prysm-pulse/beacon-chain/core/blocks/block_operations.go
Nishant Das 2c3f974361
Custom Method For Block Signing Root (#5704)
* custom block signing root

* add comment and test

* Update beacon-chain/core/helpers/signing_root.go

* Update beacon-chain/core/helpers/signing_root.go

* fix changes
2020-05-01 03:37:37 -04:00

1188 lines
44 KiB
Go

package blocks
import (
"bytes"
"context"
"encoding/binary"
"fmt"
"reflect"
"sort"
"github.com/gogo/protobuf/proto"
"github.com/pkg/errors"
ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
"github.com/prysmaticlabs/go-ssz"
"github.com/prysmaticlabs/prysm/beacon-chain/cache"
"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
v "github.com/prysmaticlabs/prysm/beacon-chain/core/validators"
stateTrie "github.com/prysmaticlabs/prysm/beacon-chain/state"
"github.com/prysmaticlabs/prysm/beacon-chain/state/stateutil"
pb "github.com/prysmaticlabs/prysm/proto/beacon/p2p/v1"
"github.com/prysmaticlabs/prysm/shared/attestationutil"
"github.com/prysmaticlabs/prysm/shared/bls"
"github.com/prysmaticlabs/prysm/shared/bytesutil"
"github.com/prysmaticlabs/prysm/shared/featureconfig"
"github.com/prysmaticlabs/prysm/shared/hashutil"
"github.com/prysmaticlabs/prysm/shared/mathutil"
"github.com/prysmaticlabs/prysm/shared/params"
"github.com/prysmaticlabs/prysm/shared/sliceutil"
"github.com/prysmaticlabs/prysm/shared/trieutil"
"github.com/sirupsen/logrus"
"go.opencensus.io/trace"
)
var log = logrus.WithField("prefix", "blocks")
var eth1DataCache = cache.NewEth1DataVoteCache()
// Deprecated: This method uses deprecated ssz.SigningRoot.
func verifyDepositDataSigningRoot(obj *ethpb.Deposit_Data, pub []byte, signature []byte, domain []byte) error {
publicKey, err := bls.PublicKeyFromBytes(pub)
if err != nil {
return errors.Wrap(err, "could not convert bytes to public key")
}
sig, err := bls.SignatureFromBytes(signature)
if err != nil {
return errors.Wrap(err, "could not convert bytes to signature")
}
root, err := ssz.SigningRoot(obj)
if err != nil {
return errors.Wrap(err, "could not get signing root")
}
sigRoot := &pb.SigningRoot{
ObjectRoot: root[:],
Domain: domain,
}
ctrRoot, err := ssz.HashTreeRoot(sigRoot)
if err != nil {
return errors.Wrap(err, "could not get container root")
}
if !sig.Verify(ctrRoot[:], publicKey) {
return helpers.ErrSigFailedToVerify
}
return nil
}
func verifySignature(signedData []byte, pub []byte, signature []byte, domain []byte) error {
publicKey, err := bls.PublicKeyFromBytes(pub)
if err != nil {
return errors.Wrap(err, "could not convert bytes to public key")
}
sig, err := bls.SignatureFromBytes(signature)
if err != nil {
return errors.Wrap(err, "could not convert bytes to signature")
}
ctr := &pb.SigningRoot{
ObjectRoot: signedData,
Domain: domain,
}
root, err := ssz.HashTreeRoot(ctr)
if err != nil {
return errors.Wrap(err, "could not hash container")
}
if !sig.Verify(root[:], publicKey) {
return helpers.ErrSigFailedToVerify
}
return nil
}
// ProcessEth1DataInBlock is an operation performed on each
// beacon block to ensure the ETH1 data votes are processed
// into the beacon state.
//
// Official spec definition:
// def process_eth1_data(state: BeaconState, body: BeaconBlockBody) -> None:
// state.eth1_data_votes.append(body.eth1_data)
// if state.eth1_data_votes.count(body.eth1_data) * 2 > EPOCHS_PER_ETH1_VOTING_PERIOD * SLOTS_PER_EPOCH:
// state.latest_eth1_data = body.eth1_data
func ProcessEth1DataInBlock(beaconState *stateTrie.BeaconState, block *ethpb.BeaconBlock) (*stateTrie.BeaconState, error) {
if beaconState == nil {
return nil, errors.New("nil state")
}
if block == nil || block.Body == nil {
return nil, errors.New("nil block or block withought body")
}
if err := beaconState.AppendEth1DataVotes(block.Body.Eth1Data); err != nil {
return nil, err
}
hasSupport, err := Eth1DataHasEnoughSupport(beaconState, block.Body.Eth1Data)
if err != nil {
return nil, err
}
if hasSupport {
if err := beaconState.SetEth1Data(block.Body.Eth1Data); err != nil {
return nil, err
}
}
return beaconState, nil
}
func areEth1DataEqual(a, b *ethpb.Eth1Data) bool {
if a == nil || b == nil {
return false
}
return a.DepositCount == b.DepositCount &&
bytes.Equal(a.BlockHash, b.BlockHash) &&
bytes.Equal(a.DepositRoot, b.DepositRoot)
}
// Eth1DataHasEnoughSupport returns true when the given eth1data has more than 50% votes in the
// eth1 voting period. A vote is cast by including eth1data in a block and part of state processing
// appends eth1data to the state in the Eth1DataVotes list. Iterating through this list checks the
// votes to see if they match the eth1data.
func Eth1DataHasEnoughSupport(beaconState *stateTrie.BeaconState, data *ethpb.Eth1Data) (bool, error) {
voteCount := uint64(0)
var eth1DataHash [32]byte
var err error
data = stateTrie.CopyETH1Data(data)
if featureconfig.Get().EnableEth1DataVoteCache {
eth1DataHash, err = hashutil.HashProto(data)
if err != nil {
return false, errors.Wrap(err, "could not hash eth1data")
}
voteCount, err = eth1DataCache.Eth1DataVote(eth1DataHash)
if err != nil {
return false, errors.Wrap(err, "could not retrieve eth1 data vote cache")
}
}
if voteCount == 0 {
for _, vote := range beaconState.Eth1DataVotes() {
if areEth1DataEqual(vote, data) {
voteCount++
}
}
} else {
voteCount++
}
if featureconfig.Get().EnableEth1DataVoteCache {
if err := eth1DataCache.AddEth1DataVote(&cache.Eth1DataVote{
Eth1DataHash: eth1DataHash,
VoteCount: voteCount,
}); err != nil {
return false, errors.Wrap(err, "could not save eth1 data vote cache")
}
}
// If 50+% majority converged on the same eth1data, then it has enough support to update the
// state.
support := params.BeaconConfig().EpochsPerEth1VotingPeriod * params.BeaconConfig().SlotsPerEpoch
return voteCount*2 > support, nil
}
// ProcessBlockHeader validates a block by its header.
//
// Spec pseudocode definition:
//
// def process_block_header(state: BeaconState, block: BeaconBlock) -> None:
// # Verify that the slots match
// assert block.slot == state.slot
// # Verify that proposer index is the correct index
// assert block.proposer_index == get_beacon_proposer_index(state)
// # Verify that the parent matches
// assert block.parent_root == signing_root(state.latest_block_header)
// # Save current block as the new latest block
// state.latest_block_header = BeaconBlockHeader(
// slot=block.slot,
// parent_root=block.parent_root,
// # state_root: zeroed, overwritten in the next `process_slot` call
// body_root=hash_tree_root(block.body),
// # signature is always zeroed
// )
// # Verify proposer is not slashed
// proposer = state.validators[get_beacon_proposer_index(state)]
// assert not proposer.slashed
// # Verify proposer signature
// assert bls_verify(proposer.pubkey, signing_root(block), block.signature, get_domain(state, DOMAIN_BEACON_PROPOSER))
func ProcessBlockHeader(
beaconState *stateTrie.BeaconState,
block *ethpb.SignedBeaconBlock,
) (*stateTrie.BeaconState, error) {
beaconState, err := ProcessBlockHeaderNoVerify(beaconState, block.Block)
if err != nil {
return nil, err
}
// Verify proposer signature.
if err := VerifyBlockHeaderSignature(beaconState, block); err != nil {
return nil, err
}
return beaconState, nil
}
// VerifyBlockHeaderSignature verifies the proposer signature of a beacon block.
func VerifyBlockHeaderSignature(beaconState *stateTrie.BeaconState, block *ethpb.SignedBeaconBlock) error {
proposer, err := beaconState.ValidatorAtIndex(block.Block.ProposerIndex)
if err != nil {
return err
}
currentEpoch := helpers.SlotToEpoch(beaconState.Slot())
domain, err := helpers.Domain(beaconState.Fork(), currentEpoch, params.BeaconConfig().DomainBeaconProposer, beaconState.GenesisValidatorRoot())
if err != nil {
return err
}
return helpers.VerifyBlockSigningRoot(block.Block, proposer.PublicKey, block.Signature, domain)
}
// ProcessBlockHeaderNoVerify validates a block by its header but skips proposer
// signature verification.
//
// WARNING: This method does not verify proposer signature. This is used for proposer to compute state root
// using a unsigned block.
//
// Spec pseudocode definition:
// def process_block_header(state: BeaconState, block: BeaconBlock) -> None:
// # Verify that the slots match
// assert block.slot == state.slot
// # Verify that proposer index is the correct index
// assert block.proposer_index == get_beacon_proposer_index(state)
// # Verify that the parent matches
// assert block.parent_root == signing_root(state.latest_block_header)
// # Save current block as the new latest block
// state.latest_block_header = BeaconBlockHeader(
// slot=block.slot,
// parent_root=block.parent_root,
// # state_root: zeroed, overwritten in the next `process_slot` call
// body_root=hash_tree_root(block.body),
// # signature is always zeroed
// )
// # Verify proposer is not slashed
// proposer = state.validators[get_beacon_proposer_index(state)]
// assert not proposer.slashed
func ProcessBlockHeaderNoVerify(
beaconState *stateTrie.BeaconState,
block *ethpb.BeaconBlock,
) (*stateTrie.BeaconState, error) {
if block == nil {
return nil, errors.New("nil block")
}
if beaconState.Slot() != block.Slot {
return nil, fmt.Errorf("state slot: %d is different than block slot: %d", beaconState.Slot(), block.Slot)
}
idx, err := helpers.BeaconProposerIndex(beaconState)
if err != nil {
return nil, err
}
if block.ProposerIndex != idx {
return nil, fmt.Errorf("proposer index: %d is different than calculated: %d", block.ProposerIndex, idx)
}
parentRoot, err := stateutil.BlockHeaderRoot(beaconState.LatestBlockHeader())
if err != nil {
return nil, err
}
if !bytes.Equal(block.ParentRoot, parentRoot[:]) {
return nil, fmt.Errorf(
"parent root %#x does not match the latest block header signing root in state %#x",
block.ParentRoot, parentRoot)
}
proposer, err := beaconState.ValidatorAtIndex(idx)
if err != nil {
return nil, err
}
if proposer.Slashed {
return nil, fmt.Errorf("proposer at index %d was previously slashed", idx)
}
bodyRoot, err := stateutil.BlockBodyRoot(block.Body)
if err != nil {
return nil, err
}
if err := beaconState.SetLatestBlockHeader(&ethpb.BeaconBlockHeader{
Slot: block.Slot,
ProposerIndex: block.ProposerIndex,
ParentRoot: block.ParentRoot,
StateRoot: params.BeaconConfig().ZeroHash[:],
BodyRoot: bodyRoot[:],
}); err != nil {
return nil, err
}
return beaconState, nil
}
// ProcessRandao checks the block proposer's
// randao commitment and generates a new randao mix to update
// in the beacon state's latest randao mixes slice.
//
// Spec pseudocode definition:
// def process_randao(state: BeaconState, body: BeaconBlockBody) -> None:
// proposer = state.validator_registry[get_beacon_proposer_index(state)]
// # Verify that the provided randao value is valid
// assert bls_verify(
// proposer.pubkey,
// hash_tree_root(get_current_epoch(state)),
// body.randao_reveal,
// get_domain(state, DOMAIN_RANDAO),
// )
// # Mix it in
// state.latest_randao_mixes[get_current_epoch(state) % LATEST_RANDAO_MIXES_LENGTH] = (
// xor(get_randao_mix(state, get_current_epoch(state)),
// hash(body.randao_reveal))
// )
func ProcessRandao(
beaconState *stateTrie.BeaconState,
body *ethpb.BeaconBlockBody,
) (*stateTrie.BeaconState, error) {
proposerIdx, err := helpers.BeaconProposerIndex(beaconState)
if err != nil {
return nil, errors.Wrap(err, "could not get beacon proposer index")
}
proposerPub := beaconState.PubkeyAtIndex(proposerIdx)
currentEpoch := helpers.SlotToEpoch(beaconState.Slot())
buf := make([]byte, 32)
binary.LittleEndian.PutUint64(buf, currentEpoch)
domain, err := helpers.Domain(beaconState.Fork(), currentEpoch, params.BeaconConfig().DomainRandao, beaconState.GenesisValidatorRoot())
if err != nil {
return nil, err
}
if err := verifySignature(buf, proposerPub[:], body.RandaoReveal, domain); err != nil {
return nil, errors.Wrap(err, "could not verify block randao")
}
beaconState, err = ProcessRandaoNoVerify(beaconState, body)
if err != nil {
return nil, errors.Wrap(err, "could not process randao")
}
return beaconState, nil
}
// ProcessRandaoNoVerify generates a new randao mix to update
// in the beacon state's latest randao mixes slice.
//
// Spec pseudocode definition:
// # Mix it in
// state.latest_randao_mixes[get_current_epoch(state) % LATEST_RANDAO_MIXES_LENGTH] = (
// xor(get_randao_mix(state, get_current_epoch(state)),
// hash(body.randao_reveal))
// )
func ProcessRandaoNoVerify(
beaconState *stateTrie.BeaconState,
body *ethpb.BeaconBlockBody,
) (*stateTrie.BeaconState, error) {
currentEpoch := helpers.SlotToEpoch(beaconState.Slot())
// If block randao passed verification, we XOR the state's latest randao mix with the block's
// randao and update the state's corresponding latest randao mix value.
latestMixesLength := params.BeaconConfig().EpochsPerHistoricalVector
latestMixSlice, err := beaconState.RandaoMixAtIndex(currentEpoch % latestMixesLength)
if err != nil {
return nil, err
}
blockRandaoReveal := hashutil.Hash(body.RandaoReveal)
if len(blockRandaoReveal) != len(latestMixSlice) {
return nil, errors.New("blockRandaoReveal length doesnt match latestMixSlice length")
}
for i, x := range blockRandaoReveal {
latestMixSlice[i] ^= x
}
if err := beaconState.UpdateRandaoMixesAtIndex(currentEpoch%latestMixesLength, latestMixSlice); err != nil {
return nil, err
}
return beaconState, nil
}
// ProcessProposerSlashings is one of the operations performed
// on each processed beacon block to slash proposers based on
// slashing conditions if any slashable events occurred.
//
// Spec pseudocode definition:
// def process_proposer_slashing(state: BeaconState, proposer_slashing: ProposerSlashing) -> None:
// """
// Process ``ProposerSlashing`` operation.
// """
// proposer = state.validator_registry[proposer_slashing.proposer_index]
// # Verify slots match
// assert proposer_slashing.header_1.slot == proposer_slashing.header_2.slot
// # But the headers are different
// assert proposer_slashing.header_1 != proposer_slashing.header_2
// # Check proposer is slashable
// assert is_slashable_validator(proposer, get_current_epoch(state))
// # Signatures are valid
// for header in (proposer_slashing.header_1, proposer_slashing.header_2):
// domain = get_domain(state, DOMAIN_BEACON_PROPOSER, slot_to_epoch(header.slot))
// assert bls_verify(proposer.pubkey, signing_root(header), header.signature, domain)
//
// slash_validator(state, proposer_slashing.proposer_index)
func ProcessProposerSlashings(
ctx context.Context,
beaconState *stateTrie.BeaconState,
body *ethpb.BeaconBlockBody,
) (*stateTrie.BeaconState, error) {
var err error
for idx, slashing := range body.ProposerSlashings {
if slashing == nil {
return nil, errors.New("nil proposer slashings in block body")
}
if err = VerifyProposerSlashing(beaconState, slashing); err != nil {
return nil, errors.Wrapf(err, "could not verify proposer slashing %d", idx)
}
beaconState, err = v.SlashValidator(
beaconState, slashing.Header_1.Header.ProposerIndex, 0, /* proposer is whistleblower */
)
if err != nil {
return nil, errors.Wrapf(err, "could not slash proposer index %d", slashing.Header_1.Header.ProposerIndex)
}
}
return beaconState, nil
}
// VerifyProposerSlashing verifies that the data provided from slashing is valid.
func VerifyProposerSlashing(
beaconState *stateTrie.BeaconState,
slashing *ethpb.ProposerSlashing,
) error {
if slashing.Header_1 == nil || slashing.Header_1.Header == nil || slashing.Header_2 == nil || slashing.Header_2.Header == nil {
return errors.New("nil header cannot be verified")
}
if slashing.Header_1.Header.Slot != slashing.Header_2.Header.Slot {
return fmt.Errorf("mismatched header slots, received %d == %d", slashing.Header_1.Header.Slot, slashing.Header_2.Header.Slot)
}
if slashing.Header_1.Header.ProposerIndex != slashing.Header_2.Header.ProposerIndex {
return fmt.Errorf("mismatched indices, received %d == %d", slashing.Header_1.Header.ProposerIndex, slashing.Header_2.Header.ProposerIndex)
}
if proto.Equal(slashing.Header_1, slashing.Header_2) {
return errors.New("expected slashing headers to differ")
}
proposer, err := beaconState.ValidatorAtIndex(slashing.Header_1.Header.ProposerIndex)
if err != nil {
return err
}
if !helpers.IsSlashableValidator(proposer, helpers.SlotToEpoch(beaconState.Slot())) {
return fmt.Errorf("validator with key %#x is not slashable", proposer.PublicKey)
}
// Using headerEpoch1 here because both of the headers should have the same epoch.
domain, err := helpers.Domain(beaconState.Fork(), helpers.SlotToEpoch(slashing.Header_1.Header.Slot), params.BeaconConfig().DomainBeaconProposer, beaconState.GenesisValidatorRoot())
if err != nil {
return err
}
headers := []*ethpb.SignedBeaconBlockHeader{slashing.Header_1, slashing.Header_2}
for _, header := range headers {
if err := helpers.VerifySigningRoot(header.Header, proposer.PublicKey, header.Signature, domain); err != nil {
return errors.Wrap(err, "could not verify beacon block header")
}
}
return nil
}
// ProcessAttesterSlashings is one of the operations performed
// on each processed beacon block to slash attesters based on
// Casper FFG slashing conditions if any slashable events occurred.
//
// Spec pseudocode definition:
// def process_attester_slashing(state: BeaconState, attester_slashing: AttesterSlashing) -> None:
// attestation_1 = attester_slashing.attestation_1
// attestation_2 = attester_slashing.attestation_2
// assert is_slashable_attestation_data(attestation_1.data, attestation_2.data)
// assert is_valid_indexed_attestation(state, attestation_1)
// assert is_valid_indexed_attestation(state, attestation_2)
//
// slashed_any = False
// indices = set(attestation_1.attesting_indices).intersection(attestation_2.attesting_indices)
// for index in sorted(indices):
// if is_slashable_validator(state.validators[index], get_current_epoch(state)):
// slash_validator(state, index)
// slashed_any = True
// assert slashed_any
func ProcessAttesterSlashings(
ctx context.Context,
beaconState *stateTrie.BeaconState,
body *ethpb.BeaconBlockBody,
) (*stateTrie.BeaconState, error) {
for idx, slashing := range body.AttesterSlashings {
if err := VerifyAttesterSlashing(ctx, beaconState, slashing); err != nil {
return nil, errors.Wrapf(err, "could not verify attester slashing %d", idx)
}
slashableIndices := slashableAttesterIndices(slashing)
sort.SliceStable(slashableIndices, func(i, j int) bool {
return slashableIndices[i] < slashableIndices[j]
})
currentEpoch := helpers.SlotToEpoch(beaconState.Slot())
var err error
var slashedAny bool
var val *ethpb.Validator
for _, validatorIndex := range slashableIndices {
val, err = beaconState.ValidatorAtIndex(validatorIndex)
if err != nil {
return nil, err
}
if helpers.IsSlashableValidator(val, currentEpoch) {
beaconState, err = v.SlashValidator(beaconState, validatorIndex, 0)
if err != nil {
return nil, errors.Wrapf(err, "could not slash validator index %d",
validatorIndex)
}
slashedAny = true
}
}
if !slashedAny {
return nil, errors.New("unable to slash any validator despite confirmed attester slashing")
}
}
return beaconState, nil
}
// VerifyAttesterSlashing validates the attestation data in both attestations in the slashing object.
func VerifyAttesterSlashing(ctx context.Context, beaconState *stateTrie.BeaconState, slashing *ethpb.AttesterSlashing) error {
if slashing == nil {
return errors.New("nil slashing")
}
if slashing.Attestation_1 == nil || slashing.Attestation_2 == nil {
return errors.New("nil attestation")
}
if slashing.Attestation_1.Data == nil || slashing.Attestation_2.Data == nil {
return errors.New("nil attestation data")
}
att1 := slashing.Attestation_1
att2 := slashing.Attestation_2
data1 := att1.Data
data2 := att2.Data
if !IsSlashableAttestationData(data1, data2) {
return errors.New("attestations are not slashable")
}
if err := VerifyIndexedAttestation(ctx, beaconState, att1); err != nil {
return errors.Wrap(err, "could not validate indexed attestation")
}
if err := VerifyIndexedAttestation(ctx, beaconState, att2); err != nil {
return errors.Wrap(err, "could not validate indexed attestation")
}
return nil
}
// IsSlashableAttestationData verifies a slashing against the Casper Proof of Stake FFG rules.
//
// Spec pseudocode definition:
// def is_slashable_attestation_data(data_1: AttestationData, data_2: AttestationData) -> bool:
// """
// Check if ``data_1`` and ``data_2`` are slashable according to Casper FFG rules.
// """
// return (
// # Double vote
// (data_1 != data_2 and data_1.target.epoch == data_2.target.epoch) or
// # Surround vote
// (data_1.source.epoch < data_2.source.epoch and data_2.target.epoch < data_1.target.epoch)
// )
func IsSlashableAttestationData(data1 *ethpb.AttestationData, data2 *ethpb.AttestationData) bool {
if data1 == nil || data2 == nil || data1.Target == nil || data2.Target == nil || data1.Source == nil || data2.Source == nil {
return false
}
isDoubleVote := !proto.Equal(data1, data2) && data1.Target.Epoch == data2.Target.Epoch
isSurroundVote := data1.Source.Epoch < data2.Source.Epoch && data2.Target.Epoch < data1.Target.Epoch
return isDoubleVote || isSurroundVote
}
func slashableAttesterIndices(slashing *ethpb.AttesterSlashing) []uint64 {
if slashing == nil || slashing.Attestation_1 == nil || slashing.Attestation_2 == nil {
return nil
}
indices1 := slashing.Attestation_1.AttestingIndices
indices2 := slashing.Attestation_2.AttestingIndices
return sliceutil.IntersectionUint64(indices1, indices2)
}
// ProcessAttestations applies processing operations to a block's inner attestation
// records. This function returns a list of pending attestations which can then be
// appended to the BeaconState's latest attestations.
func ProcessAttestations(
ctx context.Context,
beaconState *stateTrie.BeaconState,
body *ethpb.BeaconBlockBody,
) (*stateTrie.BeaconState, error) {
var err error
for idx, attestation := range body.Attestations {
beaconState, err = ProcessAttestation(ctx, beaconState, attestation)
if err != nil {
return nil, errors.Wrapf(err, "could not verify attestation at index %d in block", idx)
}
}
return beaconState, nil
}
// ProcessAttestationsNoVerify applies processing operations to a block's inner attestation
// records. The only difference would be that the attestation signature would not be verified.
func ProcessAttestationsNoVerify(
ctx context.Context,
beaconState *stateTrie.BeaconState,
body *ethpb.BeaconBlockBody,
) (*stateTrie.BeaconState, error) {
var err error
for idx, attestation := range body.Attestations {
beaconState, err = ProcessAttestationNoVerify(ctx, beaconState, attestation)
if err != nil {
return nil, errors.Wrapf(err, "could not verify attestation at index %d in block", idx)
}
}
return beaconState, nil
}
// ProcessAttestation verifies an input attestation can pass through processing using the given beacon state.
//
// Spec pseudocode definition:
// def process_attestation(state: BeaconState, attestation: Attestation) -> None:
// data = attestation.data
// assert data.index < get_committee_count_at_slot(state, data.slot)
// assert data.target.epoch in (get_previous_epoch(state), get_current_epoch(state))
// assert data.target.epoch == compute_epoch_at_slot(data.slot)
// assert data.slot + MIN_ATTESTATION_INCLUSION_DELAY <= state.slot <= data.slot + SLOTS_PER_EPOCH
//
// committee = get_beacon_committee(state, data.slot, data.index)
// assert len(attestation.aggregation_bits) == len(committee)
//
// pending_attestation = PendingAttestation(
// data=data,
// aggregation_bits=attestation.aggregation_bits,
// inclusion_delay=state.slot - data.slot,
// proposer_index=get_beacon_proposer_index(state),
// )
//
// if data.target.epoch == get_current_epoch(state):
// assert data.source == state.current_justified_checkpoint
// state.current_epoch_attestations.append(pending_attestation)
// else:
// assert data.source == state.previous_justified_checkpoint
// state.previous_epoch_attestations.append(pending_attestation)
//
// # Check signature
// assert is_valid_indexed_attestation(state, get_indexed_attestation(state, attestation))
func ProcessAttestation(
ctx context.Context,
beaconState *stateTrie.BeaconState,
att *ethpb.Attestation,
) (*stateTrie.BeaconState, error) {
beaconState, err := ProcessAttestationNoVerify(ctx, beaconState, att)
if err != nil {
return nil, err
}
return beaconState, VerifyAttestation(ctx, beaconState, att)
}
// ProcessAttestationNoVerify processes the attestation without verifying the attestation signature. This
// method is used to validate attestations whose signatures have already been verified.
func ProcessAttestationNoVerify(
ctx context.Context,
beaconState *stateTrie.BeaconState,
att *ethpb.Attestation,
) (*stateTrie.BeaconState, error) {
ctx, span := trace.StartSpan(ctx, "core.ProcessAttestationNoVerify")
defer span.End()
if att == nil || att.Data == nil || att.Data.Target == nil {
return nil, errors.New("nil attestation data target")
}
currEpoch := helpers.SlotToEpoch(beaconState.Slot())
var prevEpoch uint64
if currEpoch == 0 {
prevEpoch = 0
} else {
prevEpoch = currEpoch - 1
}
data := att.Data
if data.Target.Epoch != prevEpoch && data.Target.Epoch != currEpoch {
return nil, fmt.Errorf(
"expected target epoch (%d) to be the previous epoch (%d) or the current epoch (%d)",
data.Target.Epoch,
prevEpoch,
currEpoch,
)
}
if helpers.SlotToEpoch(data.Slot) != data.Target.Epoch {
return nil, fmt.Errorf("data slot is not in the same epoch as target %d != %d", helpers.SlotToEpoch(data.Slot), data.Target.Epoch)
}
s := att.Data.Slot
minInclusionCheck := s+params.BeaconConfig().MinAttestationInclusionDelay <= beaconState.Slot()
epochInclusionCheck := beaconState.Slot() <= s+params.BeaconConfig().SlotsPerEpoch
if !minInclusionCheck {
return nil, fmt.Errorf(
"attestation slot %d + inclusion delay %d > state slot %d",
s,
params.BeaconConfig().MinAttestationInclusionDelay,
beaconState.Slot(),
)
}
if !epochInclusionCheck {
return nil, fmt.Errorf(
"state slot %d > attestation slot %d + SLOTS_PER_EPOCH %d",
beaconState.Slot(),
s,
params.BeaconConfig().SlotsPerEpoch,
)
}
if err := helpers.VerifyAttestationBitfieldLengths(beaconState, att); err != nil {
return nil, errors.Wrap(err, "could not verify attestation bitfields")
}
proposerIndex, err := helpers.BeaconProposerIndex(beaconState)
if err != nil {
return nil, err
}
pendingAtt := &pb.PendingAttestation{
Data: data,
AggregationBits: att.AggregationBits,
InclusionDelay: beaconState.Slot() - s,
ProposerIndex: proposerIndex,
}
var ffgSourceEpoch uint64
var ffgSourceRoot []byte
var ffgTargetEpoch uint64
if data.Target.Epoch == currEpoch {
ffgSourceEpoch = beaconState.CurrentJustifiedCheckpoint().Epoch
ffgSourceRoot = beaconState.CurrentJustifiedCheckpoint().Root
ffgTargetEpoch = currEpoch
if err := beaconState.AppendCurrentEpochAttestations(pendingAtt); err != nil {
return nil, err
}
} else {
ffgSourceEpoch = beaconState.PreviousJustifiedCheckpoint().Epoch
ffgSourceRoot = beaconState.PreviousJustifiedCheckpoint().Root
ffgTargetEpoch = prevEpoch
if err := beaconState.AppendPreviousEpochAttestations(pendingAtt); err != nil {
return nil, err
}
}
if data.Source.Epoch != ffgSourceEpoch {
return nil, fmt.Errorf("expected source epoch %d, received %d", ffgSourceEpoch, data.Source.Epoch)
}
if !bytes.Equal(data.Source.Root, ffgSourceRoot) {
return nil, fmt.Errorf("expected source root %#x, received %#x", ffgSourceRoot, data.Source.Root)
}
if data.Target.Epoch != ffgTargetEpoch {
return nil, fmt.Errorf("expected target epoch %d, received %d", ffgTargetEpoch, data.Target.Epoch)
}
return beaconState, nil
}
// VerifyIndexedAttestation determines the validity of an indexed attestation.
//
// Spec pseudocode definition:
// def is_valid_indexed_attestation(state: BeaconState, indexed_attestation: IndexedAttestation) -> bool:
// """
// Check if ``indexed_attestation`` has valid indices and signature.
// """
// indices = indexed_attestation.attesting_indices
//
// # Verify max number of indices
// if not len(indices) <= MAX_VALIDATORS_PER_COMMITTEE:
// return False
// # Verify indices are sorted and unique
// if not indices == sorted(set(indices)):
// # Verify aggregate signature
// if not bls_verify(
// pubkey=bls_aggregate_pubkeys([state.validators[i].pubkey for i in indices]),
// message_hash=hash_tree_root(indexed_attestation.data),
// signature=indexed_attestation.signature,
// domain=get_domain(state, DOMAIN_BEACON_ATTESTER, indexed_attestation.data.target.epoch),
// ):
// return False
// return True
func VerifyIndexedAttestation(ctx context.Context, beaconState *stateTrie.BeaconState, indexedAtt *ethpb.IndexedAttestation) error {
ctx, span := trace.StartSpan(ctx, "core.VerifyIndexedAttestation")
defer span.End()
if indexedAtt == nil || indexedAtt.Data == nil || indexedAtt.Data.Target == nil {
return errors.New("nil or missing indexed attestation data")
}
indices := indexedAtt.AttestingIndices
if uint64(len(indices)) > params.BeaconConfig().MaxValidatorsPerCommittee {
return fmt.Errorf("validator indices count exceeds MAX_VALIDATORS_PER_COMMITTEE, %d > %d", len(indices), params.BeaconConfig().MaxValidatorsPerCommittee)
}
set := make(map[uint64]bool)
setIndices := make([]uint64, 0, len(indices))
for _, i := range indices {
if ok := set[i]; ok {
continue
}
setIndices = append(setIndices, i)
set[i] = true
}
sort.SliceStable(setIndices, func(i, j int) bool {
return setIndices[i] < setIndices[j]
})
if !reflect.DeepEqual(setIndices, indices) {
return errors.New("attesting indices is not uniquely sorted")
}
domain, err := helpers.Domain(beaconState.Fork(), indexedAtt.Data.Target.Epoch, params.BeaconConfig().DomainBeaconAttester, beaconState.GenesisValidatorRoot())
if err != nil {
return err
}
pubkeys := []*bls.PublicKey{}
if len(indices) > 0 {
for i := 0; i < len(indices); i++ {
pubkeyAtIdx := beaconState.PubkeyAtIndex(indices[i])
pk, err := bls.PublicKeyFromBytes(pubkeyAtIdx[:])
if err != nil {
return errors.Wrap(err, "could not deserialize validator public key")
}
pubkeys = append(pubkeys, pk)
}
}
messageHash, err := helpers.ComputeSigningRoot(indexedAtt.Data, domain)
if err != nil {
return errors.Wrap(err, "could not get signing root of object")
}
sig, err := bls.SignatureFromBytes(indexedAtt.Signature)
if err != nil {
return errors.Wrap(err, "could not convert bytes to signature")
}
voted := len(indices) > 0
if voted && !sig.FastAggregateVerify(pubkeys, messageHash) {
return helpers.ErrSigFailedToVerify
}
return nil
}
// VerifyAttestation converts and attestation into an indexed attestation and verifies
// the signature in that attestation.
func VerifyAttestation(ctx context.Context, beaconState *stateTrie.BeaconState, att *ethpb.Attestation) error {
if att == nil || att.Data == nil {
return fmt.Errorf("nil or missing attestation data: %v", att)
}
committee, err := helpers.BeaconCommitteeFromState(beaconState, att.Data.Slot, att.Data.CommitteeIndex)
if err != nil {
return err
}
indexedAtt := attestationutil.ConvertToIndexed(ctx, att, committee)
return VerifyIndexedAttestation(ctx, beaconState, indexedAtt)
}
// ProcessDeposits is one of the operations performed on each processed
// beacon block to verify queued validators from the Ethereum 1.0 Deposit Contract
// into the beacon chain.
//
// Spec pseudocode definition:
// For each deposit in block.body.deposits:
// process_deposit(state, deposit)
func ProcessDeposits(
ctx context.Context,
beaconState *stateTrie.BeaconState,
body *ethpb.BeaconBlockBody,
) (*stateTrie.BeaconState, error) {
var err error
deposits := body.Deposits
for _, deposit := range deposits {
if deposit == nil || deposit.Data == nil {
return nil, errors.New("got a nil deposit in block")
}
beaconState, err = ProcessDeposit(beaconState, deposit)
if err != nil {
return nil, errors.Wrapf(err, "could not process deposit from %#x", bytesutil.Trunc(deposit.Data.PublicKey))
}
}
return beaconState, nil
}
// ProcessPreGenesisDeposit processes a deposit for the beacon state before chainstart.
func ProcessPreGenesisDeposit(
ctx context.Context,
beaconState *stateTrie.BeaconState,
deposit *ethpb.Deposit,
) (*stateTrie.BeaconState, error) {
var err error
beaconState, err = ProcessDeposit(beaconState, deposit)
if err != nil {
return nil, errors.Wrap(err, "could not process deposit")
}
pubkey := deposit.Data.PublicKey
index, ok := beaconState.ValidatorIndexByPubkey(bytesutil.ToBytes48(pubkey))
if !ok {
return beaconState, nil
}
balance, err := beaconState.BalanceAtIndex(index)
if err != nil {
return nil, err
}
validator, err := beaconState.ValidatorAtIndex(index)
if err != nil {
return nil, err
}
validator.EffectiveBalance = mathutil.Min(balance-balance%params.BeaconConfig().EffectiveBalanceIncrement, params.BeaconConfig().MaxEffectiveBalance)
if validator.EffectiveBalance ==
params.BeaconConfig().MaxEffectiveBalance {
validator.ActivationEligibilityEpoch = 0
validator.ActivationEpoch = 0
}
if err := beaconState.UpdateValidatorAtIndex(uint64(index), validator); err != nil {
return nil, err
}
return beaconState, nil
}
// ProcessDeposit takes in a deposit object and inserts it
// into the registry as a new validator or balance change.
//
// Spec pseudocode definition:
// def process_deposit(state: BeaconState, deposit: Deposit) -> None:
// # Verify the Merkle branch
// assert is_valid_merkle_branch(
// leaf=hash_tree_root(deposit.data),
// branch=deposit.proof,
// depth=DEPOSIT_CONTRACT_TREE_DEPTH + 1, # Add 1 for the `List` length mix-in
// index=state.eth1_deposit_index,
// root=state.eth1_data.deposit_root,
// )
//
// # Deposits must be processed in order
// state.eth1_deposit_index += 1
//
// pubkey = deposit.data.pubkey
// amount = deposit.data.amount
// validator_pubkeys = [v.pubkey for v in state.validators]
// if pubkey not in validator_pubkeys:
// # Verify the deposit signature (proof of possession) for new validators.
// # Note: The deposit contract does not check signatures.
// # Note: Deposits are valid across forks, thus the deposit domain is retrieved directly from `compute_domain`.
// domain = compute_domain(DOMAIN_DEPOSIT)
// if not bls_verify(pubkey, signing_root(deposit.data), deposit.data.signature, domain):
// return
//
// # Add validator and balance entries
// state.validators.append(Validator(
// pubkey=pubkey,
// withdrawal_credentials=deposit.data.withdrawal_credentials,
// activation_eligibility_epoch=FAR_FUTURE_EPOCH,
// activation_epoch=FAR_FUTURE_EPOCH,
// exit_epoch=FAR_FUTURE_EPOCH,
// withdrawable_epoch=FAR_FUTURE_EPOCH,
// effective_balance=min(amount - amount % EFFECTIVE_BALANCE_INCREMENT, MAX_EFFECTIVE_BALANCE),
// ))
// state.balances.append(amount)
// else:
// # Increase balance by deposit amount
// index = ValidatorIndex(validator_pubkeys.index(pubkey))
// increase_balance(state, index, amount)
func ProcessDeposit(
beaconState *stateTrie.BeaconState,
deposit *ethpb.Deposit,
) (*stateTrie.BeaconState, error) {
if err := verifyDeposit(beaconState, deposit); err != nil {
if deposit == nil || deposit.Data == nil {
return nil, err
}
return nil, errors.Wrapf(err, "could not verify deposit from %#x", bytesutil.Trunc(deposit.Data.PublicKey))
}
if err := beaconState.SetEth1DepositIndex(beaconState.Eth1DepositIndex() + 1); err != nil {
return nil, err
}
pubKey := deposit.Data.PublicKey
amount := deposit.Data.Amount
index, ok := beaconState.ValidatorIndexByPubkey(bytesutil.ToBytes48(pubKey))
numVals := beaconState.NumValidators()
if !ok {
domain, err := helpers.ComputeDomain(params.BeaconConfig().DomainDeposit, nil, nil)
if err != nil {
return nil, err
}
depositSig := deposit.Data.Signature
if err := verifyDepositDataSigningRoot(deposit.Data, pubKey, depositSig, domain); err != nil {
// Ignore this error as in the spec pseudo code.
log.Debugf("Skipping deposit: could not verify deposit data signature: %v", err)
return beaconState, nil
}
effectiveBalance := amount - (amount % params.BeaconConfig().EffectiveBalanceIncrement)
if params.BeaconConfig().MaxEffectiveBalance < effectiveBalance {
effectiveBalance = params.BeaconConfig().MaxEffectiveBalance
}
if err := beaconState.AppendValidator(&ethpb.Validator{
PublicKey: pubKey,
WithdrawalCredentials: deposit.Data.WithdrawalCredentials,
ActivationEligibilityEpoch: params.BeaconConfig().FarFutureEpoch,
ActivationEpoch: params.BeaconConfig().FarFutureEpoch,
ExitEpoch: params.BeaconConfig().FarFutureEpoch,
WithdrawableEpoch: params.BeaconConfig().FarFutureEpoch,
EffectiveBalance: effectiveBalance,
}); err != nil {
return nil, err
}
if err := beaconState.AppendBalance(amount); err != nil {
return nil, err
}
numVals++
beaconState.SetValidatorIndexByPubkey(bytesutil.ToBytes48(pubKey), uint64(numVals-1))
} else {
if err := helpers.IncreaseBalance(beaconState, uint64(index), amount); err != nil {
return nil, err
}
}
return beaconState, nil
}
func verifyDeposit(beaconState *stateTrie.BeaconState, deposit *ethpb.Deposit) error {
// Verify Merkle proof of deposit and deposit trie root.
if deposit == nil || deposit.Data == nil {
return errors.New("received nil deposit or nil deposit data")
}
eth1Data := beaconState.Eth1Data()
if eth1Data == nil {
return errors.New("received nil eth1data in the beacon state")
}
receiptRoot := eth1Data.DepositRoot
leaf, err := ssz.HashTreeRoot(deposit.Data)
if err != nil {
return errors.Wrap(err, "could not tree hash deposit data")
}
if ok := trieutil.VerifyMerkleBranch(
receiptRoot,
leaf[:],
int(beaconState.Eth1DepositIndex()),
deposit.Proof,
); !ok {
return fmt.Errorf(
"deposit merkle branch of deposit root did not verify for root: %#x",
receiptRoot,
)
}
return nil
}
// ProcessVoluntaryExits is one of the operations performed
// on each processed beacon block to determine which validators
// should exit the state's validator registry.
//
// Spec pseudocode definition:
// def process_voluntary_exit(state: BeaconState, exit: VoluntaryExit) -> None:
// """
// Process ``VoluntaryExit`` operation.
// """
// validator = state.validator_registry[exit.validator_index]
// # Verify the validator is active
// assert is_active_validator(validator, get_current_epoch(state))
// # Verify the validator has not yet exited
// assert validator.exit_epoch == FAR_FUTURE_EPOCH
// # Exits must specify an epoch when they become valid; they are not valid before then
// assert get_current_epoch(state) >= exit.epoch
// # Verify the validator has been active long enough
// assert get_current_epoch(state) >= validator.activation_epoch + PERSISTENT_COMMITTEE_PERIOD
// # Verify signature
// domain = get_domain(state, DOMAIN_VOLUNTARY_EXIT, exit.epoch)
// assert bls_verify(validator.pubkey, signing_root(exit), exit.signature, domain)
// # Initiate exit
// initiate_validator_exit(state, exit.validator_index)
func ProcessVoluntaryExits(
ctx context.Context,
beaconState *stateTrie.BeaconState,
body *ethpb.BeaconBlockBody,
) (*stateTrie.BeaconState, error) {
exits := body.VoluntaryExits
for idx, exit := range exits {
if exit == nil || exit.Exit == nil {
return nil, errors.New("nil voluntary exit in block body")
}
if int(exit.Exit.ValidatorIndex) >= beaconState.NumValidators() {
return nil, fmt.Errorf(
"validator index out of bound %d > %d",
exit.Exit.ValidatorIndex,
beaconState.NumValidators(),
)
}
val, err := beaconState.ValidatorAtIndex(exit.Exit.ValidatorIndex)
if err != nil {
return nil, err
}
if err := VerifyExit(val, beaconState.Slot(), beaconState.Fork(), exit, beaconState.GenesisValidatorRoot()); err != nil {
return nil, errors.Wrapf(err, "could not verify exit %d", idx)
}
beaconState, err = v.InitiateValidatorExit(beaconState, exit.Exit.ValidatorIndex)
if err != nil {
return nil, err
}
}
return beaconState, nil
}
// ProcessVoluntaryExitsNoVerify processes all the voluntary exits in
// a block body, without verifying their BLS signatures.
func ProcessVoluntaryExitsNoVerify(
beaconState *stateTrie.BeaconState,
body *ethpb.BeaconBlockBody,
) (*stateTrie.BeaconState, error) {
var err error
exits := body.VoluntaryExits
for idx, exit := range exits {
if exit == nil || exit.Exit == nil {
return nil, errors.New("nil exit")
}
beaconState, err = v.InitiateValidatorExit(beaconState, exit.Exit.ValidatorIndex)
if err != nil {
return nil, errors.Wrapf(err, "failed to process voluntary exit at index %d", idx)
}
}
return beaconState, nil
}
// VerifyExit implements the spec defined validation for voluntary exits.
//
// Spec pseudocode definition:
// def process_voluntary_exit(state: BeaconState, exit: VoluntaryExit) -> None:
// """
// Process ``VoluntaryExit`` operation.
// """
// validator = state.validator_registry[exit.validator_index]
// # Verify the validator is active
// assert is_active_validator(validator, get_current_epoch(state))
// # Verify the validator has not yet exited
// assert validator.exit_epoch == FAR_FUTURE_EPOCH
// # Exits must specify an epoch when they become valid; they are not valid before then
// assert get_current_epoch(state) >= exit.epoch
// # Verify the validator has been active long enough
// assert get_current_epoch(state) >= validator.activation_epoch + PERSISTENT_COMMITTEE_PERIOD
// # Verify signature
// domain = get_domain(state, DOMAIN_VOLUNTARY_EXIT, exit.epoch)
// assert bls_verify(validator.pubkey, signing_root(exit), exit.signature, domain)
func VerifyExit(validator *ethpb.Validator, currentSlot uint64, fork *pb.Fork, signed *ethpb.SignedVoluntaryExit, genesisRoot []byte) error {
if signed == nil || signed.Exit == nil {
return errors.New("nil exit")
}
exit := signed.Exit
currentEpoch := helpers.SlotToEpoch(currentSlot)
// Verify the validator is active.
if !helpers.IsActiveValidator(validator, currentEpoch) {
return errors.New("non-active validator cannot exit")
}
// Verify the validator has not yet exited.
if validator.ExitEpoch != params.BeaconConfig().FarFutureEpoch {
return fmt.Errorf("validator has already exited at epoch: %v", validator.ExitEpoch)
}
// Exits must specify an epoch when they become valid; they are not valid before then.
if currentEpoch < exit.Epoch {
return fmt.Errorf("expected current epoch >= exit epoch, received %d < %d", currentEpoch, exit.Epoch)
}
// Verify the validator has been active long enough.
if currentEpoch < validator.ActivationEpoch+params.BeaconConfig().PersistentCommitteePeriod {
return fmt.Errorf(
"validator has not been active long enough to exit, wanted epoch %d >= %d",
currentEpoch,
validator.ActivationEpoch+params.BeaconConfig().PersistentCommitteePeriod,
)
}
domain, err := helpers.Domain(fork, exit.Epoch, params.BeaconConfig().DomainVoluntaryExit, genesisRoot)
if err != nil {
return err
}
if err := helpers.VerifySigningRoot(exit, validator.PublicKey, signed.Signature, domain); err != nil {
return helpers.ErrSigFailedToVerify
}
return nil
}
// ClearEth1DataVoteCache clears the eth1 data vote count cache.
func ClearEth1DataVoteCache() {
eth1DataCache = cache.NewEth1DataVoteCache()
}