secp256k1_ecdsa_recoverable_signature: add support.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

external/Makefile

@@ -37,7 +37,7 @@ external/libsecp256k1.% external/libwallycore.%: external/libwally-core/src/secp
 	$(MAKE) -C external/libwally-core install-exec
 
 external/libwally-core/src/libwallycore.% external/libwally-core/src/secp256k1/libsecp256k1.%: $(LIBWALLY_HEADERS) $(LIBSECP_HEADERS)
-	cd external/libwally-core && ./tools/autogen.sh && ./configure CC="$(CC)" --enable-static=yes --enable-shared=no --libdir=`pwd`/.. && $(MAKE)
+	cd external/libwally-core && ./tools/autogen.sh && ./configure CC="$(CC)" --enable-static=yes --enable-module-recovery --enable-shared=no --libdir=`pwd`/.. && $(MAKE)
 
 # Git submodules are seriously broken.
 external/jsmn/jsmn.h:

wire/fromwire.c

@@ -129,6 +129,22 @@ void fromwire_secp256k1_ecdsa_signature(const u8 **cursor,
 		fromwire_fail(cursor, max);
 }
 
+void fromwire_secp256k1_ecdsa_recoverable_signature(const u8 **cursor,
+				    size_t *max,
+				    secp256k1_ecdsa_recoverable_signature *rsig)
+{
+	u8 compact[64];
+	int recid;
+
+	fromwire(cursor, max, compact, sizeof(compact));
+	recid = fromwire_u8(cursor, max);
+
+	if (secp256k1_ecdsa_recoverable_signature_parse_compact(secp256k1_ctx,
+								rsig, compact,
+								recid) != 1)
+		fromwire_fail(cursor, max);
+}
+
 void fromwire_channel_id(const u8 **cursor, size_t *max,
 			 struct channel_id *channel_id)
 {

wire/towire.c

@@ -79,6 +79,20 @@ void towire_secp256k1_ecdsa_signature(u8 **pptr,
 	towire(pptr, compact, sizeof(compact));
 }
 
+void towire_secp256k1_ecdsa_recoverable_signature(u8 **pptr,
+			const secp256k1_ecdsa_recoverable_signature *rsig)
+{
+	u8 compact[64];
+	int recid;
+
+	secp256k1_ecdsa_recoverable_signature_serialize_compact(secp256k1_ctx,
+								compact,
+								&recid,
+								rsig);
+	towire(pptr, compact, sizeof(compact));
+	towire_u8(pptr, recid);
+}
+
 void towire_channel_id(u8 **pptr, const struct channel_id *channel_id)
 {
 	towire(pptr, channel_id, sizeof(*channel_id));

wire/wire.h

@@ -8,6 +8,7 @@
 #include <bitcoin/signature.h>
 #include <ccan/crypto/sha256/sha256.h>
 #include <ccan/short_types/short_types.h>
+#include <secp256k1_recovery.h>
 #include <stdlib.h>
 
 struct channel_id {
@@ -30,6 +31,8 @@ void towire_privkey(u8 **pptr, const struct privkey *privkey);
 void towire_secret(u8 **pptr, const struct secret *secret);
 void towire_secp256k1_ecdsa_signature(u8 **pptr,
 			      const secp256k1_ecdsa_signature *signature);
+void towire_secp256k1_ecdsa_recoverable_signature(u8 **pptr,
+			      const secp256k1_ecdsa_recoverable_signature *rsig);
 void towire_channel_id(u8 **pptr, const struct channel_id *channel_id);
 void towire_short_channel_id(u8 **pptr,
 			     const struct short_channel_id *short_channel_id);
@@ -57,6 +60,9 @@ void fromwire_privkey(const u8 **cursor, size_t *max, struct privkey *privkey);
 void fromwire_pubkey(const u8 **cursor, size_t *max, struct pubkey *pubkey);
 void fromwire_secp256k1_ecdsa_signature(const u8 **cursor, size_t *max,
 					secp256k1_ecdsa_signature *signature);
+void fromwire_secp256k1_ecdsa_recoverable_signature(const u8 **cursor,
+				    size_t *max,
+				    secp256k1_ecdsa_recoverable_signature *rsig);
 void fromwire_channel_id(const u8 **cursor, size_t *max,
 			 struct channel_id *channel_id);
 void fromwire_short_channel_id(const u8 **cursor, size_t *max,