core/vm, crypt/bls12381: fixed comments in bls (#21182)

* core/vm: crypto/bls12381: minor code comments

* crypto/bls12381: fix comment

core/vm/contracts.go

@@ -904,7 +904,7 @@ func (c *bls12381MapG1) Run(input []byte) ([]byte, error) {
 		return nil, err
 	}
 
-	// Encode the G1 point to 256 bytes
+	// Encode the G1 point to 128 bytes
 	return g.EncodePoint(r), nil
 }
 

crypto/bls12381/fp2.go

@@ -44,7 +44,7 @@ func newFp2() *fp2 {
 
 func (e *fp2) fromBytes(in []byte) (*fe2, error) {
 	if len(in) != 96 {
-		return nil, errors.New("input string should be larger than 96 bytes")
+		return nil, errors.New("length of input string should be 96 bytes")
 	}
 	c1, err := fromBytes(in[:48])
 	if err != nil {

crypto/bls12381/g2.go

@@ -165,7 +165,7 @@ func (g *G2) ToBytes(p *PointG2) []byte {
 	return out
 }
 
-// EncodePoint encodes a point into 128 bytes.
+// EncodePoint encodes a point into 256 bytes.
 func (g *G2) EncodePoint(p *PointG2) []byte {
 	// outRaw is 96 bytes
 	outRaw := g.ToBytes(p)