Major plugin refactor and cleanup.

Switched to POCO library for unified platform/library interface.
Deprecated the external module API. It was creating more problems than solving.
Removed most built-in libraries in favor of system libraries for easier maintenance.
Cleaned and secured code with help from static analyzers.

vendor/POCO/JWT/src/Serializer.cpp

@@ -0,0 +1,81 @@
+//
+// Serializer.cpp
+//
+// Library: JWT
+// Package: JWT
+// Module:  Serializer
+//
+// Copyright (c) 2019, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#include "Poco/JWT/Serializer.h"
+#include "Poco/JWT/JWTException.h"
+#include "Poco/JSON/Parser.h"
+#include "Poco/Base64Encoder.h"
+#include "Poco/Base64Decoder.h"
+#include "Poco/MemoryStream.h"
+#include "Poco/StringTokenizer.h"
+#include <sstream>
+
+
+namespace Poco {
+namespace JWT {
+
+
+std::string Serializer::serialize(const Poco::JSON::Object& object)
+{
+	std::ostringstream stream;
+	serialize(object, stream);
+	return stream.str();
+}
+
+
+void Serializer::serialize(const Poco::JSON::Object& object, std::ostream& stream)
+{
+	Poco::Base64Encoder encoder(stream, Poco::BASE64_URL_ENCODING | Poco::BASE64_NO_PADDING);
+	object.stringify(encoder);
+	encoder.close();
+}
+
+
+Poco::JSON::Object::Ptr Serializer::deserialize(const std::string& serialized)
+{
+	Poco::MemoryInputStream stream(serialized.data(), serialized.size());
+	return deserialize(stream);
+}
+
+
+Poco::JSON::Object::Ptr Serializer::deserialize(std::istream& stream)
+{
+	Poco::Base64Decoder decoder(stream, Poco::BASE64_URL_ENCODING | Poco::BASE64_NO_PADDING);
+	Poco::JSON::Parser parser;
+	try
+	{
+		Poco::Dynamic::Var json = parser.parse(decoder);
+		Poco::JSON::Object::Ptr pObject = json.extract<Poco::JSON::Object::Ptr>();
+		return pObject;
+	}
+	catch (Poco::BadCastException&)
+	{
+		throw ParseException("String does not deserialize to a JSON object");
+	}
+	catch (Poco::Exception& exc)
+	{
+		throw ParseException("Failed to deserialize JWT component", exc.displayText());
+	}
+}
+
+
+std::vector<std::string> Serializer::split(const std::string& token)
+{
+	Poco::StringTokenizer tokenizer(token, ".");
+	std::vector<std::string> result(tokenizer.begin(), tokenizer.end());
+	return result;
+}
+
+
+} } // namespace Poco::JWT