From 65def379fc4375a04e80569300705b040e953bef Mon Sep 17 00:00:00 2001
From: Pawel Jalocha <Pawel.Jalocha@gmail.com>
Date: Tue, 20 Oct 2020 00:35:45 +0100
Subject: [PATCH] Reset the LoRaWAN state when new AppKey supplied

---
 main/main.cpp     | 14 ++++++++------
 main/parameters.h | 15 ++++++++++++++-
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/main/main.cpp b/main/main.cpp
index 16de427..e5b440a 100644
--- a/main/main.cpp
+++ b/main/main.cpp
@@ -63,12 +63,14 @@ void app_main(void)
     }
 #endif
 #ifdef WITH_LORAWAN
-    WANdev.Reset(getUniqueID(), Parameters.AppKey);    // set default LoRaWAN config.
-    if(WANdev.ReadFromNVS()!=ESP_OK)                   // if can't read the LoRaWAN setup from NVS
-    { WANdev.WriteToNVS(); }                           // then store the default
-    if( /* WANdev.State<2 && */ memcmp(WANdev.AppKey, Parameters.AppKey, 16))   // if LoRaWAN key different from the one in Parameters
-    { WANdev.Reset(getUniqueID(), Parameters.AppKey);  // then reset LoRaWAN to this key
-      WANdev.WriteToNVS(); }                           // and save LoRaWAN config. to NVS
+    WANdev.Reset(getUniqueID(), Parameters.AppKey);     // set default LoRaWAN config.
+    if(WANdev.ReadFromNVS()!=ESP_OK)                    // if can't read the LoRaWAN setup from NVS
+    { WANdev.WriteToNVS(); }                            // then store the default
+    if(Parameters.hasAppKey())
+    { if(!Parameters.sameAppKey(WANdev.AppKey))         // if LoRaWAN key different from the one in Parameters
+      { WANdev.Reset(getUniqueID(), Parameters.AppKey); // then reset LoRaWAN to this key
+        WANdev.WriteToNVS(); }                          // and save LoRaWAN config. to NVS
+      Parameters.clrAppKey(); }
 #endif
 
     CONS_UART_SetBaudrate(Parameters.CONbaud);
diff --git a/main/parameters.h b/main/parameters.h
index 6bef14e..275e7c4 100644
--- a/main/parameters.h
+++ b/main/parameters.h
@@ -156,6 +156,19 @@ class FlashParameters
 
    static const uint32_t CheckInit = 0x89ABCDEF;
 
+#ifdef WITH_LORAWAN
+   bool hasAppKey(void) const
+   { uint8_t Sum=AppKey[0];
+     for(int Idx=1; Idx<16; Idx++)
+     { if(Sum!=0) break;
+       Sum|=AppKey[Idx]; }
+     return Sum!=0; }
+
+   void clrAppKey(void) { for(int Idx=0; Idx<16; Idx++) AppKey[Idx]=0; }
+   void cpyAppKey(uint8_t *Key) { memcpy(Key, AppKey, 16); }
+   bool sameAppKey(const uint8_t *RefKey) const { return memcmp(AppKey, RefKey, 16)==0; }
+#endif
+
    uint32_t static calcCheckSum(volatile uint32_t *Word, uint32_t Words)                      // calculate check-sum of pointed data
    { uint32_t Check=CheckInit;
      for(uint32_t Idx=0; Idx<Words; Idx++)
@@ -209,7 +222,7 @@ class FlashParameters
     FreqPlan       =    DEFAULT_FreqPlan; // [0..5]
     PPSdelay       =    DEFAULT_PPSdelay; // [ms]
 #ifdef WITH_LORAWAN
-    for(uint8_t Idx=0; Idx<16; Idx++) AppKey[Idx]=0;
+    clrAppKey();
 #endif
 #ifdef WITH_ENCRYPT
     for(uint8_t Idx=0; Idx<4; Idx++) EncryptKey[Idx]=0;