From fff843cfafddb43aebad6e3e5ad8b0f68143759d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Felf=C3=B6ldi=20Zsolt?= Date: Fri, 8 Dec 2023 13:38:00 +0100 Subject: [PATCH] beacon/light: add CommitteeChain (#27766) This change implements CommitteeChain which is a key component of the beacon light client. It is a passive data structure that can validate, hold and update a chain of beacon light sync committees and updates, starting from a checkpoint that proves the starting committee through a beacon block hash, header and corresponding state. Once synced to the current sync period, CommitteeChain can also validate signed beacon headers. --- beacon/light/canonical.go | 125 ++++++ beacon/light/committee_chain.go | 514 ++++++++++++++++++++++ beacon/light/committee_chain_test.go | 356 +++++++++++++++ beacon/light/range.go | 78 ++++ beacon/light/test_helpers.go | 152 +++++++ beacon/types/{update.go => light_sync.go} | 18 + core/rawdb/schema.go | 4 + 7 files changed, 1247 insertions(+) create mode 100644 beacon/light/canonical.go create mode 100644 beacon/light/committee_chain.go create mode 100644 beacon/light/committee_chain_test.go create mode 100644 beacon/light/range.go create mode 100644 beacon/light/test_helpers.go rename beacon/types/{update.go => light_sync.go} (88%) diff --git a/beacon/light/canonical.go b/beacon/light/canonical.go new file mode 100644 index 000000000..b5371493b --- /dev/null +++ b/beacon/light/canonical.go @@ -0,0 +1,125 @@ +// Copyright 2023 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see . + +package light + +import ( + "encoding/binary" + "fmt" + + "github.com/ethereum/go-ethereum/common/lru" + "github.com/ethereum/go-ethereum/ethdb" + "github.com/ethereum/go-ethereum/log" + "github.com/ethereum/go-ethereum/rlp" +) + +// canonicalStore stores instances of the given type in a database and caches +// them in memory, associated with a continuous range of period numbers. +// Note: canonicalStore is not thread safe and it is the caller's responsibility +// to avoid concurrent access. +type canonicalStore[T any] struct { + keyPrefix []byte + periods periodRange + cache *lru.Cache[uint64, T] +} + +// newCanonicalStore creates a new canonicalStore and loads all keys associated +// with the keyPrefix in order to determine the ranges available in the database. +func newCanonicalStore[T any](db ethdb.Iteratee, keyPrefix []byte) (*canonicalStore[T], error) { + cs := &canonicalStore[T]{ + keyPrefix: keyPrefix, + cache: lru.NewCache[uint64, T](100), + } + var ( + iter = db.NewIterator(keyPrefix, nil) + kl = len(keyPrefix) + first = true + ) + defer iter.Release() + + for iter.Next() { + if len(iter.Key()) != kl+8 { + log.Warn("Invalid key length in the canonical chain database", "key", fmt.Sprintf("%#x", iter.Key())) + continue + } + period := binary.BigEndian.Uint64(iter.Key()[kl : kl+8]) + if first { + cs.periods.Start = period + } else if cs.periods.End != period { + return nil, fmt.Errorf("gap in the canonical chain database between periods %d and %d", cs.periods.End, period-1) + } + first = false + cs.periods.End = period + 1 + } + return cs, nil +} + +// databaseKey returns the database key belonging to the given period. +func (cs *canonicalStore[T]) databaseKey(period uint64) []byte { + return binary.BigEndian.AppendUint64(append([]byte{}, cs.keyPrefix...), period) +} + +// add adds the given item to the database. It also ensures that the range remains +// continuous. Can be used either with a batch or database backend. +func (cs *canonicalStore[T]) add(backend ethdb.KeyValueWriter, period uint64, value T) error { + if !cs.periods.canExpand(period) { + return fmt.Errorf("period expansion is not allowed, first: %d, next: %d, period: %d", cs.periods.Start, cs.periods.End, period) + } + enc, err := rlp.EncodeToBytes(value) + if err != nil { + return err + } + if err := backend.Put(cs.databaseKey(period), enc); err != nil { + return err + } + cs.cache.Add(period, value) + cs.periods.expand(period) + return nil +} + +// deleteFrom removes items starting from the given period. +func (cs *canonicalStore[T]) deleteFrom(db ethdb.KeyValueWriter, fromPeriod uint64) (deleted periodRange) { + keepRange, deleteRange := cs.periods.split(fromPeriod) + deleteRange.each(func(period uint64) { + db.Delete(cs.databaseKey(period)) + cs.cache.Remove(period) + }) + cs.periods = keepRange + return deleteRange +} + +// get returns the item at the given period or the null value of the given type +// if no item is present. +func (cs *canonicalStore[T]) get(backend ethdb.KeyValueReader, period uint64) (T, bool) { + var null, value T + if !cs.periods.contains(period) { + return null, false + } + if value, ok := cs.cache.Get(period); ok { + return value, true + } + enc, err := backend.Get(cs.databaseKey(period)) + if err != nil { + log.Error("Canonical store value not found", "period", period, "start", cs.periods.Start, "end", cs.periods.End) + return null, false + } + if err := rlp.DecodeBytes(enc, &value); err != nil { + log.Error("Error decoding canonical store value", "error", err) + return null, false + } + cs.cache.Add(period, value) + return value, true +} diff --git a/beacon/light/committee_chain.go b/beacon/light/committee_chain.go new file mode 100644 index 000000000..d707f8cc3 --- /dev/null +++ b/beacon/light/committee_chain.go @@ -0,0 +1,514 @@ +// Copyright 2023 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see . + +package light + +import ( + "errors" + "fmt" + "math" + "sync" + "time" + + "github.com/ethereum/go-ethereum/beacon/params" + "github.com/ethereum/go-ethereum/beacon/types" + "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/common/lru" + "github.com/ethereum/go-ethereum/common/mclock" + "github.com/ethereum/go-ethereum/core/rawdb" + "github.com/ethereum/go-ethereum/ethdb" + "github.com/ethereum/go-ethereum/log" +) + +var ( + ErrNeedCommittee = errors.New("sync committee required") + ErrInvalidUpdate = errors.New("invalid committee update") + ErrInvalidPeriod = errors.New("invalid update period") + ErrWrongCommitteeRoot = errors.New("wrong committee root") + ErrCannotReorg = errors.New("can not reorg committee chain") +) + +// CommitteeChain is a passive data structure that can validate, hold and update +// a chain of beacon light sync committees and updates. It requires at least one +// externally set fixed committee root at the beginning of the chain which can +// be set either based on a BootstrapData or a trusted source (a local beacon +// full node). This makes the structure useful for both light client and light +// server setups. +// +// It always maintains the following consistency constraints: +// - a committee can only be present if its root hash matches an existing fixed +// root or if it is proven by an update at the previous period +// - an update can only be present if a committee is present at the same period +// and the update signature is valid and has enough participants. +// The committee at the next period (proven by the update) should also be +// present (note that this means they can only be added together if neither +// is present yet). If a fixed root is present at the next period then the +// update can only be present if it proves the same committee root. +// +// Once synced to the current sync period, CommitteeChain can also validate +// signed beacon headers. +type CommitteeChain struct { + // chainmu guards against concurrent access to the canonicalStore structures + // (updates, committees, fixedCommitteeRoots) and ensures that they stay consistent + // with each other and with committeeCache. + chainmu sync.RWMutex + db ethdb.KeyValueStore + updates *canonicalStore[*types.LightClientUpdate] + committees *canonicalStore[*types.SerializedSyncCommittee] + fixedCommitteeRoots *canonicalStore[common.Hash] + committeeCache *lru.Cache[uint64, syncCommittee] // cache deserialized committees + + clock mclock.Clock // monotonic clock (simulated clock in tests) + unixNano func() int64 // system clock (simulated clock in tests) + sigVerifier committeeSigVerifier // BLS sig verifier (dummy verifier in tests) + + config *types.ChainConfig + signerThreshold int + minimumUpdateScore types.UpdateScore + enforceTime bool // enforceTime specifies whether the age of a signed header should be checked +} + +// NewCommitteeChain creates a new CommitteeChain. +func NewCommitteeChain(db ethdb.KeyValueStore, config *types.ChainConfig, signerThreshold int, enforceTime bool) *CommitteeChain { + return newCommitteeChain(db, config, signerThreshold, enforceTime, blsVerifier{}, &mclock.System{}, func() int64 { return time.Now().UnixNano() }) +} + +// newCommitteeChain creates a new CommitteeChain with the option of replacing the +// clock source and signature verification for testing purposes. +func newCommitteeChain(db ethdb.KeyValueStore, config *types.ChainConfig, signerThreshold int, enforceTime bool, sigVerifier committeeSigVerifier, clock mclock.Clock, unixNano func() int64) *CommitteeChain { + s := &CommitteeChain{ + committeeCache: lru.NewCache[uint64, syncCommittee](10), + db: db, + sigVerifier: sigVerifier, + clock: clock, + unixNano: unixNano, + config: config, + signerThreshold: signerThreshold, + enforceTime: enforceTime, + minimumUpdateScore: types.UpdateScore{ + SignerCount: uint32(signerThreshold), + SubPeriodIndex: params.SyncPeriodLength / 16, + }, + } + + var err1, err2, err3 error + if s.fixedCommitteeRoots, err1 = newCanonicalStore[common.Hash](db, rawdb.FixedCommitteeRootKey); err1 != nil { + log.Error("Error creating fixed committee root store", "error", err1) + } + if s.committees, err2 = newCanonicalStore[*types.SerializedSyncCommittee](db, rawdb.SyncCommitteeKey); err2 != nil { + log.Error("Error creating committee store", "error", err2) + } + if s.updates, err3 = newCanonicalStore[*types.LightClientUpdate](db, rawdb.BestUpdateKey); err3 != nil { + log.Error("Error creating update store", "error", err3) + } + if err1 != nil || err2 != nil || err3 != nil || !s.checkConstraints() { + log.Info("Resetting invalid committee chain") + s.Reset() + } + // roll back invalid updates (might be necessary if forks have been changed since last time) + for !s.updates.periods.isEmpty() { + update, ok := s.updates.get(s.db, s.updates.periods.End-1) + if !ok { + log.Error("Sync committee update missing", "period", s.updates.periods.End-1) + s.Reset() + break + } + if valid, err := s.verifyUpdate(update); err != nil { + log.Error("Error validating update", "period", s.updates.periods.End-1, "error", err) + } else if valid { + break + } + if err := s.rollback(s.updates.periods.End); err != nil { + log.Error("Error writing batch into chain database", "error", err) + } + } + if !s.committees.periods.isEmpty() { + log.Trace("Sync committee chain loaded", "first period", s.committees.periods.Start, "last period", s.committees.periods.End-1) + } + return s +} + +// checkConstraints checks committee chain validity constraints +func (s *CommitteeChain) checkConstraints() bool { + isNotInFixedCommitteeRootRange := func(r periodRange) bool { + return s.fixedCommitteeRoots.periods.isEmpty() || + r.Start < s.fixedCommitteeRoots.periods.Start || + r.Start >= s.fixedCommitteeRoots.periods.End + } + + valid := true + if !s.updates.periods.isEmpty() { + if isNotInFixedCommitteeRootRange(s.updates.periods) { + log.Error("Start update is not in the fixed roots range") + valid = false + } + if s.committees.periods.Start > s.updates.periods.Start || s.committees.periods.End <= s.updates.periods.End { + log.Error("Missing committees in update range") + valid = false + } + } + if !s.committees.periods.isEmpty() { + if isNotInFixedCommitteeRootRange(s.committees.periods) { + log.Error("Start committee is not in the fixed roots range") + valid = false + } + if s.committees.periods.End > s.fixedCommitteeRoots.periods.End && s.committees.periods.End > s.updates.periods.End+1 { + log.Error("Last committee is neither in the fixed roots range nor proven by updates") + valid = false + } + } + return valid +} + +// Reset resets the committee chain. +func (s *CommitteeChain) Reset() { + s.chainmu.Lock() + defer s.chainmu.Unlock() + + if err := s.rollback(0); err != nil { + log.Error("Error writing batch into chain database", "error", err) + } +} + +// CheckpointInit initializes a CommitteeChain based on the checkpoint. +// Note: if the chain is already initialized and the committees proven by the +// checkpoint do match the existing chain then the chain is retained and the +// new checkpoint becomes fixed. +func (s *CommitteeChain) CheckpointInit(bootstrap *types.BootstrapData) error { + s.chainmu.Lock() + defer s.chainmu.Unlock() + + if err := bootstrap.Validate(); err != nil { + return err + } + + period := bootstrap.Header.SyncPeriod() + if err := s.deleteFixedCommitteeRootsFrom(period + 2); err != nil { + s.Reset() + return err + } + if s.addFixedCommitteeRoot(period, bootstrap.CommitteeRoot) != nil { + s.Reset() + if err := s.addFixedCommitteeRoot(period, bootstrap.CommitteeRoot); err != nil { + s.Reset() + return err + } + } + if err := s.addFixedCommitteeRoot(period+1, common.Hash(bootstrap.CommitteeBranch[0])); err != nil { + s.Reset() + return err + } + if err := s.addCommittee(period, bootstrap.Committee); err != nil { + s.Reset() + return err + } + return nil +} + +// addFixedCommitteeRoot sets a fixed committee root at the given period. +// Note that the period where the first committee is added has to have a fixed +// root which can either come from a BootstrapData or a trusted source. +func (s *CommitteeChain) addFixedCommitteeRoot(period uint64, root common.Hash) error { + if root == (common.Hash{}) { + return ErrWrongCommitteeRoot + } + + batch := s.db.NewBatch() + oldRoot := s.getCommitteeRoot(period) + if !s.fixedCommitteeRoots.periods.canExpand(period) { + // Note: the fixed committee root range should always be continuous and + // therefore the expected syncing method is to forward sync and optionally + // backward sync periods one by one, starting from a checkpoint. The only + // case when a root that is not adjacent to the already fixed ones can be + // fixed is when the same root has already been proven by an update chain. + // In this case the all roots in between can and should be fixed. + // This scenario makes sense when a new trusted checkpoint is added to an + // existing chain, ensuring that it will not be rolled back (might be + // important in case of low signer participation rate). + if root != oldRoot { + return ErrInvalidPeriod + } + // if the old root exists and matches the new one then it is guaranteed + // that the given period is after the existing fixed range and the roots + // in between can also be fixed. + for p := s.fixedCommitteeRoots.periods.End; p < period; p++ { + if err := s.fixedCommitteeRoots.add(batch, p, s.getCommitteeRoot(p)); err != nil { + return err + } + } + } + if oldRoot != (common.Hash{}) && (oldRoot != root) { + // existing old root was different, we have to reorg the chain + if err := s.rollback(period); err != nil { + return err + } + } + if err := s.fixedCommitteeRoots.add(batch, period, root); err != nil { + return err + } + if err := batch.Write(); err != nil { + log.Error("Error writing batch into chain database", "error", err) + return err + } + return nil +} + +// deleteFixedCommitteeRootsFrom deletes fixed roots starting from the given period. +// It also maintains chain consistency, meaning that it also deletes updates and +// committees if they are no longer supported by a valid update chain. +func (s *CommitteeChain) deleteFixedCommitteeRootsFrom(period uint64) error { + if period >= s.fixedCommitteeRoots.periods.End { + return nil + } + batch := s.db.NewBatch() + s.fixedCommitteeRoots.deleteFrom(batch, period) + if s.updates.periods.isEmpty() || period <= s.updates.periods.Start { + // Note: the first period of the update chain should always be fixed so if + // the fixed root at the first update is removed then the entire update chain + // and the proven committees have to be removed. Earlier committees in the + // remaining fixed root range can stay. + s.updates.deleteFrom(batch, period) + s.deleteCommitteesFrom(batch, period) + } else { + // The update chain stays intact, some previously fixed committee roots might + // get unfixed but are still proven by the update chain. If there were + // committees present after the range proven by updates, those should be + // removed if the belonging fixed roots are also removed. + fromPeriod := s.updates.periods.End + 1 // not proven by updates + if period > fromPeriod { + fromPeriod = period // also not justified by fixed roots + } + s.deleteCommitteesFrom(batch, fromPeriod) + } + if err := batch.Write(); err != nil { + log.Error("Error writing batch into chain database", "error", err) + return err + } + return nil +} + +// deleteCommitteesFrom deletes committees starting from the given period. +func (s *CommitteeChain) deleteCommitteesFrom(batch ethdb.Batch, period uint64) { + deleted := s.committees.deleteFrom(batch, period) + for period := deleted.Start; period < deleted.End; period++ { + s.committeeCache.Remove(period) + } +} + +// addCommittee adds a committee at the given period if possible. +func (s *CommitteeChain) addCommittee(period uint64, committee *types.SerializedSyncCommittee) error { + if !s.committees.periods.canExpand(period) { + return ErrInvalidPeriod + } + root := s.getCommitteeRoot(period) + if root == (common.Hash{}) { + return ErrInvalidPeriod + } + if root != committee.Root() { + return ErrWrongCommitteeRoot + } + if !s.committees.periods.contains(period) { + if err := s.committees.add(s.db, period, committee); err != nil { + return err + } + s.committeeCache.Remove(period) + } + return nil +} + +// InsertUpdate adds a new update if possible. +func (s *CommitteeChain) InsertUpdate(update *types.LightClientUpdate, nextCommittee *types.SerializedSyncCommittee) error { + s.chainmu.Lock() + defer s.chainmu.Unlock() + + period := update.AttestedHeader.Header.SyncPeriod() + if !s.updates.periods.canExpand(period) || !s.committees.periods.contains(period) { + return ErrInvalidPeriod + } + if s.minimumUpdateScore.BetterThan(update.Score()) { + return ErrInvalidUpdate + } + oldRoot := s.getCommitteeRoot(period + 1) + reorg := oldRoot != (common.Hash{}) && oldRoot != update.NextSyncCommitteeRoot + if oldUpdate, ok := s.updates.get(s.db, period); ok && !update.Score().BetterThan(oldUpdate.Score()) { + // a better or equal update already exists; no changes, only fail if new one tried to reorg + if reorg { + return ErrCannotReorg + } + return nil + } + if s.fixedCommitteeRoots.periods.contains(period+1) && reorg { + return ErrCannotReorg + } + if ok, err := s.verifyUpdate(update); err != nil { + return err + } else if !ok { + return ErrInvalidUpdate + } + addCommittee := !s.committees.periods.contains(period+1) || reorg + if addCommittee { + if nextCommittee == nil { + return ErrNeedCommittee + } + if nextCommittee.Root() != update.NextSyncCommitteeRoot { + return ErrWrongCommitteeRoot + } + } + if reorg { + if err := s.rollback(period + 1); err != nil { + return err + } + } + batch := s.db.NewBatch() + if addCommittee { + if err := s.committees.add(batch, period+1, nextCommittee); err != nil { + return err + } + s.committeeCache.Remove(period + 1) + } + if err := s.updates.add(batch, period, update); err != nil { + return err + } + if err := batch.Write(); err != nil { + log.Error("Error writing batch into chain database", "error", err) + return err + } + log.Info("Inserted new committee update", "period", period, "next committee root", update.NextSyncCommitteeRoot) + return nil +} + +// NextSyncPeriod returns the next period where an update can be added and also +// whether the chain is initialized at all. +func (s *CommitteeChain) NextSyncPeriod() (uint64, bool) { + s.chainmu.RLock() + defer s.chainmu.RUnlock() + + if s.committees.periods.isEmpty() { + return 0, false + } + if !s.updates.periods.isEmpty() { + return s.updates.periods.End, true + } + return s.committees.periods.End - 1, true +} + +// rollback removes all committees and fixed roots from the given period and updates +// starting from the previous period. +func (s *CommitteeChain) rollback(period uint64) error { + max := s.updates.periods.End + 1 + if s.committees.periods.End > max { + max = s.committees.periods.End + } + if s.fixedCommitteeRoots.periods.End > max { + max = s.fixedCommitteeRoots.periods.End + } + for max > period { + max-- + batch := s.db.NewBatch() + s.deleteCommitteesFrom(batch, max) + s.fixedCommitteeRoots.deleteFrom(batch, max) + if max > 0 { + s.updates.deleteFrom(batch, max-1) + } + if err := batch.Write(); err != nil { + log.Error("Error writing batch into chain database", "error", err) + return err + } + } + return nil +} + +// getCommitteeRoot returns the committee root at the given period, either fixed, +// proven by a previous update or both. It returns an empty hash if the committee +// root is unknown. +func (s *CommitteeChain) getCommitteeRoot(period uint64) common.Hash { + if root, ok := s.fixedCommitteeRoots.get(s.db, period); ok || period == 0 { + return root + } + if update, ok := s.updates.get(s.db, period-1); ok { + return update.NextSyncCommitteeRoot + } + return common.Hash{} +} + +// getSyncCommittee returns the deserialized sync committee at the given period. +func (s *CommitteeChain) getSyncCommittee(period uint64) (syncCommittee, error) { + if c, ok := s.committeeCache.Get(period); ok { + return c, nil + } + if sc, ok := s.committees.get(s.db, period); ok { + c, err := s.sigVerifier.deserializeSyncCommittee(sc) + if err != nil { + return nil, fmt.Errorf("Sync committee #%d deserialization error: %v", period, err) + } + s.committeeCache.Add(period, c) + return c, nil + } + return nil, fmt.Errorf("Missing serialized sync committee #%d", period) +} + +// VerifySignedHeader returns true if the given signed header has a valid signature +// according to the local committee chain. The caller should ensure that the +// committees advertised by the same source where the signed header came from are +// synced before verifying the signature. +// The age of the header is also returned (the time elapsed since the beginning +// of the given slot, according to the local system clock). If enforceTime is +// true then negative age (future) headers are rejected. +func (s *CommitteeChain) VerifySignedHeader(head types.SignedHeader) (bool, time.Duration, error) { + s.chainmu.RLock() + defer s.chainmu.RUnlock() + + return s.verifySignedHeader(head) +} + +func (s *CommitteeChain) verifySignedHeader(head types.SignedHeader) (bool, time.Duration, error) { + var age time.Duration + now := s.unixNano() + if head.Header.Slot < (uint64(now-math.MinInt64)/uint64(time.Second)-s.config.GenesisTime)/12 { + age = time.Duration(now - int64(time.Second)*int64(s.config.GenesisTime+head.Header.Slot*12)) + } else { + age = time.Duration(math.MinInt64) + } + if s.enforceTime && age < 0 { + return false, age, nil + } + committee, err := s.getSyncCommittee(types.SyncPeriod(head.SignatureSlot)) + if err != nil { + return false, 0, err + } + if committee == nil { + return false, age, nil + } + if signingRoot, err := s.config.Forks.SigningRoot(head.Header); err == nil { + return s.sigVerifier.verifySignature(committee, signingRoot, &head.Signature), age, nil + } + return false, age, nil +} + +// verifyUpdate checks whether the header signature is correct and the update +// fits into the specified constraints (assumes that the update has been +// successfully validated previously) +func (s *CommitteeChain) verifyUpdate(update *types.LightClientUpdate) (bool, error) { + // Note: SignatureSlot determines the sync period of the committee used for signature + // verification. Though in reality SignatureSlot is always bigger than update.Header.Slot, + // setting them as equal here enforces the rule that they have to be in the same sync + // period in order for the light client update proof to be meaningful. + ok, age, err := s.verifySignedHeader(update.AttestedHeader) + if age < 0 { + log.Warn("Future committee update received", "age", age) + } + return ok, err +} diff --git a/beacon/light/committee_chain_test.go b/beacon/light/committee_chain_test.go new file mode 100644 index 000000000..60ea2a0ef --- /dev/null +++ b/beacon/light/committee_chain_test.go @@ -0,0 +1,356 @@ +// Copyright 2022 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see . + +package light + +import ( + "crypto/rand" + "testing" + "time" + + "github.com/ethereum/go-ethereum/beacon/params" + "github.com/ethereum/go-ethereum/beacon/types" + "github.com/ethereum/go-ethereum/common/mclock" + "github.com/ethereum/go-ethereum/ethdb/memorydb" +) + +var ( + testGenesis = newTestGenesis() + testGenesis2 = newTestGenesis() + + tfBase = newTestForks(testGenesis, types.Forks{ + &types.Fork{Epoch: 0, Version: []byte{0}}, + }) + tfAlternative = newTestForks(testGenesis, types.Forks{ + &types.Fork{Epoch: 0, Version: []byte{0}}, + &types.Fork{Epoch: 0x700, Version: []byte{1}}, + }) + tfAnotherGenesis = newTestForks(testGenesis2, types.Forks{ + &types.Fork{Epoch: 0, Version: []byte{0}}, + }) + + tcBase = newTestCommitteeChain(nil, tfBase, true, 0, 10, 400, false) + tcBaseWithInvalidUpdates = newTestCommitteeChain(tcBase, tfBase, false, 5, 10, 200, false) // signer count too low + tcBaseWithBetterUpdates = newTestCommitteeChain(tcBase, tfBase, false, 5, 10, 440, false) + tcReorgWithWorseUpdates = newTestCommitteeChain(tcBase, tfBase, true, 5, 10, 400, false) + tcReorgWithWorseUpdates2 = newTestCommitteeChain(tcBase, tfBase, true, 5, 10, 380, false) + tcReorgWithBetterUpdates = newTestCommitteeChain(tcBase, tfBase, true, 5, 10, 420, false) + tcReorgWithFinalizedUpdates = newTestCommitteeChain(tcBase, tfBase, true, 5, 10, 400, true) + tcFork = newTestCommitteeChain(tcBase, tfAlternative, true, 7, 10, 400, false) + tcAnotherGenesis = newTestCommitteeChain(nil, tfAnotherGenesis, true, 0, 10, 400, false) +) + +func TestCommitteeChainFixedCommitteeRoots(t *testing.T) { + for _, reload := range []bool{false, true} { + c := newCommitteeChainTest(t, tfBase, 300, true) + c.setClockPeriod(7) + c.addFixedCommitteeRoot(tcBase, 4, nil) + c.addFixedCommitteeRoot(tcBase, 5, nil) + c.addFixedCommitteeRoot(tcBase, 6, nil) + c.addFixedCommitteeRoot(tcBase, 8, ErrInvalidPeriod) // range has to be continuous + c.addFixedCommitteeRoot(tcBase, 3, nil) + c.addFixedCommitteeRoot(tcBase, 2, nil) + if reload { + c.reloadChain() + } + c.addCommittee(tcBase, 4, nil) + c.addCommittee(tcBase, 6, ErrInvalidPeriod) // range has to be continuous + c.addCommittee(tcBase, 5, nil) + c.addCommittee(tcBase, 6, nil) + c.addCommittee(tcAnotherGenesis, 3, ErrWrongCommitteeRoot) + c.addCommittee(tcBase, 3, nil) + if reload { + c.reloadChain() + } + c.verifyRange(tcBase, 3, 6) + } +} + +func TestCommitteeChainCheckpointSync(t *testing.T) { + for _, enforceTime := range []bool{false, true} { + for _, reload := range []bool{false, true} { + c := newCommitteeChainTest(t, tfBase, 300, enforceTime) + if enforceTime { + c.setClockPeriod(6) + } + c.insertUpdate(tcBase, 3, true, ErrInvalidPeriod) + c.addFixedCommitteeRoot(tcBase, 3, nil) + c.addFixedCommitteeRoot(tcBase, 4, nil) + c.insertUpdate(tcBase, 4, true, ErrInvalidPeriod) // still no committee + c.addCommittee(tcBase, 3, nil) + c.addCommittee(tcBase, 4, nil) + if reload { + c.reloadChain() + } + c.verifyRange(tcBase, 3, 4) + c.insertUpdate(tcBase, 3, false, nil) // update can be added without committee here + c.insertUpdate(tcBase, 4, false, ErrNeedCommittee) // but not here as committee 5 is not there yet + c.insertUpdate(tcBase, 4, true, nil) + c.verifyRange(tcBase, 3, 5) + c.insertUpdate(tcBaseWithInvalidUpdates, 5, true, ErrInvalidUpdate) // signer count too low + c.insertUpdate(tcBase, 5, true, nil) + if reload { + c.reloadChain() + } + if enforceTime { + c.insertUpdate(tcBase, 6, true, ErrInvalidUpdate) // future update rejected + c.setClockPeriod(7) + } + c.insertUpdate(tcBase, 6, true, nil) // when the time comes it's accepted + if reload { + c.reloadChain() + } + if enforceTime { + c.verifyRange(tcBase, 3, 6) // committee 7 is there but still in the future + c.setClockPeriod(8) + } + c.verifyRange(tcBase, 3, 7) // now period 7 can also be verified + // try reverse syncing an update + c.insertUpdate(tcBase, 2, false, ErrInvalidPeriod) // fixed committee is needed first + c.addFixedCommitteeRoot(tcBase, 2, nil) + c.addCommittee(tcBase, 2, nil) + c.insertUpdate(tcBase, 2, false, nil) + c.verifyRange(tcBase, 2, 7) + } + } +} + +func TestCommitteeChainReorg(t *testing.T) { + for _, reload := range []bool{false, true} { + for _, addBetterUpdates := range []bool{false, true} { + c := newCommitteeChainTest(t, tfBase, 300, true) + c.setClockPeriod(11) + c.addFixedCommitteeRoot(tcBase, 3, nil) + c.addFixedCommitteeRoot(tcBase, 4, nil) + c.addCommittee(tcBase, 3, nil) + for period := uint64(3); period < 10; period++ { + c.insertUpdate(tcBase, period, true, nil) + } + if reload { + c.reloadChain() + } + c.verifyRange(tcBase, 3, 10) + c.insertUpdate(tcReorgWithWorseUpdates, 5, true, ErrCannotReorg) + c.insertUpdate(tcReorgWithWorseUpdates2, 5, true, ErrCannotReorg) + if addBetterUpdates { + // add better updates for the base chain and expect first reorg to fail + // (only add updates as committees should be the same) + for period := uint64(5); period < 10; period++ { + c.insertUpdate(tcBaseWithBetterUpdates, period, false, nil) + } + if reload { + c.reloadChain() + } + c.verifyRange(tcBase, 3, 10) // still on the same chain + c.insertUpdate(tcReorgWithBetterUpdates, 5, true, ErrCannotReorg) + } else { + // reorg with better updates + c.insertUpdate(tcReorgWithBetterUpdates, 5, false, ErrNeedCommittee) + c.verifyRange(tcBase, 3, 10) // no success yet, still on the base chain + c.verifyRange(tcReorgWithBetterUpdates, 3, 5) + c.insertUpdate(tcReorgWithBetterUpdates, 5, true, nil) + // successful reorg, base chain should only match before the reorg period + if reload { + c.reloadChain() + } + c.verifyRange(tcBase, 3, 5) + c.verifyRange(tcReorgWithBetterUpdates, 3, 6) + for period := uint64(6); period < 10; period++ { + c.insertUpdate(tcReorgWithBetterUpdates, period, true, nil) + } + c.verifyRange(tcReorgWithBetterUpdates, 3, 10) + } + // reorg with finalized updates; should succeed even if base chain updates + // have been improved because a finalized update beats everything else + c.insertUpdate(tcReorgWithFinalizedUpdates, 5, false, ErrNeedCommittee) + c.insertUpdate(tcReorgWithFinalizedUpdates, 5, true, nil) + if reload { + c.reloadChain() + } + c.verifyRange(tcReorgWithFinalizedUpdates, 3, 6) + for period := uint64(6); period < 10; period++ { + c.insertUpdate(tcReorgWithFinalizedUpdates, period, true, nil) + } + c.verifyRange(tcReorgWithFinalizedUpdates, 3, 10) + } + } +} + +func TestCommitteeChainFork(t *testing.T) { + c := newCommitteeChainTest(t, tfAlternative, 300, true) + c.setClockPeriod(11) + // trying to sync a chain on an alternative fork with the base chain data + c.addFixedCommitteeRoot(tcBase, 0, nil) + c.addFixedCommitteeRoot(tcBase, 1, nil) + c.addCommittee(tcBase, 0, nil) + // shared section should sync without errors + for period := uint64(0); period < 7; period++ { + c.insertUpdate(tcBase, period, true, nil) + } + c.insertUpdate(tcBase, 7, true, ErrInvalidUpdate) // wrong fork + // committee root #7 is still the same but signatures are already signed with + // a different fork id so period 7 should only verify on the alternative fork + c.verifyRange(tcBase, 0, 6) + c.verifyRange(tcFork, 0, 7) + for period := uint64(7); period < 10; period++ { + c.insertUpdate(tcFork, period, true, nil) + } + c.verifyRange(tcFork, 0, 10) + // reload the chain while switching to the base fork + c.config = tfBase + c.reloadChain() + // updates 7..9 should be rolled back now + c.verifyRange(tcFork, 0, 6) // again, period 7 only verifies on the right fork + c.verifyRange(tcBase, 0, 7) + c.insertUpdate(tcFork, 7, true, ErrInvalidUpdate) // wrong fork + for period := uint64(7); period < 10; period++ { + c.insertUpdate(tcBase, period, true, nil) + } + c.verifyRange(tcBase, 0, 10) +} + +type committeeChainTest struct { + t *testing.T + db *memorydb.Database + clock *mclock.Simulated + config types.ChainConfig + signerThreshold int + enforceTime bool + chain *CommitteeChain +} + +func newCommitteeChainTest(t *testing.T, config types.ChainConfig, signerThreshold int, enforceTime bool) *committeeChainTest { + c := &committeeChainTest{ + t: t, + db: memorydb.New(), + clock: &mclock.Simulated{}, + config: config, + signerThreshold: signerThreshold, + enforceTime: enforceTime, + } + c.chain = newCommitteeChain(c.db, &config, signerThreshold, enforceTime, dummyVerifier{}, c.clock, func() int64 { return int64(c.clock.Now()) }) + return c +} + +func (c *committeeChainTest) reloadChain() { + c.chain = newCommitteeChain(c.db, &c.config, c.signerThreshold, c.enforceTime, dummyVerifier{}, c.clock, func() int64 { return int64(c.clock.Now()) }) +} + +func (c *committeeChainTest) setClockPeriod(period float64) { + target := mclock.AbsTime(period * float64(time.Second*12*params.SyncPeriodLength)) + wait := time.Duration(target - c.clock.Now()) + if wait < 0 { + c.t.Fatalf("Invalid setClockPeriod") + } + c.clock.Run(wait) +} + +func (c *committeeChainTest) addFixedCommitteeRoot(tc *testCommitteeChain, period uint64, expErr error) { + if err := c.chain.addFixedCommitteeRoot(period, tc.periods[period].committee.Root()); err != expErr { + c.t.Errorf("Incorrect error output from addFixedCommitteeRoot at period %d (expected %v, got %v)", period, expErr, err) + } +} + +func (c *committeeChainTest) addCommittee(tc *testCommitteeChain, period uint64, expErr error) { + if err := c.chain.addCommittee(period, tc.periods[period].committee); err != expErr { + c.t.Errorf("Incorrect error output from addCommittee at period %d (expected %v, got %v)", period, expErr, err) + } +} + +func (c *committeeChainTest) insertUpdate(tc *testCommitteeChain, period uint64, addCommittee bool, expErr error) { + var committee *types.SerializedSyncCommittee + if addCommittee { + committee = tc.periods[period+1].committee + } + if err := c.chain.InsertUpdate(tc.periods[period].update, committee); err != expErr { + c.t.Errorf("Incorrect error output from InsertUpdate at period %d (expected %v, got %v)", period, expErr, err) + } +} + +func (c *committeeChainTest) verifySignedHeader(tc *testCommitteeChain, period float64, expOk bool) { + slot := uint64(period * float64(params.SyncPeriodLength)) + signedHead := GenerateTestSignedHeader(types.Header{Slot: slot}, &tc.config, tc.periods[types.SyncPeriod(slot)].committee, slot+1, 400) + if ok, _, _ := c.chain.VerifySignedHeader(signedHead); ok != expOk { + c.t.Errorf("Incorrect output from VerifySignedHeader at period %f (expected %v, got %v)", period, expOk, ok) + } +} + +func (c *committeeChainTest) verifyRange(tc *testCommitteeChain, begin, end uint64) { + if begin > 0 { + c.verifySignedHeader(tc, float64(begin)-0.5, false) + } + for period := begin; period <= end; period++ { + c.verifySignedHeader(tc, float64(period)+0.5, true) + } + c.verifySignedHeader(tc, float64(end)+1.5, false) +} + +func newTestGenesis() types.ChainConfig { + var config types.ChainConfig + rand.Read(config.GenesisValidatorsRoot[:]) + return config +} + +func newTestForks(config types.ChainConfig, forks types.Forks) types.ChainConfig { + for _, fork := range forks { + config.AddFork(fork.Name, fork.Epoch, fork.Version) + } + return config +} + +func newTestCommitteeChain(parent *testCommitteeChain, config types.ChainConfig, newCommittees bool, begin, end int, signerCount int, finalizedHeader bool) *testCommitteeChain { + tc := &testCommitteeChain{ + config: config, + } + if parent != nil { + tc.periods = make([]testPeriod, len(parent.periods)) + copy(tc.periods, parent.periods) + } + if newCommittees { + if begin == 0 { + tc.fillCommittees(begin, end+1) + } else { + tc.fillCommittees(begin+1, end+1) + } + } + tc.fillUpdates(begin, end, signerCount, finalizedHeader) + return tc +} + +type testPeriod struct { + committee *types.SerializedSyncCommittee + update *types.LightClientUpdate +} + +type testCommitteeChain struct { + periods []testPeriod + config types.ChainConfig +} + +func (tc *testCommitteeChain) fillCommittees(begin, end int) { + if len(tc.periods) <= end { + tc.periods = append(tc.periods, make([]testPeriod, end+1-len(tc.periods))...) + } + for i := begin; i <= end; i++ { + tc.periods[i].committee = GenerateTestCommittee() + } +} + +func (tc *testCommitteeChain) fillUpdates(begin, end int, signerCount int, finalizedHeader bool) { + for i := begin; i <= end; i++ { + tc.periods[i].update = GenerateTestUpdate(&tc.config, uint64(i), tc.periods[i].committee, tc.periods[i+1].committee, signerCount, finalizedHeader) + } +} diff --git a/beacon/light/range.go b/beacon/light/range.go new file mode 100644 index 000000000..76ebe2381 --- /dev/null +++ b/beacon/light/range.go @@ -0,0 +1,78 @@ +// Copyright 2023 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see . + +package light + +// periodRange represents a (possibly zero-length) range of integers (sync periods). +type periodRange struct { + Start, End uint64 +} + +// isEmpty returns true if the length of the range is zero. +func (a periodRange) isEmpty() bool { + return a.End == a.Start +} + +// contains returns true if the range includes the given period. +func (a periodRange) contains(period uint64) bool { + return period >= a.Start && period < a.End +} + +// canExpand returns true if the range includes or can be expanded with the given +// period (either the range is empty or the given period is inside, right before or +// right after the range). +func (a periodRange) canExpand(period uint64) bool { + return a.isEmpty() || (period+1 >= a.Start && period <= a.End) +} + +// expand expands the range with the given period. +// This method assumes that canExpand returned true: otherwise this is a no-op. +func (a *periodRange) expand(period uint64) { + if a.isEmpty() { + a.Start, a.End = period, period+1 + return + } + if a.Start == period+1 { + a.Start-- + } + if a.End == period { + a.End++ + } +} + +// split splits the range into two ranges. The 'fromPeriod' will be the first +// element in the second range (if present). +// The original range is unchanged by this operation +func (a *periodRange) split(fromPeriod uint64) (periodRange, periodRange) { + if fromPeriod <= a.Start { + // First range empty, everything in second range, + return periodRange{}, *a + } + if fromPeriod >= a.End { + // Second range empty, everything in first range, + return *a, periodRange{} + } + x := periodRange{a.Start, fromPeriod} + y := periodRange{fromPeriod, a.End} + return x, y +} + +// each invokes the supplied function fn once per period in range +func (a *periodRange) each(fn func(uint64)) { + for p := a.Start; p < a.End; p++ { + fn(p) + } +} diff --git a/beacon/light/test_helpers.go b/beacon/light/test_helpers.go new file mode 100644 index 000000000..f537d963a --- /dev/null +++ b/beacon/light/test_helpers.go @@ -0,0 +1,152 @@ +// Copyright 2023 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see . + +package light + +import ( + "crypto/rand" + "crypto/sha256" + mrand "math/rand" + + "github.com/ethereum/go-ethereum/beacon/merkle" + "github.com/ethereum/go-ethereum/beacon/params" + "github.com/ethereum/go-ethereum/beacon/types" + "github.com/ethereum/go-ethereum/common" +) + +func GenerateTestCommittee() *types.SerializedSyncCommittee { + s := new(types.SerializedSyncCommittee) + rand.Read(s[:32]) + return s +} + +func GenerateTestUpdate(config *types.ChainConfig, period uint64, committee, nextCommittee *types.SerializedSyncCommittee, signerCount int, finalizedHeader bool) *types.LightClientUpdate { + update := new(types.LightClientUpdate) + update.NextSyncCommitteeRoot = nextCommittee.Root() + var attestedHeader types.Header + if finalizedHeader { + update.FinalizedHeader = new(types.Header) + *update.FinalizedHeader, update.NextSyncCommitteeBranch = makeTestHeaderWithMerkleProof(types.SyncPeriodStart(period)+100, params.StateIndexNextSyncCommittee, merkle.Value(update.NextSyncCommitteeRoot)) + attestedHeader, update.FinalityBranch = makeTestHeaderWithMerkleProof(types.SyncPeriodStart(period)+200, params.StateIndexFinalBlock, merkle.Value(update.FinalizedHeader.Hash())) + } else { + attestedHeader, update.NextSyncCommitteeBranch = makeTestHeaderWithMerkleProof(types.SyncPeriodStart(period)+2000, params.StateIndexNextSyncCommittee, merkle.Value(update.NextSyncCommitteeRoot)) + } + update.AttestedHeader = GenerateTestSignedHeader(attestedHeader, config, committee, attestedHeader.Slot+1, signerCount) + return update +} + +func GenerateTestSignedHeader(header types.Header, config *types.ChainConfig, committee *types.SerializedSyncCommittee, signatureSlot uint64, signerCount int) types.SignedHeader { + bitmask := makeBitmask(signerCount) + signingRoot, _ := config.Forks.SigningRoot(header) + c, _ := dummyVerifier{}.deserializeSyncCommittee(committee) + return types.SignedHeader{ + Header: header, + Signature: types.SyncAggregate{ + Signers: bitmask, + Signature: makeDummySignature(c.(dummySyncCommittee), signingRoot, bitmask), + }, + SignatureSlot: signatureSlot, + } +} + +func GenerateTestCheckpoint(period uint64, committee *types.SerializedSyncCommittee) *types.BootstrapData { + header, branch := makeTestHeaderWithMerkleProof(types.SyncPeriodStart(period)+200, params.StateIndexSyncCommittee, merkle.Value(committee.Root())) + return &types.BootstrapData{ + Header: header, + Committee: committee, + CommitteeRoot: committee.Root(), + CommitteeBranch: branch, + } +} + +func makeBitmask(signerCount int) (bitmask [params.SyncCommitteeBitmaskSize]byte) { + for i := 0; i < params.SyncCommitteeSize; i++ { + if mrand.Intn(params.SyncCommitteeSize-i) < signerCount { + bitmask[i/8] += byte(1) << (i & 7) + signerCount-- + } + } + return +} + +func makeTestHeaderWithMerkleProof(slot, index uint64, value merkle.Value) (types.Header, merkle.Values) { + var branch merkle.Values + hasher := sha256.New() + for index > 1 { + var proofHash merkle.Value + rand.Read(proofHash[:]) + hasher.Reset() + if index&1 == 0 { + hasher.Write(value[:]) + hasher.Write(proofHash[:]) + } else { + hasher.Write(proofHash[:]) + hasher.Write(value[:]) + } + hasher.Sum(value[:0]) + index >>= 1 + branch = append(branch, proofHash) + } + return types.Header{Slot: slot, StateRoot: common.Hash(value)}, branch +} + +// syncCommittee holds either a blsSyncCommittee or a fake dummySyncCommittee used for testing +type syncCommittee interface{} + +// committeeSigVerifier verifies sync committee signatures (either proper BLS +// signatures or fake signatures used for testing) +type committeeSigVerifier interface { + deserializeSyncCommittee(s *types.SerializedSyncCommittee) (syncCommittee, error) + verifySignature(committee syncCommittee, signedRoot common.Hash, aggregate *types.SyncAggregate) bool +} + +// blsVerifier implements committeeSigVerifier +type blsVerifier struct{} + +// deserializeSyncCommittee implements committeeSigVerifier +func (blsVerifier) deserializeSyncCommittee(s *types.SerializedSyncCommittee) (syncCommittee, error) { + return s.Deserialize() +} + +// verifySignature implements committeeSigVerifier +func (blsVerifier) verifySignature(committee syncCommittee, signingRoot common.Hash, aggregate *types.SyncAggregate) bool { + return committee.(*types.SyncCommittee).VerifySignature(signingRoot, aggregate) +} + +type dummySyncCommittee [32]byte + +// dummyVerifier implements committeeSigVerifier +type dummyVerifier struct{} + +// deserializeSyncCommittee implements committeeSigVerifier +func (dummyVerifier) deserializeSyncCommittee(s *types.SerializedSyncCommittee) (syncCommittee, error) { + var sc dummySyncCommittee + copy(sc[:], s[:32]) + return sc, nil +} + +// verifySignature implements committeeSigVerifier +func (dummyVerifier) verifySignature(committee syncCommittee, signingRoot common.Hash, aggregate *types.SyncAggregate) bool { + return aggregate.Signature == makeDummySignature(committee.(dummySyncCommittee), signingRoot, aggregate.Signers) +} + +func makeDummySignature(committee dummySyncCommittee, signingRoot common.Hash, bitmask [params.SyncCommitteeBitmaskSize]byte) (sig [params.BLSSignatureSize]byte) { + for i, b := range committee[:] { + sig[i] = b ^ signingRoot[i] + } + copy(sig[32:], bitmask[:]) + return +} diff --git a/beacon/types/update.go b/beacon/types/light_sync.go similarity index 88% rename from beacon/types/update.go rename to beacon/types/light_sync.go index 06c1b6179..3284081e4 100644 --- a/beacon/types/update.go +++ b/beacon/types/light_sync.go @@ -25,6 +25,24 @@ import ( "github.com/ethereum/go-ethereum/common" ) +// BootstrapData contains a sync committee where light sync can be started, +// together with a proof through a beacon header and corresponding state. +// Note: BootstrapData is fetched from a server based on a known checkpoint hash. +type BootstrapData struct { + Header Header + CommitteeRoot common.Hash + Committee *SerializedSyncCommittee `rlp:"-"` + CommitteeBranch merkle.Values +} + +// Validate verifies the proof included in BootstrapData. +func (c *BootstrapData) Validate() error { + if c.CommitteeRoot != c.Committee.Root() { + return errors.New("wrong committee root") + } + return merkle.VerifyProof(c.Header.StateRoot, params.StateIndexSyncCommittee, c.CommitteeBranch, merkle.Value(c.CommitteeRoot)) +} + // LightClientUpdate is a proof of the next sync committee root based on a header // signed by the sync committee of the given period. Optionally, the update can // prove quasi-finality by the signed header referring to a previous, finalized diff --git a/core/rawdb/schema.go b/core/rawdb/schema.go index 8e82459e8..be0372355 100644 --- a/core/rawdb/schema.go +++ b/core/rawdb/schema.go @@ -132,6 +132,10 @@ var ( CliqueSnapshotPrefix = []byte("clique-") + BestUpdateKey = []byte("update-") // bigEndian64(syncPeriod) -> RLP(types.LightClientUpdate) (nextCommittee only referenced by root hash) + FixedCommitteeRootKey = []byte("fixedRoot-") // bigEndian64(syncPeriod) -> committee root hash + SyncCommitteeKey = []byte("committee-") // bigEndian64(syncPeriod) -> serialized committee + preimageCounter = metrics.NewRegisteredCounter("db/preimage/total", nil) preimageHitCounter = metrics.NewRegisteredCounter("db/preimage/hits", nil) )