Difference Between SSLCACertificateFile and SSLCertificateChainFile
I provide SSL pages on my web server, and I have a question. What is the difference between SSLCACertificateFile and SSLCertificateChainFile?
When I use SSLCertificateChainFile, I got warnings from Japanese cellular phone browser, but when I use PC browser(like IE, FF), there was no problem. On the other hand, SSLCACertificateFile didn't cause any problem for both browsers.
Is there any difference when browsers connect to apache?
Answer
SSLCertificateChainFile was a correct option to choose but this directive became obsolete as of Apache 2.4.8. This directive caused the listed file to be sent along with the certificate to any clients that connect.
SSLCACertificateFile (hereafter "CACert") supersedes SSLCertificateChainFile (hereafter "Chain"), and additionally permits the use of the cert in question to sign client certificates. This sort of authentication is quite rare (at least for the moment), and if you aren't using it, there's IMHO no reason to augment its functionality by using CACert instead of Chain. On the flipside, one could argue that there's no harm in the additional functionality, and CACert covers all cases. Both arguments are valid.
Needless to say, if you ask the cert vendor, they'll always push for CACert over Chain, since it gives them another thing (client certs) that they can potentially sell you down the line. ;)