diff --git a/src/lib/synergy/SubscriptionKey.h b/src/lib/synergy/SubscriptionKey.h
new file mode 100644
index 00000000..0d65a17c
--- /dev/null
+++ b/src/lib/synergy/SubscriptionKey.h
@@ -0,0 +1,28 @@
+/*
+ * synergy -- mouse and keyboard sharing utility
+ * Copyright (C) 2015 Synergy Seamless Inc.
+ * 
+ * This package is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * found in the file LICENSE that should have accompanied this file.
+ * 
+ * This package is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "base/String.h"
+
+struct SubscriptionKey {
+	String				m_name;
+	String				m_type;
+	int					m_userLimit;
+	int					m_warnTime;
+	int					m_expireTime;
+};
diff --git a/src/lib/synergy/SubscriptionManager.cpp b/src/lib/synergy/SubscriptionManager.cpp
new file mode 100644
index 00000000..e13cf4c7
--- /dev/null
+++ b/src/lib/synergy/SubscriptionManager.cpp
@@ -0,0 +1,210 @@
+/*
+ * synergy -- mouse and keyboard sharing utility
+ * Copyright (C) 2015 Synergy Seamless Inc.
+ * 
+ * This package is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * found in the file LICENSE that should have accompanied this file.
+ * 
+ * This package is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "synergy/SubscriptionManager.h"
+
+#include "synergy/XSynergy.h"
+#include "arch/Arch.h"
+#include "base/Log.h"
+#include "base/String.h"
+#include "common/Version.h"
+
+#include <fstream>
+#include <iostream>
+#include <algorithm>
+#include <ctime>
+//#include <stdexcept>
+
+#if SYSAPI_WIN32
+const char* kFile = "Synergy.subkey";
+#else
+const char* kFile = ".synergy.subkey";
+#endif
+
+//
+// SubscriptionManager
+//
+
+SubscriptionManager::SubscriptionManager() :
+	m_key()
+{
+}
+
+void
+SubscriptionManager::checkFile(const String& filename_)
+{
+	String filename = filename_;
+	if (filename.empty()) {
+		filename = getFilename();
+	}
+
+	std::ifstream stream(filename.c_str());
+	if (!stream.is_open()) {
+		throw XSubscription(synergy::string::sprintf(
+			"Could not open, path=%s", filename.c_str()));
+	}
+
+	String serial;
+	stream >> serial;
+	
+	String plainText = decode(serial);
+	parsePlainSerial(plainText, m_key);
+	
+	LOG((CLOG_DEBUG "subscription is valid"));
+}
+
+void
+SubscriptionManager::activate(const String& serial)
+{
+	String plainText = decode(serial);
+	parsePlainSerial(plainText, m_key);
+	
+	String filename = getFilename();
+	std::ofstream stream(filename.c_str());
+	if (!stream.is_open()) {
+		throw XSubscription(synergy::string::sprintf(
+			"Could not open, file=%s", filename.c_str()));
+	}
+
+	stream << serial << std::endl;
+	LOG((CLOG_DEBUG "subscription file created, path=%s", filename.c_str()));
+}
+
+String
+SubscriptionManager::decode(const String& input)
+{
+    static const char* const lut = "0123456789ABCDEF";
+    size_t len = input.length();
+    if (len & 1) {
+		throw XSubscription("Invalid serial, wrong length.");
+	}
+
+    String output;
+    output.reserve(len / 2);
+    for (size_t i = 0; i < len; i += 2) {
+
+        char a = input[i];
+        char b = input[i + 1];
+
+        const char* p = std::lower_bound(lut, lut + 16, a);
+        const char* q = std::lower_bound(lut, lut + 16, b);
+
+        if (*q != b || *p != a) {
+			throw XSubscription("Invalid serial, unrecognized digit.");
+		}
+
+        output.push_back(static_cast<char>(((p - lut) << 4) | (q - lut)));
+    }
+
+    return output;
+}
+
+void
+SubscriptionManager::parsePlainSerial(const String& plainText, SubscriptionKey& key)
+{
+	String serial;
+	bool parity = false;
+	String parityStart = plainText.substr(0, 1);
+	String parityEnd = plainText.substr(plainText.length() - 1, 1);
+
+	// check for parity chars { and }, record parity result, then remove them.
+	if (parityStart == "{" && parityEnd == "}") {
+		parity = true;
+		serial = plainText.substr(1, plainText.length() - 2);
+	}
+	else {
+		serial = plainText;
+	}
+
+	// tokenize serialised subscription.
+	std::vector<String> parts;
+	std::string::size_type pos = 0;
+	bool look = true;
+	while (look) {
+		std::string::size_type start = pos;
+		pos = serial.find(";", pos);
+		if (pos == String::npos) {
+			pos = plainText.length();
+			look = false;
+		}
+		parts.push_back(serial.substr(start, pos - start));
+		pos += 1;
+	}
+
+	// e.g.: {v1;trial;Bob;1;1398297600;1398384000}
+	if (parity
+		&& (parts.size() == 6)
+		&& (parts.at(0).find("v1") != String::npos)) {
+		key.m_type = parts.at(1);
+		key.m_name = parts.at(2);
+		sscanf(parts.at(3).c_str(), "%d", &key.m_userLimit);
+		sscanf(parts.at(4).c_str(), "%d", &key.m_warnTime);
+		sscanf(parts.at(5).c_str(), "%d", &key.m_expireTime);
+
+		// TODO: use Arch time
+		if (time(0) > key.m_expireTime) {
+			throw XSubscription(synergy::string::sprintf(
+				"%s subscription has expired",
+				key.m_type.c_str()));
+		}
+		else if (time(0) > key.m_warnTime) {
+			LOG((CLOG_WARN "%s subscription will expire soon",
+				key.m_type.c_str()));
+		}
+
+		const char* userText = (key.m_userLimit == 1) ? "user" : "users";
+		LOG((CLOG_INFO "%s subscription valid is for %d %s, registered to %s",
+			key.m_type.c_str(),
+			key.m_userLimit,
+			userText,
+			key.m_name.c_str()));
+
+		return;
+	}
+	else if ((parts.size() == 2) && (parts.at(1) == kApplication)) {
+		key.m_name = parts.at(0);
+		LOG((CLOG_INFO "subscription is valid, registered to %s",
+			 key.m_name.c_str()));
+		return;
+	}
+	else if ((parts.size() == 2) && (parts.at(0) == kApplication)) {
+		key.m_name = parts.at(1);
+		LOG((CLOG_INFO "subscription is valid, registered to %s",
+			 key.m_name.c_str()));
+		return;
+	}
+
+	throw XSubscription(synergy::string::sprintf("Serial is invalid."));
+}
+
+String
+SubscriptionManager::getFilename()
+{
+	String path = ARCH->getUserDirectory();
+	path = ARCH->concatPath(path, kFile);
+	if (path.empty()) {
+		throw XSubscription("Could not get filename.");
+	}
+
+	return path;
+}
+
+void 
+SubscriptionManager::printFilename()
+{
+	std::cout << getFilename() << std::endl;
+}
diff --git a/src/lib/synergy/SubscriptionManager.h b/src/lib/synergy/SubscriptionManager.h
new file mode 100644
index 00000000..bf86f7c1
--- /dev/null
+++ b/src/lib/synergy/SubscriptionManager.h
@@ -0,0 +1,42 @@
+/*
+ * synergy -- mouse and keyboard sharing utility
+ * Copyright (C) 2015 Synergy Seamless Inc.
+ * 
+ * This package is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * found in the file LICENSE that should have accompanied this file.
+ * 
+ * This package is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "SubscriptionKey.h"
+#include "common/common.h"
+
+class SubscriptionManager {
+public:
+	SubscriptionManager();
+	
+	//! Check the subscription activation file
+	void				checkFile(const String& filename);
+
+	//! Create a subscription activation file based on a serial
+	void				activate(const String& serial);
+
+	//! Use standard output to return subscription filename to gui
+	void				printFilename();
+	
+private:
+	String				decode(const String& input);
+	void				parsePlainSerial(const String& plainText, SubscriptionKey& key);
+	String				getFilename();
+
+	SubscriptionKey		m_key;
+};
diff --git a/src/lib/synergy/XSynergy.h b/src/lib/synergy/XSynergy.h
index a6361d90..78d4d86f 100644
--- a/src/lib/synergy/XSynergy.h
+++ b/src/lib/synergy/XSynergy.h
@@ -23,6 +23,12 @@
 //! Generic synergy exception
 XBASE_SUBCLASS(XSynergy, XBase);
 
+//! Subscription error
+/*!
+Thrown when there is a problem with the subscription.
+*/
+XBASE_SUBCLASS(XSubscription, XSynergy);
+
 //! Client error exception
 /*!
 Thrown when the client fails to follow the protocol.