Client certificates from multiple CAs

[jjjaime]

Is it possible to configure nginx to perform client certificate
validation when the client certificates are generated by different CAs?
I've seen that it's rather easy when the client certificates are
generated by only one (using the directive: ssl_client_certificate), but
I cannot assure that all the certificates will be generated by only one
CA.
Any suggestion?
Thanks,
Jaime

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,217172,217172#msg-217172