core-lightning/common/initial_channel.c
Rusty Russell ee3480e56b derive_keyset: don't rotate key for remote iff option_static_remotekey.
The largest change is inside hsmd: it hands a null per-commitment key
to the wallet to tell it to spend the to_remote output.

It can also now resolve unknown commitments, even if it doesn't have a
possible_remote_per_commitment_point from the peer.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2019-09-10 16:18:25 -05:00

143 lines
4.4 KiB
C

#include <assert.h>
#include <bitcoin/chainparams.h>
#include <bitcoin/script.h>
#include <ccan/tal/str/str.h>
#include <common/initial_channel.h>
#include <common/initial_commit_tx.h>
#include <common/keyset.h>
#include <common/type_to_string.h>
#include <inttypes.h>
struct channel *new_initial_channel(const tal_t *ctx,
const struct bitcoin_blkid *chain_hash,
const struct bitcoin_txid *funding_txid,
unsigned int funding_txout,
u32 minimum_depth,
struct amount_sat funding,
struct amount_msat local_msatoshi,
u32 feerate_per_kw,
const struct channel_config *local,
const struct channel_config *remote,
const struct basepoints *local_basepoints,
const struct basepoints *remote_basepoints,
const struct pubkey *local_funding_pubkey,
const struct pubkey *remote_funding_pubkey,
bool option_static_remotekey,
enum side funder)
{
struct channel *channel = tal(ctx, struct channel);
struct amount_msat remote_msatoshi;
channel->funding_txid = *funding_txid;
channel->funding_txout = funding_txout;
channel->funding = funding;
channel->minimum_depth = minimum_depth;
if (!amount_sat_sub_msat(&remote_msatoshi,
channel->funding, local_msatoshi))
return tal_free(channel);
channel->funder = funder;
channel->config[LOCAL] = *local;
channel->config[REMOTE] = *remote;
channel->funding_pubkey[LOCAL] = *local_funding_pubkey;
channel->funding_pubkey[REMOTE] = *remote_funding_pubkey;
channel->htlcs = NULL;
channel->changes_pending[LOCAL] = channel->changes_pending[REMOTE]
= false;
channel->view[LOCAL].feerate_per_kw
= channel->view[REMOTE].feerate_per_kw
= feerate_per_kw;
channel->view[LOCAL].owed[LOCAL]
= channel->view[REMOTE].owed[LOCAL]
= local_msatoshi;
channel->view[REMOTE].owed[REMOTE]
= channel->view[LOCAL].owed[REMOTE]
= remote_msatoshi;
channel->basepoints[LOCAL] = *local_basepoints;
channel->basepoints[REMOTE] = *remote_basepoints;
channel->commitment_number_obscurer
= commit_number_obscurer(&channel->basepoints[funder].payment,
&channel->basepoints[!funder].payment);
channel->chainparams = chainparams_by_chainhash(chain_hash);
if (channel->chainparams == NULL)
return tal_free(channel);
channel->option_static_remotekey = option_static_remotekey;
return channel;
}
/* FIXME: We could cache this. */
struct bitcoin_tx *initial_channel_tx(const tal_t *ctx,
const u8 **wscript,
const struct channel *channel,
const struct pubkey *per_commitment_point,
enum side side,
char** err_reason)
{
struct keyset keyset;
/* This assumes no HTLCs! */
assert(!channel->htlcs);
if (!derive_keyset(per_commitment_point,
&channel->basepoints[side],
&channel->basepoints[!side],
channel->option_static_remotekey,
&keyset)) {
*err_reason = "Cannot derive keyset";
return NULL;
}
*wscript = bitcoin_redeem_2of2(ctx,
&channel->funding_pubkey[side],
&channel->funding_pubkey[!side]);
return initial_commit_tx(ctx, channel->chainparams,
&channel->funding_txid,
channel->funding_txout,
channel->funding,
channel->funder,
/* They specify our to_self_delay and v.v. */
channel->config[!side].to_self_delay,
&keyset,
channel->view[side].feerate_per_kw,
channel->config[side].dust_limit,
channel->view[side].owed[side],
channel->view[side].owed[!side],
channel->config[!side].channel_reserve,
0 ^ channel->commitment_number_obscurer,
side,
err_reason);
}
static char *fmt_channel_view(const tal_t *ctx, const struct channel_view *view)
{
return tal_fmt(ctx, "{ feerate_per_kw=%"PRIu32","
" owed_local=%s,"
" owed_remote=%s }",
view->feerate_per_kw,
type_to_string(tmpctx, struct amount_msat,
&view->owed[LOCAL]),
type_to_string(tmpctx, struct amount_msat,
&view->owed[REMOTE]));
}
/* FIXME: This should reference HTLCs somehow. */
static char *fmt_channel(const tal_t *ctx, const struct channel *channel)
{
return tal_fmt(ctx, "{ funding=%s,"
" funder=%s,"
" local=%s,"
" remote=%s }",
type_to_string(tmpctx, struct amount_sat,
&channel->funding),
side_to_str(channel->funder),
fmt_channel_view(ctx, &channel->view[LOCAL]),
fmt_channel_view(ctx, &channel->view[REMOTE]));
}
REGISTER_TYPE_TO_STRING(channel, fmt_channel);