Certificate on HTTPS upstream is not verified

[runesoerensen]

I need to send data to some backend servers using HTTPS, but it seems like
nginx doesn't verify the certificate on the backend server. For instance, if
I specify `proxy_pass https://example.com` and the certificate on
example.com is invalid, nginx still completes the request without any
warning.

I'd prefer it if nginx checked whether the certificate could be verified
during the SSL handshake, and abort the request if the certificate isn't
valid.

Is it possible to somehow enable certificate verification of the proxied
server's certificate? And if it's not possible to verify the certificate,
what's the point in using (or being able to use) an HTTPS backend then?

The reason I need SSL encryption is that traffic from my nginx server will
be passed via public networks to the backend servers.

Thanks,
Rune

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,235567,235567#msg-235567