You are logging to copr.fedoraproject.org using your FAS account, right? Do you know you that you can use Kerberos ticket?
In your browser set up network negotiation. E.g., for Firefox open about:config and set
network.negotiate-auth.delegation-uris = .FEDORAPROJECT.ORG
network.negotiate-auth.trusted-uris = .FEDORAPROJECT.ORG
Mind the leading dot.
If there is already some value, you can extend the list and separate it using a comma:
network.negotiate-auth.delegation-uris = .REDHAT.COM,.FEDORAPROJECT.ORG
network.negotiate-auth.trusted-uris = .REDHAT.COM,.FEDORAPROJECT.ORG
Than obtain Kerberos ticket:
kinit msuchy@FEDORAPROJECT.ORG
And you can go to copr.fedoraproject.org. Click on “Log in” in the upper right corner and voilá - you are in. You do not need to provide your credentials.