Move SSL/TLS context options to SecureConnector

[clue]

• TLS endpoints do not have to match connection endpoints (proxy setup)
• More SOLID design, better separation of concerns

This change also makes it easy to introduce additional SSL/TLS context options in the future.
Required for SOCKS proxy (clue/reactphp-socks#28) and eventually HTTP proxy (reactphp/http-client#44).

[WyriHaximus]

How can we make this work well with #17?

[clue]

How can we make this work well with #17?

Afaict this isn't (directly) affected. I've updated #4 to list some concerns (separation of concerns, API design, usability etc.) with the initial approach in #17, so I'm not sure #17 should block this feature.

This change also makes it easy to introduce additional SSL/TLS context options in the future

Personally, I would suggest building SSL/TLS context options on top of this changeset, also for the following reason:

Required for SOCKS proxy (clue/reactphp-socks#28) and eventually HTTP proxy (reactphp/http-client#44).

The underlying TCP/IP connection endpoints (handled via Connector) don't necessarily represent the TLS endpoints:

Client A connects to proxy B which connects to target C

In this scenario, client A needs to establish an underlying TCP/IP connection to proxy B while its TLS endpoint would be target C. See also the linked tickets for some background.

I'll look into filing an alternative to #17 in the next days :)

[clue]

I'll look into filing an alternative to #17 in the next days :)

See linked WIP PR #45.

Is there anything else I can do to help this PR progress faster? :-)

[clue]

Is there anything else I can do to help this PR progress faster? :-)

Ping @WyriHaximus, @cboden

[WyriHaximus]

@clue alright good makes sense LGTM 👍