Accept HTTPS certificate for other domain
Using cheap webspace, I do not have a HTTPS-certificate by myself for my domain, but my webhoster delivers one for their main domain, when using my webmail with HTTPS. Now when I open my webmail URL https://webmail.foothebar.net/ the site then uses the HTTPS certificate for server2.mywebhoster.com – of course Vivaldi warns me, that the certificates domain does not match my domain. How can I tell Vivaldi "yes, I know and it's OK for me, please do not ask again"?
No, you cant have a exception of checking the SSL certificate in Vivaldi.
You have to add the certificate to your local certificates database.
Please read http://superuser.com/questions/104146/add-permanent-ssl-certificate-exception-in-chrome-linux#107465
OK, just noticed that today (after an unrelated restart of the computer) Vivaldi had no problems anymore with the certificate (no idea why)
(FTR: under Debian, the 'certutil' tool (described in the links Gwen-Dragon provided) is located in the package libnss3-tools)