def _crypt(self, msg):
assert(type(msg) == type("hello"))
"""
_crypt, takes a cipher text/plain text and decrypts/encrypts it.
INPUT:
msg, either Plain Text or Cipher Text.
OUTPUT:
new_msg, if PT, then output is CT and vice-versa.
"""
# ======== IMPLEMENTATION GOES HERE =========
new_msg=""
new_msg_array=[]
#Iterate the bytearray of the msg
for byte in bytearray(msg):
#For every byte perform the encipher/decipher function
newByte=byte^auxillary.msb(self.r_i)
#Update the register
self.updateShiftRegister()
#Append the new byte to the new message array
new_msg_array.append(newByte)
#Turn the new_msg_array into a byte array
new_msg_array=bytearray(new_msg_array)
new_msg=str(new_msg_array)
# ======== END IMPLEMENTATION ===============
return new_msg
def _crypt(self, msg):
"""
_crypt, takes a cipher text/plain text and decrypts/encrypts it.
INPUT:
msg, either Plain Text or Cipher Text.
OUTPUT:
new_msg, if PT, then output is CT and vice-versa.
"""
# ======== IMPLEMENTATION GOES HERE =========
#msgarray should store the msg as byte array.
msgarray = bytearray()
msgarray = bytearray(msg)
# enumerate byte by byte with XOR
for count, elem in enumerate(msgarray):
#store the byte after XOR operation
msgarray[count] = elem^auxillary.msb(self.r_i)
#update the the register.
self.updateShiftRegister()
pass
# ======== END IMPLEMENTATION ===============
return msgarray
