[SCTP]: Implete SCTP-AUTH parameter processing

Implement processing for the CHUNKS, RANDOM, and HMAC parameters and
deal with how this parameters are effected by association restarts.
In particular, during unexpeted INIT processing, we need to reply with
parameters from the original INIT chunk.  Also, after restart, we need
to update the old association with new peer parameters and change the
association shared keys.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sctp/command.h

@@ -102,6 +102,7 @@ typedef enum {
 	SCTP_CMD_SET_SK_ERR,	 /* Set sk_err */
 	SCTP_CMD_ASSOC_CHANGE,	 /* generate and send assoc_change event */
 	SCTP_CMD_ADAPTATION_IND, /* generate and send adaptation event */
+	SCTP_CMD_ASSOC_SHKEY,    /* generate the association shared keys */
 	SCTP_CMD_LAST
 } sctp_verb_t;