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.
<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
Makes it possible to compactly provide a delibrately invalid signature
for use with CHECK(MULTI)SIG. For instance with BIP19 if m != n invalid
signatures need to be provided in the scriptSig; prior to this change
those invalid signatures would need to be large DER-encoded signatures.
Note that we may want to further expand on this change in the future by
saying that only OP_0 is a "valid" invalid signature; BIP19 even with
this change is inherently malleable as the invalid signatures can be any
validly encoded DER signature.
If uint256() constructor takes a string, uint256(0) will become
dangerous when uint256 does not take integers anymore (it will go
through std::string(const char*) making a NULL string, and the explicit
keyword is no help).
SignatureHash and its test function SignatureHashOld
return uint256(1) as a special error signaling value.
Return a local static constant with the same value instead.
Based on an earlier patch by Peter Todd, though the rules here are different
(P2SH scripts should not have a CLEANSTACK check before the P2SH evaluation).
This turns STRICTENC turn into a softforking-safe change (even though it
is not intended as a consensus rule), and as a result guarantee that using
it for mempool validation only results in consensus-valid transactions in
the mempool.
NOP1 to NOP10 are reserved for future soft-fork upgrades. In the event
of an upgrade such NOPs have *VERIFY behavior, meaning that if their
arguments are not correct the script fails. Discouraging these NOPs by
rejecting transactions containing them from the mempool ensures that
we'll never accept transactions, nor mine blocks, with scripts that are
now invalid according to the majority of hashing power even if we're not
yet upgraded. Previously this wasn't an issue as the IsStandard() rules
didn't allow upgradable NOPs anyway, but 7f3b4e95 relaxed the
IsStandard() rules for P2SH redemptions allowing any redeemScript to be
spent.
We *do* allow upgradable NOPs in scripts so long as they are not
executed. This is harmless as there is no opportunity for the script to
be invalid post-upgrade.
