Since the light client work introduced in v0.33 it appears full nodes
are no longer fully verifying commit signatures during block execution -
they stop after +2/3. See in VerifyCommit:
0c7fd316eb/types/validator_set.go (L700-L703)
This means proposers can propose blocks that contain valid +2/3
signatures and then the rest of the signatures can be whatever they
want. They can claim that all the other validators signed just by
including a CommitSig with arbitrary signature data. While this doesn't
seem to impact safety of Tendermint per se, it means that Commits may
contain a lot of invalid data. This is already true of blocks, since
they can include invalid txs filled with garbage, but in that case the
application knows they they are invalid and can punish the proposer. But
since applications dont verify commit signatures directly (they trust
tendermint to do that), they won't be able to detect it.
This can impact incentivization logic in the application that depends on
the LastCommitInfo sent in BeginBlock, which includes which validators
signed. For instance, Gaia incentivizes proposers with a bonus for
including more than +2/3 of the signatures. But a proposer can now claim
that bonus just by including arbitrary data for the final -1/3 of
validators without actually waiting for their signatures. There may be
other tricks that can be played because of this.
In general, the full node should be a fully verifying machine. While
it's true that the light client can avoid verifying all signatures by
stopping after +2/3, the full node can not. Thus the light client and
full node should use distinct VerifyCommit functions if one is going to
stop after +2/3 or otherwise perform less validation (for instance light
clients can also skip verifying votes for nil while full nodes can not).
See a commit with a bad signature that verifies here: 56367fd. From what
I can tell, Tendermint will go on to think this commit is valid and
forward this data to the app, so the app will think the second validator
actually signed when it clearly did not.
In order to have more control over the mempool implementation,
introduce a new exported function RemoveTxByKey.
Export also TxKey() and TxKeySize. Use TxKeySize const instead of
sha256.size, so future changes on the hash function won't break the API.
Allows using a TxKey (32 bytes reference) as parameter instead of
the complete array set. So the application layer does not need to
keep track of the whole transaction but only of the sha256 hash (32 bytes).
This function is useful when mempool.Recheck is disabled.
Allows the Application layer to implement its own cleaning mechanism
without having to re-implement the whole mempool interface.
Mempool.Update() would probably also need to change from txBytes to txKey,
but that would require to change the Interface thus will break backwards
compatibility. For now RemoveTxByKey() looks like a good compromise,
it won't break anything and will help to solve some mempool issues from the
application layer.
Signed-off-by: p4u <pau@dabax.net>
## Description
This PR removes simple prefix from all types in the crypto/merkle directory.
The two proto types `Proof` & `ProofOp` have been moved to the `proto/crypto/merkle` directory.
proto messge `Proof` was renamed to `ProofOps` and `SimpleProof` message to `Proof`.
Closes: #2755
LastCommitRound should always be >= 0 for heights > 1.
In State.updateToState, last precommit is computed only when round
greater than -1 and has votes. But "LastCommit" is always updated
regardless of the condition. If there's no last precommit, "LastCommit"
is set to (*types.VoteSet)(nil). That's why "LastCommit" can be -1 for
heights > 1.
To fix it, only update State.RoundState.LastCommit when there is last
precommit.
Fixes#2737
Co-authored-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
* lite2: check header w/ witnesses only when doing bisection
Closes#4872
We don't need to check witnesses if we're doing backwards hash chain
verification. I also think we don't need to do it when sequential
verification is being used.
* lite2: require 1 witness only when verificationMode=skipping
https://github.com/tendermint/tendermint/pull/4929#pullrequestreview-423256477
we don't need witnesses when performing sequential verification (except
when primary fails)
* proto: move mempool to proto
- changes according to moving the mempool reactor to proto
Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>
Closes: #2883
Ethermint currently has to maintain a map height-> block hash on the store (see here) as it needs to expose the eth_getBlockByHash JSON-RPC query for Web3 compatibility. This query is currently not supported by the tendermint RPC client.
## Description
in consensus/state.go, when calulating metrics, retrieve address (ergo, pubkey) once prior to iterating over validatorset to ensure we do not make excessive calls to signer.
Partially closes: #4865
## Description
In https://github.com/tendermint/tendermint/pull/4466 a new type was created (EventAttribute) that replaced KV.Pair. This made the type Pair deadcode, this pr removes that type.
I don't think a changelog entry is needed since it is not being used anymore. But will add a section to the upgrading.md to let users know that it was replaced
Closes: #XXX
Marko
Anton Kaliaev
Pau
Callum Waters
Erik Grinaker
Alessio Treglia
Federico Kunze
Tess Rinearson
Joe Bowman