[PATCH 2/4] [SCTP]: Add check for hmac_algo parameter in sctp_verify_param()
From: Vlad Yasevich <hidden>
Date: 2008-03-28 14:56:24
Subsystem:
networking [general], sctp protocol, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Marcelo Ricardo Leitner, Xin Long, Linus Torvalds
From: Wei Yongjun <redacted> 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 <redacted> Signed-off-by: Vlad Yasevich <redacted> --- net/sctp/sm_make_chunk.c | 29 ++++++++++++++++++++++++++--- 1 files changed, 26 insertions(+), 3 deletions(-)
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index b489f51..63c1490 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c@@ -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) - break; - /* Fall Through */ + 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; fallthrough: default: SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n",
--
1.5.3.5