package stateutil import ( "encoding/binary" "github.com/prysmaticlabs/prysm/crypto/hash" "github.com/prysmaticlabs/prysm/encoding/ssz" ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1" "github.com/prysmaticlabs/prysm/shared/bytesutil" ) // BlockHeaderRoot computes the HashTreeRoot Merkleization of // a BeaconBlockHeader struct according to the Ethereum // Simple Serialize specification. func BlockHeaderRoot(header *ethpb.BeaconBlockHeader) ([32]byte, error) { fieldRoots := make([][]byte, 5) if header != nil { headerSlotBuf := make([]byte, 8) binary.LittleEndian.PutUint64(headerSlotBuf, uint64(header.Slot)) headerSlotRoot := bytesutil.ToBytes32(headerSlotBuf) fieldRoots[0] = headerSlotRoot[:] proposerIdxBuf := make([]byte, 8) binary.LittleEndian.PutUint64(proposerIdxBuf, uint64(header.ProposerIndex)) proposerIndexRoot := bytesutil.ToBytes32(proposerIdxBuf) fieldRoots[1] = proposerIndexRoot[:] parentRoot := bytesutil.ToBytes32(header.ParentRoot) fieldRoots[2] = parentRoot[:] stateRoot := bytesutil.ToBytes32(header.StateRoot) fieldRoots[3] = stateRoot[:] bodyRoot := bytesutil.ToBytes32(header.BodyRoot) fieldRoots[4] = bodyRoot[:] } return ssz.BitwiseMerkleize(hash.CustomSHA256Hasher(), fieldRoots, uint64(len(fieldRoots)), uint64(len(fieldRoots))) }