Browse Source

create-commit-tx: create a commit tx.

Required for unilateral close.  Also lets us test stealing funds
from a revoked transaction.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
ppa-0.6.1
Rusty Russell 10 years ago
parent
commit
2d714f5ad4
  1. 2
      Makefile
  2. 125
      create-commit-tx.c

2
Makefile

@ -3,7 +3,7 @@
# Needs to have oneof support: Ubuntu vivid's is too old :(
PROTOCC:=protoc-c
PROGRAMS := open-channel open-anchor-scriptsigs leak-anchor-sigs open-commit-sig check-commit-sig check-anchor-scriptsigs get-anchor-depth create-steal-tx create-commit-spend-tx close-channel create-close-tx update-channel update-channel-accept update-channel-signature update-channel-complete
PROGRAMS := open-channel open-anchor-scriptsigs leak-anchor-sigs open-commit-sig check-commit-sig check-anchor-scriptsigs get-anchor-depth create-steal-tx create-commit-spend-tx close-channel create-close-tx update-channel update-channel-accept update-channel-signature update-channel-complete create-commit-tx
HELPER_OBJS := base58.o lightning.pb-c.o shadouble.o pkt.o bitcoin_script.o permute_tx.o signature.o bitcoin_tx.o bitcoin_address.o anchor.o commit_tx.o pubkey.o opt_bits.o close_tx.o find_p2sh_out.o

125
create-commit-tx.c

@ -0,0 +1,125 @@
/* My example:
* ./open-commit-sig A-open.pb B-open.pb cUBCjrdJu8tfvM7FT8So6aqs6G6bZS1Cax6Rc9rFzYL6nYG4XNEC A-leak-anchor-sigs.pb B-leak-anchor-sigs.pb > A-commit-sig.pb
* ./open-commit-sig B-open.pb A-open.pb cQXhbUnNRsFcdzTQwjbCrud5yVskHTEas7tZPUWoJYNk5htGQrpi B-leak-anchor-sigs.pb A-leak-anchor-sigs.pb > B-commit-sig.pb
*/
#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 "base58.h"
#include "pkt.h"
#include "bitcoin_script.h"
#include "permute_tx.h"
#include "signature.h"
#include "commit_tx.h"
#include "pubkey.h"
#include "find_p2sh_out.h"
#include <openssl/ec.h>
#include <unistd.h>
int main(int argc, char *argv[])
{
const tal_t *ctx = tal_arr(NULL, char, 0);
OpenChannel *o1, *o2;
Update *update;
UpdateAccept *update_acc;
struct bitcoin_tx *anchor, *commit;
struct sha256_double anchor_txid;
EC_KEY *privkey;
bool testnet;
struct bitcoin_signature sig1, sig2;
size_t i;
struct pubkey pubkey1, pubkey2;
u8 *redeemscript, *tx_arr;
char *tx_hex;
int64_t delta;
struct sha256 rhash;
err_set_progname(argv[0]);
opt_register_noarg("--help|-h", opt_usage_and_exit,
"<anchor-tx> <open-channel-file1> <open-channel-file2> <final-update> <final-update-accept> <commit-privkey> [<previous-updates>]\n"
"Create the signature needed for the commit transaction",
"Print this message.");
opt_parse(&argc, argv, opt_log_stderr_exit);
if (argc < 7)
opt_usage_exit_fail("Expected 6+ arguments");
anchor = bitcoin_tx_from_file(ctx, argv[1]);
bitcoin_txid(anchor, &anchor_txid);
o1 = pkt_from_file(argv[2], PKT__PKT_OPEN)->open;
o2 = pkt_from_file(argv[3], PKT__PKT_OPEN)->open;
update = pkt_from_file(argv[4], PKT__PKT_UPDATE)->update;
update_acc = pkt_from_file(argv[5], PKT__PKT_UPDATE_ACCEPT)->update_accept;
privkey = key_from_base58(argv[6], strlen(argv[6]), &testnet, &pubkey1);
if (!privkey)
errx(1, "Invalid private key '%s'", argv[6]);
if (!testnet)
errx(1, "Private key '%s' not on testnet!", argv[6]);
/* Get pubkeys */
if (!proto_to_pubkey(o1->anchor->pubkey, &pubkey2))
errx(1, "Invalid o1 anchor 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 anchor pubkey");
/* Figure out cumulative delta since anchor. */
delta = update->delta;
for (i = 7; i < argc; i++) {
Update *u = pkt_from_file(argv[i], PKT__PKT_UPDATE)->update;
delta += u->delta;
}
redeemscript = bitcoin_redeem_2of2(ctx, &pubkey1, &pubkey2);
/* Now create commitment tx to spend 2/2 output of anchor. */
proto_to_sha256(update->revocation_hash, &rhash);
commit = create_commit_tx(ctx, o1, o2, &rhash, delta, &anchor_txid,
find_p2sh_out(anchor, redeemscript));
/* If contributions don't exceed fees, this fails. */
if (!commit)
errx(1, "Bad commit amounts");
/* We generate our signature. */
sig1.stype = SIGHASH_ALL;
sign_tx_input(ctx, commit, 0, redeemscript, tal_count(redeemscript),
privkey, &pubkey1, &sig1.sig);
/* Their signatures comes from the update_accept packet. */
sig2.stype = SIGHASH_ALL;
if (!proto_to_signature(update_acc->sig, &sig2.sig))
errx(1, "Invalid update-accept sig");
if (!check_2of2_sig(commit, 0, redeemscript, tal_count(redeemscript),
&pubkey1, &pubkey2, &sig1, &sig2))
errx(1, "Signature failed");
/* Create p2sh input for commit */
commit->input[0].script = scriptsig_p2sh_2of2(commit, &sig1, &sig2,
&pubkey1, &pubkey2);
commit->input[0].script_length = tal_count(commit->input[0].script);
/* Print it out in hex. */
tx_arr = linearize_tx(ctx, commit);
tx_hex = tal_arr(tx_arr, char, hex_str_size(tal_count(tx_arr)));
hex_encode(tx_arr, tal_count(tx_arr), tx_hex, tal_count(tx_hex));
if (!write_all(STDOUT_FILENO, tx_hex, strlen(tx_hex)))
err(1, "Writing out transaction");
tal_free(ctx);
return 0;
}
Loading…
Cancel
Save