NRF9160 AWS FOTA over HTTPS

[odwraca]

I have been reviewing this merge: https://github.com/NordicPlayground/fw-nrfconnect-nrf/pull/1982 and it appears that there is capability in the fota example to enable https/tls download for the aws fota example. It appears that DOWNLOAD_CLIENT_TLS needs to be set in the config, but when I set it in the KConfig it failed to build. I am using CLI, not Segger. 

My guess is that I am setting this in the wrong place but my attempt at backtracking this is failing a bit. Was hoping that someone could chime in with where I need to enable the TLS. 

• I am planning on using S3 as the bin source, so the sample cert that was setup should suffice (from what I can tell).
• I have successfully used the AWS FOTA example over http, but https is required for the project. 

Apologies for the noob questions, just trying to sort this out. 

[odwraca]

After pulling in some changes from https://github.com/NordicPlayground/fw-nrfconnect-nrf/pull/1986/files I was able to build the sample app successfully, but have received the following error. 

Still working through to see what happened, but my guess is that the TLS credentials were not setup correctly. 

I: Start downloading firmware from <Bucket Name>.s3.amazonaws.com/app_update.bin
I: Attempting to connect over IPv4
I: Setting up TLS credentials
E: Unable to connect, errno 95
E: Error (-22) when trying to start firmware download
aws_fota_mqtt_evt_handler: Failed! -22[mqtt_evt_handler:239]
MQTT PUBLISH result=0 len=41mqtt_read_publish_payload: Failed! -5
Disconnecting MQTT client...