2 files changed, 48 insertions, 0 deletions
diff --git a/ffi/go/bls/bls.go b/ffi/go/bls/bls.go
index 9b2691c..ff4f951 100644
--- a/ffi/go/bls/bls.go
+++ b/ffi/go/bls/bls.go
@@ -347,3 +347,21 @@ func HashAndMapToSignature(buf []byte) *Sign {
 func VerifyPairing(X *Sign, Y *Sign, pub *PublicKey) bool {
 	return C.blsVerifyPairing(X.getPointer(), Y.getPointer(), pub.getPointer()) == 1
 }
+
+// SignHash --
+func (sec *SecretKey) SignHash(hash []byte) (sign *Sign) {
+	sign = new(Sign)
+	// #nosec
+	err := C.blsSignHash(sign.getPointer(), sec.getPointer(), unsafe.Pointer(&hash[0]), C.size_t(len(hash)))
+	if err == 0 {
+		return sign
+	} else {
+		return nil
+	}
+}
+
+// VerifyHash --
+func (sign *Sign) VerifyHash(pub *PublicKey, hash []byte) bool {
+	// #nosec
+	return C.blsVerifyHash(sign.getPointer(), pub.getPointer(), unsafe.Pointer(&hash[0]), C.size_t(len(hash))) == 1
+}
diff --git a/ffi/go/bls/bls_test.go b/ffi/go/bls/bls_test.go
index 7626156..72f1838 100644
--- a/ffi/go/bls/bls_test.go
+++ b/ffi/go/bls/bls_test.go
@@ -2,6 +2,8 @@ package bls
 
 import "testing"
 import "strconv"
+import "crypto/sha256"
+import "crypto/sha512"
 
 var unitN = 0
 
@@ -392,6 +394,33 @@ func testAggregate2(t *testing.T) {
 	}
 }
 
+func testHash(t *testing.T) {
+	var sec SecretKey
+	sec.SetByCSPRNG()
+	pub := sec.GetPublicKey()
+	m := "abc"
+	var h []byte
+	if GetOpUnitSize() == 4 {
+		d := sha256.Sum256([]byte(m))
+		h = d[:]
+	} else {
+		// use SHA512 if bitSize > 256
+		d := sha512.Sum512([]byte(m))
+		h = d[:]
+	}
+	sig1 := sec.Sign(m)
+	sig2 := sec.SignHash(h)
+	if !sig1.IsEqual(sig2) {
+		t.Errorf("SignHash")
+	}
+	if !sig1.Verify(pub, m) {
+		t.Errorf("sig1.Verify")
+	}
+	if !sig2.VerifyHash(pub, h) {
+		t.Errorf("sig2.VerifyHash")
+	}
+}
+
 func test(t *testing.T, c int) {
 	err := Init(c)
 	if err != nil {
@@ -411,6 +440,7 @@ func test(t *testing.T, c int) {
 	testSerializeToHexStr(t)
 	testPairing(t)
 	testAggregate2(t)
+	testHash(t)
 }
 
 func TestMain(t *testing.T) {