def breakSingleByteXOR(byteStr):
strings = []
for key in range(256):
strings.append(xor(byteStr, bytearray([key] * len(byteStr))))
return max(strings, key=lambda s: s.count(' '.encode('utf-8')))
def decryptAES_ECB_CBC(ciphertext, key, iv):
plaintext = bytearray(len(ciphertext))
for n in range(0, len(ciphertext), AES.block_size):
plaintext[n: n+AES.block_size] = xor(decryptAES_ECB(ciphertext[n: n+AES.block_size], key), iv)
iv = ciphertext[n: n+AES.block_size]
return plaintext
def hammingDistance(string1, string2):
xorString = ''.join(format(x, '08b') for x in xor(string1, string2))
distance = 0
for num in xorString:
if num == "1":
distance += 1
return distance
def encryptAES_ECB_CBC(plaintext, key, iv):
plaintext = addPKCS7Padding(plaintext, AES.block_size)
ciphertext = bytearray(len(plaintext))
for n in range(0, len(plaintext), AES.block_size):
ciphertext[n: n+AES.block_size] = encryptAES_ECB(xor(plaintext[n: n+AES.block_size], iv), key)
iv = ciphertext[n: n+AES.block_size]
return ciphertext
def breakSingleByteXOR(encryptedText):
keys = []
strings = []
for key in range(256):
keys.append(chr(key))
strings.append(
xor(encryptedText, bytearray([key] * len(encryptedText))))
bestString = max(strings, key=lambda s: s.count(' '.encode('utf-8')))
for i in range(len(strings)):
if bestString == strings[i]:
return keys[i]
def repeatingKeyXOR(text, key):
assert len(text) >= len(key)
if not len(text) % len(key):
return xor(text, key * (len(text) / len(key)))
else:
count = 0
encoded = bytearray()
for char in range(len(text)):
encoded += bytearray([text[char] ^ key[count]])
if count == len(key) - 1:
count = 0
else:
count += 1
return encoded