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#include <bitcoin/preimage.h>
#include <bitcoin/script.h>
#include <bitcoin/tx.h>
#include <common/htlc_tx.h>
#include <common/keyset.h>
static struct bitcoin_tx *htlc_tx(const tal_t *ctx,
const struct chainparams *chainparams,
const struct bitcoin_txid *commit_txid,
unsigned int commit_output_number,
struct amount_msat msat,
u16 to_self_delay,
const struct pubkey *revocation_pubkey,
const struct pubkey *local_delayedkey,
struct amount_sat htlc_fee,
u32 locktime)
{
/* BOLT #3:
* * locktime: `0` for HTLC-success, `cltv_expiry` for HTLC-timeout
*/
struct bitcoin_tx *tx = bitcoin_tx(ctx, chainparams, 1, 1, locktime);
u8 *wscript;
struct amount_sat amount;
/* BOLT #3:
*
* ## HTLC-Timeout and HTLC-Success Transactions
*
* These HTLC transactions are almost identical, except the
* HTLC-timeout transaction is timelocked. Both
* HTLC-timeout/HTLC-success transactions can be spent by a valid
* penalty transaction.
*/
/* BOLT #3:
* * version: 2
*/
assert(tx->wtx->version == 2);
/* BOLT #3:
* * txin count: 1
* * `txin[0]` outpoint: `txid` of the commitment transaction and
* `output_index` of the matching HTLC output for the HTLC
* transaction
* * `txin[0]` sequence: `0`
*/
amount = amount_msat_to_sat_round_down(msat);
bitcoin_tx_add_input(tx, commit_txid, commit_output_number, 0, amount,
NULL);
/* BOLT #3:
* * txout count: 1
* * `txout[0]` amount: the HTLC amount minus fees
* (see [Fee Calculation](#fee-calculation))
* * `txout[0]` script: version-0 P2WSH with witness script as shown
* below
*/
if (!amount_sat_sub(&amount, amount, htlc_fee))
abort();
wscript = bitcoin_wscript_htlc_tx(tx, to_self_delay, revocation_pubkey,
local_delayedkey);
bitcoin_tx_add_output(tx, scriptpubkey_p2wsh(tx, wscript), amount);
elements_tx_add_fee_output(tx);
tal_free(wscript);
return tx;
}
struct bitcoin_tx *htlc_success_tx(const tal_t *ctx,
const struct chainparams *chainparams,
const struct bitcoin_txid *commit_txid,
unsigned int commit_output_number,
struct amount_msat htlc_msatoshi,
u16 to_self_delay,
u32 feerate_per_kw,
const struct keyset *keyset)
{
/* BOLT #3:
* * locktime: `0` for HTLC-success, `cltv_expiry` for HTLC-timeout
*/
return htlc_tx(ctx, chainparams, commit_txid, commit_output_number, htlc_msatoshi,
to_self_delay,
&keyset->self_revocation_key,
&keyset->self_delayed_payment_key,
htlc_success_fee(feerate_per_kw), 0);
}
/* Fill in the witness for HTLC-success tx produced above. */
void htlc_success_tx_add_witness(struct bitcoin_tx *htlc_success,
const struct abs_locktime *htlc_abstimeout,
const struct pubkey *localhtlckey,
const struct pubkey *remotehtlckey,
const struct bitcoin_signature *localhtlcsig,
const struct bitcoin_signature *remotehtlcsig,
const struct preimage *payment_preimage,
const struct pubkey *revocationkey)
{
struct sha256 hash;
u8 *wscript, **witness;
sha256(&hash, payment_preimage, sizeof(*payment_preimage));
wscript = bitcoin_wscript_htlc_receive(htlc_success,
htlc_abstimeout,
localhtlckey, remotehtlckey,
&hash, revocationkey);
witness = bitcoin_witness_htlc_success_tx(htlc_success,
localhtlcsig, remotehtlcsig,
payment_preimage, wscript);
bitcoin_tx_input_set_witness(htlc_success, 0, take(witness));
tal_free(wscript);
}
struct bitcoin_tx *htlc_timeout_tx(const tal_t *ctx,
const struct chainparams *chainparams,
const struct bitcoin_txid *commit_txid,
unsigned int commit_output_number,
struct amount_msat htlc_msatoshi,
u32 cltv_expiry,
u16 to_self_delay,
u32 feerate_per_kw,
const struct keyset *keyset)
{
/* BOLT #3:
* * locktime: `0` for HTLC-success, `cltv_expiry` for HTLC-timeout
*/
return htlc_tx(ctx, chainparams, commit_txid, commit_output_number,
htlc_msatoshi, to_self_delay,
&keyset->self_revocation_key,
&keyset->self_delayed_payment_key,
htlc_timeout_fee(feerate_per_kw), cltv_expiry);
}
/* Fill in the witness for HTLC-timeout tx produced above. */
void htlc_timeout_tx_add_witness(struct bitcoin_tx *htlc_timeout,
const struct pubkey *localhtlckey,
const struct pubkey *remotehtlckey,
const struct sha256 *payment_hash,
const struct pubkey *revocationkey,
const struct bitcoin_signature *localhtlcsig,
const struct bitcoin_signature *remotehtlcsig)
{
u8 **witness;
u8 *wscript = bitcoin_wscript_htlc_offer(htlc_timeout,
localhtlckey, remotehtlckey,
payment_hash, revocationkey);
witness = bitcoin_witness_htlc_timeout_tx(htlc_timeout, localhtlcsig,
remotehtlcsig, wscript);
bitcoin_tx_input_set_witness(htlc_timeout, 0, take(witness));
tal_free(wscript);
}
u8 *htlc_offered_wscript(const tal_t *ctx,
const struct ripemd160 *ripemd,
const struct keyset *keyset)
{
return bitcoin_wscript_htlc_offer_ripemd160(ctx,
&keyset->self_htlc_key,
&keyset->other_htlc_key,
ripemd,
&keyset->self_revocation_key);
}
u8 *htlc_received_wscript(const tal_t *ctx,
const struct ripemd160 *ripemd,
const struct abs_locktime *expiry,
const struct keyset *keyset)
{
return bitcoin_wscript_htlc_receive_ripemd(ctx,
expiry,
&keyset->self_htlc_key,
&keyset->other_htlc_key,
ripemd,
&keyset->self_revocation_key);
}