From 0b6e1d0e78f6768e0bd3e459204ba4a076827c42 Mon Sep 17 00:00:00 2001
From: deadprogram <ron@hybridgroup.com>
Date: Sun, 15 Jan 2023 21:28:30 +0100
Subject: [PATCH] lorawan: increment devnonce don't just create a new one each
 join attempt

Signed-off-by: deadprogram <ron@hybridgroup.com>
---
 lora/lorawan/otaa.go | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lora/lorawan/otaa.go b/lora/lorawan/otaa.go
index 0f7c228..ea3ed72 100644
--- a/lora/lorawan/otaa.go
+++ b/lora/lorawan/otaa.go
@@ -31,6 +31,12 @@ func (o *Otaa) generateDevNonce() {
 	o.devNonce[1] = rnd[1]
 }
 
+func (o *Otaa) incrementDevNonce() {
+	nonce := uint16(o.devNonce[1])<<8 | uint16(o.devNonce[0]) + 1
+	o.devNonce[0] = uint8(nonce)
+	o.devNonce[1] = uint8((nonce >> 8))
+}
+
 // Set configures the Otaa AppEUI, DevEUI, AppKey for the device
 func (o *Otaa) Set(appEUI []uint8, devEUI []uint8, appKey []uint8) {
 	o.SetAppEUI(appEUI)
@@ -99,7 +105,7 @@ func (o *Otaa) SetNetID(netID []uint8) error {
 
 // GenerateJoinRequest Generates a LoraWAN Join request
 func (o *Otaa) GenerateJoinRequest() ([]uint8, error) {
-	o.generateDevNonce()
+	o.incrementDevNonce()
 
 	// TODO: Add checks
 	o.buf = o.buf[:0]