I host a website that uses mTLS for authentication. I created a client cert and installed it in Firefox on Linux, and when I visit the site for the first time, Firefox asks me to choose my cert and then I’m able to visit the site (and every subsequent visit to the site is successful without having to select the cert each time). This is all good.
But when I install that client cert into GrapheneOS (settings -> encryption & credentials -> install a certificate -> vpn & app user certificate), no browser app seems to recognize that it exists at all. Visiting the website from Vanadium, Fennec, or Mull browsers all return “ERR_BAD_SSL_CLIENT_AUTH_CERT” errors.
Does anyone have experience successfully using an mTLS cert in GrapheneOS?
I’m pretty sure you need to install it using “CA certificate” rather than the “VPN and app user certificate” option.
Thanks for the reply, @Evkob@lemmy.ca.
I tried to install my client cert in “CA Certificate” but the certificate manager app in GrapheneOS said that it was the wrong kind of cert to be used in “CA Certificate”. It is, after all, a client cert, not a CA cert.
:(
After some searching, maybe following the instructions on this blog post would work?
I’m by no means an expert though, so take my suggestions with a grain of salt.
Thanks for your research and the suggestion, @Evkob@lemmy.ca.
I wasn’t able to make that work, but I don’t think it was trying to solve the problem I’m having, anyway. That procedure was to add self signed SSL certificate to Android, but my certificate is neither self-signed nor an SSL cert. At least I think not - I find certs very confusing. The cert I’m trying to work with is an mTLS cert, a client cert. It’s not used to establish a secure SSL connections, it’s used to verify that I (the person with the cert) and authorized to use the app.
Additionally, I’m able to successfully install the cert into Android, but the problem is that it seems to be ignored. The mTLS cert is installed in GrapheneOS’s “VPN & App User Certificate” section, and my CA cert is installed in the “CA Certificate” section. Vanadium, Fennec, and Mull browsers just aren’t using them. :(
