LetsEncrypt and error message

Question

I have configured my Headwind Server version 5.02 for my device. My device is running android version 8.1

When I try to connect over HTTPS I get the following error:

Failure in SSL library, usually a protocol error
03-16 13:40:34.004  2819  3672 W System.err: error:100000f7:SSL routines:OPENSSL_internal:WRONG_VERSION_NUMBER

What can I do?

Comments

Can you please provide the URL of your instance? Which application is generating the error, Headwind MDM or another one?

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I figured out the problem. When installing the HmDm server the installation prompt asks you on which port you want to run the server. I was entering 8080. The installation prompt then asks you if you want to use http or https. I chose https. It then has you setup an encryption key through let's encrypt. The problem is 8080 is http and https is 8443. When the HmDm app makes contact with the HmDm server it is providing app download URLs with 8080 which is http. So OpenSSL on the device is trying to establish an https connection with an http end point and it is throwing this error.

Even if with the HMDM android app you specify the endpoint with the a port number IE https://hmdm.myendpoint.com:8443 it still uses 8080 which is http. I ended up using the hmdm app from github and compiling it myself and locking in the port number with the build.settings configuration.

Answer 1

You have specified port 8080 which is for plain HTTP, but also specified https:// in the URL scheme. This is not correct. HTTPS works on port 8443.

To fix the issue, restart the Headwind MDM installer, and enter the consistent parameters, one of the following:

1. Port 8080 and http:// scheme

2. Port 8443 and https:// scheme

Note that the Android app receives the URL in the QR code when you follow the enrollment instructions. However if you need to change the default URL, then you need to change it in build.gradle and rebuild.