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#include "config.h"
#include <assert.h>
#include <bitcoin/address.h>
#include <bitcoin/locktime.h>
#include <bitcoin/preimage.h>
#include <bitcoin/pubkey.h>
#include <bitcoin/script.h>
#include <ccan/endian/endian.h>
#include <ccan/mem/mem.h>
#include <common/utils.h>
#include <sodium/randombytes.h>
/* To push 0-75 bytes onto stack. */
#define OP_PUSHBYTES(val) (val)
/* Bitcoin's OP_HASH160 is RIPEMD(SHA256()) */
static void hash160(struct ripemd160 *redeemhash, const void *mem, size_t len)
{
struct sha256 h;
sha256(&h, mem, len);
ripemd160(redeemhash, h.u.u8, sizeof(h));
}
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);
}
void script_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, memcheck(mem, len), 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 {
le64 n = cpu_to_le64(num);
/* Beware: encoding is signed! */
if (num <= 0x0000007F)
script_push_bytes(script, &n, 1);
else if (num <= 0x00007FFF)
script_push_bytes(script, &n, 2);
else if (num <= 0x007FFFFF)
script_push_bytes(script, &n, 3);
else if (num <= 0x7FFFFFFF)
script_push_bytes(script, &n, 4);
else
script_push_bytes(script, &n, 5);
}
}
static void add_push_key(u8 **scriptp, const struct pubkey *key)
{
u8 der[PUBKEY_CMPR_LEN];
pubkey_to_der(der, key);
script_push_bytes(scriptp, der, sizeof(der));
}
static void add_push_sig(u8 **scriptp, const struct bitcoin_signature *sig)
{
u8 der[73];
size_t len = signature_to_der(der, sig);
script_push_bytes(scriptp, der, len);
}
static u8 *stack_key(const tal_t *ctx, const struct pubkey *key)
{
u8 der[PUBKEY_CMPR_LEN];
pubkey_to_der(der, key);
return tal_dup_arr(ctx, u8, der, sizeof(der), 0);
}
/* Bitcoin wants DER encoding. */
static u8 *stack_sig(const tal_t *ctx, const struct bitcoin_signature *sig)
{
u8 der[73];
size_t len = signature_to_der(der, sig);
return tal_dup_arr(ctx, u8, der, len, 0);
}
static u8 *stack_preimage(const tal_t *ctx, const struct preimage *preimage)
{
return tal_dup_arr(ctx, u8, preimage->r, sizeof(preimage->r), 0);
}
/* Bitcoin script stack values are a special, special snowflake.
*
* They're little endian values, but 0 is an empty value. We only
* handle single byte values here. */
static u8 *stack_number(const tal_t *ctx, unsigned int num)
{
u8 val;
if (num == 0)
return tal_arr(ctx, u8, 0);
val = num;
assert(val == num);
/* We use tal_dup_arr since we want tal_count() to work */
return tal_dup_arr(ctx, u8, &val, 1, 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 (pubkey_cmp(key1, key2) < 0) {
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;
}
u8 *scriptpubkey_p2sh_hash(const tal_t *ctx, const struct ripemd160 *redeemhash)
{
u8 *script = tal_arr(ctx, u8, 0);
add_op(&script, OP_HASH160);
script_push_bytes(&script, redeemhash->u.u8, sizeof(redeemhash->u.u8));
add_op(&script, OP_EQUAL);
assert(tal_count(script) == BITCOIN_SCRIPTPUBKEY_P2SH_LEN);
return script;
}
/* Create p2sh for this redeem script. */
u8 *scriptpubkey_p2sh(const tal_t *ctx, const u8 *redeemscript)
{
struct ripemd160 redeemhash;
hash160(&redeemhash, redeemscript, tal_count(redeemscript));
return scriptpubkey_p2sh_hash(ctx, &redeemhash);
}
/* Create an output script using p2pkh */
u8 *scriptpubkey_p2pkh(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);
script_push_bytes(&script, &addr->addr, sizeof(addr->addr));
add_op(&script, OP_EQUALVERIFY);
add_op(&script, OP_CHECKSIG);
assert(tal_count(script) == BITCOIN_SCRIPTPUBKEY_P2PKH_LEN);
return script;
}
u8 *scriptpubkey_opreturn_padded(const tal_t *ctx)
{
u8 *script = tal_arr(ctx, u8, 0);
u8 random[20];
randombytes_buf(random, sizeof(random));
add_op(&script, OP_RETURN);
script_push_bytes(&script, random, sizeof(random));
return script;
}
/* Create an input script which spends p2pkh */
u8 *bitcoin_redeem_p2pkh(const tal_t *ctx, const struct pubkey *pubkey,
const struct bitcoin_signature *sig)
{
u8 *script = tal_arr(ctx, u8, 0);
add_push_sig(&script, sig);
add_push_key(&script, pubkey);
return script;
}
/* Create the redeemscript for a P2SH + P2WPKH (for signing tx) */
u8 *bitcoin_redeem_p2sh_p2wpkh(const tal_t *ctx, const struct pubkey *key)
{
struct ripemd160 keyhash;
u8 *script = tal_arr(ctx, u8, 0);
/* BIP141: BIP16 redeemScript pushed in the scriptSig is exactly a
* push of a version byte plus a push of a witness program. */
add_number(&script, 0);
pubkey_to_hash160(key, &keyhash);
script_push_bytes(&script, &keyhash, sizeof(keyhash));
assert(tal_count(script) == BITCOIN_SCRIPTPUBKEY_P2WPKH_LEN);
return script;
}
u8 *bitcoin_scriptsig_redeem(const tal_t *ctx,
const u8 *redeemscript TAKES)
{
u8 *script;
/* BIP141: The scriptSig must be exactly a push of the BIP16
* redeemScript or validation fails. */
script = tal_arr(ctx, u8, 0);
script_push_bytes(&script, redeemscript,
tal_count(redeemscript));
if (taken(redeemscript))
tal_free(redeemscript);
return script;
}
u8 *bitcoin_scriptsig_p2sh_p2wpkh(const tal_t *ctx, const struct pubkey *key)
{
u8 *redeemscript =
bitcoin_redeem_p2sh_p2wpkh(NULL, key);
return bitcoin_scriptsig_redeem(ctx, take(redeemscript));
}
u8 **bitcoin_witness_p2wpkh(const tal_t *ctx,
const struct bitcoin_signature *sig,
const struct pubkey *key)
{
u8 **witness;
/* BIP141: The witness must consist of exactly 2 items (≤ 520
* bytes each). The first one a signature, and the second one
* a public key. */
witness = tal_arr(ctx, u8 *, 2);
witness[0] = stack_sig(witness, sig);
witness[1] = stack_key(witness, key);
return witness;
}
/* Create an output script for a 32-byte witness. */
u8 *scriptpubkey_p2wsh(const tal_t *ctx, const u8 *witnessscript)
{
struct sha256 h;
u8 *script = tal_arr(ctx, u8, 0);
add_op(&script, OP_0);
sha256(&h, witnessscript, tal_count(witnessscript));
script_push_bytes(&script, h.u.u8, sizeof(h.u.u8));
assert(tal_count(script) == BITCOIN_SCRIPTPUBKEY_P2WSH_LEN);
return script;
}
/* Create an output script for a 20-byte witness. */
u8 *scriptpubkey_p2wpkh(const tal_t *ctx, const struct pubkey *key)
{
struct ripemd160 h;
u8 *script = tal_arr(ctx, u8, 0);
add_op(&script, OP_0);
pubkey_to_hash160(key, &h);
script_push_bytes(&script, &h, sizeof(h));
return script;
}
u8 *scriptpubkey_p2wpkh_derkey(const tal_t *ctx, const u8 der[33])
{
u8 *script = tal_arr(ctx, u8, 0);
struct ripemd160 h;
add_op(&script, OP_0);
hash160(&h, der, PUBKEY_CMPR_LEN);
script_push_bytes(&script, &h, sizeof(h));
return script;
}
u8 *scriptpubkey_witness_raw(const tal_t *ctx, u8 version,
const u8 *wprog, size_t wprog_size)
{
u8 *script = tal_arr(ctx, u8, 0);
add_number(&script, version);
script_push_bytes(&script, wprog, wprog_size);
return script;
}
/* BOLT #3:
*
* #### `to_remote` Output
*
* If `option_anchors` applies to the commitment
* transaction, the `to_remote` output is encumbered by a one
* block csv lock.
* <remotepubkey> OP_CHECKSIGVERIFY 1 OP_CHECKSEQUENCEVERIFY
*/
/* BOLT- #3
* ##### Leased channel (`option_will_fund`)
*
* If a `lease` applies to the channel, the `to_remote` output
* of the `initiator` ensures the `leasor` funds are not
* spendable until the lease expires.
*
* <remote_pubkey> OP_CHECKSIGVERIFY MAX(1, lease_end - blockheight) OP_CHECKSEQUENCEVERIFY
*/
u8 *anchor_to_remote_redeem(const tal_t *ctx,
const struct pubkey *remote_key,
u32 csv_lock)
{
u8 *script = tal_arr(ctx, u8, 0);
add_push_key(&script, remote_key);
add_op(&script, OP_CHECKSIGVERIFY);
add_number(&script, csv_lock);
add_op(&script, OP_CHECKSEQUENCEVERIFY);
assert(is_anchor_witness_script(script, tal_bytelen(script)));
return script;
}
bool is_anchor_witness_script(const u8 *script, size_t script_len)
{
size_t len = 34 + 1 + 1 + 1;
/* With option_will_fund, the pushbytes can be up to 2 bytes more
*
* <remote_pubkey> OP_CHECKSIGVERIFY
* MAX(1, lease_end - blockheight)
* OP_CHECKSEQUENCEVERIFY
*/
if (script_len < len || script_len > len + 2)
return false;
if (script[0] != OP_PUSHBYTES(33))
return false;
if (script[34] != OP_CHECKSIGVERIFY)
return false;
/* FIXME: check for push value */
if (script[script_len - 1] != OP_CHECKSEQUENCEVERIFY)
return false;
return true;
}
/* Create a witness which spends the 2of2. */
u8 **bitcoin_witness_2of2(const tal_t *ctx,
const struct bitcoin_signature *sig1,
const struct bitcoin_signature *sig2,
const struct pubkey *key1,
const struct pubkey *key2)
{
u8 **witness = tal_arr(ctx, u8 *, 4);
/* OP_CHECKMULTISIG has an out-by-one bug, which MBZ */
witness[0] = stack_number(witness, 0);
/* sig order should match key order. */
if (pubkey_cmp(key1, key2) < 0) {
witness[1] = stack_sig(witness, sig1);
witness[2] = stack_sig(witness, sig2);
} else {
witness[1] = stack_sig(witness, sig2);
witness[2] = stack_sig(witness, sig1);
}
witness[3] = bitcoin_redeem_2of2(witness, key1, key2);
return witness;
}
/* Create scriptcode (fake witness, basically) for P2WPKH */
u8 *p2wpkh_scriptcode(const tal_t *ctx, const struct pubkey *key)
{
struct ripemd160 pkhash;
u8 *script = tal_arr(ctx, u8, 0);
pubkey_to_hash160(key, &pkhash);
/* BIP143:
*
* For P2WPKH witness program, the scriptCode is
* 0x1976a914{20-byte-pubkey-hash}88ac.
*/
/* PUSH(25): OP_DUP OP_HASH160 PUSH(20) 20-byte-pubkey-hash
* OP_EQUALVERIFY OP_CHECKSIG */
add_op(&script, OP_DUP);
add_op(&script, OP_HASH160);
script_push_bytes(&script, &pkhash, sizeof(pkhash));
add_op(&script, OP_EQUALVERIFY);
add_op(&script, OP_CHECKSIG);
return script;
}
bool is_p2pkh(const u8 *script, struct bitcoin_address *addr)
{
size_t script_len = tal_count(script);
if (script_len != BITCOIN_SCRIPTPUBKEY_P2PKH_LEN)
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;
if (addr)
memcpy(addr, script+3, 20);
return true;
}
bool is_p2sh(const u8 *script, struct ripemd160 *addr)
{
size_t script_len = tal_count(script);
if (script_len != BITCOIN_SCRIPTPUBKEY_P2SH_LEN)
return false;
if (script[0] != OP_HASH160)
return false;
if (script[1] != OP_PUSHBYTES(20))
return false;
if (script[22] != OP_EQUAL)
return false;
if (addr)
memcpy(addr, script+2, 20);
return true;
}
bool is_p2wsh(const u8 *script, struct sha256 *addr)
{
size_t script_len = tal_count(script);
if (script_len != BITCOIN_SCRIPTPUBKEY_P2WSH_LEN)
return false;
if (script[0] != OP_0)
return false;
if (script[1] != OP_PUSHBYTES(sizeof(struct sha256)))
return false;
if (addr)
memcpy(addr, script+2, sizeof(struct sha256));
return true;
}
bool is_p2wpkh(const u8 *script, struct bitcoin_address *addr)
{
size_t script_len = tal_count(script);
if (script_len != BITCOIN_SCRIPTPUBKEY_P2WPKH_LEN)
return false;
if (script[0] != OP_0)
return false;
if (script[1] != OP_PUSHBYTES(sizeof(struct ripemd160)))
return false;
if (addr)
memcpy(addr, script+2, sizeof(*addr));
return true;
}
bool is_known_scripttype(const u8 *script)
{
return is_p2wpkh(script, NULL) || is_p2wsh(script, NULL)
|| is_p2sh(script, NULL) || is_p2pkh(script, NULL);
}
u8 **bitcoin_witness_sig_and_element(const tal_t *ctx,
const struct bitcoin_signature *sig,
const void *elem, size_t elemsize,
const u8 *witnessscript)
{
u8 **witness = tal_arr(ctx, u8 *, 3);
witness[0] = stack_sig(witness, sig);
witness[1] = tal_dup_arr(witness, u8, elem, elemsize, 0);
witness[2] = tal_dup_talarr(witness, u8, witnessscript);
return witness;
}
/* BOLT #3:
*
* This output sends funds back to the owner of this commitment transaction and
* thus must be timelocked using `OP_CHECKSEQUENCEVERIFY`. It can be claimed, without delay,
* by the other party if they know the revocation private key. The output is a
* version-0 P2WSH, with a witness script:
*
* OP_IF
* # Penalty transaction
* <revocationpubkey>
* OP_ELSE
* `to_self_delay`
* OP_CHECKSEQUENCEVERIFY
* OP_DROP
* <local_delayedpubkey>
* OP_ENDIF
* OP_CHECKSIG
*/
/* BOLT- #3
* ##### Leased channel (`option_will_fund`)
* If a `lease` applies to the channel, the `to_local` output of the `accepter`
* ensures the `leasor` funds are not spendable until the lease expires.
*
* In a leased channel, the `to_local` output that pays the `accepter` node
* is modified so that its CSV is equal to the greater of the
* `to_self_delay` or the `lease_end` - `blockheight`.
*
* OP_IF
* # Penalty transaction
* <revocationpubkey>
* OP_ELSE
* MAX(`to_self_delay`, `lease_end` - `blockheight`)
* OP_CHECKSEQUENCEVERIFY
* OP_DROP
* <local_delayedpubkey>
* OP_ENDIF
* OP_CHECKSIG
*/
u8 *bitcoin_wscript_to_local(const tal_t *ctx, u16 to_self_delay,
u32 lease_remaining,
const struct pubkey *revocation_pubkey,
const struct pubkey *local_delayedkey)
{
u8 *script = tal_arr(ctx, u8, 0);
add_op(&script, OP_IF);
add_push_key(&script, revocation_pubkey);
add_op(&script, OP_ELSE);
add_number(&script, max_unsigned(lease_remaining, to_self_delay));
add_op(&script, OP_CHECKSEQUENCEVERIFY);
add_op(&script, OP_DROP);
add_push_key(&script, local_delayedkey);
add_op(&script, OP_ENDIF);
add_op(&script, OP_CHECKSIG);
return script;
}
/* BOLT #3:
*
* #### Offered HTLC Outputs
*
* This output sends funds to either an HTLC-timeout transaction after the
* HTLC-timeout or to the remote node using the payment preimage or the
* revocation key. The output is a P2WSH, with a witness script (no
* option_anchors):
*
* # To remote node with revocation key
* OP_DUP OP_HASH160 <RIPEMD160(SHA256(revocationpubkey))> OP_EQUAL
* OP_IF
* OP_CHECKSIG
* OP_ELSE
* <remote_htlcpubkey> OP_SWAP OP_SIZE 32 OP_EQUAL
* OP_NOTIF
* # To local node via HTLC-timeout transaction (timelocked).
* OP_DROP 2 OP_SWAP <local_htlcpubkey> 2 OP_CHECKMULTISIG
* OP_ELSE
* # To remote node with preimage.
* OP_HASH160 <RIPEMD160(payment_hash)> OP_EQUALVERIFY
* OP_CHECKSIG
* OP_ENDIF
* OP_ENDIF
*
* Or, with `option_anchors`:
*
* # To remote node with revocation key
* OP_DUP OP_HASH160 <RIPEMD160(SHA256(revocationpubkey))> OP_EQUAL
* OP_IF
* OP_CHECKSIG
* OP_ELSE
* <remote_htlcpubkey> OP_SWAP OP_SIZE 32 OP_EQUAL
* OP_NOTIF
* # To local node via HTLC-timeout transaction (timelocked).
* OP_DROP 2 OP_SWAP <local_htlcpubkey> 2 OP_CHECKMULTISIG
* OP_ELSE
* # To remote node with preimage.
* OP_HASH160 <RIPEMD160(payment_hash)> OP_EQUALVERIFY
* OP_CHECKSIG
* OP_ENDIF
* 1 OP_CHECKSEQUENCEVERIFY OP_DROP
* OP_ENDIF
*/
u8 *bitcoin_wscript_htlc_offer_ripemd160(const tal_t *ctx,
const struct pubkey *localhtlckey,
const struct pubkey *remotehtlckey,
const struct ripemd160 *payment_ripemd,
const struct pubkey *revocationkey,
bool option_anchor_outputs)
{
u8 *script = tal_arr(ctx, u8, 0);
struct ripemd160 ripemd;
add_op(&script, OP_DUP);
add_op(&script, OP_HASH160);
pubkey_to_hash160(revocationkey, &ripemd);
script_push_bytes(&script, &ripemd, sizeof(ripemd));
add_op(&script, OP_EQUAL);
add_op(&script, OP_IF);
add_op(&script, OP_CHECKSIG);
add_op(&script, OP_ELSE);
add_push_key(&script, remotehtlckey);
add_op(&script, OP_SWAP);
add_op(&script, OP_SIZE);
add_number(&script, 32);
add_op(&script, OP_EQUAL);
add_op(&script, OP_NOTIF);
add_op(&script, OP_DROP);
add_number(&script, 2);
add_op(&script, OP_SWAP);
add_push_key(&script, localhtlckey);
add_number(&script, 2);
add_op(&script, OP_CHECKMULTISIG);
add_op(&script, OP_ELSE);
add_op(&script, OP_HASH160);
script_push_bytes(&script,
payment_ripemd->u.u8, sizeof(payment_ripemd->u.u8));
add_op(&script, OP_EQUALVERIFY);
add_op(&script, OP_CHECKSIG);
add_op(&script, OP_ENDIF);
if (option_anchor_outputs) {
add_number(&script, 1);
add_op(&script, OP_CHECKSEQUENCEVERIFY);
add_op(&script, OP_DROP);
}
add_op(&script, OP_ENDIF);
return script;
}
u8 *bitcoin_wscript_htlc_offer(const tal_t *ctx,
const struct pubkey *localhtlckey,
const struct pubkey *remotehtlckey,
const struct sha256 *payment_hash,
const struct pubkey *revocationkey,
bool option_anchor_outputs)
{
struct ripemd160 ripemd;
ripemd160(&ripemd, payment_hash->u.u8, sizeof(payment_hash->u));
return bitcoin_wscript_htlc_offer_ripemd160(ctx, localhtlckey,
remotehtlckey,
&ripemd, revocationkey,
option_anchor_outputs);
}
/* BOLT #3:
*
* #### Received HTLC Outputs
*
* This output sends funds to either the remote node after the HTLC-timeout or
* using the revocation key, or to an HTLC-success transaction with a
* successful payment preimage. The output is a P2WSH, with a witness script
* (no `option_anchors`):
*
* # To remote node with revocation key
* OP_DUP OP_HASH160 <RIPEMD160(SHA256(revocationpubkey))> OP_EQUAL
* OP_IF
* OP_CHECKSIG
* OP_ELSE
* <remote_htlcpubkey> OP_SWAP
* OP_SIZE 32 OP_EQUAL
* OP_IF
* # To local node via HTLC-success transaction.
* OP_HASH160 <RIPEMD160(payment_hash)> OP_EQUALVERIFY
* 2 OP_SWAP <local_htlcpubkey> 2 OP_CHECKMULTISIG
* OP_ELSE
* # To remote node after timeout.
* OP_DROP <cltv_expiry> OP_CHECKLOCKTIMEVERIFY OP_DROP
* OP_CHECKSIG
* OP_ENDIF
* OP_ENDIF
*
* Or, with `option_anchors`:
*
* # To remote node with revocation key
* OP_DUP OP_HASH160 <RIPEMD160(SHA256(revocationpubkey))> OP_EQUAL
* OP_IF
* OP_CHECKSIG
* OP_ELSE
* <remote_htlcpubkey> OP_SWAP OP_SIZE 32 OP_EQUAL
* OP_IF
* # To local node via HTLC-success transaction.
* OP_HASH160 <RIPEMD160(payment_hash)> OP_EQUALVERIFY
* 2 OP_SWAP <local_htlcpubkey> 2 OP_CHECKMULTISIG
* OP_ELSE
* # To remote node after timeout.
* OP_DROP <cltv_expiry> OP_CHECKLOCKTIMEVERIFY OP_DROP
* OP_CHECKSIG
* OP_ENDIF
* 1 OP_CHECKSEQUENCEVERIFY OP_DROP
* OP_ENDIF
*/
u8 *bitcoin_wscript_htlc_receive_ripemd(const tal_t *ctx,
const struct abs_locktime *htlc_abstimeout,
const struct pubkey *localhtlckey,
const struct pubkey *remotehtlckey,
const struct ripemd160 *payment_ripemd,
const struct pubkey *revocationkey,
bool option_anchor_outputs)
{
u8 *script = tal_arr(ctx, u8, 0);
struct ripemd160 ripemd;
add_op(&script, OP_DUP);
add_op(&script, OP_HASH160);
pubkey_to_hash160(revocationkey, &ripemd);
script_push_bytes(&script, &ripemd, sizeof(ripemd));
add_op(&script, OP_EQUAL);
add_op(&script, OP_IF);
add_op(&script, OP_CHECKSIG);
add_op(&script, OP_ELSE);
add_push_key(&script, remotehtlckey);
add_op(&script, OP_SWAP);
add_op(&script, OP_SIZE);
add_number(&script, 32);
add_op(&script, OP_EQUAL);
add_op(&script, OP_IF);
add_op(&script, OP_HASH160);
script_push_bytes(&script,
payment_ripemd->u.u8, sizeof(payment_ripemd->u.u8));
add_op(&script, OP_EQUALVERIFY);
add_number(&script, 2);
add_op(&script, OP_SWAP);
add_push_key(&script, localhtlckey);
add_number(&script, 2);
add_op(&script, OP_CHECKMULTISIG);
add_op(&script, OP_ELSE);
add_op(&script, OP_DROP);
add_number(&script, htlc_abstimeout->locktime);
add_op(&script, OP_CHECKLOCKTIMEVERIFY);
add_op(&script, OP_DROP);
add_op(&script, OP_CHECKSIG);
add_op(&script, OP_ENDIF);
if (option_anchor_outputs) {
add_number(&script, 1);
add_op(&script, OP_CHECKSEQUENCEVERIFY);
add_op(&script, OP_DROP);
}
add_op(&script, OP_ENDIF);
return script;
}
u8 *bitcoin_wscript_htlc_receive(const tal_t *ctx,
const struct abs_locktime *htlc_abstimeout,
const struct pubkey *localhtlckey,
const struct pubkey *remotehtlckey,
const struct sha256 *payment_hash,
const struct pubkey *revocationkey,
bool option_anchor_outputs)
{
struct ripemd160 ripemd;
ripemd160(&ripemd, payment_hash->u.u8, sizeof(payment_hash->u));
return bitcoin_wscript_htlc_receive_ripemd(ctx, htlc_abstimeout,
localhtlckey, remotehtlckey,
&ripemd, revocationkey,
option_anchor_outputs);
}
/* BOLT #3:
*
* ## HTLC-Timeout and HTLC-Success Transactions
*
*...
* * `txin[0]` witness stack: `0 <remotehtlcsig> <localhtlcsig> <payment_preimage>` for HTLC-success, `0 <remotehtlcsig> <localhtlcsig> <>` for HTLC-timeout
*/
u8 **bitcoin_witness_htlc_timeout_tx(const tal_t *ctx,
const struct bitcoin_signature *localhtlcsig,
const struct bitcoin_signature *remotehtlcsig,
const u8 *wscript)
{
u8 **witness = tal_arr(ctx, u8 *, 5);
witness[0] = stack_number(witness, 0);
witness[1] = stack_sig(witness, remotehtlcsig);
witness[2] = stack_sig(witness, localhtlcsig);
witness[3] = stack_number(witness, 0);
witness[4] = tal_dup_talarr(witness, u8, wscript);
return witness;
}
u8 **bitcoin_witness_htlc_success_tx(const tal_t *ctx,
const struct bitcoin_signature *localhtlcsig,
const struct bitcoin_signature *remotesig,
const struct preimage *preimage,
const u8 *wscript)
{
u8 **witness = tal_arr(ctx, u8 *, 5);
witness[0] = stack_number(witness, 0);
witness[1] = stack_sig(witness, remotesig);
witness[2] = stack_sig(witness, localhtlcsig);
witness[3] = stack_preimage(witness, preimage);
witness[4] = tal_dup_talarr(witness, u8, wscript);
return witness;
}
u8 *bitcoin_wscript_htlc_tx(const tal_t *ctx,
u16 to_self_delay,
const struct pubkey *revocation_pubkey,
const struct pubkey *local_delayedkey)
{
u8 *script = tal_arr(ctx, u8, 0);
/* BOLT #3:
*
* The witness script for the output is:
*
* OP_IF
* # Penalty transaction
* <revocationpubkey>
* OP_ELSE
* `to_self_delay`
* OP_CHECKSEQUENCEVERIFY
* OP_DROP
* <local_delayedpubkey>
* OP_ENDIF
* OP_CHECKSIG
*/
add_op(&script, OP_IF);
add_push_key(&script, revocation_pubkey);
add_op(&script, OP_ELSE);
add_number(&script, to_self_delay);
add_op(&script, OP_CHECKSEQUENCEVERIFY);
add_op(&script, OP_DROP);
add_push_key(&script, local_delayedkey);
add_op(&script, OP_ENDIF);
add_op(&script, OP_CHECKSIG);
return script;
}
u8 *bitcoin_wscript_anchor(const tal_t *ctx,
const struct pubkey *funding_pubkey)
{
u8 *script = tal_arr(ctx, u8, 0);
/* BOLT #3:
* #### `to_local_anchor` and `to_remote_anchor` Output (option_anchors)
*...
* <local_funding_pubkey/remote_funding_pubkey> OP_CHECKSIG OP_IFDUP
* OP_NOTIF
* OP_16 OP_CHECKSEQUENCEVERIFY
* OP_ENDIF
*/
add_push_key(&script, funding_pubkey);
add_op(&script, OP_CHECKSIG);
add_op(&script, OP_IFDUP);
add_op(&script, OP_NOTIF);
add_number(&script, 16);
add_op(&script, OP_CHECKSEQUENCEVERIFY);
add_op(&script, OP_ENDIF);
return script;
}
bool scripteq(const u8 *s1, const u8 *s2)
{
memcheck(s1, tal_count(s1));
memcheck(s2, tal_count(s2));
if (tal_count(s1) != tal_count(s2))
return false;
return memcmp(s1, s2, tal_count(s1)) == 0;
}