def ecb_decrypt(self):
cipher_arr = split_string_into_list_of_length_n(self.bplain, 128)
result = ""
for i in cipher_arr:
f = Feistel(i, self.bkey)
result += f.decrypt()
result = last_byte_check(result)
return result
def cbc_encrypt(self):
iv = 'rypythencryption'
index = 0
result = ''
for i in self.bplain_encrypt:
if index == 0:
c = iv
i = bin(int(i, 2) ^ int(change_ascii_to_bits(c), 2))[2:].zfill(128)
f = Feistel(i, self.bkey)
c = f.encrypt()
result += c
index += 1
return result
def cbc_decrypt(self):
input_bcipher = split_string_into_list_of_length_n(self.bplain, 128)
iv = 'rypythencryption'
index = 0
result = ''
for i in input_bcipher:
f = Feistel(i, self.bkey)
if index == 0:
c = change_ascii_to_bits(iv)
p = f.decrypt()
p = bin(int(p, 2) ^ int(c, 2))[2:].zfill(128)
c = i
result += p
index += 1
result = last_byte_check(result)
return result
def counter_decrypt(self):
iv = 'rypythen'
counter = int(
'1011000111110000101010101111111100000001000101011010111110001111',
2)
index = 0
result = ''
bitplain = split_string_into_list_of_length_n(self.bplain, 128)
for i in bitplain:
if index == 0:
x = change_ascii_to_bits(iv) + bin(counter)[2:]
f = Feistel(x, self.bkey)
m = change_ascii_to_bits(f.encrypt())
c = bin(int(m, 2) ^ int(i, 2))[2:].zfill(128)
result += c
x = change_ascii_to_bits(iv) + bin(counter + 3)[2:]
index += 1
result = last_byte_check(result)
return result
def counter_encrypt(self):
iv = 'rypythen'
counter = int(
'1011000111110000101010101111111100000001000101011010111110001111',
2)
index = 0
result = ''
for i in self.bplain_encrypt:
if index == 0:
x = change_ascii_to_bits(iv) + bin(counter)[2:]
f = Feistel(x, self.bkey)
m = change_ascii_to_bits(f.encrypt())
c = bin(int(m, 2) ^ int(i, 2))[2:].zfill(128)
result += c
x = change_ascii_to_bits(iv) + bin(counter + 3)[2:]
index += 1
result = change_bits_to_ascii(result)
return result
def cfb_encrypt(self):
n = 1 #size of unit in bytes
iv = 'rypythencryption'
bitplain = ''
for i in self.bplain_encrypt:
bitplain += i
bitplain = split_string_into_list_of_length_n(bitplain, (n * 8))
index = 0
result = ''
for i in bitplain:
if index == 0:
x = change_ascii_to_bits(iv)
f = Feistel(x, self.bkey)
c = bin(int(change_ascii_to_bits(f.encrypt()[0]), 2)
^ int(i, 2))[2:].zfill(n * 8)
result += c
x = x[:(len(x) - (n * 8))] + c
index += 1
result = change_bits_to_ascii(result)
return result
def ofb_decrypt(self):
n = 1 #size of unit in bytes
iv = 'rypythencryption'
bitplain = ''
# not using self.bplain_encrypt because not using padding
for i in self.bplain:
bitplain += i
bitplain = split_string_into_list_of_length_n(bitplain, (n * 8))
index = 0
result = ''
for i in bitplain:
if index == 0:
x = change_ascii_to_bits(iv)
f = Feistel(x, self.bkey)
m = change_ascii_to_bits(f.encrypt()[0])
c = bin(int(m, 2) ^ int(i, 2))[2:].zfill(n * 8)
result += c
x = x[:(len(x) - (n * 8))] + m
index += 1
result = last_byte_check(result)
return result
def ecb_encrypt(self):
result = ''
for i in self.bplain_encrypt:
f = Feistel(i, self.bkey)
result += f.encrypt()
return result