prysm-pulse/beacon-chain/core/blocks/randao.go
Nishant Das caf9bdbc6f
Use Block Interface Across Prysm (#8918)
* commit initial work

* checkpoint current work

* gaz

* checkpoint

* req/resp changes

* initial-sync

* finally works

* fix error

* fix bugs

* fix issue

* fix issues

* fix refs

* tests

* more text fixes

* more text fixes

* more text fixes

* fix tests

* fix tests

* tests

* finally fix builds

* finally

* comments

* fix fuzz

* share common library

* fix

* fix

* add in more defensive nil checks

* add in more defensive nil checks

* imports

* Apply suggestions from code review

Co-authored-by: terence tsao <terence@prysmaticlabs.com>

* Apply suggestions from code review

Co-authored-by: terence tsao <terence@prysmaticlabs.com>

* Update shared/interfaces/block_interface.go

Co-authored-by: terence tsao <terence@prysmaticlabs.com>

* Update shared/interfaces/block_wrapper.go

Co-authored-by: terence tsao <terence@prysmaticlabs.com>

* Update shared/interfaces/block_interface.go

Co-authored-by: terence tsao <terence@prysmaticlabs.com>

* imports

* fix bad changes

* fix

* terence's review

* terence's review

* fmt

* Update beacon-chain/rpc/beacon/blocks.go

Co-authored-by: Radosław Kapka <rkapka@wp.pl>

* fix tests

* fix

* fix all tests

Co-authored-by: terence tsao <terence@prysmaticlabs.com>
Co-authored-by: Radosław Kapka <rkapka@wp.pl>
2021-05-26 16:19:54 +00:00

85 lines
3.0 KiB
Go

package blocks
import (
"context"
"github.com/pkg/errors"
"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
iface "github.com/prysmaticlabs/prysm/beacon-chain/state/interface"
"github.com/prysmaticlabs/prysm/shared/hashutil"
"github.com/prysmaticlabs/prysm/shared/interfaces"
"github.com/prysmaticlabs/prysm/shared/params"
)
// 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:
// epoch = get_current_epoch(state)
// # Verify RANDAO reveal
// proposer = state.validators[get_beacon_proposer_index(state)]
// signing_root = compute_signing_root(epoch, get_domain(state, DOMAIN_RANDAO))
// assert bls.Verify(proposer.pubkey, signing_root, body.randao_reveal)
// # Mix in RANDAO reveal
// mix = xor(get_randao_mix(state, epoch), hash(body.randao_reveal))
// state.randao_mixes[epoch % EPOCHS_PER_HISTORICAL_VECTOR] = mix
func ProcessRandao(
_ context.Context,
beaconState iface.BeaconState,
b interfaces.SignedBeaconBlock,
) (iface.BeaconState, error) {
if err := helpers.VerifyNilBeaconBlock(b); err != nil {
return nil, err
}
body := b.Block().Body()
buf, proposerPub, domain, err := randaoSigningData(beaconState)
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.RandaoReveal())
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 iface.BeaconState,
randaoReveal []byte,
) (iface.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(uint64(currentEpoch % latestMixesLength))
if err != nil {
return nil, err
}
blockRandaoReveal := hashutil.Hash(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(uint64(currentEpoch%latestMixesLength), latestMixSlice); err != nil {
return nil, err
}
return beaconState, nil
}