plugeth/beacon/types/config.go

177 lines
5.3 KiB
Go
Raw Normal View History

// 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 <http://www.gnu.org/licenses/>.
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"
"gopkg.in/yaml.v3"
)
// 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
}