Merge pull request #55 from kevaundray/kw/fix-hash-to-bls-field

Write PolyDegree and Number of polynomials to the buffer
holiman · Nov 18, 2022 · 0bb217d · 0bb217d
2 parents c4dbf02 + 6a58261
commit 0bb217d
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/crypto/kzg/kzg.go b/crypto/kzg/kzg.go
@@ -250,9 +250,17 @@ func HashToBLSField(polys Polynomials, comms KZGCommitmentSequence) (*bls.Fr, er
 
 	bytes := make([]byte, 8)
 	binary.LittleEndian.PutUint64(bytes, uint64(params.FieldElementsPerBlob))
+	_, err = sha.Write(bytes)
+	if err != nil {
+		return nil, err
+	}
 
 	bytes = make([]byte, 8)
 	binary.LittleEndian.PutUint64(bytes, uint64(len(polys)))
+	_, err = sha.Write(bytes)
+	if err != nil {
+		return nil, err
+	}
 
 	for _, poly := range polys {
 		for _, fe := range poly {