I have an apache web server, ssl on that has a server certificate signed by a trusted official CA. Can I configure apache ssl to accept clients with valid certificates signed by CAs other than the CA that signed the server certificate ?

I'm getting an ssl_error_unknown_ca_alert even though I have configured other CAs in apache and the server started with no errors. I have created a file containing the CA certificate of the CA that signed the server certificate and the other CAs certificates of the CAs I want to trust. Then I pointed the SSLCertificateChainFile directive to this file.

I'm using Apache 2.2.22


I'm using
SSLCertificateFile pointing to server certificate
SSLCertificateKeyFile poiting to server key
SSLCertificateChainFile pointing to the certificate chain that signed the server certificate
SSLCACertificateFile pointing to a file with all the certificate chains I want to be accepted

SSLVerifyClient require
SSLVerifyDepth  1

Apache recognizes them all in the log when I restart server and there's no errors. Yet, I still got a ssl_error_certificate_unknown_alert error. I also verified that the client certificate chain is present in the SSLCACertificateFile by text comparing in Meld.

2 Answers 2


Found out what's the problem. The certificate is signed by a chain of 3 CAs and I set SSLVerifyDepth to 1. Set it to 10 and it worked.


I believe you want a directory containing the certs you want to use. You may need to use some SSL magic to create the symlinks for the certificates. See mod_ssl SSLCACertificatePath Proper Usage or What is the Best way to Handle Multiple Acceptable Client Certificate CAs for the required commands.

  • Well I tried these commands. See my edit. Dec 17, 2013 at 14:46

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