MIT-Curricular/IS/Lab/Lab2/des.py
2025-08-05 09:25:24 +05:30

36 lines
No EOL
872 B
Python

from Crypto.Cipher import DES
def des_cipher(key):
return DES.new(key.encode('utf-8'), DES.MODE_ECB)
def despad_ptext(text):
n = len(text) % 8
if n != 0:
return text + (' ' * (8 - n))
else:
return text
def des_en(ptext, key):
cipher = des_cipher(key)
ptext = despad_ptext(ptext).encode('utf-8')
return cipher.encrypt(ptext)
def des_de(ctext, key):
cipher = des_cipher(key)
return cipher.decrypt(ctext).decode('utf-8').rstrip()
def despad_key(key):
return key.ljust(8)[:8]
def main():
print("Welcome to DES (Original)")
ptext = input("Enter plaintext: ")
despad_ptext(ptext)
key = input("Enter key: ")
key = despad_key(key)
ctext = des_en(ptext, key)
print("Your ciphertext: ", ctext)
print("Your decrypted plaintext: ", des_de(ctext, key))
if __name__ == '__main__':
main()