core-lightning/commit_tx.c
Rusty Russell 29d0cdc3cd open-channel: use pubkey, not arbitrary script for final outout address.
We need to pay to this from two places: on their side, it's a simple
payment, on our side, it's a complex timeout-or-mutual-or-hval script,
which doesn't lend itself to arbitrary scripts.

Use P2SH, of course.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-05 11:37:27 +09:30

60 lines
1.8 KiB
C

#include "commit_tx.h"
#include "shadouble.h"
#include "bitcoin_tx.h"
#include "bitcoin_script.h"
#include "permute_tx.h"
#include "pubkey.h"
#include "pkt.h"
struct bitcoin_tx *create_commit_tx(const tal_t *ctx,
OpenChannel *ours,
OpenChannel *theirs,
const struct sha256_double *anchor_txid,
unsigned int anchor_output)
{
struct bitcoin_tx *tx;
const u8 *redeemscript;
struct pubkey ourkey, theirkey, to_me;
struct sha256 redeem;
/* Now create commitment tx: one input, two outputs. */
tx = bitcoin_tx(ctx, 1, 2);
/* Our input spends the anchor tx output. */
tx->input[0].txid = *anchor_txid;
tx->input[0].index = anchor_output;
if (!proto_to_pubkey(ours->anchor->pubkey, &ourkey))
return tal_free(tx);
if (!proto_to_pubkey(theirs->anchor->pubkey, &theirkey))
return tal_free(tx);
proto_to_sha256(ours->revocation_hash, &redeem);
/* First output is a P2SH to a complex redeem script (usu. for me) */
redeemscript = bitcoin_redeem_revocable(tx, &ourkey,
ours->locktime_seconds,
&theirkey,
&redeem);
tx->output[0].script = scriptpubkey_p2sh(tx, redeemscript);
tx->output[0].script_length = tal_count(tx->output[0].script);
if (ours->anchor->total < ours->commitment_fee)
return tal_free(tx);
tx->output[0].amount = ours->anchor->total - ours->commitment_fee;
/* Second output is a P2SH payment to them. */
if (!proto_to_pubkey(theirs->to_me, &to_me))
return tal_free(tx);
tx->output[1].script = scriptpubkey_p2sh(ctx,
bitcoin_redeem_single(ctx,
&to_me));
tx->output[1].script_length = tal_count(tx->output[1].script);
if (theirs->anchor->total < theirs->commitment_fee)
return tal_free(tx);
tx->output[1].amount = theirs->anchor->total - theirs->commitment_fee;
permute_outputs(ours->seed, theirs->seed, 1, tx->output, 2, NULL);
return tx;
}