Create time class

include/controller.h

@@ -4,12 +4,13 @@
 #include "servo.h"
 #include "message.h"
 #include "storage.h"
+#include "fresh.h"
 #include <ESPAsyncWebServer.h>
 
 class SesameController: public ServerConnectionCallbacks {
 
 public:
-    SesameController(ServerConnection* server, ServoController* servo, AsyncWebServer* local, uint8_t remoteDeviceCount);
+    SesameController(ServerConnection* server, ServoController* servo, AsyncWebServer* local, TimeCheck* timeCheck, uint8_t remoteDeviceCount);
 
     void configure();
 
@@ -18,6 +19,7 @@ private:
     ServerConnection* server;
     ServoController* servo;
     AsyncWebServer* local;
+    TimeCheck* timeCheck;
     Storage storage;
 
     // The buffer to hold a received message while it is read

include/fresh.h

@@ -3,50 +3,81 @@
 #include <stdint.h>
 #include "config.h"
 
-/**
- * @brief Configure an NTP server to get the current time
- * 
- * @param offsetToGMT The timezone offset in seconds
- * @param offsetDaylightSavings The daylight savings offset in seconds
- * @param serverUrl The url of the NTP server
- */
-void configureNTP(int32_t offsetToGMT, int32_t offsetDaylightSavings, const char* serverUrl);
+class TimeCheck {
 
-/**
- * @brief Print the current time to the serial output
- * 
- * The time must be initialized by calling `configureNTP()` before use.
- */
-void printLocalTime();
+public:
 
-/** 
- * Gets the current epoch time
- */
-uint32_t getEpochTime();
+    /**
+     * @brief Create a time checker instance
+     * 
+     * Specify the allowed discrepancy between the time of a received message
+     * and the device time (in seconds).
+     * 
+     * A stricter (lower) value better prevents against replay attacks,
+     * but may lead to issues when dealing with slow networks and other
+     * routing delays.
+     * 
+     * @param offset The allowed time discrepancy in both directions (seconds)
+     */
+    TimeCheck(uint32_t allowedTimeOffset = 60);
 
-/**
- * @brief The allowed time discrepancy (in seconds)
- * 
- * Specifies the allowed discrepancy between the time of a received message
- * and the device time (in seconds).
- * 
- * A stricter (lower) value better prevents against replay attacks,
- * but may lead to issues when dealing with slow networks and other
- * routing delays.
- * 
- * @param offset The offset in both directions (seconds)
- */
-void setMessageTimeAllowedOffset(uint32_t offset);
+    /**
+     * @brief Configure an NTP server to get the current time
+     * 
+     * @param offsetToGMT The timezone offset in seconds
+     * @param offsetDaylightSavings The daylight savings offset in seconds
+     * @param serverUrl The url of the NTP server
+     */
+    void configureNTP(int32_t offsetToGMT, int32_t offsetDaylightSavings, const char* serverUrl);
 
-/**
- * @brief Check wether the time of a message is within the allowed bounds regarding freshness.
- * 
- * The timestamp is used to ensure 'freshness' of the messages,
- * i.e. that they are not unreasonably delayed or captured and
- * later replayed by an attacker.
- * 
- * @param messageTime The timestamp of the message (seconds since epoch) 
- * @return true The time is within the acceptable offset of the local time
- * @return false The message time is invalid
- */
-bool isMessageTimeAcceptable(uint32_t messageTime);
+    /**
+     * @brief Print the current time to the serial output
+     * 
+     * The time must be initialized by calling `configureNTP()` before use.
+     */
+    void printLocalTime();
+
+    /** 
+     * Gets the current epoch time
+     */
+    uint32_t getEpochTime();
+
+    /**
+     * @brief The allowed time discrepancy (in seconds)
+     * 
+     * Specifies the allowed discrepancy between the time of a received message
+     * and the device time (in seconds).
+     * 
+     * A stricter (lower) value better prevents against replay attacks,
+     * but may lead to issues when dealing with slow networks and other
+     * routing delays.
+     * 
+     * @param offset The offset in both directions (seconds)
+     */
+    void setMessageTimeAllowedOffset(uint32_t offset);
+
+    /**
+     * @brief Check wether the time of a message is within the allowed bounds regarding freshness.
+     * 
+     * The timestamp is used to ensure 'freshness' of the messages,
+     * i.e. that they are not unreasonably delayed or captured and
+     * later replayed by an attacker.
+     * 
+     * @param messageTime The timestamp of the message (seconds since epoch) 
+     * @return true The time is within the acceptable offset of the local time
+     * @return false The message time is invalid
+     */
+    bool isMessageTimeAcceptable(uint32_t messageTime);
+
+private:
+    
+    /**
+     * @brief The allowed discrepancy between the time of a received message
+     * and the device time (in seconds)
+     * 
+     * A stricter (lower) value better prevents against replay attacks,
+     * but may lead to issues when dealing with slow networks and other
+     * routing delays.
+     */
+    uint32_t allowedOffset;
+};