tlnbase: make function for building htlc_tx depending on if it is for_us/we_receive - electrum - Electrum Bitcoin wallet
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---
DIR commit d96b80ad1f40a2ec3f099f963e35f097464a7e92
DIR parent 309aca69b848a2fbdd14098213a13a53151413f0
HTML Author: Janus <ysangkok@gmail.com>
Date: Wed, 2 May 2018 18:24:40 +0200
lnbase: make function for building htlc_tx depending on if it is for_us/we_receive
Diffstat:
M lib/lnbase.py | 73 ++++++++++++++++---------------
1 file changed, 38 insertions(+), 35 deletions(-)
---
DIR diff --git a/lib/lnbase.py b/lib/lnbase.py
t@@ -425,6 +425,40 @@ def make_received_htlc(revocation_pubkey, remote_htlcpubkey, local_htlcpubkey, p
+ bitcoin.add_number_to_script(cltv_expiry) \
+ bytes([opcodes.OP_CLTV, opcodes.OP_DROP, opcodes.OP_CHECKSIG, opcodes.OP_ENDIF, opcodes.OP_ENDIF])
+def make_htlc_tx_with_open_channel(chan, pcp, for_us, we_receive, amount_msat, cltv_expiry, payment_hash, commit, original_htlc_output_index):
+ conf = chan.local_config if for_us else chan.remote_config
+ other_conf = chan.local_config if not for_us else chan.remote_config
+
+ revocation_pubkey = derive_blinded_pubkey(other_conf.revocation_basepoint.pubkey, pcp)
+ delayedpubkey = derive_pubkey(conf.delayed_basepoint.pubkey, pcp)
+ other_revocation_pubkey = derive_blinded_pubkey(other_conf.revocation_basepoint.pubkey, pcp)
+ other_htlc_pubkey = derive_pubkey(other_conf.htlc_basepoint.pubkey, pcp)
+ htlc_pubkey = derive_pubkey(conf.htlc_basepoint.pubkey, pcp)
+ # HTLC-success for the HTLC spending from a received HTLC output
+ # if we do not receive, and the commitment tx is not for us, they receive, so it is also an HTLC-success
+ is_htlc_success = for_us == we_receive
+ htlc_tx_output = make_htlc_tx_output(
+ amount_msat = amount_msat,
+ local_feerate = chan.constraints.feerate,
+ revocationpubkey=revocation_pubkey,
+ local_delayedpubkey=delayedpubkey,
+ success = is_htlc_success,
+ to_self_delay = other_conf.to_self_delay)
+ if is_htlc_success:
+ preimage_script = make_received_htlc(other_revocation_pubkey, other_htlc_pubkey, htlc_pubkey, payment_hash, cltv_expiry)
+ else:
+ preimage_script = make_offered_htlc(other_revocation_pubkey, other_htlc_pubkey, htlc_pubkey, payment_hash)
+ htlc_tx_inputs = make_htlc_tx_inputs(
+ commit.txid(), commit.htlc_output_indices[original_htlc_output_index],
+ revocationpubkey=revocation_pubkey,
+ local_delayedpubkey=delayedpubkey,
+ amount_msat=amount_msat,
+ witness_script=bh2u(preimage_script))
+ if is_htlc_success:
+ cltv_expiry = 0
+ htlc_tx = make_htlc_tx(cltv_expiry, inputs=htlc_tx_inputs, output=htlc_tx_output)
+ return htlc_tx
+
def make_commitment_using_open_channel(chan, ctn, for_us, pcp, local_sat, remote_sat, htlcs=[]):
conf = chan.local_config if for_us else chan.remote_config
other_conf = chan.local_config if not for_us else chan.remote_config
t@@ -952,27 +986,11 @@ class Peer(PrintError):
local_last_per_commitment_point = secret_to_pubkey(int.from_bytes(
local_last_per_commitment_secret,
byteorder="big"))
- revocation_pubkey = derive_blinded_pubkey(chan.remote_config.revocation_basepoint.pubkey, local_last_per_commitment_point)
- remote_delayedpubkey = derive_pubkey(chan.local_config.delayed_basepoint.pubkey, local_last_per_commitment_point)
- htlc_tx_output = make_htlc_tx_output(
- amount_msat = amount_msat,
- local_feerate = chan.constraints.feerate,
- revocationpubkey=revocation_pubkey,
- local_delayedpubkey=remote_delayedpubkey,
- success = True, # HTLC-success for the HTLC spending from a received HTLC output
- to_self_delay = chan.remote_config.to_self_delay)
- preimage_script = htlcs_in_local[0][0]
- htlc_tx_inputs = make_htlc_tx_inputs(
- new_commitment.txid(), new_commitment.htlc_output_indices[0],
- revocationpubkey=revocation_pubkey,
- local_delayedpubkey=remote_delayedpubkey,
- amount_msat=amount_msat,
- witness_script=bh2u(preimage_script))
- htlc_tx = make_htlc_tx(0, inputs=htlc_tx_inputs, output=htlc_tx_output)
- print("htlc tx preimage", htlc_tx.serialize_preimage(0))
+ htlc_tx = make_htlc_tx_with_open_channel(chan, local_last_per_commitment_point, True, True, amount_msat, cltv_expiry, payment_hash, new_commitment, 0)
pre_hash = bitcoin.Hash(bfh(htlc_tx.serialize_preimage(0)))
remote_htlc_pubkey = derive_pubkey(chan.remote_config.htlc_basepoint.pubkey, local_last_per_commitment_point)
- assert bitcoin.verify_signature(remote_htlc_pubkey, commitment_signed_msg["htlc_signature"], pre_hash)
+ if not bitcoin.verify_signature(remote_htlc_pubkey, commitment_signed_msg["htlc_signature"], pre_hash):
+ raise Exception("failed verifying signature an HTLC tx spending from one of our commit tx'es HTLC outputs")
local_last_pcs_index = 2**48 - chan.local_state.ctn - 1
local_last_per_commitment_secret = get_per_commitment_secret_from_seed(local_per_commitment_secret_seed, local_last_pcs_index)
t@@ -1000,22 +1018,7 @@ class Peer(PrintError):
r, s = sigdecode_der(sig[:-1], SECP256k1.generator.order())
sig_64 = sigencode_string_canonize(r, s, SECP256k1.generator.order())
- remote_delayedpubkey = derive_pubkey(chan.remote_config.delayed_basepoint.pubkey, chan.remote_state.next_per_commitment_point)
- htlc_tx_output = make_htlc_tx_output(
- amount_msat = amount_msat,
- local_feerate = chan.constraints.feerate,
- revocationpubkey=revocation_pubkey,
- local_delayedpubkey=remote_delayedpubkey,
- success = False, # timeout for the one offering an HTLC
- to_self_delay = chan.local_config.to_self_delay)
- preimage_script = htlcs_in_remote[0][0]
- htlc_tx_inputs = make_htlc_tx_inputs(
- remote_ctx.txid(), remote_ctx.htlc_output_indices[0],
- revocationpubkey=revocation_pubkey,
- local_delayedpubkey=remote_delayedpubkey,
- amount_msat=amount_msat,
- witness_script=bh2u(preimage_script))
- htlc_tx = make_htlc_tx(cltv_expiry, inputs=htlc_tx_inputs, output=htlc_tx_output)
+ htlc_tx = make_htlc_tx_with_open_channel(chan, chan.remote_state.next_per_commitment_point, False, True, amount_msat, cltv_expiry, payment_hash, remote_ctx, 0)
# htlc_sig signs the HTLC transaction that spends from THEIR commitment transaction's offered_htlc output
sig = bfh(htlc_tx.sign_txin(0, their_remote_htlc_privkey))