And use this to resolve old transactions by comparing outputs with
HTLCs.
Rather than remembering the output ordering for every one of their
previous commitment transactions, we just remember the commitment
number for each commitment txid, and when we see it, derive all the
HTLC scriptpubkeys and the to-us and to-them scriptpubkeys, and figure
out which is which.
This avoids us having to save information on disk, except for the
txid->commitment-number mapping (and the shachain).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We use libsecp256k1 to convert signatures to DER; we were creating a
temporary one, but we really should be handing the one we have in dstate
through. This does that, everywhere.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We now need to use bitcoin_witness_htlc with the r value, so that API
is updated to take 'struct rval' or 'struct sha256'.
We use the nc->delay amount (ie. dstate->config.min_htlc_expiry) to
wait for a timeout refund to be buried before "failing" upstream.
This should probably be made into a clearer parameter rather than
overloading this one.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Header from folded patch 'dont-use-peer-nc-in-onchain-code.patch':
peer: Don't use peer->nc->delay for onchain case.
Use the config var directly. We should be freeing peer->nc when the
connection dies anyway.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We need to enforce this onchain as we do in the protocol off-chain,
otherwise we can have an onchain redemption we can't redeem upstream
via the protocol. While Laolu points out there's a 520 byte limit on
witness stack element, that can still make for a larger tx and make
problems for the steal tx case.
The downside is that even the timeout transaction, which used to spend
the HTLC with an empty 'secret', now needs a 32-byte secret, making it
a little larger. We create a 'bitcoin_witness_htlc' helper for this
case.
See: http://lists.linuxfoundation.org/pipermail/lightning-dev/2016-May/000529.html
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
They could be scriptpubkeys, but they're actually used inside p2wsh,
so they're really witness scripts. We use the term "redeem" elsewhere
from when we were using p2sh, though.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We want this because P2SH is something we can tell bitcoind to pay to;
we can't (yet?) do that with "raw" P2WPKH.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
sign_tx_input() now takes a witness_script arg: P2WPKH doesn't really
have a witness_script, but for signing it behaves as if it does.
This helper constructs that "fake" witness_script.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I got confused navigating these, especially since Alpha and Bitcoin
have diverged (BIP68 was proposed after Elements Alpha).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
As documented in the paper; it's also two bytes shorter, and allows
us to use the exact same script for three cases.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
DER encoding introduces problems for non-canonical encodings; we should
do that only at the lightning<->bitcoin interface.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rusty Russell