github.com/klaytn/klaytn@v1.10.2/blockchain/types/istanbul.go (about)

     1  // Modifications Copyright 2018 The klaytn Authors
     2  // Copyright 2017 The go-ethereum Authors
     3  // This file is part of the go-ethereum library.
     4  //
     5  // The go-ethereum library is free software: you can redistribute it and/or modify
     6  // it under the terms of the GNU Lesser General Public License as published by
     7  // the Free Software Foundation, either version 3 of the License, or
     8  // (at your option) any later version.
     9  //
    10  // The go-ethereum library is distributed in the hope that it will be useful,
    11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    13  // GNU Lesser General Public License for more details.
    14  //
    15  // You should have received a copy of the GNU Lesser General Public License
    16  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    17  //
    18  // This file is derived from core/types/istanbul.go (2018/06/04).
    19  // Modified and improved for the klaytn development.
    20  
    21  package types
    22  
    23  import (
    24  	"errors"
    25  	"io"
    26  
    27  	"github.com/klaytn/klaytn/common"
    28  	"github.com/klaytn/klaytn/rlp"
    29  )
    30  
    31  var (
    32  	// IstanbulDigest represents a hash of "Istanbul practical byzantine fault tolerance"
    33  	// to identify whether the block is from Istanbul consensus engine
    34  	IstanbulDigest = common.HexToHash("0x63746963616c2062797a616e74696e65206661756c7420746f6c6572616e6365")
    35  
    36  	IstanbulExtraVanity = 32 // Fixed number of extra-data bytes reserved for validator vanity
    37  	IstanbulExtraSeal   = 65 // Fixed number of extra-data bytes reserved for validator seal
    38  
    39  	// ErrInvalidIstanbulHeaderExtra is returned if the length of extra-data is less than 32 bytes
    40  	ErrInvalidIstanbulHeaderExtra = errors.New("invalid istanbul header extra-data")
    41  )
    42  
    43  type IstanbulExtra struct {
    44  	Validators    []common.Address
    45  	Seal          []byte
    46  	CommittedSeal [][]byte
    47  }
    48  
    49  // EncodeRLP serializes the istanbul fields into the Klaytn RLP format.
    50  func (ist *IstanbulExtra) EncodeRLP(w io.Writer) error {
    51  	return rlp.Encode(w, []interface{}{
    52  		ist.Validators,
    53  		ist.Seal,
    54  		ist.CommittedSeal,
    55  	})
    56  }
    57  
    58  // DecodeRLP implements rlp.Decoder, and load the istanbul fields from a RLP stream.
    59  func (ist *IstanbulExtra) DecodeRLP(s *rlp.Stream) error {
    60  	var istanbulExtra struct {
    61  		Validators    []common.Address
    62  		Seal          []byte
    63  		CommittedSeal [][]byte
    64  	}
    65  	if err := s.Decode(&istanbulExtra); err != nil {
    66  		return err
    67  	}
    68  	ist.Validators, ist.Seal, ist.CommittedSeal = istanbulExtra.Validators, istanbulExtra.Seal, istanbulExtra.CommittedSeal
    69  	return nil
    70  }
    71  
    72  // ExtractIstanbulExtra extracts all values of the IstanbulExtra from the header. It returns an
    73  // error if the length of the given extra-data is less than 32 bytes or the extra-data can not
    74  // be decoded.
    75  func ExtractIstanbulExtra(h *Header) (*IstanbulExtra, error) {
    76  	if len(h.Extra) < IstanbulExtraVanity {
    77  		return nil, ErrInvalidIstanbulHeaderExtra
    78  	}
    79  
    80  	var istanbulExtra *IstanbulExtra
    81  	err := rlp.DecodeBytes(h.Extra[IstanbulExtraVanity:], &istanbulExtra)
    82  	if err != nil {
    83  		return nil, err
    84  	}
    85  	return istanbulExtra, nil
    86  }
    87  
    88  // IstanbulFilteredHeader returns a filtered header which some information (like seal, committed seals)
    89  // are clean to fulfill the Istanbul hash rules. It returns nil if the extra-data cannot be
    90  // decoded/encoded by rlp.
    91  func IstanbulFilteredHeader(h *Header, keepSeal bool) *Header {
    92  	newHeader := CopyHeader(h)
    93  	istanbulExtra, err := ExtractIstanbulExtra(newHeader)
    94  	if err != nil {
    95  		return nil
    96  	}
    97  
    98  	if !keepSeal {
    99  		istanbulExtra.Seal = []byte{}
   100  	}
   101  	istanbulExtra.CommittedSeal = [][]byte{}
   102  
   103  	payload, err := rlp.EncodeToBytes(&istanbulExtra)
   104  	if err != nil {
   105  		return nil
   106  	}
   107  	newHeader = SetRoundToHeader(newHeader, 0)
   108  	newHeader.Extra = append(newHeader.Extra[:IstanbulExtraVanity], payload...)
   109  
   110  	return newHeader
   111  }
   112  
   113  func SetRoundToHeader(h *Header, r int64) *Header {
   114  	h.Extra[IstanbulExtraVanity-1] = byte(r)
   115  	return h
   116  }
   117  
   118  func SetRoundToBlock(block *Block, r int64) *Block {
   119  	header := SetRoundToHeader(block.Header(), r)
   120  	return block.WithSeal(header)
   121  }