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#include <ccan/crypto/ripemd160/ripemd160.h>
#include <ccan/crypto/sha256/sha256.h>
#include <ccan/endian/endian.h>
#include <assert.h>
#include "address.h"
#include "pubkey.h"
#include "script.h"
#include "signature.h"
/* Some standard ops */
#define OP_PUSHBYTES(val) (val)
#define OP_PUSHDATA1 0x4C
#define OP_PUSHDATA2 0x4D
#define OP_PUSHDATA4 0x4E
#define OP_NOP 0x61
#define OP_IF 0x63
#define OP_NOTIF 0x64
#define OP_ELSE 0x67
#define OP_ENDIF 0x68
#define OP_2DROP 0x6d
#define OP_DEPTH 0x74
#define OP_DROP 0x75
#define OP_DUP 0x76
#define OP_SWAP 0x7c
#define OP_EQUAL 0x87
#define OP_EQUALVERIFY 0x88
#define OP_SIZE 0x82
#define OP_1SUB 0x8C
#define OP_ADD 0x93
#define OP_CHECKSIG 0xAC
#define OP_CHECKMULTISIG 0xAE
#define OP_HASH160 0xA9
#ifdef HAS_CSV
#define OP_CHECKSEQUENCEVERIFY 0xB2
#else
/* OP_NOP, otherwise bitcoind complains */
#define OP_CHECKSEQUENCEVERIFY 0x61
#endif
#ifdef HAS_CLTV
#define OP_CHECKLOCKTIMEVERIFY 0xB1
#else
/* OP_NOP, otherwise bitcoind complains */
#define OP_CHECKLOCKTIMEVERIFY 0x61
#endif
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);
}
static void add_number(u8 **script, u32 num)
{
if (num == 0)
add_op(script, 0);
else if (num <= 16)
add_op(script, 0x50 + num);
else {
u8 n = num;
/* We could handle others, but currently unnecessary. */
assert(num < 256);
add_push_bytes(script, &n, sizeof(n));
}
}
static void add_push_key(u8 **scriptp, const struct pubkey *key)
{
add_push_bytes(scriptp, key->der, pubkey_derlen(key));
}
static void add_push_sig(u8 **scriptp, const struct bitcoin_signature *sig)
{
/* Bitcoin wants DER encoding. */
#ifdef SCRIPTS_USE_DER
u8 der[73];
size_t len = signature_to_der(der, &sig->sig);
/* Append sighash type */
der[len++] = sig->stype;
add_push_bytes(scriptp, der, len);
#else /* Alpha uses raw encoding */
u8 with_sighash[sizeof(sig->sig) + 1];
memcpy(with_sighash, &sig->sig, sizeof(sig->sig));
with_sighash[sizeof(sig->sig)] = sig->stype;
add_push_bytes(scriptp, with_sighash, sizeof(with_sighash));
#endif
}
/* FIXME: Is this really required, not a simple add_number? */
static void add_push_le32(u8 **scriptp, u32 val)
{
le32 val_le = cpu_to_le32(val);
add_push_bytes(scriptp, &val_le, sizeof(val_le));
}
/* FIXME: permute? */
/* Is a < b? (If equal we don't care) */
static bool key_less(const struct pubkey *a, const struct pubkey *b)
{
/* Shorter one wins. */
if (pubkey_derlen(a) != pubkey_derlen(b))
return pubkey_derlen(a) < pubkey_derlen(b);
return memcmp(a->der, b->der, pubkey_derlen(a)) < 0;
}
/* tal_count() gives the length of the script. */
u8 *bitcoin_redeem_2of2(const tal_t *ctx,
const struct pubkey *key1,
const struct pubkey *key2)
{
u8 *script = tal_arr(ctx, u8, 0);
add_number(&script, 2);
if (key_less(key1, key2)) {
add_push_key(&script, key1);
add_push_key(&script, key2);
} else {
add_push_key(&script, key2);
add_push_key(&script, key1);
}
add_number(&script, 2);
add_op(&script, OP_CHECKMULTISIG);
return script;
}
/* tal_count() gives the length of the script. */
u8 *bitcoin_redeem_single(const tal_t *ctx, const struct pubkey *key)
{
u8 *script = tal_arr(ctx, u8, 0);
add_push_key(&script, key);
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;
struct ripemd160 redeemhash;
u8 *script = tal_arr(ctx, u8, 0);
add_op(&script, OP_HASH160);
sha256(&h, redeemscript, tal_count(redeemscript));
ripemd160(&redeemhash, h.u.u8, sizeof(h));
add_push_bytes(&script, redeemhash.u.u8, sizeof(redeemhash.u.u8));
add_op(&script, OP_EQUAL);
return script;
}
/* Create a script for our HTLC output: sending. */
u8 *scriptpubkey_htlc_send(const tal_t *ctx,
const struct pubkey *ourkey,
const struct pubkey *theirkey,
uint32_t htlc_abstimeout,
uint32_t locktime,
const struct sha256 *commit_revoke,
const struct sha256 *rhash)
{
/* R value presented: -> them.
* Commit revocation value presented: -> them.
* HTLC times out -> us. */
u8 *script = tal_arr(ctx, u8, 0);
struct ripemd160 ripemd;
add_op(&script, OP_HASH160);
add_op(&script, OP_DUP);
/* Did they supply HTLC R value? */
ripemd160(&ripemd, rhash->u.u8, sizeof(rhash->u));
add_push_bytes(&script, &ripemd, sizeof(ripemd));
add_op(&script, OP_EQUAL);
add_op(&script, OP_SWAP);
/* How about commit revocation value? */
ripemd160(&ripemd, commit_revoke->u.u8, sizeof(commit_revoke->u));
add_push_bytes(&script, &ripemd, sizeof(ripemd));
add_op(&script, OP_EQUAL);
add_op(&script, OP_ADD);
/* If either matched... */
add_op(&script, OP_IF);
add_push_key(&script, theirkey);
add_op(&script, OP_ELSE);
/* If HTLC times out, they can collect after a delay. */
add_push_le32(&script, htlc_abstimeout);
add_op(&script, OP_CHECKLOCKTIMEVERIFY);
add_push_le32(&script, locktime);
add_op(&script, OP_CHECKSEQUENCEVERIFY);
add_op(&script, OP_2DROP);
add_push_key(&script, ourkey);
add_op(&script, OP_ENDIF);
add_op(&script, OP_CHECKSIG);
return script;
}
/* Create a script for our HTLC output: receiving. */
u8 *scriptpubkey_htlc_recv(const tal_t *ctx,
const struct pubkey *ourkey,
const struct pubkey *theirkey,
uint32_t htlc_abstimeout,
uint32_t locktime,
const struct sha256 *commit_revoke,
const struct sha256 *rhash)
{
/* R value presented: -> us.
* Commit revocation value presented: -> them.
* HTLC times out -> them. */
u8 *script = tal_arr(ctx, u8, 0);
struct ripemd160 ripemd;
add_op(&script, OP_HASH160);
add_op(&script, OP_DUP);
/* Did we supply HTLC R value? */
ripemd160(&ripemd, rhash->u.u8, sizeof(rhash->u));
add_push_bytes(&script, &ripemd, sizeof(ripemd));
add_op(&script, OP_EQUAL);
add_op(&script, OP_IF);
add_push_le32(&script, locktime);
add_op(&script, OP_CHECKSEQUENCEVERIFY);
/* Drop extra hash as well as locktime. */
add_op(&script, OP_2DROP);
add_push_key(&script, ourkey);
add_op(&script, OP_ELSE);
/* If they provided commit revocation, available immediately. */
ripemd160(&ripemd, commit_revoke->u.u8, sizeof(commit_revoke->u));
add_push_bytes(&script, &ripemd, sizeof(ripemd));
add_op(&script, OP_EQUAL);
add_op(&script, OP_NOTIF);
/* Otherwise, they must wait for HTLC timeout. */
add_push_le32(&script, htlc_abstimeout);
add_op(&script, OP_CHECKLOCKTIMEVERIFY);
add_op(&script, OP_DROP);
add_op(&script, OP_ENDIF);
add_push_key(&script, theirkey);
add_op(&script, OP_ENDIF);
add_op(&script, OP_CHECKSIG);
return script;
}
u8 *scriptsig_pay_to_pubkeyhash(const tal_t *ctx,
const struct pubkey *key,
const struct bitcoin_signature *sig)
{
u8 *script = tal_arr(ctx, u8, 0);
add_push_sig(&script, sig);
add_push_key(&script, key);
return script;
}
/* Assumes redeemscript contains CHECKSIG, not CHECKMULTISIG */
u8 *scriptsig_p2sh_single_sig(const tal_t *ctx,
const u8 *redeem_script,
size_t redeem_len,
const struct bitcoin_signature *sig)
{
u8 *script = tal_arr(ctx, u8, 0);
add_push_sig(&script, sig);
add_push_bytes(&script, redeem_script, redeem_len);
return script;
}
u8 *scriptsig_p2sh_2of2(const tal_t *ctx,
const struct bitcoin_signature *sig1,
const struct bitcoin_signature *sig2,
const struct pubkey *key1,
const struct pubkey *key2)
{
u8 *script = tal_arr(ctx, u8, 0);
u8 *redeemscript;
/* OP_CHECKMULTISIG has an out-by-one bug, which MBZ */
add_number(&script, 0);
/* sig order should match key order. */
if (key_less(key1, key2)) {
add_push_sig(&script, sig1);
add_push_sig(&script, sig2);
} else {
add_push_sig(&script, sig2);
add_push_sig(&script, sig1);
}
redeemscript = bitcoin_redeem_2of2(script, key1, key2);
add_push_bytes(&script, redeemscript, tal_count(redeemscript));
return script;
}
/* Is this a normal pay to pubkey hash? */
bool is_pay_to_pubkey_hash(const u8 *script, size_t script_len)
{
if (script_len != 25)
return false;
if (script[0] != OP_DUP)
return false;
if (script[1] != OP_HASH160)
return false;
if (script[2] != OP_PUSHBYTES(20))
return false;
if (script[23] != OP_EQUALVERIFY)
return false;
if (script[24] != OP_CHECKSIG)
return false;
return true;
}
bool is_p2sh(const u8 *script, size_t script_len)
{
if (script_len != 23)
return false;
if (script[0] != OP_HASH160)
return false;
if (script[1] != OP_PUSHBYTES(20))
return false;
if (script[22] != OP_EQUAL)
return false;
return true;
}
/* A common script pattern: A can have it with secret, or B can have
* it after delay. */
u8 *bitcoin_redeem_secret_or_delay(const tal_t *ctx,
const struct pubkey *delayed_key,
u32 locktime,
const struct pubkey *key_if_secret_known,
const struct sha256 *hash_of_secret)
{
struct ripemd160 ripemd;
u8 *script = tal_arr(ctx, u8, 0);
ripemd160(&ripemd, hash_of_secret->u.u8, sizeof(hash_of_secret->u));
/* If the secret is supplied.... */
add_op(&script, OP_HASH160);
add_push_bytes(&script, ripemd.u.u8, sizeof(ripemd.u.u8));
add_op(&script, OP_EQUAL);
add_op(&script, OP_IF);
/* They can collect the funds. */
add_push_key(&script, key_if_secret_known);
add_op(&script, OP_ELSE);
/* Other can collect after a delay. */
add_push_le32(&script, locktime);
add_op(&script, OP_CHECKSEQUENCEVERIFY);
add_op(&script, OP_DROP);
add_push_key(&script, delayed_key);
add_op(&script, OP_ENDIF);
add_op(&script, OP_CHECKSIG);
return script;
}
u8 *scriptsig_p2sh_secret(const tal_t *ctx,
const void *secret, size_t secret_len,
const struct bitcoin_signature *sig,
const u8 *redeemscript,
size_t redeem_len)
{
u8 *script = tal_arr(ctx, u8, 0);
add_push_sig(&script, sig);
add_push_bytes(&script, secret, secret_len);
add_push_bytes(&script, redeemscript, redeem_len);
return script;
}