Isolate verification to a ProofVerifier context object that allows verification behavior to be tuned by the caller.
This is an alternative foundation for #1892, i.e., #1892 will have to be changed if this PR is accepted.
I think this is a safer approach because it allows us to isolate verification behavior to a single object. This will come in handy when @arielgabizon finishes the batching code.
Fix issue where z_sendmany amount parameter is too strict
Upstream treats an amount parameter of `1` the same as `1.0`. Third-party would like this fixed.
Simple implementation does not try to optimize coin or note selection.
Caller can send from a taddr or zaddr to multiple recipients.
Currently only one of the recipients can be a zaddr.
A fix for transaction malleability
This PR fixes transaction malleability by not including the sigscript of transaction inputs and joinsplit sigs when hashing the txid.
This PR supercedes PR #1101 which was a minimal solution based on a new serialization flag.
This PR introduces GetTxid() to distinguish between getting a transaction id and the double sha256 hash.
The key changes are:
- Adding GetTxid() method to CTransaction which makes a copy of the transaction, clearing out the sigscript and joinsplitsig fields, before hashing.
- Verifying that every call to GetHash() actually wants a txid, and replacing with GetTxid().
- Renaming GetHash() to GetSerializeHash()
- Rationale: In future, upstream code we want to merge will use GetHash() but we don't know the intent. We should check to see if the intent is to receive a txid (most likely) in which case we replace with GetTxid(), or if upstream actually wants a double hash of the transaction we can use GetSerializeHash().
- Updated genesis data in chainparams.cpp
Note that coinbase transactions are excluded as they need the sigscript hashed to help avoid duplicate txids per BIP34:
- This modification is related to a question from @ebfull on PR #1101 - "Can we think of a way this change allows us to construct two transactions with the same txid which can simultaneously appear in the blockchain? My guess is it would be possible to construct a coinbase transaction of such a form... this surely breaks invariants."
This PR Passes all tests in test_bitcoin (test data was updated in bloom_tests, miner_tests and script_tests).
