diff --git a/lightningd/channel_config.c b/lightningd/channel_config.c
index e6b4f26a6..bace60853 100644
--- a/lightningd/channel_config.c
+++ b/lightningd/channel_config.c
@@ -12,11 +12,9 @@ void towire_channel_config(u8 **pptr, const struct channel_config *config)
 	towire_u16(pptr, config->max_accepted_htlcs);
 }
 
-struct channel_config *fromwire_channel_config(const tal_t *ctx,
-				       const u8 **ptr, size_t *max)
+void fromwire_channel_config(const u8 **ptr, size_t *max,
+			     struct channel_config *config)
 {
-	struct channel_config *config = tal(ctx, struct channel_config);
-
 	config->dust_limit_satoshis = fromwire_u64(ptr, max);
 	config->max_htlc_value_in_flight_msat = fromwire_u64(ptr, max);
 	config->channel_reserve_satoshis = fromwire_u64(ptr, max);
@@ -24,8 +22,4 @@ struct channel_config *fromwire_channel_config(const tal_t *ctx,
 	config->htlc_minimum_msat = fromwire_u32(ptr, max);
 	config->to_self_delay = fromwire_u16(ptr, max);
 	config->max_accepted_htlcs = fromwire_u16(ptr, max);
-
-	if (!*ptr)
-		return tal_free(config);
-	return config;
 }
diff --git a/lightningd/channel_config.h b/lightningd/channel_config.h
index 7d1e7c4a9..f9f6a2865 100644
--- a/lightningd/channel_config.h
+++ b/lightningd/channel_config.h
@@ -41,6 +41,6 @@ struct channel_config {
 };
 
 void towire_channel_config(u8 **pptr, const struct channel_config *config);
-struct channel_config *fromwire_channel_config(const tal_t *ctx,
-					       const u8 **ptr, size_t *max);
+void fromwire_channel_config(const u8 **ptr, size_t *max,
+			     struct channel_config *config);
 #endif /* LIGHTNING_LIGHTNINGD_CHANNEL_CONFIG_H */
diff --git a/lightningd/cryptomsg.c b/lightningd/cryptomsg.c
index 49986c2b1..b39becdec 100644
--- a/lightningd/cryptomsg.c
+++ b/lightningd/cryptomsg.c
@@ -12,23 +12,6 @@
 #include <wire/wire.h>
 #include <wire/wire_io.h>
 
-struct crypto_state {
-	/* Received and sent nonces. */
-	u64 rn, sn;
-	/* Sending and receiving keys. */
-	struct sha256 sk, rk;
-	/* Chaining key for re-keying */
-	struct sha256 s_ck, r_ck;
-
-	/* Peer who owns us: peer->crypto_state == this */
-	struct peer *peer;
-
-	/* Output and input buffers. */
-	u8 *out, *in;
-	struct io_plan *(*next_in)(struct io_conn *, struct peer *, u8 *);
-	struct io_plan *(*next_out)(struct io_conn *, struct peer *);
-};
-
 static void hkdf_two_keys(struct sha256 *out1, struct sha256 *out2,
 			  const struct sha256 *in1,
 			  const struct sha256 *in2)
@@ -332,20 +315,12 @@ void towire_crypto_state(u8 **ptr, const struct crypto_state *cs)
 	towire_sha256(ptr, &cs->r_ck);
 }
 
-struct crypto_state *fromwire_crypto_state(const tal_t *ctx,
-					   const u8 **ptr, size_t *max)
+void fromwire_crypto_state(const u8 **ptr, size_t *max, struct crypto_state *cs)
 {
-	struct crypto_state *cs = tal(ctx, struct crypto_state);
-
 	cs->rn = fromwire_u64(ptr, max);
 	cs->sn = fromwire_u64(ptr, max);
 	fromwire_sha256(ptr, max, &cs->sk);
 	fromwire_sha256(ptr, max, &cs->rk);
 	fromwire_sha256(ptr, max, &cs->s_ck);
 	fromwire_sha256(ptr, max, &cs->r_ck);
-	cs->peer = (struct peer *)ctx;
-
-	if (!*ptr)
-		return tal_free(cs);
-	return cs;
 }
diff --git a/lightningd/cryptomsg.h b/lightningd/cryptomsg.h
index 9fbecf81c..675bbdfec 100644
--- a/lightningd/cryptomsg.h
+++ b/lightningd/cryptomsg.h
@@ -1,12 +1,29 @@
 #ifndef LIGHTNING_LIGHTNINGD_CRYPTOMSG_H
 #define LIGHTNING_LIGHTNINGD_CRYPTOMSG_H
 #include "config.h"
+#include <ccan/crypto/sha256/sha256.h>
 #include <ccan/short_types/short_types.h>
 #include <ccan/tal/tal.h>
 
 struct io_conn;
 struct peer;
-struct sha256;
+
+struct crypto_state {
+	/* Received and sent nonces. */
+	u64 rn, sn;
+	/* Sending and receiving keys. */
+	struct sha256 sk, rk;
+	/* Chaining key for re-keying */
+	struct sha256 s_ck, r_ck;
+
+	/* Peer who owns us: peer->crypto_state == this */
+	struct peer *peer;
+
+	/* Output and input buffers. */
+	u8 *out, *in;
+	struct io_plan *(*next_in)(struct io_conn *, struct peer *, u8 *);
+	struct io_plan *(*next_out)(struct io_conn *, struct peer *);
+};
 
 /* Initializes peer->crypto_state */
 struct crypto_state *crypto_state(struct peer *peer,
@@ -31,7 +48,5 @@ struct io_plan *peer_write_message(struct io_conn *conn,
 							   struct peer *));
 
 void towire_crypto_state(u8 **pptr, const struct crypto_state *cs);
-struct crypto_state *fromwire_crypto_state(const tal_t *ctx,
-					   const u8 **ptr, size_t *max);
-
+void fromwire_crypto_state(const u8 **ptr, size_t *max, struct crypto_state *cs);
 #endif /* LIGHTNING_LIGHTNINGD_CRYPTOMSG_H */
diff --git a/lightningd/gossip/gossip.c b/lightningd/gossip/gossip.c
index 52d3f7d95..68edfd028 100644
--- a/lightningd/gossip/gossip.c
+++ b/lightningd/gossip/gossip.c
@@ -14,6 +14,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
+#include <lightningd/cryptomsg.h>
 #include <lightningd/gossip/gen_gossip_control_wire.h>
 #include <lightningd/gossip/gen_gossip_status_wire.h>
 #include <secp256k1_ecdh.h>
@@ -69,9 +70,10 @@ static void destroy_peer(struct peer *peer)
 static struct peer *setup_new_peer(struct daemon *daemon, const u8 *msg)
 {
 	struct peer *peer = tal(daemon, struct peer);
-	if (!fromwire_gossipctl_new_peer(peer, msg, NULL,
-					 &peer->unique_id, &peer->cs))
+	peer->cs = tal(peer, struct crypto_state);
+	if (!fromwire_gossipctl_new_peer(msg, NULL, &peer->unique_id, peer->cs))
 		return tal_free(peer);
+	peer->cs->peer = peer;
 	peer->daemon = daemon;
 	peer->error = NULL;
 	list_add_tail(&daemon->peers, &peer->list);
diff --git a/lightningd/gossip_control.c b/lightningd/gossip_control.c
index 18063cd98..57bbbdc33 100644
--- a/lightningd/gossip_control.c
+++ b/lightningd/gossip_control.c
@@ -7,6 +7,7 @@
 #include <daemon/jsonrpc.h>
 #include <daemon/log.h>
 #include <inttypes.h>
+#include <lightningd/cryptomsg.h>
 #include <lightningd/gossip/gen_gossip_control_wire.h>
 #include <lightningd/gossip/gen_gossip_status_wire.h>
 
@@ -45,16 +46,17 @@ static void peer_nongossip(struct subdaemon *gossip, const u8 *msg, int fd)
 	u64 unique_id;
 	struct peer *peer;
 	u8 *inner;
-	struct crypto_state *cs;
+	struct crypto_state *cs = tal(msg, struct crypto_state);
 
 	if (!fromwire_gossipstatus_peer_nongossip(msg, msg, NULL,
-						  &unique_id, &cs, &inner))
+						  &unique_id, cs, &inner))
 		fatal("Gossip gave bad PEER_NONGOSSIP message %s",
 		      tal_hex(msg, msg));
 
 	peer = peer_by_unique_id(gossip->ld, unique_id);
 	if (!peer)
 		fatal("Gossip gave bad peerid %"PRIu64, unique_id);
+	cs->peer = peer;
 
 	log_debug(gossip->log, "Peer %s said %s",
 		  type_to_string(msg, struct pubkey, peer->id),
diff --git a/lightningd/peer_control.c b/lightningd/peer_control.c
index 481b46d9e..bd7f6387f 100644
--- a/lightningd/peer_control.c
+++ b/lightningd/peer_control.c
@@ -88,22 +88,23 @@ struct peer *peer_by_unique_id(struct lightningd *ld, u64 unique_id)
 static void handshake_succeeded(struct subdaemon *hs, const u8 *msg,
 				struct peer *peer)
 {
-	struct crypto_state *cs;
+	struct crypto_state *cs = tal(peer, struct crypto_state);
 
 	if (!peer->id) {
 		struct pubkey id;
 
-		if (!fromwire_handshake_responder_resp(msg, msg, NULL, &id, &cs))
+		if (!fromwire_handshake_responder_resp(msg, NULL, &id, cs))
 			goto err;
 		peer->id = tal_dup(peer, struct pubkey, &id);
 		log_info_struct(hs->log, "Peer in from %s",
 				struct pubkey, peer->id);
 	} else {
-		if (!fromwire_handshake_initiator_resp(msg, msg, NULL, &cs))
+		if (!fromwire_handshake_initiator_resp(msg, NULL, cs))
 			goto err;
 		log_info_struct(hs->log, "Peer out to %s",
 				struct pubkey, peer->id);
 	}
+	cs->peer = peer;
 
 	/* FIXME: Look for peer duplicates! */
 
diff --git a/tools/generate-wire.py b/tools/generate-wire.py
index 60fd67070..c3b27c377 100755
--- a/tools/generate-wire.py
+++ b/tools/generate-wire.py
@@ -54,7 +54,6 @@ class Field(object):
         self.comments = comments
         self.name = name.replace('-', '_')
         self.is_len_var = False
-        self.is_unknown = False
         self.lenvar = None
 
         # Size could be a literal number (eg. 33), or a field (eg 'len'), or
@@ -78,7 +77,6 @@ class Field(object):
 
         # Unknown types are assumed to have base_size: div by 0 if that's unknown.
         if self.fieldtype.tsize == 0:
-            self.is_unknown = True
             self.fieldtype.tsize = base_size
 
         if base_size % self.fieldtype.tsize != 0:
@@ -185,8 +183,6 @@ class Message(object):
         if field.is_variable_size():
             self.checkLenField(field)
             self.has_variable_fields = True
-        elif field.is_unknown:
-            self.has_variable_fields = True
         self.fields.append(field)
 
     def print_fromwire(self,is_header):
@@ -205,7 +201,7 @@ class Message(object):
                 continue
             if f.is_array():
                 print(', {} {}[{}]'.format(f.fieldtype.name, f.name, f.num_elems), end='')
-            elif f.is_variable_size() or f.is_unknown:
+            elif f.is_variable_size():
                 print(', {} **{}'.format(f.fieldtype.name, f.name), end='')
             else:
                 print(', {} *{}'.format(f.fieldtype.name, f.name), end='')
@@ -240,14 +236,7 @@ class Message(object):
             for c in f.comments:
                 print('\t/*{} */'.format(c))
 
-            if f.is_unknown:
-                if f.is_variable_size():
-                    print('\t*{} = fromwire_{}_array(ctx, &cursor, plen, {});'
-                      .format(f.name, basetype, f.lenvar))
-                else:
-                    print('\t*{} = fromwire_{}(ctx, &cursor, plen);'
-                          .format(f.name, basetype))
-            elif f.is_padding():
+            if f.is_padding():
                 print('\tfromwire_pad(&cursor, plen, {});'
                       .format(f.num_elems))
             elif f.is_array():