Feature #15215: HTTPS server name indication (SNI): explicit server_name in Net::HTTP

• Status: Closed
• Assignee: -
• Target version: -

Current behavior and problem:
At the moment, the host name or IP address given in the URL is used to provide the server name for SNI in HTTPS connections. While this behavior is sufficient in most cases, establishing a connection to a fixed IP using a certain server name is not possible.

Proposed solution:
Decouple the server name used for SNI from the address used for connecting. Add a new ssl_server_name attribute in Net::HTTP that defaults to the address (so the default behavior stays exactly the same).

Notes

• There are scenarios where a client would like to select a specific host when e.g. DNS round robin is configured. Examples: fallback strategies, monitoring of individual hosts.
• This has nothing to do with the HTTP "Host" header, which one needs to set additionally.

For my "proposed solution", a patch is attached (or see https://github.com/ruby/ruby/pull/1977).
Please let me know about any ideas for improvement or other approaches, thanks!

aspettl (Aaron Spettl) wrote:

Proposed solution:
Decouple the server name used for SNI from the address used for connecting. Add a new ssl_server_name attribute in Net::HTTP that defaults to the address (so the default behavior stays exactly the same).

One comment on a corner case:
When ssl_server_name is set, then it is always used for verifying the certificate - even when OpenSSL is old and does not support SNI yet. In such a case, the certificate presented by the server will not match probably (and, thus, verification fails). I think this is desired behavior.

I still like to have this feature. Any opinion on this? Especially @naruse (Yui NARUSE) as a maintainer of lib/net/http(s).rb?

Thanks!

[waf (felix wong)]

aspettl (Aaron Spettl) wrote:

I still like to have this feature. Any opinion on this? Especially @naruse (Yui NARUSE) as a maintainer of lib/net/http(s).rb?

Thanks!

+1 as well

[naruse (Yui NARUSE)]

• Is duplicate of Feature #5180: net/http の接続時に用いる IP アドレスの指定 added

[naruse (Yui NARUSE)]

Duplicated with #5180.
Since there're 3 layers:

• host address for TCP/IP
• TLS server name
• HTTP Host header

In this use case, I think you wan to set different value for IP layer.
If you forget to change HTTP Host header, it will cause unexpected result if the server uses VirtualHost.

I understand this ticket and related GitHub PRs as +1 for #5180, and I reopen it and commit.

[naruse (Yui NARUSE)]

• Status changed from Open to Closed

Applied in changeset git|54072e329cab7207fba133caba4fc12b45add8f9.

---

Add ipaddr optional parameter to Net::HTTP#start

to replace the address for TCP/IP connection [Feature #5180]

There're 3 layers of hostname:

• host address for TCP/IP
• TLS server name
• HTTP Host header value
  To test DNS round robin or check server certificate from server local,
  people sometimes want to connect server with given IP address but keep
  TLS server name and HTTP Host header value.

closes [Feature #15215]
closes https://github.com/ruby/ruby/pull/1893
closes https://github.com/ruby/ruby/pull/1977