Copy from http://stackoverflow.com/questions/12524994/encrypt-decrypt-using-pycrypto-aes-256

aes-demo.py

import base64
from Crypto.Cipher import AES
from Crypto import Random

BS = 16
pad = lambda s: s + (BS - len(s) % BS) * chr(BS - len(s) % BS)
unpad = lambda s : s[:-ord(s[len(s)-1:])]

class AESCipher:
	'''AES
	>>> aes = AESCipher('N6pm5ykRJhoDlsJlPFEYjVgUk5PiZwpQ')
	>>> msg = 'hello world'
	>>> msg == aes.decrypt(aes.encrypt(msg))
	True
	>>> msg = 'just a test :-)'
	>>> msg == aes.decrypt(aes.encrypt(msg))
	True
	'''
	def __init__( self, key ):
		self.key = key

	def encrypt( self, raw ):
		raw = pad(raw)
		iv = Random.new().read( AES.block_size )
		cipher = AES.new( self.key, AES.MODE_CBC, iv )
		return base64.b64encode( iv + cipher.encrypt( raw ) )

	def decrypt( self, enc ):
		enc = base64.b64decode(enc)
		iv = enc[:16]
		cipher = AES.new(self.key, AES.MODE_CBC, iv )
		return unpad(cipher.decrypt( enc[16:] ))

if __name__ == '__main__':
	import doctest
	doctest.testmod()