def hamming_distance(x, y):
assert len(x) == len(y)
sum = 0
for b in xor(x, y):
sum += bin(ord(b)).count('1')
return sum
def decrypt(k,c):
"""
xors the ciphertext bytestring with key k and returns as bytestring
param k: key
param c: ciphertext bytes
return a string of bytes
"""
decrypted = ''
for byte in c:
decrypted += xor(byte, k)
return decrypted
def hex_string_xor(hex1string, hex2string):
"""
A complete function for reading in two hex strings and outputting a string of the xor of the two inputs
:param hex1_string: a string of ASCII encoded hex characters
:param hex2_string: a string of ASCII encoded hex characters
:return: a string of ASCII encoded hex characters
"""
assert type(hex1string) == str
assert type(hex2string) == str
hex1bytes = hex_to_bytestr(hex1string)
hex2bytes = hex_to_bytestr(hex2string)
outputbytes = xor(hex1bytes, hex2bytes)
print(outputbytes)
outputstring = bytestr_to_hex(outputbytes)
return outputstring
if __name__ == "__main__":
input1='1b37373331363f78151b7f2b783431333d78397828372d363c78373e783a393b3736'
Bytes = converters.hex_to_bytestr(input1)
print('Bytes:', Bytes)
potential_keys=[]
# if a repeated character exists, the potential keys are reduced to keys which
# will decrypt to a repeated character found in the English language, namely s,e,t,m,o
if len(repeated(Bytes))>0:
for item in repeated(Bytes):
for k in ['s', 'e', 't', 'l', 'm', 'o']:
potential_keys.append(xor(item, k))
# Unique potential keys.
potential_keys = list(set(potential_keys))
print('Repeated letters found. Only relevant keys added.')
print('Current potential keys:', potential_keys)
print('Current number of potential keys:', len(potential_keys))
# removes potential keys which are not printable characters
for k in potential_keys:
if not converters.valid_characters(k):
potential_keys.remove(k)
print('Current number of potential keys:', len(potential_keys))
print('Current potential keys:', potential_keys)
else:
for k in range (32,127):
potential_keys.append(chr(k))
