You can do that I think. Your webserver sends your certificate(s) along with a chain of CA certificates up to a known root certificate. It is acceptable to send

You can do that I think. Your webserver sends your certificate(s) along with a chain of CA certificates up to a known root certificate. It is acceptable to send CA certificates that the browser already knows, that form signing loops, that lead nowhere, etc. It is the browser's job to figure out a signature path from a known root CA through the sent-along CA certificates to the leaf certificate you are using. The only thing I'm not quite sure of is if sending along more than one leaf certificate will work. However, if you want to try it out, create your two leaf certificates from the same RSA private key, and configure your webserver to send along the relevant CA certificates as well as your two leafs in a CertificateChainFile (i believe thats what the config option is called in apache). The ChainFile is just the concatenation of the text-form, PEM-encoded leaf and CA certificates you want.