def guessNextByte(file, knownBytes, delay):
suffixlen = 20 - len(knownBytes)
start = time.perf_counter()
durations = [0] * 256
count = 10
for k in range(count):
for i in range(256):
suffix = bytes([i]) + (b'\x00' * (suffixlen - 1))
signature = knownBytes + suffix
durations[i] += challenge31.isValidSignature(
file,
binascii.hexlify(signature).decode('ascii'))[1]
end = time.perf_counter()
print('Made {0} requests in {1:.2f}s; rps = {2:.2f}'.format(
count * 256, end - start, count * 256 / (end - start)))
for i in range(256):
durations[i] /= count
avg_duration = sum(durations) / 256
argmax = max(range(256), key=lambda i: durations[i])
if durations[argmax] > avg_duration + 0.80 * delay:
return knownBytes + bytes([argmax])
else:
return knownBytes[:-1]
def guessNextByte(file, knownBytes, delay):
suffixlen = 20 - len(knownBytes)
start = time.perf_counter()
durations = [0] * 256
count = 10
for k in range(count):
for i in range(256):
suffix = bytes([i]) + (b'\x00' * (suffixlen - 1))
signature = knownBytes + suffix
durations[i] += challenge31.isValidSignature(file, binascii.hexlify(signature).decode('ascii'))[1]
end = time.perf_counter()
print('Made {0} requests in {1:.2f}s; rps = {2:.2f}'.format(count * 256, end - start, count * 256 / (end - start)))
for i in range(256):
durations[i] /= count
avg_duration = sum(durations) / 256
argmax = max(range(256), key=lambda i: durations[i])
if durations[argmax] > avg_duration + 0.80 * delay:
return knownBytes + bytes([argmax])
else:
return knownBytes[:-1]
print('Made {0} requests in {1:.2f}s; rps = {2:.2f}'.format(
count * 256, end - start, count * 256 / (end - start)))
for i in range(256):
durations[i] /= count
avg_duration = sum(durations) / 256
argmax = max(range(256), key=lambda i: durations[i])
if durations[argmax] > avg_duration + 0.80 * delay:
return knownBytes + bytes([argmax])
else:
return knownBytes[:-1]
if __name__ == '__main__':
file = sys.argv[1]
knownBytes = b''
DELAY = 0.005
while True:
if len(knownBytes) == 20:
if challenge31.isValidSignature(
file,
binascii.hexlify(knownBytes).decode('ascii'))[0]:
break
else:
knownBytes = knownBytes[:-1]
knownBytes = guessNextByte(file, knownBytes, DELAY)
print(binascii.hexlify(knownBytes))
print(binascii.hexlify(knownBytes))
signature = knownBytes + suffix
durations[i] += challenge31.isValidSignature(file, binascii.hexlify(signature).decode('ascii'))[1]
end = time.perf_counter()
print('Made {0} requests in {1:.2f}s; rps = {2:.2f}'.format(count * 256, end - start, count * 256 / (end - start)))
for i in range(256):
durations[i] /= count
avg_duration = sum(durations) / 256
argmax = max(range(256), key=lambda i: durations[i])
if durations[argmax] > avg_duration + 0.80 * delay:
return knownBytes + bytes([argmax])
else:
return knownBytes[:-1]
if __name__ == '__main__':
file = sys.argv[1]
knownBytes = b''
DELAY = 0.005
while True:
if len(knownBytes) == 20:
if challenge31.isValidSignature(file, binascii.hexlify(knownBytes).decode('ascii'))[0]:
break
else:
knownBytes = knownBytes[:-1]
knownBytes = guessNextByte(file, knownBytes, DELAY)
print(binascii.hexlify(knownBytes))
print(binascii.hexlify(knownBytes))