Mattermost Android app cannot access self hosted self signed server

Troubleshooting
1

Summary
Set up self hosted Mattermost Omnibus Ubuntu server. Using self signed certificate, accessed using https://192… IP address. Imported self signed certificate into Windows and Mattermost app works perfectly. In Android, the app simply says “Cannot connect to the server”, even though the self signed certificate has been imported into the user store.

Steps to reproduce

  1. Install mattermost on Android 12.
  2. Import self signed certificate into user store
  3. Try to connect Mattermost using local IP, https://192…

Expected behavior
Should connect to server and provide login screen like Windows. On Firefox Android, works perfectly.

Observed behavior
App simply says “Cannot connect to the server”. Refuses to connect to server and does not present the login scren.

2

Any updates or anyone have any suggestions?

I have a feeling because the Android app does not trust self signed certifcates from the user store, only certificates from the system/root store. But without feedback from any developer/staff I cannot confirm.

Is it possible for Matter Android to trust self signed certificates like on Windows? This helps a lot with airgapped/local only deployments.

3

Hi @BlackOpsDown! Thanks for sharing your detailed setup and issue. Your suspicion about the Android app only trusting certificates from the system/root store sounds plausible. While I don’t have a turnkey solution available for you off the top of my head, some other community members might have encountered similar issues and could share their insights. Hang tight! :crossed_fingers:t2:

4

Thanks. One workaround is to use the browser on phone and everything works except notifications. Chrome by default trusts the user installed certificates. Firefox doesn’t but you can still use it.

Do you know why calling isn’t available on the web from phone browsers? On mobile Chrome/Firefox I can switch to desktop mode and calling works perfectly.

Is there anyway to make a suggestion to the developers? To trust the user store on the Android app and/or enable calling from mobile browsers?

I have seen a fair bit of users who prefer to deploy mattermost internally in their organization.

5

Hi @BlackOpsDown, great workaround with the browser! For your suggestion: You can make feature requests directly on our UserVoice forum, where our developers actively review feedback from the community. Thanks in advance for your input! It’s invaluable for improving Mattermost!