def decrypt(b64cipher_text, passwd):
def _good_decipher(fpt):
return fpt[-len(_KNOWN_STR):] == _KNOWN_STR
ct0 = b64cipher_text.decode('base64')
s, ct = ct0[:8], ct0[8:]
c = PyCrypto(passwd)
fpt = c.decrypt(s, ct)
if not _good_decipher(fpt): raise safe.BadPwdException()
return fpt[:-len(_KNOWN_STR)]
def encrypt(plain_text, passwd):
c = PyCrypto(passwd)
s, ct = c.encrypt(plain_text + _KNOWN_STR)
return (s + ct).encode('base64')
