mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-24 21:41:08 +00:00
c909da9b08
* pre-commit: Upgrade psf/black for stable style 2023 Updating https://github.com/psf/black ... updating 22.12.0 -> 23.1.0 for their `2023 stable style`. * https://github.com/psf/black/blob/main/CHANGES.md#2310 > This is the first [psf/black] release of 2023, and following our stability policy, it comes with a number of improvements to our stable style… Also, add https://github.com/tox-dev/pyproject-fmt and https://github.com/abravalheri/validate-pyproject to pre-commit. I only modified `.pre-commit-config.yaml` and all other files were modified by pre-commit.ci and psf/black. * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci --------- Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
97 lines
2.6 KiB
Python
97 lines
2.6 KiB
Python
def apply_table(inp, table):
|
|
"""
|
|
>>> apply_table("0123456789", list(range(10)))
|
|
'9012345678'
|
|
>>> apply_table("0123456789", list(range(9, -1, -1)))
|
|
'8765432109'
|
|
"""
|
|
res = ""
|
|
for i in table:
|
|
res += inp[i - 1]
|
|
return res
|
|
|
|
|
|
def left_shift(data):
|
|
"""
|
|
>>> left_shift("0123456789")
|
|
'1234567890'
|
|
"""
|
|
return data[1:] + data[0]
|
|
|
|
|
|
def xor(a, b):
|
|
"""
|
|
>>> xor("01010101", "00001111")
|
|
'01011010'
|
|
"""
|
|
res = ""
|
|
for i in range(len(a)):
|
|
if a[i] == b[i]:
|
|
res += "0"
|
|
else:
|
|
res += "1"
|
|
return res
|
|
|
|
|
|
def apply_sbox(s, data):
|
|
row = int("0b" + data[0] + data[-1], 2)
|
|
col = int("0b" + data[1:3], 2)
|
|
return bin(s[row][col])[2:]
|
|
|
|
|
|
def function(expansion, s0, s1, key, message):
|
|
left = message[:4]
|
|
right = message[4:]
|
|
temp = apply_table(right, expansion)
|
|
temp = xor(temp, key)
|
|
l = apply_sbox(s0, temp[:4]) # noqa: E741
|
|
r = apply_sbox(s1, temp[4:])
|
|
l = "0" * (2 - len(l)) + l # noqa: E741
|
|
r = "0" * (2 - len(r)) + r
|
|
temp = apply_table(l + r, p4_table)
|
|
temp = xor(left, temp)
|
|
return temp + right
|
|
|
|
|
|
if __name__ == "__main__":
|
|
key = input("Enter 10 bit key: ")
|
|
message = input("Enter 8 bit message: ")
|
|
|
|
p8_table = [6, 3, 7, 4, 8, 5, 10, 9]
|
|
p10_table = [3, 5, 2, 7, 4, 10, 1, 9, 8, 6]
|
|
p4_table = [2, 4, 3, 1]
|
|
IP = [2, 6, 3, 1, 4, 8, 5, 7]
|
|
IP_inv = [4, 1, 3, 5, 7, 2, 8, 6]
|
|
expansion = [4, 1, 2, 3, 2, 3, 4, 1]
|
|
s0 = [[1, 0, 3, 2], [3, 2, 1, 0], [0, 2, 1, 3], [3, 1, 3, 2]]
|
|
s1 = [[0, 1, 2, 3], [2, 0, 1, 3], [3, 0, 1, 0], [2, 1, 0, 3]]
|
|
|
|
# key generation
|
|
temp = apply_table(key, p10_table)
|
|
left = temp[:5]
|
|
right = temp[5:]
|
|
left = left_shift(left)
|
|
right = left_shift(right)
|
|
key1 = apply_table(left + right, p8_table)
|
|
left = left_shift(left)
|
|
right = left_shift(right)
|
|
left = left_shift(left)
|
|
right = left_shift(right)
|
|
key2 = apply_table(left + right, p8_table)
|
|
|
|
# encryption
|
|
temp = apply_table(message, IP)
|
|
temp = function(expansion, s0, s1, key1, temp)
|
|
temp = temp[4:] + temp[:4]
|
|
temp = function(expansion, s0, s1, key2, temp)
|
|
CT = apply_table(temp, IP_inv)
|
|
print("Cipher text is:", CT)
|
|
|
|
# decryption
|
|
temp = apply_table(CT, IP)
|
|
temp = function(expansion, s0, s1, key2, temp)
|
|
temp = temp[4:] + temp[:4]
|
|
temp = function(expansion, s0, s1, key1, temp)
|
|
PT = apply_table(temp, IP_inv)
|
|
print("Plain text after decypting is:", PT)
|