Files
lightwalletd/parser/block.go
2018-09-03 23:45:49 -04:00

70 lines
2.1 KiB
Go

package parser
import (
"encoding/binary"
"io"
"github.com/pkg/errors"
)
const (
EQUIHASH_SIZE = 1344 // size of an Equihash solution in bytes
)
// A block header as defined in version 2018.0-beta-29 of the Zcash Protocol Spec.
type RawBlockHeader struct {
// The block version number indicates which set of block validation rules
// to follow. The current and only defined block version number for Zcash
// is 4.
Version int32
// A SHA-256d hash in internal byte order of the previous block's header. This
// ensures no previous block can be changed without also changing this block's
// header.
HashPrevBlock [32]byte
// A SHA-256d hash in internal byte order. The merkle root is derived from
// the hashes of all transactions included in this block, ensuring that
// none of those transactions can be modified without modifying the header.
HashMerkleRoot [32]byte
// [Pre-Sapling] A reserved field which should be ignored.
// [Sapling onward] The root LEBS2OSP_256(rt) of the Sapling note
// commitment tree corresponding to the final Sapling treestate of this
// block.
HashFinalSaplingRoot [32]byte
// The block time is a Unix epoch time (UTC) when the miner started hashing
// the header (according to the miner).
Time uint32
// An encoded version of the target threshold this block's header hash must
// be less than or equal to, in the same nBits format used by Bitcoin.
NBits [4]byte
// An arbitrary field that miners can change to modify the header hash in
// order to produce a hash less than or equal to the target threshold.
Nonce [32]byte
// The size of an Equihash solution in bytes (always 1344).
SolutionSize EquihashSize
// The Equihash solution.
Solution [EQUIHASH_SIZE]byte
}
// EquihashSize is a concrete instance of Bitcoin's CompactSize encoding.
type EquihashSize struct {
_ byte // always the byte value 253
Size uint16 // always 1344
}
func ReadBlockHeader(r io.Reader) (*RawBlockHeader, error) {
var blockHeader RawBlockHeader
err := binary.Read(r, binary.LittleEndian, &blockHeader)
if err != nil {
return nil, errors.Wrap(err, "failed reading block header")
}
return &blockHeader, nil
}