We roll the `elements_add_fee_output` function and the cropping of
overallocated arrays into the `bitcoin_tx_finalize` function. This is supposed
to be the final cleanup and compaction step before a tx can be sent to bitcoin
or passed off to other daemons.
This is the cleanup promised in #3491
This sets the nLockTime to the tip (and accordingly each input's nSequence to
0xfffffffe) for withdrawal transactions.
Even if the anti fee-sniping argument might not be valid until some time yet,
this makes our regular wallet transactions far less distinguishable from
bitcoind's ones since it now defaults to using native Segwit transactions
(like us). Moreover other wallets are likely to implement this (if they
haven't already).
Changelog-Added: wallet: withdrawal transactions now sets nlocktime to the current tip.
Currently the only source for amount_asset is the value getter on a tx output,
and we don't hand it too far around (mainly ignoring it if it isn't the
chain's main currency). Eventually we could bubble them up to the wallet, use
them to select outputs or actually support assets in the channels.
Since we don't hand them around too widely I thought it was ok for them to be
pass-by-value rather than having to allocate them and pass them around by
reference. They're just 41 bytes currently so the overhead should be ok.
Signed-off-by: Christian Decker <@cdecker>
Especially when we grind fees we may end up setting the fees several times, so
instead of always adding a new fee output look for an existing one and set its
value.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
This is the normal convention for this type; it makes using converters
a little easier. See next patch.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The way we build transactions, serialize them, and compute fees depends on the
chain we are working on, so let's add some context to the transactions.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
This is what all of this has been working towards: ripping out the handwoven
transaction handling. By removing the custom parsing we can finally switch
over to using `wally_tx` as sole representation of transactions in
memory. The commit is a bit larger but it's mostly removing setters and old
references to the input and output fields.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
These are handled internally in the `wally_tx` and do not conform to our usual
tallocated strings that can by inspected using `tal_bytelen`, and we don't
really want to litter our code with whitelisting comments for the
`amount_sat.satoshis` access, so these just do read-only on the fly conversions.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
The `wally_tx_input`s do not keep track of their input value, which means we
need to track them ourselves if we try to sign these transactions at a later
point in time.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
These are used when grinding the feerate and signing. These are just simple
facades that keep both wally and old style transactions in sync.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
During the migration to `libwally` we want to make absolutely sure that both
transactions are generated identical, and can eventually be switched over.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
We are slowly migrating towards a wally-transactions only world, but to make
this reviewable we start building both old and new style transactions in
parallel. In a second pass we'll then start removing the old ones and use
libwally only.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
We currently make sure that all the bitcoin_tx input scripts are NULL
and set the input script of the input we're signing, so we can easily
reuse the tx hashing code for signature checks. This means that we
sometimes jump through hoops to make sure input scripts are NULL, and
also means that the tx can't be const.
Put more logic inside bitcoin/tx so it can simply ignore things we
don't want to hash.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
structeq() is too dangerous: if a structure has padding, it can fail
silently.
The new ccan/structeq instead provides a macro to define foo_eq(),
which does the right thing in case of padding (which none of our
structures currently have anyway).
Upgrade ccan, and use it everywhere. Except run-peer-wire.c, which
is only testing code and can use raw memcmp(): valgrind will tell us
if padding exists.
Interestingly, we still declared short_channel_id_eq, even though
we didn't define it any more!
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The deserialization of bitcoin transactions in wire/ is rather
annoying in that we first allocate a new bitcoin_tx, then copy it's
contents onto the destination and then still carry the newly allocated
one around due to the tal-tree. This splits `pull_bitcoin_tx` into
two: one part that does the allocation and another one that proceeds
to parse.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
It's just a sha256_double, but importantly when we convert it to a
string (in type_to_string, which is used in logging) we use
bitcoin_txid_to_hex() so it's reversed as people expect.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
BIP141 indicates that the rule for block size has changed: witness
bytes effectively count for 1, and non-witness bytes count for 4, but
the maximum total has increased to 4,000,000.
This means that fee estimates should use the witness cost (divided by
4), not the raw txlen.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We currently linearize and then measure the string; this is better since
we're about to do it in a second place.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We need this for signing segwitness txs. Unfortunately, we don't have it
for transactions we received as hex, only ones we created; to make this safe
we use a pointer which is NULL if we don't know, and those will crash if
we try to sign or check their sigs.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I had already disabled it, and this clears the decks for Segregated Witness
which gives us everything we want.
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>
