/
field_root_attestation.go
55 lines (48 loc) · 1.85 KB
/
field_root_attestation.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
package stateutil
import (
"bytes"
"encoding/binary"
"fmt"
"github.com/pkg/errors"
params "github.com/prysmaticlabs/prysm/v4/config/params"
"github.com/prysmaticlabs/prysm/v4/encoding/ssz"
ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
)
// RootsArrayHashTreeRoot computes the Merkle root of arrays of 32-byte hashes, such as [64][32]byte
// according to the Simple Serialize specification of Ethereum.
func RootsArrayHashTreeRoot(vals [][]byte, length uint64) ([32]byte, error) {
return ArraysRoot(vals, length)
}
func EpochAttestationsRoot(atts []*ethpb.PendingAttestation) ([32]byte, error) {
max := params.BeaconConfig().CurrentEpochAttestationsLength()
if uint64(len(atts)) > max {
return [32]byte{}, fmt.Errorf("epoch attestation exceeds max length %d", max)
}
roots := make([][32]byte, len(atts))
for i := 0; i < len(atts); i++ {
pendingRoot, err := pendingAttestationRoot(atts[i])
if err != nil {
return [32]byte{}, errors.Wrap(err, "could not attestation merkleization")
}
roots[i] = pendingRoot
}
attsRootsRoot, err := ssz.BitwiseMerkleize(roots, uint64(len(roots)), params.BeaconConfig().CurrentEpochAttestationsLength())
if err != nil {
return [32]byte{}, errors.Wrap(err, "could not compute epoch attestations merkleization")
}
attsLenBuf := new(bytes.Buffer)
if err := binary.Write(attsLenBuf, binary.LittleEndian, uint64(len(atts))); err != nil {
return [32]byte{}, errors.Wrap(err, "could not marshal epoch attestations length")
}
// We need to mix in the length of the slice.
attsLenRoot := make([]byte, 32)
copy(attsLenRoot, attsLenBuf.Bytes())
res := ssz.MixInLength(attsRootsRoot, attsLenRoot)
return res, nil
}
func pendingAttestationRoot(att *ethpb.PendingAttestation) ([32]byte, error) {
if att == nil {
return [32]byte{}, errors.New("nil pending attestation")
}
return PendingAttRootWithHasher(att)
}