Re: unauthorized deletion of IPsec (and ISAKMP) SAs in racoon

> 0 Preface
>
> Now that most bugs in isakmpd that allowed for unauthorized SA
> deletion are "fixed", it's time to release some information on racoon.
>
> By the way: About 5 months ago I tried to contact the KAME developers.

        sorry that we did not take necessary actions that time. the attached
        patch should remedy the problem (credit: IIJ SEIL team).
        kame as well as netbsd repository are updated, and vendors are informed.

itojun

Index: isakmp_inf.c
===================================================================
RCS file: /cvsroot/kame/kame/kame/kame/racoon/isakmp_inf.c,v
retrieving revision 1.82
diff -u -r1.82 isakmp_inf.c
--- isakmp_inf.c 13 Nov 2003 02:30:20 -0000 1.82
+++ isakmp_inf.c 14 Jan 2004 09:14:31 -0000
@@ -136,10 +136,81 @@
 
         isakmp = (struct isakmp *)msg->v;
         gen = (struct isakmp_gen *)((caddr_t)isakmp + sizeof(struct isakmp));
- if (isakmp->np == ISAKMP_NPTYPE_HASH)
- np = gen->np;
- else
- np = isakmp->np;
+
+ if (isakmp->np != ISAKMP_NPTYPE_HASH) {
+ plog(LLV_ERROR, LOCATION, NULL,
+ "ignore information because the message has no hash payload.\n");
+ goto end;
+ }
+
+ if (iph1->status != PHASE1ST_ESTABLISHED) {
+ plog(LLV_ERROR, LOCATION, NULL,
+ "ignore information because ISAKMP-SA has not been established yet.\n");
+ goto end;
+ }
+
+ np = gen->np;
+
+ {
+ void *p;
+ vchar_t *hash, *payload;
+ struct isakmp_gen *nd;
+
+ /*
+ * XXX: gen->len includes isakmp header length
+ */
+ p = (caddr_t) gen + sizeof(struct isakmp_gen);
+ nd = (struct isakmp_gen *) ((caddr_t) gen + gen->len);
+
+ /* nd length check */
+ if (nd->len > msg->l - (sizeof(struct isakmp) + gen->len)) {
+ plog(LLV_ERROR, LOCATION, NULL,
+ "too long payload length (broken message?)\n");
+ goto end;
+ }
+
+ payload = vmalloc(nd->len);
+ if (payload == NULL) {
+ plog(LLV_ERROR, LOCATION, NULL,
+ "cannot allocate memory\n");
+ goto end;
+ }
+
+ memcpy(payload->v, (caddr_t) nd, nd->len);
+
+ /* compute HASH */
+ hash = oakley_compute_hash1(iph1, isakmp->msgid, payload);
+ if (hash == NULL) {
+ plog(LLV_ERROR, LOCATION, NULL,
+ "cannot compute hash\n");
+
+ vfree(payload);
+ goto end;
+ }
+
+ if (gen->len - sizeof(struct isakmp_gen) != hash->l) {
+ plog(LLV_ERROR, LOCATION, NULL,
+ "ignore information due to hash length mismatch\n");
+
+ vfree(hash);
+ vfree(payload);
+ goto end;
+ }
+
+ if (memcmp(p, hash->v, hash->l) != 0) {
+ plog(LLV_ERROR, LOCATION, NULL,
+ "ignore information due to hash mismatch\n");
+
+ vfree(hash);
+ vfree(payload);
+ goto end;
+ }
+
+ plog(LLV_DEBUG, LOCATION, NULL, "hash validated.\n");
+
+ vfree(hash);
+ vfree(payload);
+ }
                 
         /* make sure the packet were encrypted. */
         if (!encrypted) {
Received on Jan 14 2004