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>
The wire protocol uses this, in the assumption that we'll never see feerates
in excess of 4294967 satoshi per kiloweight.
So let's use that consistently internally as well.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
All the callers need to pass it in: currently channeld and openingd just
fake it by copying the payment point.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
For non-delayed HTLC success spends, we have a similar pattern ("<sig>
<preimage> <wscript>") so a we want to use the same function.
The other routines don't say "witness" in them, and should.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
To avoid everything pulling in HTLCs stuff to the opening daemon, we
split the channel and commit_tx routines into initial_channel and
initial_commit_tx (no HTLC support) and move full HTLC supporting versions
into channeld.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>