def read(self,s):
try: s = unb64(s)
except: raise ValueError("key must be base64 encoded.")
if len(s)%2: raise ValueError("invalid key")
k = s[0:len(s)/2]
m = s[len(s)/2:]
self.set(hexpack(k),hexpack(m))
def pdecrypt(self, s):
i = self.crypt(hexpack(unb64(s)))
return hexunpack(i)