Re: Vendor Connection via Proxy to SNI Server response 403 Forbidden

[Luca Toscano <toscano.luca@xxxxxxxxx>]

Hi Reid,

 while re-reading the logs I noticed one thing: 

2017-06-07 2:42 GMT+02:00 Reid Watson <reid.watson@xxxxxxxxxxxxxx>:

[Wed Jun 07 11:54:28.887001 2017] [ssl:trace3] [pid 9177:tid 140532624602880] ssl_engine_io.c(1086): [remote 54.230.144.17:443] SNI extension for SSL Proxy request set to 'Internal-site.test.com'
[Wed Jun 07 11:54:28.887011 2017] [ssl:trace3] [pid 9177:tid 140532624602880] ssl_engine_kernel.c(1788): [remote 54.230.144.17:443] OpenSSL: Handshake: start

[..] 

[Wed Jun 07 11:54:29.302044 2017] [proxy_http:trace3] [pid 9177:tid 140532624602880] mod_proxy_http.c(1424): [client 10.0.0.1:19478] Status from backend: 403
[Wed Jun 07 11:54:29.302056 2017] [proxy_http:trace4] [pid 9177:tid 140532624602880] mod_proxy_http.c(1099): [client 10.0.0.1:19478] Headers received from backend:
[Wed Jun 07 11:54:29.302063 2017] [proxy_http:trace4] [pid 9177:tid 140532624602880] mod_proxy_http.c(1101): [client 10.0.0.1:19478] Server: CloudFront
[Wed Jun 07 11:54:29.302068 2017] [proxy_http:trace4] [pid 9177:tid 140532624602880] mod_proxy_http.c(1101): [client 10.0.0.1:19478] Date: Tue, 06 Jun 2017 23:54:29 GMT
[Wed Jun 07 11:54:29.302075 2017] [proxy_http:trace4] [pid 9177:tid 140532624602880] mod_proxy_http.c(1101): [client 10.0.0.1:19478] Content-Type: text/html
[Wed Jun 07 11:54:29.302078 2017] [proxy_http:trace4] [pid 9177:tid 140532624602880] mod_proxy_http.c(1101): [client 10.0.0.1:19478] Content-Length: 555
[Wed Jun 07 11:54:29.302082 2017] [proxy_http:trace4] [pid 9177:tid 140532624602880] mod_proxy_http.c(1101): [client 10.0.0.1:19478] Connection: close
[Wed Jun 07 11:54:29.302085 2017] [proxy_http:trace4] [pid 9177:tid 140532624602880] mod_proxy_http.c(1101): [client 10.0.0.1:19478] X-Cache: Error from cloudfront
[Wed Jun 07 11:54:29.302089 2017] [proxy_http:trace4] [pid 9177:tid 140532624602880] mod_proxy_http.c(1101): [client 10.0.0.1:19478] Via: 1.1 515297ac55a7ae01bf8c7d03df4fecb1.cloudfront.net (CloudFront)
[Wed Jun 07 11:54:29.302092 2017] [proxy_http:trace4] [pid 9177:tid 140532624602880] mod_proxy_http.c(1101): [client 10.0.0.1:19478] X-Amz-Cf-Id: xxxxxxxx
[Wed Jun 07 11:54:29.302103 2017] [proxy_http:trace3] [pid 9177:tid 140532624602880] mod_proxy_http.c(1687): [client 10.0.0.1:19478] start body send

There is a clear indication that the SNI is wrong: 

SNI extension for SSL Proxy request set to 'Internal-site.test.com'

So my understanding is that you perform correctly the TLS handshake to Amazon Cloudfront (used as CDN), but since the SNI is wrong you get a 403 from the backend. Can you try to replace your Rewrite rules with mod_proxy_http and ProxyPass (https://httpd.apache.org/docs/2.4/mod/mod_proxy.html) and see if anything changes (namely if the SNI is set to the one that you expect) ?

Luca