Move bitcoin stuff into bitcoin subdir.

It's not very interesting if you're looking for LN code.

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

bitcoin/signature.h

@@ -0,0 +1,54 @@
+#ifndef LIGHTNING_BITCOIN_SIGNATURE_H
+#define LIGHTNING_BITCOIN_SIGNATURE_H
+#include <ccan/short_types/short_types.h>
+#include <openssl/ecdsa.h>
+#include <ccan/tal/tal.h>
+#include "../lightning.pb-c.h"
+
+enum sighash_type {
+    SIGHASH_ALL = 1,
+    SIGHASH_NONE = 2,
+    SIGHASH_SINGLE = 3,
+    SIGHASH_ANYONECANPAY = 0x80
+};
+
+/* ECDSA of double SHA256. */
+struct signature {
+	u8 r[32];
+	u8 s[32];
+};
+
+struct sha256_double;
+struct bitcoin_tx;
+struct pubkey;
+struct bitcoin_tx_output;
+struct bitcoin_signature;
+
+bool sign_hash(const tal_t *ctx, EC_KEY *private_key,
+	       const struct sha256_double *h,
+	       struct signature *s);
+
+/* All tx input scripts must be set to 0 len. */
+bool sign_tx_input(const tal_t *ctx, struct bitcoin_tx *tx,
+		   unsigned int in,
+		   const u8 *subscript, size_t subscript_len,
+		   EC_KEY *privkey, const struct pubkey *pubkey,
+		   struct signature *sig);
+
+/* Does this sig sign the tx with this input for this pubkey. */
+bool check_tx_sig(struct bitcoin_tx *tx, size_t input_num,
+		  const u8 *redeemscript, size_t redeemscript_len,
+		  const struct pubkey *key,
+		  const struct bitcoin_signature *sig);
+
+bool check_2of2_sig(struct bitcoin_tx *tx, size_t input_num,
+		    const u8 *redeemscript, size_t redeemscript_len,
+		    const struct pubkey *key1, const struct pubkey *key2,
+		    const struct bitcoin_signature *sig1,
+		    const struct bitcoin_signature *sig2);
+
+/* Convert to-from protobuf to internal representation. */
+Signature *signature_to_proto(const tal_t *ctx, const struct signature *sig);
+bool proto_to_signature(const Signature *pb, struct signature *sig);
+
+#endif /* LIGHTNING_BITCOIN_SIGNATURE_H */