feat: Add KeyType API. (#105)

* feat: Add KeyType API.

cshared/main.go

@@ -149,4 +149,29 @@ func SignForPython(configFilePath *C.char, digest *byte, digestLen int, sigHolde
 	return len(signature)
 }
 
+// GetKeyType returns a string representing ECP's key type.
+// The key is derived from the ECP configuration.
+//
+//export GetKeyType
+func GetKeyType(configFilePath *C.char) *C.char {
+	key, err := client.Cred(C.GoString(configFilePath))
+	if err != nil {
+		log.Printf("Could not create client using config %s: %v", C.GoString(configFilePath), err)
+		return C.CString("unknown")
+	}
+	defer func() {
+		if err = key.Close(); err != nil {
+			log.Printf("Failed to clean up key. %v", err)
+		}
+	}()
+	switch key.Public().(type) {
+	case *ecdsa.PublicKey:
+		return C.CString("EC")
+	case *rsa.PublicKey:
+		return C.CString("RSA")
+	default:
+		return C.CString("unknown")
+	}
+}
+
 func main() {}