Files
ethdo/cmd/chain/verify/signedcontributionandproof/process.go
Jim McDonald 72a9390f97 Linting.
2024-10-01 13:02:39 +01:00

319 lines
9.8 KiB
Go

// Copyright © 2021 Weald Technology Trading.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package chainverifysignedcontributionandproof
import (
"context"
"crypto/sha256"
"encoding/binary"
"encoding/json"
"fmt"
"os"
eth2client "github.com/attestantio/go-eth2-client"
"github.com/attestantio/go-eth2-client/api"
"github.com/attestantio/go-eth2-client/spec/altair"
"github.com/attestantio/go-eth2-client/spec/phase0"
"github.com/pkg/errors"
"github.com/wealdtech/ethdo/util"
e2types "github.com/wealdtech/go-eth2-types/v2"
)
func (c *command) process(ctx context.Context) error {
// Parse the data.
if c.data == "" {
return errors.New("no data supplied")
}
c.item = &altair.SignedContributionAndProof{}
err := json.Unmarshal([]byte(c.data), c.item)
if err != nil {
c.additionalInfo = err.Error()
//nolint:nilerr
return nil
}
c.itemStructureValid = true
// Obtain information we need to process.
if err := c.setup(ctx); err != nil {
return err
}
for _, validatorIndex := range c.syncCommittee.Validators {
if validatorIndex == c.item.Message.AggregatorIndex {
c.validatorInSyncCommittee = true
break
}
}
if !c.validatorInSyncCommittee {
return nil
}
// Ensure the validator is an aggregator.
isAggregator, err := c.isAggregator(ctx)
if err != nil {
return errors.Wrap(err, "failed to ascertain if sync committee member is aggregator")
}
if !isAggregator {
return nil
}
c.validatorIsAggregator = true
// Confirm the contribution signature.
if err := c.confirmContributionSignature(ctx); err != nil {
return errors.Wrap(err, "failed to confirm the contribution signature")
}
// Confirm the contribution and proof signature.
if err := c.confirmContributionAndProofSignature(ctx); err != nil {
return errors.Wrap(err, "failed to confirm the contribution and proof signature")
}
return nil
}
func (c *command) setup(ctx context.Context) error {
var err error
// Connect to the client.
c.eth2Client, err = util.ConnectToBeaconNode(ctx, &util.ConnectOpts{
Address: c.connection,
Timeout: c.timeout,
AllowInsecure: c.allowInsecureConnections,
LogFallback: !c.quiet,
})
if err != nil {
return errors.Wrap(err, "failed to connect to beacon node")
}
// Obtain the validator.
var isProvider bool
c.validatorsProvider, isProvider = c.eth2Client.(eth2client.ValidatorsProvider)
if !isProvider {
return errors.New("connection does not provide validator information")
}
stateID := fmt.Sprintf("%d", c.item.Message.Contribution.Slot)
response, err := c.validatorsProvider.Validators(ctx, &api.ValidatorsOpts{
State: stateID,
Indices: []phase0.ValidatorIndex{c.item.Message.AggregatorIndex},
})
if err != nil {
return errors.Wrap(err, "failed to obtain validator information")
}
if len(response.Data) == 0 || response.Data[c.item.Message.AggregatorIndex] == nil {
return nil
}
c.validatorKnown = true
c.validator = response.Data[c.item.Message.AggregatorIndex]
// Obtain the sync committee
syncCommitteesProvider, isProvider := c.eth2Client.(eth2client.SyncCommitteesProvider)
if !isProvider {
return errors.New("connection does not provide sync committee information")
}
syncCommitteeResponse, err := syncCommitteesProvider.SyncCommittee(ctx, &api.SyncCommitteeOpts{
State: stateID,
})
if err != nil {
return errors.Wrap(err, "failed to obtain sync committee information")
}
c.syncCommittee = syncCommitteeResponse.Data
return nil
}
// isAggregator returns true if the given.
func (c *command) isAggregator(ctx context.Context) (bool, error) {
// Calculate the modulo.
specProvider, isProvider := c.eth2Client.(eth2client.SpecProvider)
if !isProvider {
return false, errors.New("connection does not provide spec information")
}
specResponse, err := specProvider.Spec(ctx, &api.SpecOpts{})
if err != nil {
return false, errors.Wrap(err, "failed to obtain spec information")
}
c.spec = specResponse.Data
tmp, exists := c.spec["SYNC_COMMITTEE_SIZE"]
if !exists {
return false, errors.New("spec does not contain SYNC_COMMITTEE_SIZE")
}
if _, isUint64 := tmp.(uint64); !isUint64 {
return false, errors.New("spec returned non-integer value for SYNC_COMMITTEE_SIZE")
}
syncCommitteeSize := tmp.(uint64)
if c.debug {
fmt.Fprintf(os.Stderr, "sync committee size is %d\n", syncCommitteeSize)
}
tmp, exists = c.spec["SYNC_COMMITTEE_SUBNET_COUNT"]
if !exists {
return false, errors.New("spec does not contain SYNC_COMMITTEE_SUBNET_COUNT")
}
if _, isUint64 := tmp.(uint64); !isUint64 {
return false, errors.New("spec returned non-integer value for SYNC_COMMITTEE_SUBNET_COUNT")
}
syncCommitteeSubnetCount := tmp.(uint64)
if c.debug {
fmt.Fprintf(os.Stderr, "sync committee subnet count is %d\n", syncCommitteeSubnetCount)
}
tmp, exists = c.spec["TARGET_AGGREGATORS_PER_SYNC_SUBCOMMITTEE"]
if !exists {
return false, errors.New("spec does not contain TARGET_AGGREGATORS_PER_SYNC_SUBCOMMITTEE")
}
if _, isUint64 := tmp.(uint64); !isUint64 {
return false, errors.New("spec returned non-integer value for TARGET_AGGREGATORS_PER_SYNC_SUBCOMMITTEE")
}
targetAggregatorsPerSyncSubcommittee := tmp.(uint64)
if c.debug {
fmt.Fprintf(os.Stderr, "target aggregators per sync subcommittee is %d\n", targetAggregatorsPerSyncSubcommittee)
}
modulo := syncCommitteeSize / syncCommitteeSubnetCount / targetAggregatorsPerSyncSubcommittee
if modulo < 1 {
modulo = 1
}
if c.debug {
fmt.Fprintf(os.Stderr, "modulo is %d\n", modulo)
}
// Hash the selection proof.
sigHash := sha256.New()
n, err := sigHash.Write(c.item.Message.SelectionProof[:])
if err != nil {
return false, errors.Wrap(err, "failed to hash the selection proof")
}
if n != len(c.item.Signature[:]) {
return false, errors.New("failed to write all bytes of the selection proof to the hash")
}
hash := sigHash.Sum(nil)
if c.debug {
fmt.Fprintf(os.Stderr, "hash of selection proof is %#x\n", hash)
}
return binary.LittleEndian.Uint64(hash[:8])%modulo == 0, nil
}
func (c *command) confirmContributionSignature(ctx context.Context) error {
sigBytes := make([]byte, 96)
copy(sigBytes, c.item.Message.Contribution.Signature[:])
_, err := e2types.BLSSignatureFromBytes(sigBytes)
if err != nil {
c.additionalInfo = err.Error()
//nolint:nilerr
return nil
}
c.contributionSignatureValidFormat = true
subCommittee := c.syncCommittee.ValidatorAggregates[c.item.Message.Contribution.SubcommitteeIndex]
includedIndices := make([]phase0.ValidatorIndex, 0, len(subCommittee))
for i := range c.item.Message.Contribution.AggregationBits.Len() {
if c.item.Message.Contribution.AggregationBits.BitAt(i) {
includedIndices = append(includedIndices, subCommittee[int(i)])
}
}
if c.debug {
fmt.Fprintf(os.Stderr, "Contribution validator indices: %v (%d)\n", includedIndices, len(includedIndices))
}
response, err := c.validatorsProvider.Validators(ctx, &api.ValidatorsOpts{
State: "head",
Indices: includedIndices,
})
if err != nil {
return errors.Wrap(err, "failed to obtain subcommittee validators")
}
if len(response.Data) == 0 {
return errors.New("obtained empty subcommittee validator list")
}
var aggregatePubKey *e2types.BLSPublicKey
for _, v := range response.Data {
pubKeyBytes := make([]byte, 48)
copy(pubKeyBytes, v.Validator.PublicKey[:])
pubKey, err := e2types.BLSPublicKeyFromBytes(pubKeyBytes)
if err != nil {
return errors.Wrap(err, "failed to aggregate public key")
}
if aggregatePubKey == nil {
aggregatePubKey = pubKey
} else {
aggregatePubKey.Aggregate(pubKey)
}
}
if c.debug {
fmt.Fprintf(os.Stderr, "Aggregate public key is %#x\n", aggregatePubKey.Marshal())
}
// Don't have the ability to carry out the batch verification at current.
return nil
}
func (c *command) confirmContributionAndProofSignature(ctx context.Context) error {
sigBytes := make([]byte, 96)
copy(sigBytes, c.item.Signature[:])
sig, err := e2types.BLSSignatureFromBytes(sigBytes)
if err != nil {
c.additionalInfo = err.Error()
//nolint:nilerr
return nil
}
c.contributionAndProofSignatureValidFormat = true
pubKeyBytes := make([]byte, 48)
copy(pubKeyBytes, c.validator.Validator.PublicKey[:])
pubKey, err := e2types.BLSPublicKeyFromBytes(pubKeyBytes)
if err != nil {
return errors.Wrap(err, "failed to configure public key")
}
objectRoot, err := c.item.Message.HashTreeRoot()
if err != nil {
return errors.Wrap(err, "failed to obtain signging root")
}
tmp, exists := c.spec["DOMAIN_CONTRIBUTION_AND_PROOF"]
if !exists {
return errors.New("spec does not contain DOMAIN_CONTRIBUTION_AND_PROOF")
}
if _, isUint64 := tmp.(phase0.DomainType); !isUint64 {
return errors.New("spec returned non-domain type value for DOMAIN_CONTRIBUTION_AND_PROOF")
}
contributionAndProofDomainType := tmp.(phase0.DomainType)
if c.debug {
fmt.Fprintf(os.Stderr, "contribution and proof domain type is %#x\n", contributionAndProofDomainType)
}
domain, err := c.eth2Client.(eth2client.DomainProvider).Domain(ctx, contributionAndProofDomainType, phase0.Epoch(c.item.Message.Contribution.Slot/32))
if err != nil {
return errors.Wrap(err, "failed to obtain domain")
}
container := &phase0.SigningData{
ObjectRoot: objectRoot,
Domain: domain,
}
signingRoot, err := container.HashTreeRoot()
if err != nil {
return errors.Wrap(err, "failed to obtain signging root")
}
c.contributionAndProofSignatureValid = sig.Verify(signingRoot[:], pubKey)
return nil
}