Certify key.

In-place editing with a popup if user is allowed in app config file.
User must of course manage at least a private key. User identities of
target key may be selectively chosen. Optionally, certification may be
exportable and non-revocable.

Tools.cpp

@@ -0,0 +1,35 @@
+/* 
+ * File:   Tools.cpp
+ * Author: SET - nmset@yandex.com
+ * License : GPL v2
+ * Copyright SET - © 2019
+ * 
+ * Created on November 1, 2020, 8:31 PM
+ */
+
+#include "Tools.h"
+#include <sstream>
+#include <iostream>
+
+using namespace std;
+
+Tools::Tools() {
+}
+
+Tools::~Tools() {
+}
+
+bool Tools::ConfigKeyIdMatchesKey(const GpgME::Key& k, const WString& configKeyId)
+{
+    // We want key identifier in config file to be real and complete.
+    return (configKeyId == WString(k.shortKeyID())
+            || configKeyId == WString(k.keyID())
+            || configKeyId == WString(k.primaryFingerprint()));
+}
+
+int Tools::ToInt(const string& s) {
+    istringstream buffer(s.c_str());
+    int num;
+    buffer >> num;
+    return num;
+}