x8],rax
mov eax,DWORD PTR [rip+0x20157e] # 6021d8 <key+0x18>
mov edx,DWORD PTR [rip+0x20156c] # 6021cc <key+0xc>
mov ecx,DWORD PTR [rip+0x20157a] # 6021e0 <key+0x20>
mov edi,DWORD PTR [rip+0x201564] # 6021d0 <key+0x10>
mov esi,DWORD PTR [rip+0x201552] # 6021c4 <key+0x4>
add esi,edi
sub ecx,esi
add ecx,edx
mov edx,DWORD PTR [rip+0x201556] # 6021d4 <key+0x14>
sub ecx,edx
mov edx,DWORD PTR [rip+0x201556] # 6021dc <key+0x1c>
xor ecx,edx
mov edx,DWORD PTR [rip+0x20153a] # 6021c8 <key+0x8>
add edx,ecx
sub edx,0x45bdbb01
cmp eax,edx
je 400c9f <_Z5func6v+0x94>
call 40096d <_Z14wrong_passwordv>
mov rax,QWORD PTR [rbp-0x8]
leave
ret
push rbp
mov rbp,rsp
sub rsp,0x10
mov edx,DWORD PTR [rip+0x201511] # 6021c4 <key+0x4>
mov eax,DWORD PTR [rip+0x20150f] # 6021c8 <key+0x8>
add edx,eax
mov eax,DWORD PTR [rip+0x201523] # 6021e4 <key+0x24>
sub edx,eax
mov eax,edx
sub eax,0x5d342bfc
mov eax,eax
mov QWORD PTR [rbp-0x8],rax
mov eax,DWORD PTR [rip+0x201506] # 6021dc <key+0x1c>
mov ecx,DWORD PTR [rip+0x2014e8] # 6021c4 <key+0x4>
mov edx,DWORD PTR [rip+0x2014e6] # 6021c8 <key+0x8>
add ecx,edx
mov edx,DWORD PTR [rip+0x2014fa] # 6021e4 <key+0x24>
sub ecx,edx
mov edx,ecx
sub edx,0x5d342bfc
cmp eax,edx
je 400cfd <_Z5func7v+0x58>
call 40096d <_Z14wrong_passwordv>
mov rax,QWORD PTR [rbp-0x8]
leave
ret
push rbp
mov rbp,rsp
sub rsp,0x10
mov eax,DWORD PTR [rip+0x2014af] # 6021c0 <key>
mov ecx,DWORD PTR [rip+0x2014c5] # 6021dc <key+0x1c>
mov edx,DWORD PTR [rip+0x2014bb] # 6021d8 <key+0x18>
xor ecx,edx
mov edx,DWORD PTR [rip+0x20149f] # 6021c4 <key+0x4>
xor edx,ecx
add edx,eax
mov eax,DWORD PTR [rip+0x2014ad] # 6021dc <key+0x1c>
sub edx,eax
mov eax,edx
sub eax,0x2b402ece
mov eax,eax
mov QWORD PTR [rbp-0x8],rax
mov eax,DWORD PTR [rip+0x20149c] # 6021e0 <key+0x20>
mov edx,DWORD PTR [rip+0x201476] # 6021c0 <key>
mov esi,DWORD PTR [rip+0x20148c] # 6021dc <key+0x1c>
mov ecx,DWORD PTR [rip+0x201482] # 6021d8 <key+0x18>
xor esi,ecx
mov ecx,DWORD PTR [rip+0x201466] # 6021c4 <key+0x4>
xor ecx,esi
add ecx,edx
mov edx,DWORD PTR [rip+0x201474] # 6021dc <key+0x1c>
sub ecx,edx
mov edx,ecx
sub edx,0x2b402ece
cmp eax,edx
je 400d7b <_Z5func8v+0x78>
call 40096d <_Z14wrong_passwordv>
mov rax,QWORD PTR [rbp-0x8]
leave
ret
push rbp
mov rbp,rsp
sub rsp,0x10
mov edx,DWORD PTR [rip+0x201435] # 6021c4 <key+0x4>
mov eax,DWORD PTR [rip+0x20143b] # 6021d0 <key+0x10>
imul eax,edx
mov esi,DWORD PTR [rip+0x201442] # 6021e0 <key+0x20>
mov edx,0x0
div esi
mov edx,eax
mov eax,DWORD PTR [rip+0x20141b] # 6021c8 <key+0x8>
xor eax,edx
sub eax,0x352afe01
mov eax,eax
mov QWORD PTR [rbp-0x8],rax
mov ecx,DWORD PTR [rip+0x201424] # 6021e4 <key+0x24>
mov edx,DWORD PTR [rip+0x2013fe] # 6021c4 <key+0x4>
mov eax,DWORD PTR [rip+0x201404] # 6021d0 <key+0x10>
imul eax,edx
mov edi,DWORD PTR [rip+0x20140b] # 6021e0 <key+0x20>
mov edx,0x0
div edi
mov edx,eax
mov eax,DWORD PTR [rip+0x2013e4] # 6021c8 <key+0x8>
xor eax,edx
sub eax,0x352afe01
cmp ecx,eax
je 400df4 <_Z5func9v+0x73>
call 40096d <_Z14wrong_passwordv>
mov rax,QWORD PTR [rbp-0x8]
leave
ret
push rbp
mov rbp,rsp
sub rsp,0x10
mov edx,DWORD PTR [rip+0x2013bc] # 6021c4 <key+0x4>
mov eax,DWORD PTR [rip+0x2013c6] # 6021d4 <key+0x14>
add edx,eax
mov eax,DWORD PTR [rip+0x2013c6] # 6021dc <key+0x1c>
sub edx,eax
mov eax,edx
mov eax,eax
mov QWORD PTR [rbp-0x8],rax
mov edx,DWORD PTR [rip+0x20139e] # 6021c4 <key+0x4>
mov eax,DWORD PTR [rip+0x2013a8] # 6021d4 <key+0x14>
add edx,eax
mov eax,DWORD PTR [rip+0x2013a8] # 6021dc <key+0x1c>
sub edx,eax
mov eax,edx
cmp eax,0x89415e34
je 400e44 <_Z6func10v+0x4a>
call 40096d <_Z14wrong_passwordv>
mov rax,QWORD PTR [rbp-0x8]
leave
ret
'''.strip().split('\n\n')
regs = {
'eax': 0,
'ecx': 0,
'edx': 0,
'edi': 0,
'esi': 0,
}
def get_value(v):
if v in ['eax', 'ecx', 'edx', 'edi', 'esi']:
return regs[v]
if v.startswith('0x'):
return int(v, 16)
raise Exception(v)
key = [BitVec('key_%x' % x, 32) for x in range(0, 0x24+1, 4)]
s = Solver()
for func in funcs:
for line in func.splitlines():
t = line.split()
if t[0] == 'add':
a, b = t[1].split(',')
regs[a] = get_value(a) + get_value(b)
elif t[0] == 'sub':
if 'rsp' in t[1]:
continue
a, b = t[1].split(',')
regs[a] = get_value(a) - get_value(b)
elif t[0] == 'xor':
a, b = t[1].split(',')
regs[a] = get_value(a) ^ get_value(b)
elif t[0] == 'div':
a = get_value(t[1])
b, c = get_value('eax') / a, get_value('eax') % a
regs['eax'] = b
regs['edx'] = c
elif t[0] == 'imul':
a, b = t[1].split(',')
regs[a] = get_value(a) * get_value(b)
elif t[0] == 'mov':
if 'QWORD' in t[1] or 'rbp' in t[1]:
continue
if len(t) == 7:
m = re.findall(r'key\+?(.*).', t[-1])[0]
m = (0 if m == '' else int(m, 16)) / 4
a, _ = t[1].split(',')
regs[a] = key[m]
else:
a, b = t[1].split(',')
regs[a] = get_value(b)
elif t[0] == 'cmp':
a, b = t[1].split(',')
a = get_value(a)
b = get_value(b)
s.add(a == b)
r = s.check()
m = s.model()
res = ''
for k in key:
h = hex(m[k].as_long())[2:]
res += ''.join(reversed(re.findall(r'.{2}', h)))
print res.decode('hex')
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