X-Git-Url: https://git.distorted.org.uk/~mdw/secnet/blobdiff_plain/cbc2519681f5fceab5c6153110215090663eb3e9..refs/heads/master:/site.c

diff --git a/site.c b/site.c
index 5146501..d0dd909 100644
--- a/site.c
+++ b/site.c
@@ -321,7 +321,7 @@ struct site {
     uint32_t local_capabilities;
     int32_t setup_retries; /* How many times to send setup packets */
     int32_t setup_retry_interval; /* Initial timeout for setup packets */
-    int32_t wait_timeout; /* How long to wait if setup unsuccessful */
+    int32_t wait_timeout_mean; /* How long to wait if setup unsuccessful */
     int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
     int32_t key_lifetime; /* How long a key lasts once set up */
     int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
@@ -535,6 +535,16 @@ struct msg {
     char *sig;
 };
 
+static int32_t wait_timeout(struct site *st) {
+    int32_t t = st->wait_timeout_mean;
+    int8_t factor;
+    if (t < INT_MAX/2) {
+	st->random->generate(st->random->st,sizeof(factor),&factor);
+	t += (t / 256) * factor;
+    }
+    return t;
+}
+
 static _Bool set_new_transform(struct site *st, char *pk)
 {
     _Bool ok;
@@ -757,7 +767,7 @@ static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
 	return False;
     }
     if (type==LABEL_MSG2) return True;
-    if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)!=0) {
+    if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
 	*error="wrong remotely-generated nonce";
 	return False;
     }
@@ -1353,7 +1363,7 @@ static void decrement_resolving_count(struct site *st, int by)
 	} else if (st->local_mobile) {
 	    /* Not very good.  We should queue (another) renegotiation
 	     * so that we can update the peer address. */
-	    st->key_renegotiate_time=st->now+st->wait_timeout;
+	    st->key_renegotiate_time=st->now+wait_timeout(st);
 	} else {
 	    slog(st,LOG_SETUP_INIT,"resolution failed: "
 		 " continuing to use source address of peer's packets");
@@ -1466,7 +1476,8 @@ static void set_link_quality(struct site *st)
 
 static void enter_state_run(struct site *st)
 {
-    slog(st,LOG_STATE,"entering state RUN");
+    slog(st,LOG_STATE,"entering state RUN%s",
+	 current_valid(st) ? " (keyed)" : " (unkeyed)");
     st->state=SITE_RUN;
     st->timeout=0;
 
@@ -1628,7 +1639,7 @@ static bool_t send_msg7(struct site *st, cstring_t reason)
 static void enter_state_wait(struct site *st)
 {
     slog(st,LOG_STATE,"entering state WAIT");
-    st->timeout=st->now+st->wait_timeout;
+    st->timeout=st->now+wait_timeout(st);
     st->state=SITE_WAIT;
     set_link_quality(st);
     BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
@@ -1770,14 +1781,34 @@ static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
 }
 
 static bool_t we_have_priority(struct site *st, const struct msg *m) {
-    if ((st->local_capabilities & m->remote_capabilities)
-	&& CAPAB_PRIORITY_MOBILE) {
+    if (st->local_capabilities & m->remote_capabilities &
+	CAPAB_PRIORITY_MOBILE) {
 	if (st->local_mobile) return True;
 	if (st-> peer_mobile) return False;
     }
     return st->our_name_later;
 }
 
+static bool_t setup_late_msg_ok(struct site *st, 
+				const struct buffer_if *buf_in,
+				uint32_t msgtype,
+				const struct comm_addr *source) {
+    /* For setup packets which seem from their type like they are
+     * late.  Maybe they came via a different path.  All we do is make
+     * a note of the sending address, iff they look like they are part
+     * of the current key setup attempt. */
+    struct msg m;
+    if (!named_for_us(st,buf_in,msgtype,&m))
+	/* named_for_us calls unpick_msg which gets the nonces */
+	return False;
+    if (!consttime_memeq(m.nR,st->remoteN,NONCELEN) ||
+	!consttime_memeq(m.nL,st->localN, NONCELEN))
+	/* spoof ?  from stale run ?  who knows */
+	return False;
+    transport_setup_msgok(st,source);
+    return True;
+}
+
 /* This function is called by the communication device to deliver
    packets from our peers.
    It should return True if the packet is recognised as being for
@@ -1839,9 +1870,21 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
 		BUF_FREE(buf);
 		return True;
 	    }
+	} else if (st->state==SITE_SENTMSG2 ||
+		   st->state==SITE_SENTMSG4) {
+	    if (consttime_memeq(named_msg.nR,st->remoteN,NONCELEN)) {
+		/* We are ahead in the protocol, but that msg1 had the
+		 * peer's nonce so presumably it is from this key
+		 * exchange run, via a slower route */
+		transport_setup_msgok(st,source);
+	    } else {
+		slog(st,LOG_UNEXPECTED,"competing incoming message 1");
+	    }
+	    BUF_FREE(buf);
+	    return True;
 	}
 	/* The message 1 was received at an unexpected stage of the
-	   key setup. XXX POLICY - what do we do? */
+	   key setup.  Well, they lost the race. */
 	slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
 	BUF_FREE(buf);
 	return True;
@@ -1886,6 +1929,10 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
 	case LABEL_MSG2:
 	    /* Setup packet: expected only in state SENTMSG1 */
 	    if (st->state!=SITE_SENTMSG1) {
+		if ((st->state==SITE_SENTMSG3 ||
+		     st->state==SITE_SENTMSG5) &&
+		    setup_late_msg_ok(st,buf,msgtype,source))
+		    break;
 		slog(st,LOG_UNEXPECTED,"unexpected MSG2");
 	    } else if (process_msg2(st,buf,source)) {
 		transport_setup_msgok(st,source);
@@ -1898,6 +1945,9 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
 	case LABEL_MSG3BIS:
 	    /* Setup packet: expected only in state SENTMSG2 */
 	    if (st->state!=SITE_SENTMSG2) {
+		if ((st->state==SITE_SENTMSG4) &&
+		    setup_late_msg_ok(st,buf,msgtype,source))
+		    break;
 		slog(st,LOG_UNEXPECTED,"unexpected MSG3");
 	    } else if (process_msg3(st,buf,source,msgtype)) {
 		transport_setup_msgok(st,source);
@@ -1909,6 +1959,9 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
 	case LABEL_MSG4:
 	    /* Setup packet: expected only in state SENTMSG3 */
 	    if (st->state!=SITE_SENTMSG3) {
+		if ((st->state==SITE_SENTMSG5) &&
+		    setup_late_msg_ok(st,buf,msgtype,source))
+		    break;
 		slog(st,LOG_UNEXPECTED,"unexpected MSG4");
 	    } else if (process_msg4(st,buf,source)) {
 		transport_setup_msgok(st,source);
@@ -2112,7 +2165,7 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
     st->key_lifetime=         CFG_NUMBER("key-lifetime",  KEY_LIFETIME);
     st->setup_retries=        CFG_NUMBER("setup-retries", SETUP_RETRIES);
     st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
-    st->wait_timeout=         CFG_NUMBER("wait-time",     WAIT_TIME);
+    st->wait_timeout_mean=    CFG_NUMBER("wait-time",     WAIT_TIME);
     st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
 
     st->mobile_peer_expiry= dict_read_number(