from Crypto.Cipher import AES
import string
import base64
import time
#import modules
PADDING = '{'
BLOCK_SIZE = 32
pad = lambda s: s + (BLOCK_SIZE - len(s) % BLOCK_SIZE) * PADDING
#prepare crypto method
EncodeAES = lambda c, s: base64.b64encode(c.encrypt(pad(s)))
DecodeAES = lambda c, e: c.decrypt(base64.b64decode(e)).rstrip(PADDING)
#set encryption/decryption variables
loop=5
while loop==5:
#set up loop, so the program can be rerun again if desired without restarting
option=raw_input("Would You Like to Encrypt Or Decrypt Text?\nEncrypt: a\nDecrypt: b\n")
if option=='a':
letter=3
while letter==3:
secret = raw_input("Please Enter An Encryption Key {must be 16 characters long}: ")
countTotal= (len(secret))
if countTotal==16:
cipher = AES.new(secret)
letter=0
else:
print "Please Ensure The Key You Entered Is 16 Characters In Length\n"
letter=3
#this checks the encryption key to ensure it matches the correct length
# encode a string
data=raw_input("Please Enter Text You'd Like Encrypted: ")
encoded = EncodeAES(cipher, data)
print 'Encrypted string:', encoded
options=raw_input("Would You Like To Encrypt/Decrypt Again? Y/N\n")
if options=='y':
loop=5
if options=='n':
loop=0
if option=='b':
encoded=raw_input("Please Enter The Encoded String:\n")
letter=3
while letter==3:
secret=raw_input("Please Enter The Decryption Key:\n")
countTotal= (len(secret))
#this checks the encryption key to ensure it matches the correct length
if countTotal==16:
cipher = AES.new(secret)
letter=0
decoded = DecodeAES(cipher, encoded)
print 'Decrypted string:', decoded
options=raw_input("Would You Like To Encrypt/Decrypt Again? Y/N\n")
if options=='y':
loop=5
if options=='n':
loop=0
else:
print "Please Ensure The Key You Entered Is 16 Characters In Length\n"
letter=3
if loop==0:
print "Goodbye!!"
time.sleep(2)
exit
#exits the program if desired by user
