This removes the bip16 bool from NewScript and adds it to flags (with
the constant ScriptBip16), and also adds a new flag,
ScriptCanonicalSignatures, which will call btcec.ParseDERSignature
parsing a signature during an Execute. This is needed to emulate
bitcoind behavior, as bitcoind performs canonical signature validation
(DER format) in some places (like mempool acceptance) but not others
(like block validation).
Updated tests and test coverage file to reflect changes.
So add entries for them that disassemble and parse ok, but will fail
when executed with the appropriate error. Add a full suite of tests to confirm
that this happens.
Found by a strange transaction in testnet.
PayToPubKeyHashScript generates a new pay to pubkey hash script to use
as the pkScript when creating new transactions. If the passed pubkey
hash is an invalid size, StackErrInvalidOpcode will be returned as an
error.
SignatureScript returns the signature script necessary to validate a
single input of a transaction.
This also adds sanity checking for serializing scripts into byte
slices. If the length of a serialized opcode does not equal the
expected length, StackErrInvalidOpcode will be returned when unparsing
a []parsedOpcode.
New internal tests were added to verify checks for valid and invalid
parsed opcodes.
Removing from the bottom of a stack (nipN(depth)) would leak the first
entry in the array by slicing [1:], leaving array[0] dangling an
inaccessible (but unable to be freed until the whole slice is gone). We
left it like this for a while, but best not to leak the memory. Happens
rarely so the performance hit shouldn't matter that much. Do the same
thing for condstack.
When we do append loops, make an educated guess as to the size and make an array
with that capacity to avoid extra copying.
Doesn't affect the speed of the tests, over 4 runs the difference was lost in
the noise.
We were counting the number of push ops instead of the number of non
push ops. Add tests that found this (checking tha the max operations
check fires).
