update

pkg/client/client.go

@@ -153,7 +153,7 @@ func (p *sClient) DecryptMessage(pMsg []byte) (asymmetric.IDSAPubKey, []byte, er
 
 	// Load public key and check standart size.
 	signerPubKey := asymmetric.LoadDSAPubKey(pkey)
-	if signerPubKey == nil { // || pubKey.GetSize() != p.GetPubKey().GetSize()
+	if signerPubKey == nil {
 		return nil, nil, ErrDecodePublicKey
 	}
 

pkg/client/client_test.go

@@ -70,3 +70,46 @@ func TestClient(t *testing.T) {
 	// fmt.Println(client.GetPayloadLimit(), client.GetMessageSize())
 	// fmt.Println(len(client.GetPrivKey().GetPubKey().ToString()))
 }
+
+func TestDecrypt(t *testing.T) {
+	t.Parallel()
+
+	client := NewClient(
+		asymmetric.NewPrivKey(),
+		(8 << 10),
+	)
+
+	if _, _, err := client.DecryptMessage([]byte{123}); err == nil {
+		t.Error("success decrypt with invalid ciphertext (1)")
+		return
+	}
+
+	kemPubKey := client.GetPrivKey().GetKEMPrivKey().GetPubKey()
+	msg := []byte("hello, world!")
+
+	enc, err := client.EncryptMessage(kemPubKey, msg)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	enc[0] ^= 1
+	if _, _, err := client.DecryptMessage(enc); err == nil {
+		t.Error("success decrypt with invalid ciphertext (2)")
+		return
+	}
+
+	enc[0] ^= 1
+	enc[len(enc)-1] ^= 1
+	if _, _, err := client.DecryptMessage(enc); err == nil {
+		t.Error("success decrypt with invalid ciphertext (3)")
+		return
+	}
+
+	enc[len(enc)-1] ^= 1
+	enc[len(enc)-2000] ^= 1
+	if _, _, err := client.DecryptMessage(enc); err == nil {
+		t.Error("success decrypt with invalid ciphertext (4)")
+		return
+	}
+}