We do not need to be able to calculate multiple SignatureHash versions for a
single transaction format; instead, we use the transaction format to determine
the SigVersion.
The consensus branch ID *does* need to be passed in from the outside, as only
the caller knows the context in which the SignatureHash is being calculated
(ie. mempool acceptance vs. block validation).
JoinSplit signature verification has been moved into ContextualCheckTransaction,
where the consensus branch ID can be obtained.
The argument to the sign command for zcash-tx has been modified to take a height
in addition to the optional sigtype flags.
Transactions of version 2 and above contain a `vpour` field which is a vector of `CPourTx`
objects that embody our protocol. We introduce serialization primitives for boost::array
(we intend for changing the amount of inputs and outputs in the circuit to be simple).
SIGHASH_* operations hash this field like any other for now.
Transactions that fail CLTV verification will be rejected from the
mempool, making it easy to test the feature. However blocks containing
"invalid" CLTV-using transactions will still be accepted; this is *not*
the soft-fork required to actually enable CLTV for production use.
Rebased-From: ffd75adce01a78b3461b3ff05bcc2b530a9ce994
<nLockTime> CHECKLOCKTIMEVERIFY -> <nLockTime>
Fails if tx.nLockTime < nLockTime, allowing the funds in a txout to be
locked until some block height or block time in the future is reached.
Only the logic and unittests are implemented; this commit does not have
any actual soft-fork logic in it.
Thanks to Pieter Wuille for rebase.
Credit goes to Gregory Maxwell for the suggestion of comparing the
argument against the transaction nLockTime rather than the current
time/blockheight directly.
Rebased-From: bc60b2b4b401f0adff5b8b9678903ff8feb5867b
