From 4cd57c8078fae0a4b1bf421191e94626d0cba92a Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Sun, 16 Sep 2007 19:32:45 -0700 Subject: [SCTP]: Enable the sending of the AUTH chunk. SCTP-AUTH, Section 6.2: Endpoints MUST send all requested chunks authenticated where this has been requested by the peer. The other chunks MAY be sent authenticated or not. If endpoint pair shared keys are used, one of them MUST be selected for authentication. To send chunks in an authenticated way, the sender MUST include these chunks after an AUTH chunk. This means that a sender MUST bundle chunks in order to authenticate them. If the endpoint has no endpoint pair shared key for the peer, it MUST use Shared Key Identifier 0 with an empty endpoint pair shared key. If there are multiple endpoint shared keys the sender selects one and uses the corresponding Shared Key Identifier Signed-off-by: Vlad Yasevich Signed-off-by: David S. Miller --- net/sctp/sm_make_chunk.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'net/sctp/sm_make_chunk.c') diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 4c02875786ac..fa2ba543183d 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -1111,6 +1111,41 @@ nodata: return retval; } +struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) +{ + struct sctp_chunk *retval; + struct sctp_hmac *hmac_desc; + struct sctp_authhdr auth_hdr; + __u8 *hmac; + + /* Get the first hmac that the peer told us to use */ + hmac_desc = sctp_auth_asoc_get_hmac(asoc); + if (unlikely(!hmac_desc)) + return NULL; + + retval = sctp_make_chunk(asoc, SCTP_CID_AUTH, 0, + hmac_desc->hmac_len + sizeof(sctp_authhdr_t)); + if (!retval) + return NULL; + + auth_hdr.hmac_id = htons(hmac_desc->hmac_id); + auth_hdr.shkey_id = htons(asoc->active_key_id); + + retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t), + &auth_hdr); + + hmac = skb_put(retval->skb, hmac_desc->hmac_len); + memset(hmac, 0, hmac_desc->hmac_len); + + /* Adjust the chunk header to include the empty MAC */ + retval->chunk_hdr->length = + htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); + retval->chunk_end = skb_tail_pointer(retval->skb); + + return retval; +} + + /******************************************************************** * 2nd Level Abstractions ********************************************************************/ @@ -1225,6 +1260,10 @@ struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, retval->chunk_hdr = chunk_hdr; retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); + /* Determine if the chunk needs to be authenticated */ + if (sctp_auth_send_cid(type, asoc)) + retval->auth = 1; + /* Set the skb to the belonging sock for accounting. */ skb->sk = sk; -- cgit v1.2.2