I Want to update ssl certificates on my iMac G4, macOS Tiger (10.4.11). I already tried to copy from a newer mac the certificate "Actalis Authentication Root CA", trust in in Keychain Access but when with safari i go on the website "alternativalinux.it" i recive the error "Safari cannot enstabilish a safe connection with alternativalinux.com".
According to https://observatory.mozilla.org/analyze/www.alternativalinux.it#tls, the site requires TLS 1.2 and Safari 5. I didn‘t find a technical documentation for Safari 4 but assume that it doesn‘t support TLS 1.2. TLS 1.2 needs code to handle it, a simple certificate update will not help here.
So you can‘t use Safari 4 any longer to connect to modern web pages.