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#include <ccan/crypto/shachain/shachain.h>
#include <ccan/short_types/short_types.h>
#include <ccan/tal/tal.h>
#include <ccan/opt/opt.h>
#include <ccan/str/hex/hex.h>
#include <ccan/err/err.h>
#include <ccan/read_write_all/read_write_all.h>
#include "lightning.pb-c.h"
#include "anchor.h"
#include "bitcoin/base58.h"
#include "pkt.h"
#include "bitcoin/script.h"
#include "permute_tx.h"
#include "bitcoin/signature.h"
#include "commit_tx.h"
#include "bitcoin/pubkey.h"
#include "find_p2sh_out.h"
#include "protobuf_convert.h"
#include <openssl/ec.h>
#include <unistd.h>
int main(int argc, char *argv[])
{
const tal_t *ctx = tal_arr(NULL, char, 0);
struct sha256 seed, revocation_hash, preimage;
OpenChannel *o1, *o2;
UpdateAccept *ua;
Update *update;
struct bitcoin_tx *anchor, *commit;
struct sha256_double anchor_txid;
struct pkt *pkt;
struct bitcoin_signature sig;
EC_KEY *privkey;
bool testnet;
struct pubkey pubkey1, pubkey2;
u8 *redeemscript;
int64_t delta;
size_t i, p2sh_out;
err_set_progname(argv[0]);
opt_register_noarg("--help|-h", opt_usage_and_exit,
"<seed> <anchor-tx> <open-channel-file1> <open-channel-file2> <commit-privkey> <update-protobuf> <update-accept-protobuf> [previous-updates]...\n"
"Create a new update-channel-signature message",
"Print this message.");
opt_parse(&argc, argv, opt_log_stderr_exit);
if (argc < 8)
opt_usage_exit_fail("Expected 7+ arguments");
if (!hex_decode(argv[1], strlen(argv[1]), &seed, sizeof(seed)))
errx(1, "Invalid seed '%s' - need 256 hex bits", argv[1]);
anchor = bitcoin_tx_from_file(ctx, argv[2]);
bitcoin_txid(anchor, &anchor_txid);
o1 = pkt_from_file(argv[3], PKT__PKT_OPEN)->open;
o2 = pkt_from_file(argv[4], PKT__PKT_OPEN)->open;
privkey = key_from_base58(argv[5], strlen(argv[5]), &testnet, &pubkey1);
if (!privkey)
errx(1, "Invalid private key '%s'", argv[5]);
if (!testnet)
errx(1, "Private key '%s' not on testnet!", argv[5]);
update = pkt_from_file(argv[6], PKT__PKT_UPDATE)->update;
ua = pkt_from_file(argv[7], PKT__PKT_UPDATE_ACCEPT)->update_accept;
sig.stype = SIGHASH_ALL;
if (!proto_to_signature(ua->sig, &sig.sig))
errx(1, "Invalid update signature");
/* Figure out cumulative delta since anchor. */
delta = 0;
for (i = 8; i < argc; i++) {
Update *u = pkt_from_file(argv[i], PKT__PKT_UPDATE)->update;
delta += u->delta;
}
/* Give up revocation preimage for old tx. */
shachain_from_seed(&seed, argc - 7 - 1, &preimage);
/* Get pubkeys */
if (!proto_to_pubkey(o1->anchor->pubkey, &pubkey2))
errx(1, "Invalid o1 commit pubkey");
if (pubkey_len(&pubkey1) != pubkey_len(&pubkey2)
|| memcmp(pubkey1.key, pubkey2.key, pubkey_len(&pubkey2)) != 0)
errx(1, "o1 pubkey != this privkey");
if (!proto_to_pubkey(o2->anchor->pubkey, &pubkey2))
errx(1, "Invalid o2 final pubkey");
/* This is what the anchor pays to; figure out whick output. */
redeemscript = bitcoin_redeem_2of2(ctx, &pubkey1, &pubkey2);
p2sh_out = find_p2sh_out(anchor, redeemscript);
/* Check our new commit is signed correctly by them. */
proto_to_sha256(update->revocation_hash, &revocation_hash);
commit = create_commit_tx(ctx, o1, o2, &revocation_hash, delta,
&anchor_txid, p2sh_out);
if (!commit)
errx(1, "Delta too large");
/* Check their signature signs this input correctly. */
if (!check_tx_sig(commit, 0, redeemscript, tal_count(redeemscript),
&pubkey2, &sig))
errx(1, "Invalid signature.");
/* Now create THEIR new commitment tx to spend 2/2 output of anchor. */
proto_to_sha256(ua->revocation_hash, &revocation_hash);
commit = create_commit_tx(ctx, o2, o1, &revocation_hash, -delta,
&anchor_txid,
find_p2sh_out(anchor, redeemscript));
/* If contributions don't exceed fees, this fails. */
if (!commit)
errx(1, "Delta too large");
/* Their pubkey must be valid */
if (!proto_to_pubkey(o2->anchor->pubkey, &pubkey2))
errx(1, "Invalid public open-channel-file2");
/* Sign it for them. */
sign_tx_input(ctx, commit, 0, redeemscript, tal_count(redeemscript),
privkey, &pubkey1, &sig.sig);
pkt = update_signature_pkt(ctx, &sig.sig, &preimage);
if (!write_all(STDOUT_FILENO, pkt, pkt_totlen(pkt)))
err(1, "Writing out packet");
tal_free(ctx);
return 0;
}