Desktop App Error - Failed to Fetch, unable to login

Thanks Monty, this was exactly the issue!
I finally got around to fixing this, which also fixed it so that I can now use the apps on Mobile Devices too!

Admittedly my use case is probably quite small, as our local CA is Microsoft (Running on a Windows DC).

For anyone else having this issue, what I did was:

  • Before generating the CSR on the BitWarden server, an amendment to the OpenSSL Config file is required to allow providing of an Subject Alt Name for the cert.

  • Add the following field under the heading ‘[ req_distinguished_name ]’ in the file /etc/ssl/openssl.cnf
    subjectAltName = SubjectAltName (e.g. DNS:mia.theden.home,IP:10.0.0.13)

  • Generate a new CSR from the BitWarden server, using the following command:
    openssl req -new -newkey rsa:2048 -nodes -keyout mia.theden.home.key -out mia.theden.home.csr

  • You will need to make the following change on your MS CA to allow the CA to provide the cert with a SAN (Subject Alternative Name)

  • Logon to the CA, and run the following cmd as admin:
    certutil -setreg policy\EditFlags +EDITF_ATTRIBUTESUBJECTALTNAME2

  • Restart the CertSvc service on the CA for the changes to take affect

  • Logon to the CA webportal: https://CA/certsrv

  • Paste the CSR from the BitWarden server into the request field, and select the ‘Web Server’ template from the drop down

  • Add the following into the ‘Additional Attributes’ section:
    san:dns=mia.theden.home&ipaddress=10.0.0.13

Submit the request, and obtain the certificate in Base 64 encoded format