open-anchor-sig, many fixes for open-channel.

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

bitcoin_script.c

@@ -0,0 +1,161 @@
+#include "bitcoin_script.h"
+#include "bitcoin_address.h"
+#include <openssl/ripemd.h>
+#include <ccan/endian/endian.h>
+#include <ccan/crypto/sha256/sha256.h>
+
+/* Some standard ops */
+#define OP_PUSHBYTES(val) (val)
+#define OP_LITERAL(val) (0x51 + (val))
+#define OP_PUSHDATA1	0x4C
+#define OP_PUSHDATA2	0x4D
+#define OP_PUSHDATA4	0x4E
+#define OP_NOP		0x61
+#define OP_DUP		0x76
+#define OP_EQUAL	0x87
+#define OP_EQUALVERIFY	0x88
+#define OP_CHECKSIG	0xAC
+#define OP_CHECKMULTISIG	0xAE
+#define OP_HASH160	0xA9
+
+static void add(u8 **scriptp, const void *mem, size_t len)
+{
+	size_t oldlen = tal_count(*scriptp);
+	tal_resize(scriptp, oldlen + len);
+	memcpy(*scriptp + oldlen, mem, len);
+}
+
+static void add_op(u8 **scriptp, u8 op)
+{
+	add(scriptp, &op, 1);
+}
+
+static void add_push_bytes(u8 **scriptp, const void *mem, size_t len)
+{
+	if (len < 76)
+		add_op(scriptp, OP_PUSHBYTES(len));
+	else if (len < 256) {
+		char c = len;
+		add_op(scriptp, OP_PUSHDATA1);
+		add(scriptp, &c, 1);
+	} else if (len < 65536) {
+		le16 v = cpu_to_le16(len);
+		add_op(scriptp, OP_PUSHDATA2);
+		add(scriptp, &v, 2);
+	} else {
+		le32 v = cpu_to_le32(len);
+		add_op(scriptp, OP_PUSHDATA4);
+		add(scriptp, &v, 4);
+	}
+
+	add(scriptp, mem, len);
+}
+
+/* FIXME: permute? */
+/* Is a < b? (If equal we don't care) */
+static bool key_less(const BitcoinPubkey *a, const BitcoinPubkey *b)
+{
+	size_t len;
+	int cmp;
+
+	if (a->key.len < b->key.len)
+		len = a->key.len;
+	else
+		len = b->key.len;
+
+	cmp = memcmp(a->key.data, b->key.data, len);
+	if (cmp < 0)
+		return true;
+	else if (cmp > 0)
+		return false;
+
+	/* Corner case: if it's shorter, it's less. */
+	return a->key.len < b->key.len;
+}
+	
+/* tal_count() gives the length of the script. */
+u8 *bitcoin_redeem_2of2(const tal_t *ctx,
+			const BitcoinPubkey *key1,
+			const BitcoinPubkey *key2)
+{
+	u8 *script = tal_arr(ctx, u8, 0);
+	add_op(&script, OP_LITERAL(2));
+	if (key_less(key1, key2)) {
+		add_push_bytes(&script, key1->key.data, key1->key.len);
+		add_push_bytes(&script, key2->key.data, key2->key.len);
+	} else {
+		add_push_bytes(&script, key2->key.data, key2->key.len);
+		add_push_bytes(&script, key1->key.data, key1->key.len);
+	}
+	add_op(&script, OP_CHECKMULTISIG);
+	return script;
+}
+
+/* tal_count() gives the length of the script. */
+u8 *bitcoin_redeem_single(const tal_t *ctx, const u8 *key, size_t keylen)
+{
+	u8 *script = tal_arr(ctx, u8, 0);
+	add_push_bytes(&script, key, keylen);
+	add_op(&script, OP_CHECKSIG);
+	return script;
+}
+
+/* Create p2sh for this redeem script. */
+u8 *scriptpubkey_p2sh(const tal_t *ctx, const u8 *redeemscript)
+{
+	struct sha256 h;
+	u8 redeemhash[RIPEMD160_DIGEST_LENGTH];
+	u8 *script = tal_arr(ctx, u8, 0);
+
+	add_op(&script, OP_HASH160);
+	sha256(&h, redeemscript, tal_count(redeemscript));
+	RIPEMD160(h.u.u8, sizeof(h), redeemhash);
+	add_push_bytes(&script, redeemhash, sizeof(redeemhash));
+	add_op(&script, OP_EQUAL);
+	return script;
+}
+
+u8 *scriptpubkey_pay_to_pubkeyhash(const tal_t *ctx,
+				   const struct bitcoin_address *addr)
+{
+	u8 *script = tal_arr(ctx, u8, 0);
+
+	add_op(&script, OP_DUP);
+	add_op(&script, OP_HASH160);
+	add_push_bytes(&script, addr, sizeof(addr));
+	add_op(&script, OP_EQUALVERIFY);
+	add_op(&script, OP_CHECKSIG);
+
+	return script;
+}
+
+u8 *scriptsig_pay_to_pubkeyhash(const tal_t *ctx,
+				const struct bitcoin_address *addr,
+				const u8 *signature,
+				size_t sig_len)
+{
+	u8 *script = tal_arr(ctx, u8, 0);
+
+	add_push_bytes(&script, signature, sig_len);
+	add_push_bytes(&script, addr, sizeof(*addr));
+
+	return script;
+}
+
+/* Is this a normal pay to pubkey hash? */
+bool is_pay_to_pubkey_hash(const ProtobufCBinaryData *script)
+{
+	if (script->len != 25)
+		return false;
+	if (script->data[0] != OP_DUP)
+		return false;
+	if (script->data[1] != OP_HASH160)
+		return false;
+	if (script->data[2] != OP_PUSHBYTES(20))
+		return false;
+	if (script->data[23] != OP_EQUALVERIFY)
+		return false;
+	if (script->data[24] != OP_CHECKSIG)
+		return false;
+	return true;
+}