X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=secnet.git;a=blobdiff_plain;f=site.c;h=2cb53f6038a8fc8775eabdc7e88b33e9298d42e9;hp=2e8335ae634bb297035f2761f0ec6a4ecb06810e;hb=45a1170652384baf744a5e61d576af534c7b8b14;hpb=1737eeef9bc4aec1b4d7baa220ce48238b498006

diff --git a/site.c b/site.c
index 2e8335a..2cb53f6 100644
--- a/site.c
+++ b/site.c
@@ -244,6 +244,7 @@ struct site {
     struct hash_if *hash;
 
     uint32_t index; /* Index of this 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 */
@@ -253,9 +254,6 @@ struct site {
 				      after this time, initiate a new
 				      key exchange */
 
-    uint8_t *setupsig; /* Expected signature of incoming MSG1 packets */
-    int32_t setupsiglen; /* Allows us to discard packets quickly if
-			    they are not for us */
     bool_t setup_priority; /* Do we have precedence if both sites emit
 			      message 1 simultaneously? */
     uint32_t log_events;
@@ -278,6 +276,7 @@ struct site {
        packet; we keep trying to continue the exchange, and have to
        timeout before we can listen for another setup packet); perhaps
        we should keep a list of 'bad' sources for setup packets. */
+    uint32_t remote_capabilities;
     uint32_t setup_session_id;
     transport_peers setup_peers;
     uint8_t localN[NONCELEN]; /* Nonces for key exchange */
@@ -335,11 +334,42 @@ static bool_t enter_new_state(struct site *st,uint32_t next);
 static void enter_state_wait(struct site *st);
 static void activate_new_key(struct site *st);
 
+static bool_t is_transform_valid(struct transform_inst_if *transform)
+{
+    return transform && transform->valid(transform->st);
+}
+
 static bool_t current_valid(struct site *st)
 {
-    return st->current.transform->valid(st->current.transform->st);
+    return is_transform_valid(st->current.transform);
 }
 
+#define DEFINE_CALL_TRANSFORM(fwdrev)					\
+static int call_transform_##fwdrev(struct site *st,			\
+				   struct transform_inst_if *transform,	\
+				   struct buffer_if *buf,		\
+				   const char **errmsg)			\
+{									\
+    if (!is_transform_valid(transform)) {				\
+	*errmsg="transform not set up";					\
+	return 1;							\
+    }									\
+    return transform->fwdrev(transform->st,buf,errmsg);			\
+}
+
+DEFINE_CALL_TRANSFORM(forwards)
+DEFINE_CALL_TRANSFORM(reverse)
+
+static void dispose_transform(struct transform_inst_if **transform_var)
+{
+    struct transform_inst_if *transform=*transform_var;
+    if (transform) {
+	transform->delkey(transform->st);
+	transform->destroy(transform->st);
+    }
+    *transform_var = 0;
+}    
+
 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
 #define CHECK_TYPE(b,t) do { uint32_t type; \
@@ -350,8 +380,7 @@ static bool_t current_valid(struct site *st)
 struct parsedname {
     int32_t len;
     uint8_t *name;
-    int32_t extrainfo_len;
-    uint8_t *extrainfo;
+    struct buffer_if extrainfo;
 };
 
 struct msg {
@@ -360,6 +389,7 @@ struct msg {
     uint32_t source;
     struct parsedname remote;
     struct parsedname local;
+    uint32_t remote_capabilities;
     uint8_t *nR;
     uint8_t *nL;
     int32_t pklen;
@@ -369,6 +399,44 @@ struct msg {
     char *sig;
 };
 
+static void set_new_transform(struct site *st)
+{
+    struct transform_if *generator=st->transform;
+    struct transform_inst_if *generated=generator->create(generator->st);
+    generated->setkey(generated->st,st->sharedsecret,
+		      st->sharedsecretlen,st->setup_priority);
+    dispose_transform(&st->new_transform);
+    st->new_transform=generated;
+}
+
+struct xinfoadd {
+    int32_t lenpos, afternul;
+};
+static void append_string_xinfo_start(struct buffer_if *buf,
+				      struct xinfoadd *xia,
+				      const char *str)
+    /* Helps construct one of the names with additional info as found
+     * in MSG1..4.  Call this function first, then append all the
+     * desired extra info (not including the nul byte) to the buffer,
+     * then call append_string_xinfo_done. */
+{
+    xia->lenpos = buf->size;
+    buf_append_string(buf,str);
+    buf_append_uint8(buf,0);
+    xia->afternul = buf->size;
+}
+static void append_string_xinfo_done(struct buffer_if *buf,
+				     struct xinfoadd *xia)
+{
+    /* we just need to adjust the string length */
+    if (buf->size == xia->afternul) {
+	/* no extra info, strip the nul too */
+	buf_unappend_uint8(buf);
+    } else {
+	put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
+    }
+}
+
 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
    out using a transform of config data supplied by netlink */
 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
@@ -384,7 +452,14 @@ static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
 	(type==LABEL_MSG1?0:st->setup_session_id));
     buf_append_uint32(&st->buffer,st->index);
     buf_append_uint32(&st->buffer,type);
-    buf_append_string(&st->buffer,st->localname);
+
+    struct xinfoadd xia;
+    append_string_xinfo_start(&st->buffer,&xia,st->localname);
+    if ((st->local_capabilities & CAPAB_EARLY) || (type != LABEL_MSG1)) {
+	buf_append_uint32(&st->buffer,st->local_capabilities);
+    }
+    append_string_xinfo_done(&st->buffer,&xia);
+
     buf_append_string(&st->buffer,st->remotename);
     memcpy(buf_append(&st->buffer,NONCELEN),st->localN,NONCELEN);
     if (type==LABEL_MSG1) return True;
@@ -415,11 +490,9 @@ static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
     nm->name=buf_unprepend(msg,nm->len);
     uint8_t *nul=memchr(nm->name,0,nm->len);
     if (!nul) {
-	nm->extrainfo_len=0;
-	nm->extrainfo=0;
+	buffer_readonly_view(&nm->extrainfo,0,0);
     } else {
-	nm->extrainfo=nul+1;
-	nm->extrainfo_len=msg->start-nm->extrainfo;
+	buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
 	nm->len=nul-nm->name;
     }
     return True;
@@ -435,6 +508,11 @@ static bool_t unpick_msg(struct site *st, uint32_t type,
     m->source=buf_unprepend_uint32(msg);
     CHECK_TYPE(msg,type);
     if (!unpick_name(msg,&m->remote)) return False;
+    m->remote_capabilities=0;
+    if (m->remote.extrainfo.size) {
+	CHECK_AVAIL(&m->remote.extrainfo,4);
+	m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
+    }
     if (!unpick_name(msg,&m->local)) return False;
     CHECK_AVAIL(msg,NONCELEN);
     m->nR=buf_unprepend(msg,NONCELEN);
@@ -493,7 +571,13 @@ static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
 	*error="wrong remotely-generated nonce";
 	return False;
     }
+    /* MSG3 has complicated rules about capabilities, which are
+     * handled in process_msg3. */
     if (type==LABEL_MSG3) return True;
+    if (m->remote_capabilities!=st->remote_capabilities) {
+	*error="remote capabilities changed";
+	return False;
+    }
     if (type==LABEL_MSG4) return True;
     *error="unknown message type";
     return False;
@@ -506,19 +590,16 @@ static bool_t generate_msg1(struct site *st)
 }
 
 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
-			   const struct comm_addr *src)
+			   const struct comm_addr *src, struct msg *m)
 {
-    struct msg m;
-
     /* We've already determined we're in an appropriate state to
        process an incoming MSG1, and that the MSG1 has correct values
        of A and B. */
 
-    if (!unpick_msg(st,LABEL_MSG1,msg1,&m)) return False;
-
     transport_record_peer(st,&st->setup_peers,src,"msg1");
-    st->setup_session_id=m.source;
-    memcpy(st->remoteN,m.nR,NONCELEN);
+    st->setup_session_id=m->source;
+    st->remote_capabilities=m->remote_capabilities;
+    memcpy(st->remoteN,m->nR,NONCELEN);
     return True;
 }
 
@@ -540,6 +621,7 @@ static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
 	return False;
     }
     st->setup_session_id=m.source;
+    st->remote_capabilities=m.remote_capabilities;
     memcpy(st->remoteN,m.nR,NONCELEN);
     return True;
 }
@@ -565,6 +647,15 @@ static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
 	slog(st,LOG_SEC,"msg3: %s",err);
 	return False;
     }
+    uint32_t capab_adv_late = m.remote_capabilities
+	& ~st->remote_capabilities & CAPAB_EARLY;
+    if (capab_adv_late) {
+	slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
+	     " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
+	     capab_adv_late, st->remote_capabilities, m.remote_capabilities);
+	return False;
+    }
+    st->remote_capabilities|=m.remote_capabilities;
 
     /* Check signature and store g^x mod m */
     hash=safe_malloc(st->hash->len, "process_msg3");
@@ -590,8 +681,7 @@ static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
 		       st->sharedsecret,st->sharedsecretlen);
 
     /* Set up the transform */
-    st->new_transform->setkey(st->new_transform->st,st->sharedsecret,
-			      st->sharedsecretlen,st->setup_priority);
+    set_new_transform(st);
 
     return True;
 }
@@ -637,8 +727,7 @@ static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
     st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,m.pk,
 		       st->sharedsecret,st->sharedsecretlen);
     /* Set up the transform */
-    st->new_transform->setkey(st->new_transform->st,st->sharedsecret,
-			      st->sharedsecretlen,st->setup_priority);
+    set_new_transform(st);
 
     return True;
 }
@@ -672,8 +761,9 @@ static bool_t generate_msg5(struct site *st)
     /* Give the netlink code an opportunity to put its own stuff in the
        message (configuration information, etc.) */
     buf_prepend_uint32(&st->buffer,LABEL_MSG5);
-    st->new_transform->forwards(st->new_transform->st,&st->buffer,
-				&transform_err);
+    if (call_transform_forwards(st,st->new_transform,
+				&st->buffer,&transform_err))
+	return False;
     buf_prepend_uint32(&st->buffer,LABEL_MSG5);
     buf_prepend_uint32(&st->buffer,st->index);
     buf_prepend_uint32(&st->buffer,st->setup_session_id);
@@ -691,7 +781,7 @@ static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
 
     if (!unpick_msg0(st,msg5,&m)) return False;
 
-    if (transform->reverse(transform->st,msg5,&transform_err)) {
+    if (call_transform_reverse(st,transform,msg5,&transform_err)) {
 	/* There's a problem */
 	slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
 	return False;
@@ -718,7 +808,9 @@ static void create_msg6(struct site *st, struct transform_inst_if *transform,
     /* Give the netlink code an opportunity to put its own stuff in the
        message (configuration information, etc.) */
     buf_prepend_uint32(&st->buffer,LABEL_MSG6);
-    transform->forwards(transform->st,&st->buffer,&transform_err);
+    int problem = call_transform_forwards(st,transform,
+					  &st->buffer,&transform_err);
+    assert(!problem);
     buf_prepend_uint32(&st->buffer,LABEL_MSG6);
     buf_prepend_uint32(&st->buffer,st->index);
     buf_prepend_uint32(&st->buffer,session_id);
@@ -726,6 +818,8 @@ static void create_msg6(struct site *st, struct transform_inst_if *transform,
 
 static bool_t generate_msg6(struct site *st)
 {
+    if (!is_transform_valid(st->new_transform))
+	return False;
     create_msg6(st,st->new_transform,st->setup_session_id);
     st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
     return True;
@@ -739,8 +833,7 @@ static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
 
     if (!unpick_msg0(st,msg6,&m)) return False;
 
-    if (st->new_transform->reverse(st->new_transform->st,
-				   msg6,&transform_err)) {
+    if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
 	/* There's a problem */
 	slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
 	return False;
@@ -768,8 +861,8 @@ static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0,
     /* Keep a copy so we can try decrypting it with multiple keys */
     buffer_copy(&st->scratch, msg0);
 
-    problem = st->current.transform->reverse(st->current.transform->st,
-					     msg0,&transform_err);
+    problem = call_transform_reverse(st,st->current.transform,
+				     msg0,&transform_err);
     if (!problem) {
 	if (!st->auxiliary_is_new)
 	    delete_one_key(st,&st->auxiliary_key,
@@ -780,8 +873,8 @@ static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0,
 	goto skew;
 
     buffer_copy(msg0, &st->scratch);
-    problem = st->auxiliary_key.transform->reverse
-	(st->auxiliary_key.transform->st,msg0,&auxkey_err);
+    problem = call_transform_reverse(st,st->auxiliary_key.transform,
+				     msg0,&auxkey_err);
     if (problem==0) {
 	slog(st,LOG_DROP,"processing packet which uses auxiliary key");
 	if (st->auxiliary_is_new) {
@@ -806,8 +899,8 @@ static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0,
 
     if (st->state==SITE_SENTMSG5) {
 	buffer_copy(msg0, &st->scratch);
-	problem = st->new_transform->reverse(st->new_transform->st,
-					     msg0,&newkey_err);
+	problem = call_transform_reverse(st,st->new_transform,
+					 msg0,&newkey_err);
 	if (!problem) {
 	    /* It looks like we didn't get the peer's MSG6 */
 	    /* This is like a cut-down enter_new_state(SITE_RUN) */
@@ -866,9 +959,9 @@ static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
 static void dump_packet(struct site *st, struct buffer_if *buf,
 			const struct comm_addr *addr, bool_t incoming)
 {
-    uint32_t dest=ntohl(*(uint32_t *)buf->start);
-    uint32_t source=ntohl(*(uint32_t *)(buf->start+4));
-    uint32_t msgtype=ntohl(*(uint32_t *)(buf->start+8));
+    uint32_t dest=get_uint32(buf->start);
+    uint32_t source=get_uint32(buf->start+4);
+    uint32_t msgtype=get_uint32(buf->start+8);
 
     if (st->log_events & LOG_DUMP)
 	slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x:",
@@ -897,8 +990,8 @@ static bool_t send_msg(struct site *st)
 	t=st->auxiliary_key.transform;
 	st->auxiliary_key.transform=st->new_transform;
 	st->new_transform=t;
+	dispose_transform(&st->new_transform);
 
-	t->delkey(t->st);
 	st->auxiliary_is_new=1;
 	st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
 	st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
@@ -967,8 +1060,8 @@ static void activate_new_key(struct site *st)
     st->auxiliary_key.transform=st->current.transform;
     st->current.transform=st->new_transform;
     st->new_transform=t;
+    dispose_transform(&st->new_transform);
 
-    t->delkey(t->st);
     st->timeout=0;
     st->auxiliary_is_new=0;
     st->auxiliary_key.key_timeout=st->current.key_timeout;
@@ -984,9 +1077,9 @@ static void activate_new_key(struct site *st)
 static void delete_one_key(struct site *st, struct data_key *key,
 			   cstring_t reason, cstring_t which, uint32_t loglevel)
 {
-    if (!key->transform->valid(key->transform->st)) return;
+    if (!is_transform_valid(key->transform)) return;
     if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
-    key->transform->delkey(key->transform->st);
+    dispose_transform(&key->transform);
     key->key_timeout=0;
 }
 
@@ -1011,7 +1104,7 @@ static void enter_state_stop(struct site *st)
     st->state=SITE_STOP;
     st->timeout=0;
     delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
-    st->new_transform->delkey(st->new_transform->st);
+    dispose_transform(&st->new_transform);
 }
 
 static void set_link_quality(struct site *st)
@@ -1041,7 +1134,7 @@ static void enter_state_run(struct site *st)
     transport_peers_clear(st,&st->setup_peers);
     memset(st->localN,0,NONCELEN);
     memset(st->remoteN,0,NONCELEN);
-    st->new_transform->delkey(st->new_transform->st);
+    dispose_transform(&st->new_transform);
     memset(st->dhsecret,0,st->dh->len);
     memset(st->sharedsecret,0,st->sharedsecretlen);
     set_link_quality(st);
@@ -1135,13 +1228,15 @@ static bool_t send_msg7(struct site *st, cstring_t reason)
 	buffer_init(&st->buffer,st->transform->max_start_pad+(4*3));
 	buf_append_uint32(&st->buffer,LABEL_MSG7);
 	buf_append_string(&st->buffer,reason);
-	st->current.transform->forwards(st->current.transform->st,
-					&st->buffer, &transform_err);
+	if (call_transform_forwards(st, st->current.transform,
+				    &st->buffer, &transform_err))
+	    goto free_out;
 	buf_prepend_uint32(&st->buffer,LABEL_MSG0);
 	buf_prepend_uint32(&st->buffer,st->index);
 	buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
 	transport_xmit(st,&st->peers,&st->buffer,True);
 	BUF_FREE(&st->buffer);
+    free_out:
 	return True;
     }
     return False;
@@ -1238,13 +1333,15 @@ static void site_outgoing(void *sst, struct buffer_if *buf)
 	/* Transform it and send it */
 	if (buf->size>0) {
 	    buf_prepend_uint32(buf,LABEL_MSG9);
-	    st->current.transform->forwards(st->current.transform->st,
-					    buf, &transform_err);
+	    if (call_transform_forwards(st, st->current.transform,
+					buf, &transform_err))
+		goto free_out;
 	    buf_prepend_uint32(buf,LABEL_MSG0);
 	    buf_prepend_uint32(buf,st->index);
 	    buf_prepend_uint32(buf,st->current.remote_session_id);
 	    transport_xmit(st,&st->peers,buf,False);
 	}
+    free_out:
 	BUF_FREE(buf);
 	return;
     }
@@ -1254,6 +1351,18 @@ static void site_outgoing(void *sst, struct buffer_if *buf)
     initiate_key_setup(st,"outgoing packet");
 }
 
+static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
+			   uint32_t type, struct msg *m)
+    /* For packets which are identified by the local and remote names.
+     * If it has our name and our peer's name in it it's for us. */
+{
+    struct buffer_if buf[1];
+    buffer_readonly_clone(buf,buf_in);
+    return unpick_msg(st,type,buf,m)
+	&& name_matches(&m->remote,st->remotename)
+	&& name_matches(&m->local,st->localname);
+}
+
 /* This function is called by the communication device to deliver
    packets from our peers. */
 static bool_t site_incoming(void *sst, struct buffer_if *buf,
@@ -1263,60 +1372,57 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
 
     if (buf->size < 12) return False;
 
-    uint32_t dest=ntohl(*(uint32_t *)buf->start);
-
-    if (dest==0) {
-	/* It could be for any site - it should have LABEL_MSG1 and
-	   might have our name and our peer's name in it */
-	if (buf->size<(st->setupsiglen+8+NONCELEN)) return False;
-	if (memcmp(buf->start+8,st->setupsig,st->setupsiglen)==0) {
-	    /* It's addressed to us. Decide what to do about it. */
-	    dump_packet(st,buf,source,True);
-	    if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
-		st->state==SITE_WAIT) {
-		/* We should definitely process it */
-		if (process_msg1(st,buf,source)) {
-		    slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
+    uint32_t dest=get_uint32(buf->start);
+    uint32_t msgtype=get_uint32(buf->start+8);
+    struct msg named_msg;
+
+    if (msgtype==LABEL_MSG1) {
+	if (!named_for_us(st,buf,msgtype,&named_msg))
+	    return False;
+	/* It's a MSG1 addressed to us. Decide what to do about it. */
+	dump_packet(st,buf,source,True);
+	if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
+	    st->state==SITE_WAIT) {
+	    /* We should definitely process it */
+	    if (process_msg1(st,buf,source,&named_msg)) {
+		slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
+		enter_new_state(st,SITE_SENTMSG2);
+	    } else {
+		slog(st,LOG_ERROR,"failed to process incoming msg1");
+	    }
+	    BUF_FREE(buf);
+	    return True;
+	} else if (st->state==SITE_SENTMSG1) {
+	    /* We've just sent a message 1! They may have crossed on
+	       the wire. If we have priority then we ignore the
+	       incoming one, otherwise we process it as usual. */
+	    if (st->setup_priority) {
+		BUF_FREE(buf);
+		slog(st,LOG_DUMP,"crossed msg1s; we are higher "
+		     "priority => ignore incoming msg1");
+		return True;
+	    } else {
+		slog(st,LOG_DUMP,"crossed msg1s; we are lower "
+		     "priority => use incoming msg1");
+		if (process_msg1(st,buf,source,&named_msg)) {
+		    BUF_FREE(&st->buffer); /* Free our old message 1 */
 		    enter_new_state(st,SITE_SENTMSG2);
 		} else {
-		    slog(st,LOG_ERROR,"failed to process incoming msg1");
+		    slog(st,LOG_ERROR,"failed to process an incoming "
+			 "crossed msg1 (we have low priority)");
 		}
 		BUF_FREE(buf);
 		return True;
-	    } else if (st->state==SITE_SENTMSG1) {
-		/* We've just sent a message 1! They may have crossed on
-		   the wire. If we have priority then we ignore the
-		   incoming one, otherwise we process it as usual. */
-		if (st->setup_priority) {
-		    BUF_FREE(buf);
-		    slog(st,LOG_DUMP,"crossed msg1s; we are higher "
-			 "priority => ignore incoming msg1");
-		    return True;
-		} else {
-		    slog(st,LOG_DUMP,"crossed msg1s; we are lower "
-			 "priority => use incoming msg1");
-		    if (process_msg1(st,buf,source)) {
-			BUF_FREE(&st->buffer); /* Free our old message 1 */
-			enter_new_state(st,SITE_SENTMSG2);
-		    } else {
-			slog(st,LOG_ERROR,"failed to process an incoming "
-			     "crossed msg1 (we have low priority)");
-		    }
-		    BUF_FREE(buf);
-		    return True;
-		}
 	    }
-	    /* The message 1 was received at an unexpected stage of the
-	       key setup. XXX POLICY - what do we do? */
-	    slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
-	    BUF_FREE(buf);
-	    return True;
 	}
-	return False; /* Not for us. */
+	/* The message 1 was received at an unexpected stage of the
+	   key setup. XXX POLICY - what do we do? */
+	slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
+	BUF_FREE(buf);
+	return True;
     }
     if (dest==st->index) {
 	/* Explicitly addressed to us */
-	uint32_t msgtype=ntohl(get_uint32(buf->start+8));
 	if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True);
 	switch (msgtype) {
 	case LABEL_NAK:
@@ -1491,6 +1597,7 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
 
     assert(index_sequence < 0xffffffffUL);
     st->index = ++index_sequence;
+    st->local_capabilities = 0;
     st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
 
     list_t *comms_cfg=dict_lookup(dict,"comm");
@@ -1565,14 +1672,6 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
     /* The information we expect to see in incoming messages of type 1 */
     /* fixme: lots of unchecked overflows here, but the results are only
        corrupted packets rather than undefined behaviour */
-    st->setupsiglen=strlen(st->remotename)+strlen(st->localname)+8;
-    st->setupsig=safe_malloc(st->setupsiglen,"site_apply");
-    put_uint32(st->setupsig+0,LABEL_MSG1);
-    put_uint16(st->setupsig+4,strlen(st->remotename));
-    memcpy(&st->setupsig[6],st->remotename,strlen(st->remotename));
-    put_uint16(st->setupsig+(6+strlen(st->remotename)),strlen(st->localname));
-    memcpy(&st->setupsig[8+strlen(st->remotename)],st->localname,
-	   strlen(st->localname));
     st->setup_priority=(strcmp(st->localname,st->remotename)>0);
 
     buffer_new(&st->buffer,SETUP_BUFFER_LEN);
@@ -1585,6 +1684,7 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
     register_for_poll(st, site_beforepoll, site_afterpoll, 0, "site");
     st->timeout=0;
 
+    st->remote_capabilities=0;
     st->current.key_timeout=0;
     st->auxiliary_key.key_timeout=0;
     transport_peers_clear(st,&st->peers);
@@ -1603,20 +1703,18 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
 	    worst_##pad=thispad;		\
     }
     COMPUTE_WORST(min_start_pad)
-    COMPUTE_WORST(min_end_pad)
 
     /* We need to register the remote networks with the netlink device */
     st->netlink->reg(st->netlink->st, site_outgoing, st,
 		     st->transform->max_start_pad+(4*4)+
-		     worst_min_start_pad,
-		     st->transform->max_end_pad+worst_min_end_pad);
+		     worst_min_start_pad);
     
     for (i=0; i<st->ncomms; i++)
 	st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
 
-    st->current.transform=st->transform->create(st->transform->st);
-    st->auxiliary_key.transform=st->transform->create(st->transform->st);
-    st->new_transform=st->transform->create(st->transform->st);
+    st->current.transform=0;
+    st->auxiliary_key.transform=0;
+    st->new_transform=0;
     st->auxiliary_is_new=0;
 
     enter_state_stop(st);