From c08dc59aad35fe3fb0f6644c2816ce95e3c736ec Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Felf=C3=B6ldi=20Zsolt?= Date: Wed, 17 May 2023 16:39:33 +0200 Subject: [PATCH] beacon/types: add beacon chain data types (#27292) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * beacon/types: add beacon chain data types * beacon/merkle: added comments * go.mod: cleanups --------- Co-authored-by: Péter Szilágyi --- beacon/merkle/merkle.go | 67 ++++++++++ beacon/params/params.go | 44 +++++++ beacon/types/committee.go | 214 ++++++++++++++++++++++++++++++++ beacon/types/config.go | 176 ++++++++++++++++++++++++++ beacon/types/gen_header_json.go | 66 ++++++++++ beacon/types/header.go | 121 ++++++++++++++++++ beacon/types/update.go | 118 ++++++++++++++++++ common/types.go | 20 +++ go.mod | 3 + go.sum | 7 ++ 10 files changed, 836 insertions(+) create mode 100644 beacon/merkle/merkle.go create mode 100644 beacon/params/params.go create mode 100644 beacon/types/committee.go create mode 100644 beacon/types/config.go create mode 100644 beacon/types/gen_header_json.go create mode 100644 beacon/types/header.go create mode 100644 beacon/types/update.go diff --git a/beacon/merkle/merkle.go b/beacon/merkle/merkle.go new file mode 100644 index 000000000..30896f9b0 --- /dev/null +++ b/beacon/merkle/merkle.go @@ -0,0 +1,67 @@ +// 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 merkle implements proof verifications in binary merkle trees. +package merkle + +import ( + "crypto/sha256" + "errors" + "reflect" + + "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/common/hexutil" +) + +// Value represents either a 32 byte leaf value or hash node in a binary merkle tree/partial proof. +type Value [32]byte + +// Values represent a series of merkle tree leaves/nodes. +type Values []Value + +var valueT = reflect.TypeOf(Value{}) + +// UnmarshalJSON parses a merkle value in hex syntax. +func (m *Value) UnmarshalJSON(input []byte) error { + return hexutil.UnmarshalFixedJSON(valueT, input, m[:]) +} + +// VerifyProof verifies a Merkle proof branch for a single value in a +// binary Merkle tree (index is a generalized tree index). +func VerifyProof(root common.Hash, index uint64, branch Values, value Value) error { + hasher := sha256.New() + for _, sibling := range branch { + hasher.Reset() + if index&1 == 0 { + hasher.Write(value[:]) + hasher.Write(sibling[:]) + } else { + hasher.Write(sibling[:]) + hasher.Write(value[:]) + } + hasher.Sum(value[:0]) + if index >>= 1; index == 0 { + return errors.New("branch has extra items") + } + } + if index != 1 { + return errors.New("branch is missing items") + } + if common.Hash(value) != root { + return errors.New("root mismatch") + } + return nil +} diff --git a/beacon/params/params.go b/beacon/params/params.go new file mode 100644 index 000000000..ee9feb1ac --- /dev/null +++ b/beacon/params/params.go @@ -0,0 +1,44 @@ +// 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 params + +const ( + EpochLength = 32 + SyncPeriodLength = 8192 + + BLSSignatureSize = 96 + BLSPubkeySize = 48 + + SyncCommitteeSize = 512 + SyncCommitteeBitmaskSize = SyncCommitteeSize / 8 + SyncCommitteeSupermajority = (SyncCommitteeSize*2 + 2) / 3 +) + +const ( + StateIndexGenesisTime = 32 + StateIndexGenesisValidators = 33 + StateIndexForkVersion = 141 + StateIndexLatestHeader = 36 + StateIndexBlockRoots = 37 + StateIndexStateRoots = 38 + StateIndexHistoricRoots = 39 + StateIndexFinalBlock = 105 + StateIndexSyncCommittee = 54 + StateIndexNextSyncCommittee = 55 + StateIndexExecPayload = 56 + StateIndexExecHead = 908 +) diff --git a/beacon/types/committee.go b/beacon/types/committee.go new file mode 100644 index 000000000..9d3b9ff9e --- /dev/null +++ b/beacon/types/committee.go @@ -0,0 +1,214 @@ +// 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 types + +import ( + "crypto/sha256" + "encoding/json" + "fmt" + "math/bits" + + "github.com/ethereum/go-ethereum/beacon/params" + "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/common/hexutil" + bls "github.com/protolambda/bls12-381-util" +) + +// SerializedSyncCommitteeSize is the size of the sync committee plus the +// aggregate public key. +const SerializedSyncCommitteeSize = (params.SyncCommitteeSize + 1) * params.BLSPubkeySize + +// SerializedSyncCommittee is the serialized version of a sync committee +// plus the aggregate public key. +type SerializedSyncCommittee [SerializedSyncCommitteeSize]byte + +// jsonSyncCommittee is the JSON representation of a sync committee. +// +// See data structure definition here: +// https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/beacon-chain.md#syncaggregate +type jsonSyncCommittee struct { + Pubkeys []hexutil.Bytes `json:"pubkeys"` + Aggregate hexutil.Bytes `json:"aggregate_pubkey"` +} + +// MarshalJSON implements json.Marshaler. +func (s *SerializedSyncCommittee) MarshalJSON() ([]byte, error) { + sc := jsonSyncCommittee{Pubkeys: make([]hexutil.Bytes, params.SyncCommitteeSize)} + for i := range sc.Pubkeys { + sc.Pubkeys[i] = make(hexutil.Bytes, params.BLSPubkeySize) + copy(sc.Pubkeys[i][:], s[i*params.BLSPubkeySize:(i+1)*params.BLSPubkeySize]) + } + sc.Aggregate = make(hexutil.Bytes, params.BLSPubkeySize) + copy(sc.Aggregate[:], s[params.SyncCommitteeSize*params.BLSPubkeySize:]) + return json.Marshal(&sc) +} + +// UnmarshalJSON implements json.Marshaler. +func (s *SerializedSyncCommittee) UnmarshalJSON(input []byte) error { + var sc jsonSyncCommittee + if err := json.Unmarshal(input, &sc); err != nil { + return err + } + if len(sc.Pubkeys) != params.SyncCommitteeSize { + return fmt.Errorf("invalid number of pubkeys %d", len(sc.Pubkeys)) + } + for i, key := range sc.Pubkeys { + if len(key) != params.BLSPubkeySize { + return fmt.Errorf("pubkey %d has invalid size %d", i, len(key)) + } + copy(s[i*params.BLSPubkeySize:], key[:]) + } + if len(sc.Aggregate) != params.BLSPubkeySize { + return fmt.Errorf("invalid aggregate pubkey size %d", len(sc.Aggregate)) + } + copy(s[params.SyncCommitteeSize*params.BLSPubkeySize:], sc.Aggregate[:]) + return nil +} + +// Root calculates the root hash of the binary tree representation of a sync +// committee provided in serialized format. +// +// TODO(zsfelfoldi): Get rid of this when SSZ encoding lands. +func (s *SerializedSyncCommittee) Root() common.Hash { + var ( + hasher = sha256.New() + padding [64 - params.BLSPubkeySize]byte + data [params.SyncCommitteeSize]common.Hash + l = params.SyncCommitteeSize + ) + for i := range data { + hasher.Reset() + hasher.Write(s[i*params.BLSPubkeySize : (i+1)*params.BLSPubkeySize]) + hasher.Write(padding[:]) + hasher.Sum(data[i][:0]) + } + for l > 1 { + for i := 0; i < l/2; i++ { + hasher.Reset() + hasher.Write(data[i*2][:]) + hasher.Write(data[i*2+1][:]) + hasher.Sum(data[i][:0]) + } + l /= 2 + } + hasher.Reset() + hasher.Write(s[SerializedSyncCommitteeSize-params.BLSPubkeySize : SerializedSyncCommitteeSize]) + hasher.Write(padding[:]) + hasher.Sum(data[1][:0]) + hasher.Reset() + hasher.Write(data[0][:]) + hasher.Write(data[1][:]) + hasher.Sum(data[0][:0]) + return data[0] +} + +// Deserialize splits open the pubkeys into proper BLS key types. +func (s *SerializedSyncCommittee) Deserialize() (*SyncCommittee, error) { + sc := new(SyncCommittee) + for i := 0; i <= params.SyncCommitteeSize; i++ { + key := new(bls.Pubkey) + + var bytes [params.BLSPubkeySize]byte + copy(bytes[:], s[i*params.BLSPubkeySize:(i+1)*params.BLSPubkeySize]) + + if err := key.Deserialize(&bytes); err != nil { + return nil, err + } + if i < params.SyncCommitteeSize { + sc.keys[i] = key + } else { + sc.aggregate = key + } + } + return sc, nil +} + +// SyncCommittee is a set of sync committee signer pubkeys and the aggregate key. +// +// See data structure definition here: +// https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/beacon-chain.md#syncaggregate +type SyncCommittee struct { + keys [params.SyncCommitteeSize]*bls.Pubkey + aggregate *bls.Pubkey +} + +// VerifySignature returns true if the given sync aggregate is a valid signature +// or the given hash. +func (sc *SyncCommittee) VerifySignature(signingRoot common.Hash, signature *SyncAggregate) bool { + var ( + sig bls.Signature + keys = make([]*bls.Pubkey, 0, params.SyncCommitteeSize) + ) + if err := sig.Deserialize(&signature.Signature); err != nil { + return false + } + for i, key := range sc.keys { + if signature.Signers[i/8]&(byte(1)<<(i%8)) != 0 { + keys = append(keys, key) + } + } + return bls.FastAggregateVerify(keys, signingRoot[:], &sig) +} + +// SyncAggregate represents an aggregated BLS signature with Signers referring +// to a subset of the corresponding sync committee. +// +// See data structure definition here: +// https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/beacon-chain.md#syncaggregate +type SyncAggregate struct { + Signers [params.SyncCommitteeBitmaskSize]byte + Signature [params.BLSSignatureSize]byte +} + +type jsonSyncAggregate struct { + Signers hexutil.Bytes `json:"sync_committee_bits"` + Signature hexutil.Bytes `json:"sync_committee_signature"` +} + +// MarshalJSON implements json.Marshaler. +func (s *SyncAggregate) MarshalJSON() ([]byte, error) { + return json.Marshal(&jsonSyncAggregate{ + Signers: s.Signers[:], + Signature: s.Signature[:], + }) +} + +// UnmarshalJSON implements json.Marshaler. +func (s *SyncAggregate) UnmarshalJSON(input []byte) error { + var sc jsonSyncAggregate + if err := json.Unmarshal(input, &sc); err != nil { + return err + } + if len(sc.Signers) != params.SyncCommitteeBitmaskSize { + return fmt.Errorf("invalid signature bitmask size %d", len(sc.Signers)) + } + if len(sc.Signature) != params.BLSSignatureSize { + return fmt.Errorf("invalid signature size %d", len(sc.Signature)) + } + copy(s.Signers[:], sc.Signers) + copy(s.Signature[:], sc.Signature) + return nil +} + +// SignerCount returns the number of signers in the aggregate signature. +func (s *SyncAggregate) SignerCount() int { + var count int + for _, v := range s.Signers { + count += bits.OnesCount8(v) + } + return count +} diff --git a/beacon/types/config.go b/beacon/types/config.go new file mode 100644 index 000000000..3e5f7a6fb --- /dev/null +++ b/beacon/types/config.go @@ -0,0 +1,176 @@ +// 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 types + +import ( + "crypto/sha256" + "fmt" + "os" + "sort" + "strconv" + "strings" + + "github.com/ethereum/go-ethereum/beacon/merkle" + "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/common/hexutil" + "github.com/go-yaml/yaml" +) + +// syncCommitteeDomain specifies the signatures specific use to avoid clashes +// across signing different data structures. +const syncCommitteeDomain = 7 + +// Fork describes a single beacon chain fork and also stores the calculated +// signature domain used after this fork. +type Fork struct { + // Name of the fork in the chain config (config.yaml) file{ + Name string + + // Epoch when given fork version is activated + Epoch uint64 + + // Fork version, see https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/beacon-chain.md#custom-types + Version []byte + + // calculated by computeDomain, based on fork version and genesis validators root + domain merkle.Value +} + +// computeDomain returns the signature domain based on the given fork version +// and genesis validator set root. +func (f *Fork) computeDomain(genesisValidatorsRoot common.Hash) { + var ( + hasher = sha256.New() + forkVersion32 merkle.Value + forkDataRoot merkle.Value + ) + copy(forkVersion32[:], f.Version) + hasher.Write(forkVersion32[:]) + hasher.Write(genesisValidatorsRoot[:]) + hasher.Sum(forkDataRoot[:0]) + + f.domain[0] = syncCommitteeDomain + copy(f.domain[4:], forkDataRoot[:28]) +} + +// Forks is the list of all beacon chain forks in the chain configuration. +type Forks []*Fork + +// domain returns the signature domain for the given epoch (assumes that domains +// have already been calculated). +func (f Forks) domain(epoch uint64) (merkle.Value, error) { + for i := len(f) - 1; i >= 0; i-- { + if epoch >= f[i].Epoch { + return f[i].domain, nil + } + } + return merkle.Value{}, fmt.Errorf("unknown fork for epoch %d", epoch) +} + +// SigningRoot calculates the signing root of the given header. +func (f Forks) SigningRoot(header Header) (common.Hash, error) { + domain, err := f.domain(header.Epoch()) + if err != nil { + return common.Hash{}, err + } + var ( + signingRoot common.Hash + headerHash = header.Hash() + hasher = sha256.New() + ) + hasher.Write(headerHash[:]) + hasher.Write(domain[:]) + hasher.Sum(signingRoot[:0]) + + return signingRoot, nil +} + +func (f Forks) Len() int { return len(f) } +func (f Forks) Swap(i, j int) { f[i], f[j] = f[j], f[i] } +func (f Forks) Less(i, j int) bool { return f[i].Epoch < f[j].Epoch } + +// ChainConfig contains the beacon chain configuration. +type ChainConfig struct { + GenesisTime uint64 // Unix timestamp of slot 0 + GenesisValidatorsRoot common.Hash // Root hash of the genesis validator set, used for signature domain calculation + Forks Forks +} + +// AddFork adds a new item to the list of forks. +func (c *ChainConfig) AddFork(name string, epoch uint64, version []byte) *ChainConfig { + fork := &Fork{ + Name: name, + Epoch: epoch, + Version: version, + } + fork.computeDomain(c.GenesisValidatorsRoot) + + c.Forks = append(c.Forks, fork) + sort.Sort(c.Forks) + + return c +} + +// LoadForks parses the beacon chain configuration file (config.yaml) and extracts +// the list of forks. +func (c *ChainConfig) LoadForks(path string) error { + file, err := os.ReadFile(path) + if err != nil { + return fmt.Errorf("failed to read beacon chain config file: %v", err) + } + config := make(map[string]string) + if err := yaml.Unmarshal(file, &config); err != nil { + return fmt.Errorf("failed to parse beacon chain config file: %v", err) + } + var ( + versions = make(map[string][]byte) + epochs = make(map[string]uint64) + ) + epochs["GENESIS"] = 0 + + for key, value := range config { + if strings.HasSuffix(key, "_FORK_VERSION") { + name := key[:len(key)-len("_FORK_VERSION")] + if v, err := hexutil.Decode(value); err == nil { + versions[name] = v + } else { + return fmt.Errorf("failed to decode hex fork id %q in beacon chain config file: %v", value, err) + } + } + if strings.HasSuffix(key, "_FORK_EPOCH") { + name := key[:len(key)-len("_FORK_EPOCH")] + if v, err := strconv.ParseUint(value, 10, 64); err == nil { + epochs[name] = v + } else { + return fmt.Errorf("failed to parse epoch number %q in beacon chain config file: %v", value, err) + } + } + } + for name, epoch := range epochs { + if version, ok := versions[name]; ok { + delete(versions, name) + c.AddFork(name, epoch, version) + } else { + return fmt.Errorf("fork id missing for %q in beacon chain config file", name) + } + } + for name := range versions { + return fmt.Errorf("epoch number missing for fork %q in beacon chain config file", name) + } + sort.Sort(c.Forks) + return nil +} diff --git a/beacon/types/gen_header_json.go b/beacon/types/gen_header_json.go new file mode 100644 index 000000000..9b3ffea06 --- /dev/null +++ b/beacon/types/gen_header_json.go @@ -0,0 +1,66 @@ +// Code generated by github.com/fjl/gencodec. DO NOT EDIT. + +package types + +import ( + "encoding/json" + "errors" + + "github.com/ethereum/go-ethereum/common" +) + +var _ = (*headerMarshaling)(nil) + +// MarshalJSON marshals as JSON. +func (h Header) MarshalJSON() ([]byte, error) { + type Header struct { + Slot common.Decimal `gencodec:"required" json:"slot"` + ProposerIndex common.Decimal `gencodec:"required" json:"proposer_index"` + ParentRoot common.Hash `gencodec:"required" json:"parent_root"` + StateRoot common.Hash `gencodec:"required" json:"state_root"` + BodyRoot common.Hash `gencodec:"required" json:"body_root"` + } + var enc Header + enc.Slot = common.Decimal(h.Slot) + enc.ProposerIndex = common.Decimal(h.ProposerIndex) + enc.ParentRoot = h.ParentRoot + enc.StateRoot = h.StateRoot + enc.BodyRoot = h.BodyRoot + return json.Marshal(&enc) +} + +// UnmarshalJSON unmarshals from JSON. +func (h *Header) UnmarshalJSON(input []byte) error { + type Header struct { + Slot *common.Decimal `gencodec:"required" json:"slot"` + ProposerIndex *common.Decimal `gencodec:"required" json:"proposer_index"` + ParentRoot *common.Hash `gencodec:"required" json:"parent_root"` + StateRoot *common.Hash `gencodec:"required" json:"state_root"` + BodyRoot *common.Hash `gencodec:"required" json:"body_root"` + } + var dec Header + if err := json.Unmarshal(input, &dec); err != nil { + return err + } + if dec.Slot == nil { + return errors.New("missing required field 'slot' for Header") + } + h.Slot = uint64(*dec.Slot) + if dec.ProposerIndex == nil { + return errors.New("missing required field 'proposer_index' for Header") + } + h.ProposerIndex = uint64(*dec.ProposerIndex) + if dec.ParentRoot == nil { + return errors.New("missing required field 'parent_root' for Header") + } + h.ParentRoot = *dec.ParentRoot + if dec.StateRoot == nil { + return errors.New("missing required field 'state_root' for Header") + } + h.StateRoot = *dec.StateRoot + if dec.BodyRoot == nil { + return errors.New("missing required field 'body_root' for Header") + } + h.BodyRoot = *dec.BodyRoot + return nil +} diff --git a/beacon/types/header.go b/beacon/types/header.go new file mode 100644 index 000000000..2ddc4575f --- /dev/null +++ b/beacon/types/header.go @@ -0,0 +1,121 @@ +// 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 types implements a few types of the beacon chain for light client usage. +package types + +import ( + "crypto/sha256" + "encoding/binary" + + "github.com/ethereum/go-ethereum/beacon/merkle" + "github.com/ethereum/go-ethereum/beacon/params" + "github.com/ethereum/go-ethereum/common" +) + +//go:generate go run github.com/fjl/gencodec -type Header -field-override headerMarshaling -out gen_header_json.go + +const ( + headerIndexSlot = 8 + headerIndexProposerIndex = 9 + headerIndexParentRoot = 10 + headerIndexStateRoot = 11 + headerIndexBodyRoot = 12 +) + +// Header defines a beacon header. +// +// See data structure definition here: +// https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/beacon-chain.md#beaconblockheader +type Header struct { + // Monotonically increasing slot number for the beacon block (may be gapped) + Slot uint64 `gencodec:"required" json:"slot"` + + // Index into the validator table who created the beacon block + ProposerIndex uint64 `gencodec:"required" json:"proposer_index"` + + // SSZ hash of the parent beacon header + ParentRoot common.Hash `gencodec:"required" json:"parent_root"` + + // SSZ hash of the beacon state (https://github.com/ethereum/consensus-specs/blob/dev/specs/bellatrix/beacon-chain.md#beacon-state) + StateRoot common.Hash `gencodec:"required" json:"state_root"` + + // SSZ hash of the beacon block body (https://github.com/ethereum/consensus-specs/blob/dev/specs/bellatrix/beacon-chain.md#beaconblockbody) + BodyRoot common.Hash `gencodec:"required" json:"body_root"` +} + +// headerMarshaling is a field type overrides for gencodec. +type headerMarshaling struct { + Slot common.Decimal + ProposerIndex common.Decimal +} + +// Hash calculates the block root of the header. +// +// TODO(zsfelfoldi): Remove this when an SSZ encoder lands. +func (h *Header) Hash() common.Hash { + var values [16]merkle.Value // values corresponding to indices 8 to 15 of the beacon header tree + binary.LittleEndian.PutUint64(values[headerIndexSlot][:8], h.Slot) + binary.LittleEndian.PutUint64(values[headerIndexProposerIndex][:8], h.ProposerIndex) + values[headerIndexParentRoot] = merkle.Value(h.ParentRoot) + values[headerIndexStateRoot] = merkle.Value(h.StateRoot) + values[headerIndexBodyRoot] = merkle.Value(h.BodyRoot) + hasher := sha256.New() + for i := 7; i > 0; i-- { + hasher.Reset() + hasher.Write(values[i*2][:]) + hasher.Write(values[i*2+1][:]) + hasher.Sum(values[i][:0]) + } + return common.Hash(values[1]) +} + +// Epoch returns the epoch the header belongs to. +func (h *Header) Epoch() uint64 { + return h.Slot / params.EpochLength +} + +// SyncPeriod returns the sync period the header belongs to. +func (h *Header) SyncPeriod() uint64 { + return SyncPeriod(h.Slot) +} + +// SyncPeriodStart returns the first slot of the given period. +func SyncPeriodStart(period uint64) uint64 { + return period * params.SyncPeriodLength +} + +// SyncPeriod returns the sync period that the given slot belongs to. +func SyncPeriod(slot uint64) uint64 { + return slot / params.SyncPeriodLength +} + +// SignedHeader represents a beacon header signed by a sync committee. +// +// This structure is created from either an optimistic update or an instant update: +// - https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/light-client/sync-protocol.md#lightclientoptimisticupdate +// - https://github.com/zsfelfoldi/beacon-APIs/blob/instant_update/apis/beacon/light_client/instant_update.yaml +type SignedHeader struct { + // Beacon header being signed + Header Header + + // Sync committee BLS signature aggregate + Signature SyncAggregate + + // Slot in which the signature has been created (newer than Header.Slot, + // determines the signing sync committee) + SignatureSlot uint64 +} diff --git a/beacon/types/update.go b/beacon/types/update.go new file mode 100644 index 000000000..06c1b6179 --- /dev/null +++ b/beacon/types/update.go @@ -0,0 +1,118 @@ +// 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 types + +import ( + "errors" + "fmt" + + "github.com/ethereum/go-ethereum/beacon/merkle" + "github.com/ethereum/go-ethereum/beacon/params" + "github.com/ethereum/go-ethereum/common" +) + +// 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 +// header from the same period, and the finalized header referring to the next +// sync committee root. +// +// See data structure definition here: +// https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/light-client/sync-protocol.md#lightclientupdate +type LightClientUpdate struct { + AttestedHeader SignedHeader // Arbitrary header out of the period signed by the sync committee + NextSyncCommitteeRoot common.Hash // Sync committee of the next period advertised in the current one + NextSyncCommitteeBranch merkle.Values // Proof for the next period's sync committee + + FinalizedHeader *Header `rlp:"nil"` // Optional header to announce a point of finality + FinalityBranch merkle.Values // Proof for the announced finality + + score *UpdateScore // Weight of the update to compare between competing ones +} + +// Validate verifies the validity of the update. +func (update *LightClientUpdate) Validate() error { + period := update.AttestedHeader.Header.SyncPeriod() + if SyncPeriod(update.AttestedHeader.SignatureSlot) != period { + return errors.New("signature slot and signed header are from different periods") + } + if update.FinalizedHeader != nil { + if update.FinalizedHeader.SyncPeriod() != period { + return errors.New("finalized header is from different period") + } + if err := merkle.VerifyProof(update.AttestedHeader.Header.StateRoot, params.StateIndexFinalBlock, update.FinalityBranch, merkle.Value(update.FinalizedHeader.Hash())); err != nil { + return fmt.Errorf("invalid finalized header proof: %w", err) + } + } + if err := merkle.VerifyProof(update.AttestedHeader.Header.StateRoot, params.StateIndexNextSyncCommittee, update.NextSyncCommitteeBranch, merkle.Value(update.NextSyncCommitteeRoot)); err != nil { + return fmt.Errorf("invalid next sync committee proof: %w", err) + } + return nil +} + +// Score returns the UpdateScore describing the proof strength of the update +// Note: thread safety can be ensured by always calling Score on a newly received +// or decoded update before making it potentially available for other threads +func (update *LightClientUpdate) Score() UpdateScore { + if update.score == nil { + update.score = &UpdateScore{ + SignerCount: uint32(update.AttestedHeader.Signature.SignerCount()), + SubPeriodIndex: uint32(update.AttestedHeader.Header.Slot & 0x1fff), + FinalizedHeader: update.FinalizedHeader != nil, + } + } + return *update.score +} + +// UpdateScore allows the comparison between updates at the same period in order +// to find the best update chain that provides the strongest proof of being canonical. +// +// UpdateScores have a tightly packed binary encoding format for efficient p2p +// protocol transmission. Each UpdateScore is encoded in 3 bytes. +// When interpreted as a 24 bit little indian unsigned integer: +// - the lowest 10 bits contain the number of signers in the header signature aggregate +// - the next 13 bits contain the "sub-period index" which is he signed header's +// slot modulo params.SyncPeriodLength (which is correlated with the risk of the chain being +// re-orged before the previous period boundary in case of non-finalized updates) +// - the highest bit is set when the update is finalized (meaning that the finality +// header referenced by the signed header is in the same period as the signed +// header, making reorgs before the period boundary impossible +type UpdateScore struct { + SignerCount uint32 // number of signers in the header signature aggregate + SubPeriodIndex uint32 // signed header's slot modulo params.SyncPeriodLength + FinalizedHeader bool // update is considered finalized if has finalized header from the same period and 2/3 signatures +} + +// finalized returns true if the update has a header signed by at least 2/3 of +// the committee, referring to a finalized header that refers to the next sync +// committee. This condition is a close approximation of the actual finality +// condition that can only be verified by full beacon nodes. +func (u *UpdateScore) finalized() bool { + return u.FinalizedHeader && u.SignerCount >= params.SyncCommitteeSupermajority +} + +// BetterThan returns true if update u is considered better than w. +func (u UpdateScore) BetterThan(w UpdateScore) bool { + var ( + uFinalized = u.finalized() + wFinalized = w.finalized() + ) + if uFinalized != wFinalized { + return uFinalized + } + return u.SignerCount > w.SignerCount +} diff --git a/common/types.go b/common/types.go index 3712df2fe..bdfd96423 100644 --- a/common/types.go +++ b/common/types.go @@ -26,6 +26,7 @@ import ( "math/big" "math/rand" "reflect" + "strconv" "strings" "github.com/ethereum/go-ethereum/common/hexutil" @@ -442,3 +443,22 @@ func (addr AddressEIP55) String() string { func (addr AddressEIP55) MarshalJSON() ([]byte, error) { return json.Marshal(addr.String()) } + +type Decimal uint64 + +func isString(input []byte) bool { + return len(input) >= 2 && input[0] == '"' && input[len(input)-1] == '"' +} + +// UnmarshalJSON parses a hash in hex syntax. +func (d *Decimal) UnmarshalJSON(input []byte) error { + if !isString(input) { + return &json.UnmarshalTypeError{Value: "non-string", Type: reflect.TypeOf(uint64(0))} + } + if i, err := strconv.ParseInt(string(input[1:len(input)-1]), 10, 64); err == nil { + *d = Decimal(i) + return nil + } else { + return err + } +} diff --git a/go.mod b/go.mod index a32d65a0c..aec45bc1e 100644 --- a/go.mod +++ b/go.mod @@ -27,6 +27,7 @@ require ( github.com/gballet/go-libpcsclite v0.0.0-20190607065134-2772fd86a8ff github.com/gballet/go-verkle v0.0.0-20220902153445-097bd83b7732 github.com/go-stack/stack v1.8.1 + github.com/go-yaml/yaml v2.1.0+incompatible github.com/gofrs/flock v0.8.1 github.com/golang-jwt/jwt/v4 v4.3.0 github.com/golang/protobuf v1.5.2 @@ -51,6 +52,7 @@ require ( github.com/naoina/toml v0.1.2-0.20170918210437-9fafd6967416 github.com/olekukonko/tablewriter v0.0.5 github.com/peterh/liner v1.1.1-0.20190123174540-a2c9a5303de7 + github.com/protolambda/bls12-381-util v0.0.0-20220416220906-d8552aa452c7 github.com/rs/cors v1.7.0 github.com/shirou/gopsutil v3.21.4-0.20210419000835-c7a38de76ee5+incompatible github.com/status-im/keycard-go v0.2.0 @@ -98,6 +100,7 @@ require ( github.com/go-sourcemap/sourcemap v2.1.3+incompatible // indirect github.com/gogo/protobuf v1.3.2 // indirect github.com/influxdata/line-protocol v0.0.0-20210311194329-9aa0e372d097 // indirect + github.com/kilic/bls12-381 v0.1.0 // indirect github.com/klauspost/compress v1.15.15 // indirect github.com/kr/pretty v0.3.1 // indirect github.com/kr/text v0.2.0 // indirect diff --git a/go.sum b/go.sum index 2d02b123f..3c35d378b 100644 --- a/go.sum +++ b/go.sum @@ -164,6 +164,8 @@ github.com/go-sourcemap/sourcemap v2.1.3+incompatible h1:W1iEw64niKVGogNgBN3ePyL github.com/go-sourcemap/sourcemap v2.1.3+incompatible/go.mod h1:F8jJfvm2KbVjc5NqelyYJmf/v5J0dwNLS2mL4sNA1Jg= github.com/go-stack/stack v1.8.1 h1:ntEHSVwIt7PNXNpgPmVfMrNhLtgjlmnZha2kOpuRiDw= github.com/go-stack/stack v1.8.1/go.mod h1:dcoOX6HbPZSZptuspn9bctJ+N/CnF5gGygcUP3XYfe4= +github.com/go-yaml/yaml v2.1.0+incompatible h1:RYi2hDdss1u4YE7GwixGzWwVo47T8UQwnTLB6vQiq+o= +github.com/go-yaml/yaml v2.1.0+incompatible/go.mod h1:w2MrLa16VYP0jy6N7M5kHaCkaLENm+P+Tv+MfurjSw0= github.com/gobwas/httphead v0.0.0-20180130184737-2c6c146eadee/go.mod h1:L0fX3K22YWvt/FAX9NnzrNzcI4wNYi9Yku4O0LKYflo= github.com/gobwas/pool v0.2.0/go.mod h1:q8bcK0KcYlCgd9e7WYLm9LpyS+YeLd8JVDW6WezmKEw= github.com/gobwas/ws v1.0.2/go.mod h1:szmBTxLgaFppYjEmNtny/v3w89xOydFnnZMcgRRu/EM= @@ -270,6 +272,8 @@ github.com/kataras/iris/v12 v12.1.8/go.mod h1:LMYy4VlP67TQ3Zgriz8RE2h2kMZV2SgMYb github.com/kataras/neffos v0.0.14/go.mod h1:8lqADm8PnbeFfL7CLXh1WHw53dG27MC3pgi2R1rmoTE= github.com/kataras/pio v0.0.2/go.mod h1:hAoW0t9UmXi4R5Oyq5Z4irTbaTsOemSrDGUtaTl7Dro= github.com/kataras/sitemap v0.0.5/go.mod h1:KY2eugMKiPwsJgx7+U103YZehfvNGOXURubcGyk0Bz8= +github.com/kilic/bls12-381 v0.1.0 h1:encrdjqKMEvabVQ7qYOKu1OvhqpK4s47wDYtNiPtlp4= +github.com/kilic/bls12-381 v0.1.0/go.mod h1:vDTTHJONJ6G+P2R74EhnyotQDTliQDnFEwhdmfzw1ig= github.com/kisielk/errcheck v1.5.0/go.mod h1:pFxgyoBC7bSaBwPgfKdkLd5X25qrDl4LWUI2bnpBCr8= github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck= github.com/klauspost/compress v1.8.2/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A= @@ -375,6 +379,8 @@ github.com/prometheus/common v0.39.0 h1:oOyhkDq05hPZKItWVBkJ6g6AtGxi+fy7F4JvUV8u github.com/prometheus/common v0.39.0/go.mod h1:6XBZ7lYdLCbkAVhwRsWTZn+IN5AB9F/NXd5w0BbEX0Y= github.com/prometheus/procfs v0.9.0 h1:wzCHvIvM5SxWqYvwgVL7yJY8Lz3PKn49KQtpgMYJfhI= github.com/prometheus/procfs v0.9.0/go.mod h1:+pB4zwohETzFnmlpe6yd2lSc+0/46IYZRB/chUwxUZY= +github.com/protolambda/bls12-381-util v0.0.0-20220416220906-d8552aa452c7 h1:cZC+usqsYgHtlBaGulVnZ1hfKAi8iWtujBnRLQE698c= +github.com/protolambda/bls12-381-util v0.0.0-20220416220906-d8552aa452c7/go.mod h1:IToEjHuttnUzwZI5KBSM/LOOW3qLbbrHOEfp3SbECGY= github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc= github.com/rogpeppe/go-internal v1.8.1/go.mod h1:JeRgkft04UBgHMgCIwADu4Pn6Mtm5d4nPKWu0nJ5d+o= github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8= @@ -532,6 +538,7 @@ golang.org/x/sys v0.0.0-20200519105757-fe76b779f299/go.mod h1:h1NjWce9XRLGQEsW7w golang.org/x/sys v0.0.0-20200814200057-3d37ad5750ed/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= golang.org/x/sys v0.0.0-20200826173525-f9321e4c35a6/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= +golang.org/x/sys v0.0.0-20201101102859-da207088b7d1/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= golang.org/x/sys v0.0.0-20210316164454-77fc1eacc6aa/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=