sm2,smx509: add encoding paths for SM2 ecdh keys

sm2/sm2_test.go

@@ -424,6 +424,20 @@ func TestCipherASN1WithInvalidBytes(t *testing.T) {
 	}
 }
 
+func TestPublicKeyToECDH(t *testing.T) {
+	priv, _ := GenerateKey(rand.Reader)
+	_, err := PublicKeyToECDH(&priv.PublicKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	p256, _ := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	_, err = PublicKeyToECDH(&p256.PublicKey)
+	if err == nil {
+		t.Fatal("should be error")
+	}
+}
+
 func BenchmarkGenerateKey_SM2(b *testing.B) {
 	b.ReportAllocs()
 	b.ResetTimer()

smx509/x509_additional_test.go

@@ -12,6 +12,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/emmansun/gmsm/ecdh"
 	"github.com/emmansun/gmsm/sm2"
 )
 
@@ -186,3 +187,29 @@ func parseAndCheckCsr(csrPem []byte) error {
 	}
 	return csr.CheckSignature()
 }
+
+func TestMarshalECDHPKIXPublicKey(t *testing.T) {
+	privKey, err := ecdh.P256().GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	result1, err := MarshalPKIXPublicKey(privKey.Public())
+	if err != nil {
+		t.Fatal(err)
+	}
+	pubKey, err := ParsePKIXPublicKey(result1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	sm2PubKey, ok := pubKey.(*ecdsa.PublicKey)
+	if !ok {
+		t.Fatal("should be valid sm2 public key")
+	}
+	sm2ecdhPub, err := sm2.PublicKeyToECDH(sm2PubKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !privKey.PublicKey().Equal(sm2ecdhPub) {
+		t.Fatal("should be same")
+	}
+}