Hi, I'm working on supporting receiving and sending multiple proposals. While doing that I realized that our proposal matching algorithm might accept a proposal we can't fully accept.
The RFC specifies that to accept a proposal, we must select a transform for each transform type. We do some sanity checks, for instance we do require an encryption transform for ESP, but that's not enough. We need to check that for every proposed transform type we have found a matching transform in our own proposal. ok? Patrick diff --git a/sbin/iked/ikev2.c b/sbin/iked/ikev2.c index fbc487695a9..062b6a50b40 100644 --- a/sbin/iked/ikev2.c +++ b/sbin/iked/ikev2.c @@ -4079,9 +4079,22 @@ ikev2_match_proposals(struct iked_proposal *local, struct iked_proposal *peer, struct iked_transform *tpeer, *tlocal; unsigned int i, j, type, score, requiredh = 0; uint8_t protoid = peer->prop_protoid; + uint8_t peerxfs[IKEV2_XFORMTYPE_MAX]; + + bzero(peerxfs, sizeof(peerxfs)); for (i = 0; i < peer->prop_nxforms; i++) { tpeer = peer->prop_xforms + i; + if (tpeer->xform_type > IKEV2_XFORMTYPE_MAX) + continue; + + /* + * Record all transform types from the peer's proposal, + * because if we want this proposal we have to select + * a transform for each proposed transform type. + */ + peerxfs[tpeer->xform_type] = 1; + for (j = 0; j < local->prop_nxforms; j++) { tlocal = local->prop_xforms + j; @@ -4099,8 +4112,6 @@ ikev2_match_proposals(struct iked_proposal *local, struct iked_proposal *peer, tpeer->xform_id != tlocal->xform_id || tpeer->xform_length != tlocal->xform_length) continue; - if (tpeer->xform_type > IKEV2_XFORMTYPE_MAX) - continue; type = tpeer->xform_type; if (xforms[type] == NULL || tlocal->xform_score < @@ -4136,6 +4147,9 @@ ikev2_match_proposals(struct iked_proposal *local, struct iked_proposal *peer, (requiredh && i == IKEV2_XFORMTYPE_DH))) { score = 0; break; + } else if (peerxfs[i] && xforms[i] == NULL) { + score = 0; + break; } else if (xforms[i] == NULL) continue;