[cherry-picked] abci++: Sync implementation and spec for vote extensions (#8141)

* Refactor so building and linting works This is the first step towards implementing vote extensions: generating the relevant proto stubs and getting the build and linter to pass. Signed-off-by: Thane Thomson <connect@thanethomson.com> * Fix typo Signed-off-by: Thane Thomson <connect@thanethomson.com> * Better describe method given vote extensions Signed-off-by: Thane Thomson <connect@thanethomson.com> * Fix types tests Signed-off-by: Thane Thomson <connect@thanethomson.com> * Move CanonicalVoteExtension to canonical types proto defs Signed-off-by: Thane Thomson <connect@thanethomson.com> * Regenerate protos including latest PBTS synchrony params update Signed-off-by: Thane Thomson <connect@thanethomson.com> * Inject vote extensions into proposal Signed-off-by: Thane Thomson <connect@thanethomson.com> * Thread vote extensions through code and fix tests Signed-off-by: Thane Thomson <connect@thanethomson.com> * Remove extraneous empty value initialization Signed-off-by: Thane Thomson <connect@thanethomson.com> * Fix lint Signed-off-by: Thane Thomson <connect@thanethomson.com> * Fix missing VerifyVoteExtension request data Signed-off-by: Thane Thomson <connect@thanethomson.com> * Explicitly ensure length > 0 to sign vote extension Signed-off-by: Thane Thomson <connect@thanethomson.com> * Explicitly ensure length > 0 to sign vote extension Signed-off-by: Thane Thomson <connect@thanethomson.com> * Remove extraneous comment Signed-off-by: Thane Thomson <connect@thanethomson.com> * Update privval/file.go Co-authored-by: M. J. Fromberger <fromberger@interchain.io> * Update types/vote_test.go Co-authored-by: M. J. Fromberger <fromberger@interchain.io> * Format Signed-off-by: Thane Thomson <connect@thanethomson.com> * Fix ABCI proto generation scripts for Linux Signed-off-by: Thane Thomson <connect@thanethomson.com> * Sync intermediate and goal protos Signed-off-by: Thane Thomson <connect@thanethomson.com> * Update internal/consensus/common_test.go Co-authored-by: Sergio Mena <sergio@informal.systems> * Use dummy value with clearer meaning Signed-off-by: Thane Thomson <connect@thanethomson.com> * Rewrite loop for clarity Signed-off-by: Thane Thomson <connect@thanethomson.com> * Panic on ABCI++ method call failure Signed-off-by: Thane Thomson <connect@thanethomson.com> * Add strong correctness guarantees when constructing extended commit info for ABCI++ Signed-off-by: Thane Thomson <connect@thanethomson.com> * Add strong guarantee in extendedCommitInfo that the number of votes corresponds Signed-off-by: Thane Thomson <connect@thanethomson.com> * Make extendedCommitInfo function more robust At first extendedCommitInfo expected votes to be in the same order as their corresponding validators in the supplied CommitInfo struct, but this proved to be rather difficult since when a validator set's loaded from state it's first sorted by voting power and then by address. Instead of sorting the votes in the same way, this approach simply maps votes to their corresponding validator's address prior to constructing the extended commit info. This way it's easy to look up the corresponding vote and we don't need to care about vote order. Signed-off-by: Thane Thomson <connect@thanethomson.com> * Remove extraneous validator address assignment Signed-off-by: Thane Thomson <connect@thanethomson.com> * Sign over canonical vote extension Signed-off-by: Thane Thomson <connect@thanethomson.com> * Validate vote extension signature against canonical vote extension Signed-off-by: Thane Thomson <connect@thanethomson.com> * Update privval tests for more meaningful dummy value Signed-off-by: Thane Thomson <connect@thanethomson.com> * Add vote extension capability to E2E test app Signed-off-by: Thane Thomson <connect@thanethomson.com> * Disable lint for weak RNG usage for test app Signed-off-by: Thane Thomson <connect@thanethomson.com> * Use parseVoteExtension instead of custom parsing in PrepareProposal Signed-off-by: Thane Thomson <connect@thanethomson.com> * Only include extension if we have received txs It's unclear at this point why this is necessary to ensure that the application's local app_hash matches that committed in the previous block. Signed-off-by: Thane Thomson <connect@thanethomson.com> * Require app_hash from app to match that from last block Signed-off-by: Thane Thomson <connect@thanethomson.com> * Add contrived (possibly flaky) test to check that vote extensions code works Signed-off-by: Thane Thomson <connect@thanethomson.com> * Remove workaround for problem now solved by #8229 Signed-off-by: Thane Thomson <connect@thanethomson.com> * add tests for vote extension cases * Fix spelling mistake to appease linter Signed-off-by: Thane Thomson <connect@thanethomson.com> * Collapse redundant if statement Signed-off-by: Thane Thomson <connect@thanethomson.com> * Formatting Signed-off-by: Thane Thomson <connect@thanethomson.com> * Always expect an extension signature, regardless of whether an extension is present Signed-off-by: Thane Thomson <connect@thanethomson.com> * Votes constructed from commits cannot include extensions or signatures Signed-off-by: Thane Thomson <connect@thanethomson.com> * Pass through vote extension in test helpers Signed-off-by: Thane Thomson <connect@thanethomson.com> * Temporarily disable vote extension signature requirement Signed-off-by: Thane Thomson <connect@thanethomson.com> * Expand on vote equality test errors for clarity Signed-off-by: Thane Thomson <connect@thanethomson.com> * Expand on vote matching error messages in testing Signed-off-by: Thane Thomson <connect@thanethomson.com> * Allow for selective subscription by vote type This is an attempt to fix the intermittently failing `TestPrepareProposalReceivesVoteExtensions` test in the internal consensus package. Occasionally we get prevote messages via the subscription channel, and we're not interested in those. This change allows us to specify what types of votes we're interested in (i.e. precommits) and discard the rest. Signed-off-by: Thane Thomson <connect@thanethomson.com> * Read lock consensus state mutex in test helper to avoid data race Signed-off-by: Thane Thomson <connect@thanethomson.com> * Revert BlockIDFlag parameter in node test Signed-off-by: Thane Thomson <connect@thanethomson.com> * Perform additional check in ProcessProposal for special txs generated by vote extensions Signed-off-by: Thane Thomson <connect@thanethomson.com> * e2e: check that our added tx does not cause all txs to exceed req.MaxTxBytes Signed-off-by: Thane Thomson <connect@thanethomson.com> * Only set vote extension signatures when signing is successful Signed-off-by: Thane Thomson <connect@thanethomson.com> * Remove channel capacity constraint in test helper to avoid missing messages Signed-off-by: Thane Thomson <connect@thanethomson.com> * Add TODO to always require extension signatures in vote validation Signed-off-by: Thane Thomson <connect@thanethomson.com> * e2e: reject vote extensions if the request height does not match what we expect Signed-off-by: Thane Thomson <connect@thanethomson.com> * types: remove extraneous call to voteWithoutExtension in test Signed-off-by: Thane Thomson <connect@thanethomson.com> * Remove unnecessary address parameter from CanonicalVoteExtension Signed-off-by: Thane Thomson <connect@thanethomson.com> * privval: change test vote type to precommit since we use an extension Signed-off-by: Thane Thomson <connect@thanethomson.com> * privval: update signing logic to cater for vote extensions Signed-off-by: Thane Thomson <connect@thanethomson.com> * proto: update field descriptions for vote message Signed-off-by: Thane Thomson <connect@thanethomson.com> * proto: update field description for vote extension sig in vote message Signed-off-by: Thane Thomson <connect@thanethomson.com> * proto/types: use fixed-length 64-bit integers for rounds in CanonicalVoteExtension Signed-off-by: Thane Thomson <connect@thanethomson.com> * consensus: fix flaky TestPrepareProposalReceivesVoteExtensions Signed-off-by: Thane Thomson <connect@thanethomson.com> * consensus: remove previously added test helper functionality Signed-off-by: Thane Thomson <connect@thanethomson.com> * e2e: add error logs when we get an unexpected height in ExtendVote or VerifyVoteExtension requests Signed-off-by: Thane Thomson <connect@thanethomson.com> * node_test: get validator addresses from privvals Signed-off-by: Thane Thomson <connect@thanethomson.com> * privval/file_test: optimize filepv creation in tests Signed-off-by: Thane Thomson <connect@thanethomson.com> * privval: add test to check that vote extensions are always signed Signed-off-by: Thane Thomson <connect@thanethomson.com> * Add a script to check documentation for ToC entries. (#8356) This script verifies that each document in the docs and architecture directory has a corresponding table-of-contents entry in its README file. It can be run manually from the command line. - Hook up this script to run in CI (optional workflow). - Update ADR ToC to include missing entries this script found. * build(deps): Bump async from 2.6.3 to 2.6.4 in /docs (#8357) Bumps [async](https://github.com/caolan/async) from 2.6.3 to 2.6.4. - [Release notes](https://github.com/caolan/async/releases) - [Changelog](https://github.com/caolan/async/blob/v2.6.4/CHANGELOG.md) - [Commits](https://github.com/caolan/async/compare/v2.6.3...v2.6.4) --- updated-dependencies: - dependency-name: async dependency-type: indirect ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * privval/file_test: reset vote ext sig before signing Signed-off-by: Thane Thomson <connect@thanethomson.com> Co-authored-by: M. J. Fromberger <fromberger@interchain.io> Co-authored-by: Sergio Mena <sergio@informal.systems> Co-authored-by: William Banfield <wbanfield@gmail.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
2026-09-10 10:06:20 +00:00 · 2022-11-30 21:19:13 +01:00
parent bce38c0ecc
commit b196a7d415
30 changed files with 861 additions and 340 deletions
@@ -594,21 +594,19 @@ const (

 // CommitSig is a part of the Vote included in a Commit.
 type CommitSig struct {
-	BlockIDFlag      BlockIDFlag         `json:"block_id_flag"`
-	ValidatorAddress Address             `json:"validator_address"`
-	Timestamp        time.Time           `json:"timestamp"`
-	Signature        []byte              `json:"signature"`
-	VoteExtension    VoteExtensionToSign `json:"vote_extension"`
+	BlockIDFlag      BlockIDFlag `json:"block_id_flag"`
+	ValidatorAddress Address     `json:"validator_address"`
+	Timestamp        time.Time   `json:"timestamp"`
+	Signature        []byte      `json:"signature"`
 }

 // NewCommitSigForBlock returns new CommitSig with BlockIDFlagCommit.
-func NewCommitSigForBlock(signature []byte, valAddr Address, ts time.Time, ext VoteExtensionToSign) CommitSig {
+func NewCommitSigForBlock(signature []byte, valAddr Address, ts time.Time) CommitSig {
 	return CommitSig{
 		BlockIDFlag:      BlockIDFlagCommit,
 		ValidatorAddress: valAddr,
 		Timestamp:        ts,
 		Signature:        signature,
-		VoteExtension:    ext,
 	}
 }

@@ -641,14 +639,12 @@ func (cs CommitSig) Absent() bool {
 // 1. first 6 bytes of signature
 // 2. first 6 bytes of validator address
 // 3. block ID flag
-// 4. first 6 bytes of the vote extension
-// 5. timestamp
+// 4. timestamp
 func (cs CommitSig) String() string {
-	return fmt.Sprintf("CommitSig{%X by %X on %v with %X @ %s}",
+	return fmt.Sprintf("CommitSig{%X by %X on %v @ %s}",
 		tmbytes.Fingerprint(cs.Signature),
 		tmbytes.Fingerprint(cs.ValidatorAddress),
 		cs.BlockIDFlag,
-		tmbytes.Fingerprint(cs.VoteExtension.BytesPacked()),
 		CanonicalTime(cs.Timestamp))
 }

@@ -720,7 +716,6 @@ func (cs *CommitSig) ToProto() *tmproto.CommitSig {
 		ValidatorAddress: cs.ValidatorAddress,
 		Timestamp:        cs.Timestamp,
 		Signature:        cs.Signature,
-		VoteExtension:    cs.VoteExtension.ToProto(),
 	}
 }

@@ -732,7 +727,6 @@ func (cs *CommitSig) FromProto(csp tmproto.CommitSig) error {
 	cs.ValidatorAddress = csp.ValidatorAddress
 	cs.Timestamp = csp.Timestamp
 	cs.Signature = csp.Signature
-	cs.VoteExtension = VoteExtensionToSignFromProto(csp.VoteExtension)

 	return cs.ValidateBasic()
 }
@@ -799,7 +793,6 @@ func (commit *Commit) GetVote(valIdx int32) *Vote {
 		ValidatorAddress: commitSig.ValidatorAddress,
 		ValidatorIndex:   valIdx,
 		Signature:        commitSig.Signature,
-		VoteExtension:    commitSig.VoteExtension.ToVoteExtension(),
 	}
 }

@@ -243,7 +243,7 @@ func TestCommit(t *testing.T) {
 	require.NotNil(t, commit.BitArray())
 	assert.Equal(t, bits.NewBitArray(10).Size(), commit.BitArray().Size())

-	assert.Equal(t, voteSet.GetByIndex(0), commit.GetByIndex(0))
+	assert.Equal(t, voteWithoutExtension(voteSet.GetByIndex(0)), commit.GetByIndex(0))
 	assert.True(t, commit.IsCommit())
 }

@@ -526,7 +526,7 @@ func TestCommitToVoteSet(t *testing.T) {
 	voteSet2 := CommitToVoteSet(chainID, commit, valSet)

 	for i := int32(0); int(i) < len(vals); i++ {
-		vote1 := voteSet.GetByIndex(i)
+		vote1 := voteWithoutExtension(voteSet.GetByIndex(i))
 		vote2 := voteSet2.GetByIndex(i)
 		vote3 := commit.GetVote(i)

@@ -51,26 +51,29 @@ func CanonicalizeProposal(chainID string, proposal *tmproto.Proposal) tmproto.Ca
 	}
 }

-func GetVoteExtensionToSign(ext *tmproto.VoteExtension) *tmproto.VoteExtensionToSign {
-	if ext == nil {
-		return nil
-	}
-	return &tmproto.VoteExtensionToSign{
-		AppDataToSign: ext.AppDataToSign,
+// CanonicalizeVote transforms the given Vote to a CanonicalVote, which does
+// not contain ValidatorIndex and ValidatorAddress fields, or any fields
+// relating to vote extensions.
+func CanonicalizeVote(chainID string, vote *tmproto.Vote) tmproto.CanonicalVote {
+	return tmproto.CanonicalVote{
+		Type:      vote.Type,
+		Height:    vote.Height,       // encoded as sfixed64
+		Round:     int64(vote.Round), // encoded as sfixed64
+		BlockID:   CanonicalizeBlockID(vote.BlockID),
+		Timestamp: vote.Timestamp,
+		ChainID:   chainID,
 	}
 }

-// CanonicalizeVote transforms the given Vote to a CanonicalVote, which does
-// not contain ValidatorIndex and ValidatorAddress fields.
-func CanonicalizeVote(chainID string, vote *tmproto.Vote) tmproto.CanonicalVote {
-	return tmproto.CanonicalVote{
-		Type:          vote.Type,
-		Height:        vote.Height,       // encoded as sfixed64
-		Round:         int64(vote.Round), // encoded as sfixed64
-		BlockID:       CanonicalizeBlockID(vote.BlockID),
-		Timestamp:     vote.Timestamp,
-		ChainID:       chainID,
-		VoteExtension: GetVoteExtensionToSign(vote.VoteExtension),
+// CanonicalizeVoteExtension extracts the vote extension from the given vote
+// and constructs a CanonicalizeVoteExtension struct, whose representation in
+// bytes is what is signed in order to produce the vote extension's signature.
+func CanonicalizeVoteExtension(chainID string, vote *tmproto.Vote) tmproto.CanonicalVoteExtension {
+	return tmproto.CanonicalVoteExtension{
+		Extension: vote.Extension,
+		Height:    vote.Height,
+		Round:     int64(vote.Round),
+		ChainId:   chainID,
 	}
 }

@@ -251,6 +251,7 @@ func makeVote(
 	require.NoError(t, err)

 	v.Signature = vpb.Signature
+	v.ExtensionSignature = vpb.ExtensionSignature
 	return v
 }

@@ -77,11 +77,17 @@ func (pv MockPV) SignVote(chainID string, vote *tmproto.Vote) error {
 	}

 	signBytes := VoteSignBytes(useChainID, vote)
+	extSignBytes := VoteExtensionSignBytes(useChainID, vote)
 	sig, err := pv.PrivKey.Sign(signBytes)
 	if err != nil {
 		return err
 	}
 	vote.Signature = sig
+	extSig, err := pv.PrivKey.Sign(extSignBytes)
+	if err != nil {
+		return err
+	}
+	vote.ExtensionSignature = extSig
 	return nil
 }

@@ -44,6 +44,7 @@ func signAddVote(privVal PrivValidator, vote *Vote, voteSet *VoteSet) (signed bo
 		return false, err
 	}
 	vote.Signature = v.Signature
+	vote.ExtensionSignature = v.ExtensionSignature
 	return voteSet.AddVote(vote)
 }

@@ -77,6 +78,7 @@ func MakeVote(
 	}

 	vote.Signature = v.Signature
+	vote.ExtensionSignature = v.ExtensionSignature

 	return vote, nil
 }
@@ -99,3 +101,13 @@ func MakeBlock(height int64, txs []Tx, lastCommit *Commit, evidence []Evidence)
 	block.fillHeader()
 	return block
 }
+
+// Votes constructed from commits don't have extensions, because we don't store
+// the extensions themselves in the commit. This method is used to construct a
+// copy of a vote, but nil its extension and signature.
+func voteWithoutExtension(v *Vote) *Vote {
+	vc := v.Copy()
+	vc.Extension = nil
+	vc.ExtensionSignature = nil
+	return vc
+}
@@ -148,6 +148,7 @@ func TestValidatorSet_VerifyCommit_CheckAllSignatures(t *testing.T) {
 	err = vals[3].SignVote("CentaurusA", v)
 	require.NoError(t, err)
 	vote.Signature = v.Signature
+	vote.ExtendedSignature = v.ExtendedSignature
 	commit.Signatures[3] = vote.CommitSig()

 	err = valSet.VerifyCommit(chainID, blockID, h, commit)
@@ -174,6 +175,7 @@ func TestValidatorSet_VerifyCommitLight_ReturnsAsSoonAsMajorityOfVotingPowerSign
 	err = vals[3].SignVote("CentaurusA", v)
 	require.NoError(t, err)
 	vote.Signature = v.Signature
+	vote.ExtendedSignature = v.ExtendedSignature
 	commit.Signatures[3] = vote.CommitSig()

 	err = valSet.VerifyCommitLight(chainID, blockID, h, commit)
@@ -198,6 +200,7 @@ func TestValidatorSet_VerifyCommitLightTrusting_ReturnsAsSoonAsTrustLevelOfVotin
 	err = vals[2].SignVote("CentaurusA", v)
 	require.NoError(t, err)
 	vote.Signature = v.Signature
+	vote.ExtendedSignature = v.ExtendedSignature
 	commit.Signatures[2] = vote.CommitSig()

 	err = valSet.VerifyCommitLightTrusting(chainID, commit, tmmath.Fraction{Numerator: 1, Denominator: 3})
@@ -46,86 +46,19 @@ func NewConflictingVoteError(vote1, vote2 *Vote) *ErrVoteConflictingVotes {
 // Address is hex bytes.
 type Address = crypto.Address

-// VoteExtensionToSign is a subset of VoteExtension
-// that is signed by the validators private key
-type VoteExtensionToSign struct {
-	AppDataToSign []byte `json:"app_data_to_sign"`
-}
-
-func (ext VoteExtensionToSign) ToProto() *tmproto.VoteExtensionToSign {
-	if ext.IsEmpty() {
-		return nil
-	}
-	return &tmproto.VoteExtensionToSign{
-		AppDataToSign: ext.AppDataToSign,
-	}
-}
-
-func VoteExtensionToSignFromProto(pext *tmproto.VoteExtensionToSign) VoteExtensionToSign {
-	if pext == nil {
-		return VoteExtensionToSign{}
-	}
-	return VoteExtensionToSign{
-		AppDataToSign: pext.AppDataToSign,
-	}
-}
-
-func (ext VoteExtensionToSign) IsEmpty() bool {
-	return len(ext.AppDataToSign) == 0
-}
-
-// BytesPacked returns a bytes-packed representation for
-// debugging and human identification. This function should
-// not be used for any logical operations.
-func (ext VoteExtensionToSign) BytesPacked() []byte {
-	res := []byte{}
-	res = append(res, ext.AppDataToSign...)
-	return res
-}
-
-// ToVoteExtension constructs a VoteExtension from a VoteExtensionToSign
-func (ext VoteExtensionToSign) ToVoteExtension() VoteExtension {
-	return VoteExtension{
-		AppDataToSign: ext.AppDataToSign,
-	}
-}
-
-// VoteExtension is a set of data provided by the application
-// that is additionally included in the vote
-type VoteExtension struct {
-	AppDataToSign             []byte `json:"app_data_to_sign"`
-	AppDataSelfAuthenticating []byte `json:"app_data_self_authenticating"`
-}
-
-// ToSign constructs a VoteExtensionToSign from a VoteExtenstion
-func (ext VoteExtension) ToSign() VoteExtensionToSign {
-	return VoteExtensionToSign{
-		AppDataToSign: ext.AppDataToSign,
-	}
-}
-
-// BytesPacked returns a bytes-packed representation for
-// debugging and human identification. This function should
-// not be used for any logical operations.
-func (ext VoteExtension) BytesPacked() []byte {
-	res := []byte{}
-	res = append(res, ext.AppDataToSign...)
-	res = append(res, ext.AppDataSelfAuthenticating...)
-	return res
-}
-
 // Vote represents a prevote, precommit, or commit vote from validators for
 // consensus.
 type Vote struct {
-	Type             tmproto.SignedMsgType `json:"type"`
-	Height           int64                 `json:"height"`
-	Round            int32                 `json:"round"`    // assume there will not be greater than 2_147_483_647 rounds
-	BlockID          BlockID               `json:"block_id"` // zero if vote is nil.
-	Timestamp        time.Time             `json:"timestamp"`
-	ValidatorAddress Address               `json:"validator_address"`
-	ValidatorIndex   int32                 `json:"validator_index"`
-	Signature        []byte                `json:"signature"`
-	VoteExtension    VoteExtension         `json:"vote_extension"`
+	Type               tmproto.SignedMsgType `json:"type"`
+	Height             int64                 `json:"height"`
+	Round              int32                 `json:"round"`    // assume there will not be greater than 2_147_483_647 rounds
+	BlockID            BlockID               `json:"block_id"` // zero if vote is nil.
+	Timestamp          time.Time             `json:"timestamp"`
+	ValidatorAddress   Address               `json:"validator_address"`
+	ValidatorIndex     int32                 `json:"validator_index"`
+	Signature          []byte                `json:"signature"`
+	Extension          []byte                `json:"extension"`
+	ExtensionSignature []byte                `json:"extension_signature"`
 }

 // CommitSig converts the Vote to a CommitSig.
@@ -149,12 +82,11 @@ func (vote *Vote) CommitSig() CommitSig {
 		ValidatorAddress: vote.ValidatorAddress,
 		Timestamp:        vote.Timestamp,
 		Signature:        vote.Signature,
-		VoteExtension:    vote.VoteExtension.ToSign(),
 	}
 }

 // VoteSignBytes returns the proto-encoding of the canonicalized Vote, for
-// signing. Panics is the marshaling fails.
+// signing. Panics if the marshaling fails.
 //
 // The encoded Protobuf message is varint length-prefixed (using MarshalDelimited)
 // for backwards-compatibility with the Amino encoding, due to e.g. hardware
@@ -171,9 +103,23 @@ func VoteSignBytes(chainID string, vote *tmproto.Vote) []byte {
 	return bz
 }

+// VoteExtensionSignBytes returns the proto-encoding of the canonicalized vote
+// extension for signing. Panics if the marshaling fails.
+//
+// Similar to VoteSignBytes, the encoded Protobuf message is varint
+// length-prefixed for backwards-compatibility with the Amino encoding.
+func VoteExtensionSignBytes(chainID string, vote *tmproto.Vote) []byte {
+	pb := CanonicalizeVoteExtension(chainID, vote)
+	bz, err := protoio.MarshalDelimited(&pb)
+	if err != nil {
+		panic(err)
+	}
+
+	return bz
+}
+
 func (vote *Vote) Copy() *Vote {
 	voteCopy := *vote
-	voteCopy.VoteExtension = vote.VoteExtension.Copy()
 	return &voteCopy
 }

@@ -213,7 +159,7 @@ func (vote *Vote) String() string {
 		typeString,
 		tmbytes.Fingerprint(vote.BlockID.Hash),
 		tmbytes.Fingerprint(vote.Signature),
-		tmbytes.Fingerprint(vote.VoteExtension.BytesPacked()),
+		tmbytes.Fingerprint(vote.Extension),
 		CanonicalTime(vote.Timestamp),
 	)
 }
@@ -226,6 +172,12 @@ func (vote *Vote) Verify(chainID string, pubKey crypto.PubKey) error {
 	if !pubKey.VerifySignature(VoteSignBytes(chainID, v), vote.Signature) {
 		return ErrVoteInvalidSignature
 	}
+	extSignBytes := VoteExtensionSignBytes(chainID, v)
+	// TODO: Remove extension signature nil check to enforce vote extension
+	//       signing once we resolve https://github.com/tendermint/tendermint/issues/8272
+	if vote.ExtensionSignature != nil && !pubKey.VerifySignature(extSignBytes, vote.ExtensionSignature) {
+		return ErrVoteInvalidSignature
+	}
 	return nil
 }

@@ -272,40 +224,15 @@ func (vote *Vote) ValidateBasic() error {
 		return fmt.Errorf("signature is too big (max: %d)", MaxSignatureSize)
 	}

-	// XXX: add length verification for vote extension?
+	// TODO: Remove the extension length check such that we always require
+	//       extension signatures to be present.
+	if len(vote.Extension) > 0 && len(vote.ExtensionSignature) == 0 {
+		return errors.New("vote extension signature is missing")
+	}

 	return nil
 }

-func (ext VoteExtension) Copy() VoteExtension {
-	res := VoteExtension{
-		AppDataToSign:             ext.AppDataToSign,
-		AppDataSelfAuthenticating: ext.AppDataSelfAuthenticating,
-	}
-	return res
-}
-
-func (ext VoteExtension) IsEmpty() bool {
-	if len(ext.AppDataToSign) != 0 {
-		return false
-	}
-	if len(ext.AppDataSelfAuthenticating) != 0 {
-		return false
-	}
-	return true
-}
-
-func (ext VoteExtension) ToProto() *tmproto.VoteExtension {
-	if ext.IsEmpty() {
-		return nil
-	}
-
-	return &tmproto.VoteExtension{
-		AppDataToSign:             ext.AppDataToSign,
-		AppDataSelfAuthenticating: ext.AppDataSelfAuthenticating,
-	}
-}
-
 // ToProto converts the handwritten type to proto generated type
 // return type, nil if everything converts safely, otherwise nil, error
 func (vote *Vote) ToProto() *tmproto.Vote {
@@ -314,15 +241,16 @@ func (vote *Vote) ToProto() *tmproto.Vote {
 	}

 	return &tmproto.Vote{
-		Type:             vote.Type,
-		Height:           vote.Height,
-		Round:            vote.Round,
-		BlockID:          vote.BlockID.ToProto(),
-		Timestamp:        vote.Timestamp,
-		ValidatorAddress: vote.ValidatorAddress,
-		ValidatorIndex:   vote.ValidatorIndex,
-		Signature:        vote.Signature,
-		VoteExtension:    vote.VoteExtension.ToProto(),
+		Type:               vote.Type,
+		Height:             vote.Height,
+		Round:              vote.Round,
+		BlockID:            vote.BlockID.ToProto(),
+		Timestamp:          vote.Timestamp,
+		ValidatorAddress:   vote.ValidatorAddress,
+		ValidatorIndex:     vote.ValidatorIndex,
+		Signature:          vote.Signature,
+		Extension:          vote.Extension,
+		ExtensionSignature: vote.ExtensionSignature,
 	}
 }

@@ -342,15 +270,6 @@ func VotesToProto(votes []*Vote) []*tmproto.Vote {
 	return res
 }

-func VoteExtensionFromProto(pext *tmproto.VoteExtension) VoteExtension {
-	ext := VoteExtension{}
-	if pext != nil {
-		ext.AppDataToSign = pext.AppDataToSign
-		ext.AppDataSelfAuthenticating = pext.AppDataSelfAuthenticating
-	}
-	return ext
-}
-
 // FromProto converts a proto generetad type to a handwritten type
 // return type, nil if everything converts safely, otherwise nil, error
 func VoteFromProto(pv *tmproto.Vote) (*Vote, error) {
@@ -372,7 +291,8 @@ func VoteFromProto(pv *tmproto.Vote) (*Vote, error) {
 	vote.ValidatorAddress = pv.ValidatorAddress
 	vote.ValidatorIndex = pv.ValidatorIndex
 	vote.Signature = pv.Signature
-	vote.VoteExtension = VoteExtensionFromProto(pv.VoteExtension)
+	vote.Extension = pv.Extension
+	vote.ExtensionSignature = pv.ExtensionSignature

 	return vote, vote.ValidateBasic()
 }
@@ -118,6 +118,7 @@ func TestVoteSet_AddVote_Bad(t *testing.T) {
 			t.Errorf("expected VoteSet.Add to fail, wrong type")
 		}
 	}
+
 }

 func TestVoteSet_2_3Majority(t *testing.T) {
@@ -1,6 +1,7 @@
 package types

 import (
+	"context"
 	"testing"
 	"time"

@@ -12,6 +13,7 @@ import (
 	"github.com/tendermint/tendermint/crypto/ed25519"
 	"github.com/tendermint/tendermint/crypto/tmhash"
 	"github.com/tendermint/tendermint/libs/protoio"
+	tmtime "github.com/tendermint/tendermint/libs/time"
 	tmproto "github.com/tendermint/tendermint/proto/tendermint/types"
 )

@@ -129,12 +131,13 @@ func TestVoteSignBytesTestVectors(t *testing.T) {
 		},
 		// containing vote extension
 		5: {
-			"test_chain_id", &Vote{Height: 1, Round: 1, VoteExtension: VoteExtension{
-				AppDataToSign:             []byte("signed"),
-				AppDataSelfAuthenticating: []byte("auth"),
-			}},
+			"test_chain_id", &Vote{
+				Height:    1,
+				Round:     1,
+				Extension: []byte("extension"),
+			},
 			[]byte{
-				0x38,                                   // length
+				0x2e,                                   // length
 				0x11,                                   // (field_number << 3) | wire_type
 				0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, // height
 				0x19,                                   // (field_number << 3) | wire_type
@@ -145,13 +148,6 @@ func TestVoteSignBytesTestVectors(t *testing.T) {
 				// (field_number << 3) | wire_type
 				0x32,
 				0xd, 0x74, 0x65, 0x73, 0x74, 0x5f, 0x63, 0x68, 0x61, 0x69, 0x6e, 0x5f, 0x69, 0x64, // chainID
-				// (field_number << 3) | wire_type
-				0x3a,
-				0x8,                                // length
-				0xa,                                // (field_number << 3) | wire_type
-				0x6,                                // length
-				0x73, 0x69, 0x67, 0x6e, 0x65, 0x64, // AppDataSigned
-				// SelfAuthenticating data is excluded on signing
 			}, // chainID
 		},
 	}
@@ -204,6 +200,82 @@ func TestVoteVerifySignature(t *testing.T) {
 	require.True(t, valid)
 }

+// TestVoteExtension tests that the vote verification behaves correctly in each case
+// of vote extension being set on the vote.
+func TestVoteExtension(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	testCases := []struct {
+		name             string
+		extension        []byte
+		includeSignature bool
+		expectError      bool
+	}{
+		{
+			name:             "all fields present",
+			extension:        []byte("extension"),
+			includeSignature: true,
+			expectError:      false,
+		},
+		// TODO: Re-enable once
+		// https://github.com/tendermint/tendermint/issues/8272 is resolved.
+		//{
+		//	name:             "no extension signature",
+		//	extension:        []byte("extension"),
+		//	includeSignature: false,
+		//	expectError:      true,
+		//},
+		{
+			name:             "empty extension",
+			includeSignature: true,
+			expectError:      false,
+		},
+		// TODO: Re-enable once
+		// https://github.com/tendermint/tendermint/issues/8272 is resolved.
+		//{
+		//	name:             "no extension and no signature",
+		//	includeSignature: false,
+		//	expectError:      true,
+		//},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			height, round := int64(1), int32(0)
+			privVal := NewMockPV()
+			pk, err := privVal.GetPubKey(ctx)
+			require.NoError(t, err)
+			blk := Block{}
+			ps, err := blk.MakePartSet(BlockPartSizeBytes)
+			require.NoError(t, err)
+			vote := &Vote{
+				ValidatorAddress: pk.Address(),
+				ValidatorIndex:   0,
+				Height:           height,
+				Round:            round,
+				Timestamp:        tmtime.Now(),
+				Type:             tmproto.PrecommitType,
+				BlockID:          BlockID{blk.Hash(), ps.Header()},
+			}
+
+			v := vote.ToProto()
+			err = privVal.SignVote(ctx, "test_chain_id", v)
+			require.NoError(t, err)
+			vote.Signature = v.Signature
+			if tc.includeSignature {
+				vote.ExtensionSignature = v.ExtensionSignature
+			}
+			err = vote.Verify("test_chain_id", pk)
+			if tc.expectError {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}
+
 func TestIsVoteTypeValid(t *testing.T) {
 	tc := []struct {
 		name string