Decryption of salt encrypted attributes (encrypt=2) is incorrect

[Thrushbeard]

A cleartext value is wrong for salt encrypted attributes in a RADIUS packet (e.g. MS-CHAP2 MPPE keys).

There are two points about a hash value:

1. Decryption and encryption functions are not completely the same. The hash must use part of an encrypted value, not a decrypted one

pyrad/pyrad/packet.py

Line 595 in dd34c5a

last = result[-16:]

last = data[:16] for the decryption.

3. The initial hash value must use a request packet authenticator, not a reply packet authenticator

pyrad/pyrad/packet.py

Line 585 in dd34c5a

last = self.authenticator + salt