import struct
import string

def key_padding(key,msglen):
	orig_key = key
	result_key = ''
	block = (msglen / len(key))
	left = msglen % len(key)
	for i in range(block):
		result_key += key

	result_key += key[:left]
	return result_key

def HammingWeight(t):
	result = 0
	for i in range(32):
		if (t>>i)&1 == 1:
			result+= 1

	return result

def GetKey(msg):
	if len(msg)%11 != 0:
		print "msg len is not multiple 11"
		return

	keyList = []
	#create block list
	blockList = []
	for i in range(11):
		blockList.append([])

	#devide block
	j = 0
	for tmp in msg:
		blockList[j%11].append(tmp)
		j += 1

	for i in range(11):
		result = {blockList[i].count(x): x for x in blockList[i]}
		keyList.append(chr(ord(result[sorted(result).pop()])^ord(' ')))

	return keyList


def main():
	f = open("encrypted.txt","r")
	buf = f.read().decode('hex')
	f.close()

	################### possible key len is 11########
	for i in range(1,20):
		Ham = lambda (x,y): HammingWeight(ord(x)^ord(y))
		result = map(Ham,zip(buf,buf[i:]))
		fham = filter(lambda x: x<6, result)
		print "[*]try key len %d " %i
		avg_ham = reduce(lambda x,y: x+y, result)
		avg_ham = avg_ham / len(result)
		print "[-]"+str(avg_ham)
	###################################################

	# keyList = GetKey(buf)
	# keyList[3] = '\x76'
	# #print keyList
	# keyList = ''.join(i for i in keyList)
	# print "find key %s " %(keyList.encode('hex'))

	# pkey = key_padding(keyList,len(buf))
	# decode = map(lambda (x,y): ord(x)^ord(y), zip(pkey,buf))
	# decode = ''.join(chr(x) for x in decode)
	# print decode

if __name__ == '__main__':
	main()