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 sthen@

diff --git a/sbin/iked/ikev2.c b/sbin/iked/ikev2.c
index fbc4876..0b88d13 100644 (file)
--- a/sbin/iked/ikev2.c
+++ b/sbin/iked/ikev2.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ikev2.c,v 1.160 2017/12/01 19:49:31 patrick Exp $     */
+/*     $OpenBSD: ikev2.c,v 1.161 2017/12/03 21:02:06 patrick Exp $     */
 
 /*
  * Copyright (c) 2010-2013 Reyk Floeter <reyk@openbsd.org>
@@ -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;