RADIUS attribute from rfc5090


This attribute enables the RADIUS server to prove possession of
         the password.  If the previously received Digest-Qop Attribute
         was 'auth-int' (without surrounding quotes), the RADIUS server
         MUST send a Digest-HA1 Attribute instead of a Digest-Response-
         Auth Attribute.  The Digest-Response-Auth Attribute MUST only
         be used in Access-Accept packets.  The RADIUS client puts the
         attribute value without surrounding quotes into the rspauth
         directive of the Authentication-Info header.
         106 for Digest-Response-Auth.
         >= 3
         The RADIUS server calculates a digest according toand copies the result into this attribute.
         Digest algorithms other than the one defined in  MAY
         define digest lengths other than 32.