[SCTP]: Add check for hmac_algo parameter in sctp_verify_param()

RFC 4890 has the following text:

  The HMAC algorithm based on SHA-1 MUST be supported and
  included in the HMAC-ALGO parameter.

As a result, we need to check in sctp_verify_param() that HMAC_SHA1 is
present in the list.  If not, we should probably treat this as a
protocol violation.

It should also be a protocol violation if the HMAC parameter is empty.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Wei Yongjun 2008-04-12 18:39:19 -07:00 committed by David S. Miller
parent e56cfad132
commit 72da7b3860
1 changed files with 26 additions and 3 deletions

View File

@ -1982,7 +1982,10 @@ static sctp_ierror_t sctp_verify_param(const struct sctp_association *asoc,
struct sctp_chunk *chunk,
struct sctp_chunk **err_chunk)
{
struct sctp_hmac_algo_param *hmacs;
int retval = SCTP_IERROR_NO_ERROR;
__u16 n_elt, id = 0;
int i;
/* FIXME - This routine is not looking at each parameter per the
* chunk type, i.e., unrecognized parameters should be further
@ -2056,9 +2059,29 @@ static sctp_ierror_t sctp_verify_param(const struct sctp_association *asoc,
break;
case SCTP_PARAM_HMAC_ALGO:
if (sctp_auth_enable)
if (!sctp_auth_enable)
goto fallthrough;
hmacs = (struct sctp_hmac_algo_param *)param.p;
n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1;
/* SCTP-AUTH: Section 6.1
* The HMAC algorithm based on SHA-1 MUST be supported and
* included in the HMAC-ALGO parameter.
*/
for (i = 0; i < n_elt; i++) {
id = ntohs(hmacs->hmac_ids[i]);
if (id == SCTP_AUTH_HMAC_ID_SHA1)
break;
}
if (id != SCTP_AUTH_HMAC_ID_SHA1) {
sctp_process_inv_paramlength(asoc, param.p, chunk,
err_chunk);
retval = SCTP_IERROR_ABORT;
}
break;
/* Fall Through */
fallthrough:
default:
SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n",