diff --git a/build b/build
index 86ee83a..f70d7bb 100644
--- a/build
+++ b/build
@@ -1 +1 @@
-40
\ No newline at end of file
+42
\ No newline at end of file
diff --git a/src/MicroService.h b/src/MicroService.h
index 835f446..5fed2d1 100644
--- a/src/MicroService.h
+++ b/src/MicroService.h
@@ -131,6 +131,7 @@ namespace OpenWifi {
 		[[nodiscard]] std::string PrivateEndPoint() const { return MyPrivateEndPoint_; };
 		[[nodiscard]] std::string PublicEndPoint() const { return MyPublicEndPoint_; };
 		[[nodiscard]] std::string MakeSystemEventMessage( const std::string & Type ) const ;
+		[[nodiscard]] const Types::SubSystemVec & GetFullSubSystems() { return SubSystems_; }
 		inline uint64_t DaemonBusTimer() const { return DAEMON_BUS_TIMER; };
 
 		void BusMessageReceived( const std::string & Key, const std::string & Message);
diff --git a/src/RESTAPI_handler.cpp b/src/RESTAPI_handler.cpp
index 20fa463..9119b61 100644
--- a/src/RESTAPI_handler.cpp
+++ b/src/RESTAPI_handler.cpp
@@ -235,13 +235,23 @@ namespace OpenWifi {
 	void RESTAPIHandler::BadRequest(const std::string & Reason) {
 		PrepareResponse(Poco::Net::HTTPResponse::HTTP_BAD_REQUEST);
 		Poco::JSON::Object	ErrorObject;
-		ErrorObject.set("ErrorCode",500);
+		ErrorObject.set("ErrorCode",400);
 		ErrorObject.set("ErrorDetails",Request->getMethod());
 		ErrorObject.set("ErrorDescription",Reason.empty() ? "Command is missing parameters or wrong values." : Reason) ;
 		std::ostream &Answer = Response->send();
 		Poco::JSON::Stringifier::stringify(ErrorObject, Answer);
 	}
 
+	void RESTAPIHandler::InternalError(const std::string & Reason) {
+        PrepareResponse(Poco::Net::HTTPResponse::HTTP_INTERNAL_SERVER_ERROR);
+        Poco::JSON::Object	ErrorObject;
+        ErrorObject.set("ErrorCode",500);
+        ErrorObject.set("ErrorDetails",Request->getMethod());
+        ErrorObject.set("ErrorDescription",Reason.empty() ? "Please try later or review the data submitted." : Reason) ;
+        std::ostream &Answer = Response->send();
+        Poco::JSON::Stringifier::stringify(ErrorObject, Answer);
+    }
+
 	void RESTAPIHandler::UnAuthorized(const std::string & Reason) {
 		PrepareResponse(Poco::Net::HTTPResponse::HTTP_FORBIDDEN);
 		Poco::JSON::Object	ErrorObject;
diff --git a/src/RESTAPI_handler.h b/src/RESTAPI_handler.h
index ed27282..0ae4235 100644
--- a/src/RESTAPI_handler.h
+++ b/src/RESTAPI_handler.h
@@ -114,6 +114,7 @@ namespace OpenWifi {
 		bool GetBoolParameter(const std::string &Name, bool Default);
 
 		void BadRequest(const std::string &Reason );
+		void InternalError(const std::string &Reason = "");
 		void UnAuthorized(const std::string &Reason = "");
 		void ReturnObject(Poco::JSON::Object &Object);
 		void NotFound();
diff --git a/src/RESTAPI_system_command.cpp b/src/RESTAPI_system_command.cpp
index afcc268..8155dd4 100644
--- a/src/RESTAPI_system_command.cpp
+++ b/src/RESTAPI_system_command.cpp
@@ -9,6 +9,8 @@
 
 #include "Poco/Exception.h"
 #include "Poco/JSON/Parser.h"
+#include "Poco/DateTime.h"
+#include "Poco/DateTimeFormat.h"
 
 #include "Daemon.h"
 #include "RESTAPI_protocol.h"
@@ -113,6 +115,26 @@ namespace OpenWifi {
 			Answer.set(RESTAPI::Protocol::OS, Poco::Environment::osName());
 			Answer.set(RESTAPI::Protocol::PROCESSORS, Poco::Environment::processorCount());
 			Answer.set(RESTAPI::Protocol::HOSTNAME, Poco::Environment::nodeName());
+
+			Poco::JSON::Array   Certificates;
+			auto SubSystems = Daemon()->GetFullSubSystems();
+			std::set<std::string>   CertNames;
+			for(const auto &i:SubSystems) {
+			    auto Hosts=i->HostSize();
+			    for(uint64_t j=0;j<Hosts;++j) {
+			        auto CertFileName = i->Host(j).CertFile();
+			        auto InsertResult = CertNames.insert(CertFileName);
+			        if( InsertResult.second ) {
+			            Poco::JSON::Object  Inner;
+			            Inner.set("filename", CertFileName);
+			            Poco::Crypto::X509Certificate   C(CertFileName);
+			            auto ExpiresOn = C.expiresOn();
+			            Inner.set("expiresOn",ExpiresOn.timestamp().epochTime());
+			            Certificates.add(Inner);
+			        }
+			    }
+			}
+			Answer.set("certificates", Certificates);
 			ReturnObject(Answer);
 			return;
 		}
diff --git a/src/SubSystemServer.h b/src/SubSystemServer.h
index 3a2c374..ff5e045 100644
--- a/src/SubSystemServer.h
+++ b/src/SubSystemServer.h
@@ -76,7 +76,8 @@ class SubSystemServer : public Poco::Util::Application::Subsystem {
 	inline const std::string & Name() const { return Name_; };
 	const char * name() const override { return Name_.c_str(); }
 
-	const PropertiesFileServerEntry &Host(int index) { return ConfigServersList_[index]; };
+	const PropertiesFileServerEntry & Host(uint64_t index) { return ConfigServersList_[index]; };
+	uint64_t HostSize() const { return ConfigServersList_.size(); }
 	Poco::Logger &Logger() { return Logger_; };
 	void SetLoggingLevel(Poco::Message::Priority NewPriority) { Logger_.setLevel(NewPriority); }
 	int GetLoggingLevel() { return Logger_.getLevel(); }