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/pubkey.c

@@ -0,0 +1,67 @@
+#include "pubkey.h"
+#include <openssl/ecdsa.h>
+#include <ccan/str/hex/hex.h>
+
+/* Must agree on key validity with bitcoin!  Stolen from bitcoin/src/pubkey.h's
+ * GetLen:
+ * // Copyright (c) 2009-2010 Satoshi Nakamoto
+ * // Copyright (c) 2009-2014 The Bitcoin Core developers
+ * // Distributed under the MIT software license, see the accompanying
+ * // file COPYING or http://www.opensource.org/licenses/mit-license.php.
+ */
+static unsigned int GetLen(unsigned char chHeader)
+{
+        if (chHeader == 2 || chHeader == 3)
+		return 33;
+        if (chHeader == 4 || chHeader == 6 || chHeader == 7)
+		return 65;
+        return 0;
+}
+
+static bool valid_pubkey(const BitcoinPubkey *key)
+{
+	if (key->key.len < 1)
+		return false;
+	return (key->key.len == GetLen(key->key.data[0]));
+}
+
+size_t pubkey_len(const struct pubkey *key)
+{
+	size_t len = GetLen(key->key[0]);
+
+	assert(len);
+	return len;
+}
+
+BitcoinPubkey *pubkey_to_proto(const tal_t *ctx, const struct pubkey *key)
+{
+	BitcoinPubkey *p = tal(ctx, BitcoinPubkey);
+
+	bitcoin_pubkey__init(p);
+	p->key.len = pubkey_len(key);
+	p->key.data = tal_dup_arr(p, u8, key->key, p->key.len, 0);
+
+	assert(valid_pubkey(p));
+	return p;
+}
+
+bool proto_to_pubkey(const BitcoinPubkey *pb, struct pubkey *key)
+{
+	if (!valid_pubkey(pb))
+		return false;
+
+	memcpy(key->key, pb->key.data, pb->key.len);
+	return true;
+}
+
+bool pubkey_from_hexstr(const char *str, struct pubkey *key)
+{
+	size_t slen = strlen(str), dlen;
+	dlen = hex_data_size(slen);
+
+	if (dlen != 33 && dlen != 65)
+		return false;
+	if (!hex_decode(str, slen, key->key, dlen))
+		return false;
+	return GetLen(key->key[0]) == dlen;
+}