add SAS device key generator

Author: ryanwinter

core/src/azure_iot_mqtt/azure_iot_mqtt.h

@@ -19,7 +19,7 @@
 #define AZURE_IOT_MQTT_USERNAME_SIZE           256
 #define AZURE_IOT_MQTT_PASSWORD_SIZE           256
 #define AZURE_IOT_MQTT_TOPIC_NAME_LENGTH       256
-#define AZURE_IOT_MQTT_MESSAGE_LENGTH          512
+#define AZURE_IOT_MQTT_MESSAGE_LENGTH          1024
 #define AZURE_IOT_MQTT_DIRECT_COMMAND_RID_SIZE 6
 
 #define AZURE_IOT_MQTT_CLIENT_STACK_SIZE 4096

tools/generate-device-key.ps1

@@ -12,4 +12,4 @@ $hmacsha.key = [Convert]::FromBase64String($key)
 $deviceKey = $hmacsha.ComputeHash([Text.Encoding]::ASCII.GetBytes($id))
 $deviceKey = [Convert]::ToBase64String($deviceKey)
 
-Write-Output $deviceKey
+Write-Output "Device key = $deviceKey"