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.
Closes#4783
It looks like we're validating Commit twice. Also, height and blockID params were coming from the commit, so no need to pass them separately.
* lint: golint issue fixes
- on my local machine golint is a lot stricter than the bot so slowly going through and fixing things.
Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>
* more fixes from golint
* remove isPeerPersistentFn
* add changelog entry
* libs/common: Refactor libs/common 5
- move mathematical functions and types out of `libs/common` to math pkg
- move net functions out of `libs/common` to net pkg
- move string functions out of `libs/common` to strings pkg
- move async functions out of `libs/common` to async pkg
- move bit functions out of `libs/common` to bits pkg
- move cmap functions out of `libs/common` to cmap pkg
- move os functions out of `libs/common` to os pkg
Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>
* fix testing issues
* fix tests
closes#41417
woooooooooooooooooo kill the cmn pkg
Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>
* add changelog entry
* fix goimport issues
* run gofmt
* libs/common: refactor libs/common 2
- move random function to there own pkg
Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>
* change imports and usage throughout repo
* fix goimports
* add changelog entry
Fix for #4164
The general problem is that in certain conditions an overflow warning is issued when attempting to update a validator set even if the final set's total voting power is not over the maximum allowed.
Root cause is that in verifyUpdates(), updates are verified wrt to total voting power in the order of validator address. It is then possible that a low address validator may increase its power such that the temporary total voting power count goes over MaxTotalVotingPower.
Scenarios where removing and adding/ updating validators with high voting power, in the same update operation, cause the same false warning and the updates are not applied.
Main changes to fix this are in verifyUpdate() that now does the verification starting with the decreases in power. It also takes into account the removals that are part of the update.
## Commits:
* tests for overflow detection and prevention
* test fix
* more tests
* fix the false overflow warnings and golint
* scopelint warning fix
* review comments
* variant with using sort by amount of change in power
* compute separately number new validators in update
* types: use a switch in processChanges
* more review comments
* types: use HasAddress in numNewValidators
* types: refactor verifyUpdates
copy updates, sort them by delta and use resulting slice to calculate
tvpAfterUpdatesBeforeRemovals.
* remove unused structs
* review comments
* update changelog
* types: change `Commit` to consist of just signatures
These are final changes towards removing votes from commit and leaving
only signatures (see ADR-25)
Fixes#1648
* bring back TestCommitToVoteSetWithVotesForAnotherBlockOrNilBlock
+ add absent flag to Vote to indicate that it's for another block
* encode nil votes as CommitSig with BlockIDFlagAbsent
+ make Commit#Precommits array of non-pointers
because precommit will never be nil
* add NewCommitSigAbsent and Absent() funcs
* uncomment validation in CommitSig#ValidateBasic
* add comments to ValidatorSet funcs
* add a changelog entry
* break instead of continue
continue does not make sense in these cases
* types: rename Commit#Precommits to Signatures
* swagger: fix /commit response
* swagger: change block_id_flag type
* fix merge conflicts
* Fix long line errors in abci, crypto, and libs packages
* Fix long lines in p2p and rpc packages
* Fix long lines in abci, state, and tools packages
* Fix long lines in behaviour and blockchain packages
* Fix long lines in cmd and config packages
* Begin fixing long lines in consensus package
* Finish fixing long lines in consensus package
* Add lll exclusion for lines containing URLs
* Fix long lines in crypto package
* Fix long lines in evidence package
* Fix long lines in mempool and node packages
* Fix long lines in libs package
* Fix long lines in lite package
* Fix new long line in node package
* Fix long lines in p2p package
* Ignore gocritic warning
* Fix long lines in privval package
* Fix long lines in rpc package
* Fix long lines in scripts package
* Fix long lines in state package
* Fix long lines in tools package
* Fix long lines in types package
* Enable lll linter
When scaling and averaging is invoked, it is possible to have validators
with close priorities ending up with same priority. With the current code,
this makes it impossible to verify the priority orders before and after updates.
Fixes#3383
* fix failure in TestProposerFrequency
* Add test to check priority order after updates
* Changed applyRemovals() and removed Remove()
Changed applyRemovals() similar to applyUpdates()
Removed function Remove()
Updated comments
* review comments
* simplify applyRemovals and add more comments
* small correction in comment
* Fix check in test
* Fix priority check for centering, address review comments
* fix assert for priority centering
* review comments
* review comments
* cleanup and review comments
added upper limit check for validator voting power
moved check for empty validator set earlier
moved panic on potential negative set length in verifyRemovals
added more tests
* review comments
* types.NewCommit
* use types.NewCommit everywhere
* fix log in unsafe_reset
* memoize height and round in constructor
* notes about deprecating toVote
* bring back memoizeHeightRound
* Initial commit for 3181..still early
* unit test updates
* unit test updates
* fix check of dups accross updates and deletes
* simplify the processChange() func
* added overflow check utest
* Added checks for empty valset, new utest
* deepcopy changes in processUpdate()
* moved to new API, fixed tests
* test cleanup
* address review comments
* make sure votePower > 0
* gofmt fixes
* handle duplicates and invalid values
* more work on tests, review comments
* Renamed and explained K
* make TestVal private
* split verifyUpdatesAndComputeNewPriorities.., added check for deletes
* return error if validator set is empty after processing changes
* address review comments
* lint err
* Fixed the total voting power and added comments
* fix lint
* fix lint
* types: memoize height/round in commit instead of first vote
* types: commit.ValidateBasic in VerifyCommit
* types: new CommitSig alias for Vote
In preparation for reducing the redundancy in Commits, we introduce the
CommitSig as an alias for Vote. This is non-breaking on the protocol,
and minor breaking on the Go API, as Commit now contains a list of
CommitSig instead of Vote.
* remove dependence on ToVote
* update some comments
* fix tests
* fix tests
* fixes from review
* more proposer priority tests
- test that we don't reset to zero when updating / adding
- test that same power validators alternate
* add another test to track / simulate similar behaviour as in #2960
* address some of Chris' review comments
* address some more of Chris' review comments
* temporarily pushing branch with the following changes:
The total power might change if:
- a validator is added
- a validator is removed
- a validator is updated
Decrement the accums (of all validators) directly after any of these events
(by the inverse of the change)
* Fix 2960 by re-normalizing / scaling priorities to be in bounds of total
power, additionally:
- remove heap where it doesn't make sense
- avg. only at the end of IncrementProposerPriority instead of each
iteration
- update (and slightly improve)
TestAveragingInIncrementProposerPriorityWithVotingPower to reflect
above changes
* Fix 2960 by re-normalizing / scaling priorities to be in bounds of total
power, additionally:
- remove heap where it doesn't make sense
- avg. only at the end of IncrementProposerPriority instead of each
iteration
- update (and slightly improve)
TestAveragingInIncrementProposerPriorityWithVotingPower to reflect
above changes
* fix tests
* add comment
* update changelog pending & some minor changes
* comment about division will floor the result & fix typo
* Update TestLargeGenesisValidator:
- remove TODO and increase large genesis validator's voting power
accordingly
* move changelog entry to P2P Protocol
* Ceil instead of flooring when dividing & update test
* quickly fix failing TestProposerPriorityDoesNotGetResetToZero:
- divide by Ceil((maxPriority - minPriority) / 2*totalVotingPower)
* fix typo: rename getValWitMostPriority -> getValWithMostPriority
* test proposer frequencies
* return absolute value for diff. keep testing
* use for loop for div
* cleanup, more tests
* spellcheck
* get rid of using floats: manually ceil where necessary
* Remove float, simplify, fix tests to match chris's proof (#3157)
* WIP: tests for #2785
* rebase onto develop
* add Bucky's test without changing ValidatorSet.Update
* make TestValidatorSetBasic fail
* add ProposerPriority preserving fix to ValidatorSet.Update to fix
TestValidatorSetBasic
* fix randValidator_ to stay in bounds of MaxTotalVotingPower
* check for expected proposer and remove some duplicate code
* actually limit the voting power of random validator ...
* fix test
* types: ValidatorSet.Update preserves ProposerPriority
This solves the other issue discovered as part of #2718,
where Accum (now called ProposerPriority) is reset to
0 every time a validator is updated.
* update changelog
* add test
* update comment
* Update types/validator_set_test.go
Co-Authored-By: ebuchman <ethan@coinculture.info>
* set the accum of a new validator to (-total voting power):
- disincentivize validators to unbond, then rebon to reset their
negative Accum to zero
additional unrelated changes:
- do not capitalize error msgs
- fix typo
* review comments: (re)capitalize errors & delete obsolete comments
* More changes suggested by @melekes
* WIP: do not batch clip (#2809)
* substract avgAccum on each iteration
- temporarily skip test
* remove unused method safeMulClip / safeMul
* always substract the avg accum
- temp. skip another test
* remove overflow / underflow tests & add tests for avgAccum:
- add test for computeAvgAccum
- as we substract the avgAccum now we will not trivially over/underflow
* address @cwgoes' comments
* shift by avg at the end of IncrementAccum
* Add comment to MaxTotalVotingPower
* Guard inputs to not exceed MaxTotalVotingPower
* Address review comments:
- do not fetch current validator from set again
- update error message
* Address a few review comments:
- fix typo
- extract variable
* address more review comments:
- clarify 1.125*totalVotingPower == totalVotingPower + (totalVotingPower >> 3)
* review comments: panic instead of "clipping":
- total voting power is guarded to not exceed MaxTotalVotingPower ->
panic if this invariant is violated
* fix failing test
* WIP: switching to fixed offsets for SignBytes
* add version field to sign bytes and update order
* more comments on test-cases and add a tc with a chainID
* remove amino:"write_empty" tag
- it doesn't affect if default fixed size fields ((u)int64) are
written or not
- add comment about int->int64 casting
* update CHANGELOG_PENDING
* update documentation
* add back link to issue #1622 in documentation
* remove JSON tags and add (failing test-case)
* fix failing test
* update test-vectors due to added `Type` field
* change Type field from string to byte and add new type alias
- SignedMsgType replaces VoteTypePrevote, VoteTypePrecommit and adds new
ProposalType to separate votes from proposal when signed
- update test-vectors
* fix remains from rebasing
* use SignMessageType instead of byte everywhere
* fixes from review
Currently the top level directory contains basically all of the code
for the crypto package. This PR moves the crypto code into submodules
in a similar manner to what `golang/x/crypto` does. This improves code
organization.
Ref discussion: https://github.com/tendermint/tendermint/pull/1966Closes#1956