prysm-pulse/runtime/interop/generate_genesis_state.go
Preston Van Loon ee0a453b7b
core: refactor signing and domain methods from helper to core/signing pkg (#9520)
* Move domain function and all signing root functions from beacon-chain/core/helpers to beacon-chain/core

* @terencechain suggestion to put these methods under core/signing
2021-09-27 16:19:20 +00:00

193 lines
7.7 KiB
Go

// Package interop contains deterministic utilities for generating
// genesis states and keys.
package interop
import (
"context"
"sync"
"github.com/pkg/errors"
"github.com/prysmaticlabs/prysm/async"
"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
coreState "github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
"github.com/prysmaticlabs/prysm/config/params"
"github.com/prysmaticlabs/prysm/container/trie"
"github.com/prysmaticlabs/prysm/crypto/bls"
"github.com/prysmaticlabs/prysm/crypto/hash"
ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
"github.com/prysmaticlabs/prysm/time"
)
var (
// This is the recommended mock eth1 block hash according to the Ethereum consensus interop guidelines.
// https://github.com/ethereum/eth2.0-pm/blob/a085c9870f3956d6228ed2a40cd37f0c6580ecd7/interop/mocked_start/README.md
mockEth1BlockHash = []byte{66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66}
)
// GenerateGenesisState deterministically given a genesis time and number of validators.
// If a genesis time of 0 is supplied it is set to the current time.
func GenerateGenesisState(ctx context.Context, genesisTime, numValidators uint64) (*ethpb.BeaconState, []*ethpb.Deposit, error) {
privKeys, pubKeys, err := DeterministicallyGenerateKeys(0 /*startIndex*/, numValidators)
if err != nil {
return nil, nil, errors.Wrapf(err, "could not deterministically generate keys for %d validators", numValidators)
}
depositDataItems, depositDataRoots, err := DepositDataFromKeys(privKeys, pubKeys)
if err != nil {
return nil, nil, errors.Wrap(err, "could not generate deposit data from keys")
}
return GenerateGenesisStateFromDepositData(ctx, genesisTime, depositDataItems, depositDataRoots)
}
// GenerateGenesisStateFromDepositData creates a genesis state given a list of
// deposit data items and their corresponding roots.
func GenerateGenesisStateFromDepositData(
ctx context.Context, genesisTime uint64, depositData []*ethpb.Deposit_Data, depositDataRoots [][]byte,
) (*ethpb.BeaconState, []*ethpb.Deposit, error) {
trie, err := trie.GenerateTrieFromItems(depositDataRoots, params.BeaconConfig().DepositContractTreeDepth)
if err != nil {
return nil, nil, errors.Wrap(err, "could not generate Merkle trie for deposit proofs")
}
deposits, err := GenerateDepositsFromData(depositData, trie)
if err != nil {
return nil, nil, errors.Wrap(err, "could not generate deposits from the deposit data provided")
}
root := trie.HashTreeRoot()
if genesisTime == 0 {
genesisTime = uint64(time.Now().Unix())
}
beaconState, err := coreState.GenesisBeaconState(ctx, deposits, genesisTime, &ethpb.Eth1Data{
DepositRoot: root[:],
DepositCount: uint64(len(deposits)),
BlockHash: mockEth1BlockHash,
})
if err != nil {
return nil, nil, errors.Wrap(err, "could not generate genesis state")
}
pbState, err := v1.ProtobufBeaconState(beaconState.CloneInnerState())
if err != nil {
return nil, nil, err
}
return pbState, deposits, nil
}
// GenerateDepositsFromData a list of deposit items by creating proofs for each of them from a sparse Merkle trie.
func GenerateDepositsFromData(depositDataItems []*ethpb.Deposit_Data, trie *trie.SparseMerkleTrie) ([]*ethpb.Deposit, error) {
deposits := make([]*ethpb.Deposit, len(depositDataItems))
results, err := async.Scatter(len(depositDataItems), func(offset int, entries int, _ *sync.RWMutex) (interface{}, error) {
return generateDepositsFromData(depositDataItems[offset:offset+entries], offset, trie)
})
if err != nil {
return nil, errors.Wrap(err, "failed to generate deposits from data")
}
for _, result := range results {
if depositExtent, ok := result.Extent.([]*ethpb.Deposit); ok {
copy(deposits[result.Offset:], depositExtent)
} else {
return nil, errors.New("extent not of expected type")
}
}
return deposits, nil
}
// generateDepositsFromData a list of deposit items by creating proofs for each of them from a sparse Merkle trie.
func generateDepositsFromData(depositDataItems []*ethpb.Deposit_Data, offset int, trie *trie.SparseMerkleTrie) ([]*ethpb.Deposit, error) {
deposits := make([]*ethpb.Deposit, len(depositDataItems))
for i, item := range depositDataItems {
proof, err := trie.MerkleProof(i + offset)
if err != nil {
return nil, errors.Wrapf(err, "could not generate proof for deposit %d", i+offset)
}
deposits[i] = &ethpb.Deposit{
Proof: proof,
Data: item,
}
}
return deposits, nil
}
// DepositDataFromKeys generates a list of deposit data items from a set of BLS validator keys.
func DepositDataFromKeys(privKeys []bls.SecretKey, pubKeys []bls.PublicKey) ([]*ethpb.Deposit_Data, [][]byte, error) {
type depositData struct {
items []*ethpb.Deposit_Data
roots [][]byte
}
depositDataItems := make([]*ethpb.Deposit_Data, len(privKeys))
depositDataRoots := make([][]byte, len(privKeys))
results, err := async.Scatter(len(privKeys), func(offset int, entries int, _ *sync.RWMutex) (interface{}, error) {
items, roots, err := depositDataFromKeys(privKeys[offset:offset+entries], pubKeys[offset:offset+entries])
return &depositData{items: items, roots: roots}, err
})
if err != nil {
return nil, nil, errors.Wrap(err, "failed to generate deposit data from keys")
}
for _, result := range results {
if depositDataExtent, ok := result.Extent.(*depositData); ok {
copy(depositDataItems[result.Offset:], depositDataExtent.items)
copy(depositDataRoots[result.Offset:], depositDataExtent.roots)
} else {
return nil, nil, errors.New("extent not of expected type")
}
}
return depositDataItems, depositDataRoots, nil
}
func depositDataFromKeys(privKeys []bls.SecretKey, pubKeys []bls.PublicKey) ([]*ethpb.Deposit_Data, [][]byte, error) {
dataRoots := make([][]byte, len(privKeys))
depositDataItems := make([]*ethpb.Deposit_Data, len(privKeys))
for i := 0; i < len(privKeys); i++ {
data, err := createDepositData(privKeys[i], pubKeys[i])
if err != nil {
return nil, nil, errors.Wrapf(err, "could not create deposit data for key: %#x", privKeys[i].Marshal())
}
hash, err := data.HashTreeRoot()
if err != nil {
return nil, nil, errors.Wrap(err, "could not hash tree root deposit data item")
}
dataRoots[i] = hash[:]
depositDataItems[i] = data
}
return depositDataItems, dataRoots, nil
}
// Generates a deposit data item from BLS keys and signs the hash tree root of the data.
func createDepositData(privKey bls.SecretKey, pubKey bls.PublicKey) (*ethpb.Deposit_Data, error) {
depositMessage := &ethpb.DepositMessage{
PublicKey: pubKey.Marshal(),
WithdrawalCredentials: withdrawalCredentialsHash(pubKey.Marshal()),
Amount: params.BeaconConfig().MaxEffectiveBalance,
}
sr, err := depositMessage.HashTreeRoot()
if err != nil {
return nil, err
}
domain, err := signing.ComputeDomain(params.BeaconConfig().DomainDeposit, nil, nil)
if err != nil {
return nil, err
}
root, err := (&ethpb.SigningData{ObjectRoot: sr[:], Domain: domain}).HashTreeRoot()
if err != nil {
return nil, err
}
di := &ethpb.Deposit_Data{
PublicKey: depositMessage.PublicKey,
WithdrawalCredentials: depositMessage.WithdrawalCredentials,
Amount: depositMessage.Amount,
Signature: privKey.Sign(root[:]).Marshal(),
}
return di, nil
}
// withdrawalCredentialsHash forms a 32 byte hash of the withdrawal public
// address.
//
// The specification is as follows:
// withdrawal_credentials[:1] == BLS_WITHDRAWAL_PREFIX_BYTE
// withdrawal_credentials[1:] == hash(withdrawal_pubkey)[1:]
// where withdrawal_credentials is of type bytes32.
func withdrawalCredentialsHash(pubKey []byte) []byte {
h := hash.Hash(pubKey)
return append([]byte{blsWithdrawalPrefixByte}, h[1:]...)[:32]
}