import rijndael
import base64
# source http://stackoverflow.com/a/8232171/195722
KEY_SIZE = 16
BLOCK_SIZE = 32

def encrypt(key, plaintext):
    padded_key = key.ljust(KEY_SIZE, '\0')
    padded_text = plaintext + (BLOCK_SIZE - len(plaintext) % BLOCK_SIZE) * '\0'

    # could also be one of
    #if len(plaintext) % BLOCK_SIZE != 0:
    #    padded_text = plaintext.ljust((len(plaintext) / BLOCK_SIZE) + 1 * BLOCKSIZE), '\0')
    # -OR-
    #padded_text = plaintext.ljust((len(plaintext) + (BLOCK_SIZE - len(plaintext) % BLOCK_SIZE)), '\0')

    r = rijndael.rijndael(padded_key, BLOCK_SIZE)

    ciphertext = ''
    for start in range(0, len(padded_text), BLOCK_SIZE):
        ciphertext += r.encrypt(padded_text[start:start+BLOCK_SIZE])

    encoded = base64.b64encode(ciphertext)

    return encoded


def decrypt(key, encoded):
    padded_key = key.ljust(KEY_SIZE, '\0')

    ciphertext = base64.b64decode(encoded)

    r = rijndael.rijndael(padded_key, BLOCK_SIZE)

    padded_text = ''
    for start in range(0, len(ciphertext), BLOCK_SIZE):
        padded_text += r.decrypt(ciphertext[start:start+BLOCK_SIZE])

    plaintext = padded_text.split('\x00', 1)[0]

    return plaintext
    
key = 'MyKey'
text = 'test'

encoded = encrypt(key, text)
print repr(encoded)
# prints 'I+KlvwIK2e690lPLDQMMUf5kfZmdZRIexYJp1SLWRJY='

decoded = decrypt(key, encoded)
print repr(decoded)
# prints 'test'