When using the qop-value 'auth-int', a hash of the HTTP-style
message body's contents is required for digest calculation.
Instead of sending the complete body of the message, only its
hash value is sent. This hash value can be used directly in
the digest calculation.
The clarifications described inabout
the hash of empty entity bodies apply to the Digest-Entity-
Body-Hash Attribute. This attribute MUST only be sent in
112 for Digest-Entity-Body-Hash
The attribute holds the hexadecimal representation of
H(entity-body). This hash is required by certain
authentication mechanisms, such as HTTP Digest with quality of
protection set to 'auth-int'. RADIUS clients MUST use this
attribute to transport the hash of the entity body when HTTP
Digest is the authentication mechanism and the RADIUS server
requires that the integrity of the entity body (e.g., qop
parameter set to 'auth-int') be verified. Extensions to this
document may define support for authentication mechanisms other
than HTTP Digest.