As a side effect of computing Merkle roots, we build a list of
transaction hashes. Instead of discarding these, add them to
PreparedBlock and FinalizedBlock so that they can be reused rather than
recomputed.
This commit adds Merkle root validation to:
1. the block verifier;
2. the checkpoint verifier.
In the first case, Bitcoin Merkle tree malleability has no effect,
because only a single Merkle tree in each malleablity set is valid (the
others have duplicate transactions).
In the second case, we need to check that the Merkle tree does not contain any
duplicate transactions.
Closes#1385Closes#906
* implement inbound `FindBlocks`
* Handle inbound peer FindHeaders requests
* handle request before having any chain tip
* Split `find_chain_hashes` into smaller functions
Add a `max_len` argument to support `FindHeaders` requests.
Rewrite the hash collection code to use heights, so we can handle the
`stop` hash and "no intersection" cases correctly.
* Split state height functions into "any chain" and "best chain"
* Rename the best chain block method to `best_block`
* Move fmt utilities to zebra_chain::fmt
* Summarise Debug for some Message variants
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Jane Lusby <jlusby42@gmail.com>
This commit changes the state system and database format to track the
provenance of UTXOs, in addition to the outputs themselves.
Specifically, it tracks the following additional metadata:
- the height at which the UTXO was created;
- whether or not the UTXO was created from a coinbase transaction or
not.
This metadata will allow us to:
- check the coinbase maturity consensus rule;
- check the coinbase inputs => no transparent outputs rule;
- implement lookup of transactions by utxo (using the height to find the
block and then scanning the block) for a future RPC mechanism.
Closes#1342
This change introduces two new types:
- `PreparedBlock`, representing a block which has undergone semantic
validation and has been prepared for contextual validation;
- `FinalizedBlock`, representing a block which is ready to be finalized
immediately;
and changes the `Request::CommitBlock`,`Request::CommitFinalizedBlock`
variants to use these types instead of their previous fields.
This change solves the problem of passing data between semantic
validation and contextual validation, and cleans up the state code by
allowing it to pass around a bundle of data. Previously, the state code
just passed around an `Arc<Block>`, which forced it to needlessly
recompute block hashes and other data, and was incompatible with the
already-known but not-yet-implemented data transfer requirements, namely
passing in the Sprout and Sapling anchors computed during contextual
validation.
This commit propagates the `PreparedBlock` and `FinalizedBlock` types
through the state code but only uses their data opportunistically, e.g.,
changing .hash() computations to use the precomputed hash. In the
future, these structures can be extended to pass data through the
verification pipeline for reuse as appropriate. For instance, these
changes allow the sprout and sapling anchors to be propagated through
the state.
This change explicitly documents cancellation contracts for our Tower services,
and tries to correct a bug in the implementation of the CheckpointVerifier,
which duplicates information from the state service but did not ensure that it
would be kept in sync.
* make service use both finalized and non-finalized state
* Document new functions
* add documentation to sled fns
* cleanup tip fn now that errors are gone
* rename height unwrap fn
This commit begins the process of integrating `zcash_script` with the rest of the system for verifying scripts while syncing the block chain. It does so by adding the necessary support for looking up UTXOs from the state service and implements the first parts of the `script::Verifier` for looking up the necessary UTXOs in the state and then generating the necessary call to `zcash_script` to verify the script itself.
Co-authored-by: teor <teor@riseup.net>
Henry de Valence
Alfredo Garcia
teor
Jane Lusby