feat(translator): client tls session resumption

[guydc]

What type of PR is this?

What this PR does / why we need it:

Introduces an API for TLS session management:

• Disable TLS resumption by default. Allow users to opt-in.
• Adds E2E Tests and Docs for ClientTrafficPolicy TLS settings

Which issue(s) this PR fixes:
Fixes #4268, #2422, #2421

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 65.79%. Comparing base (e0455ac) to head (bffd67f).
Report is 7 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4293      +/-   ##
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- Coverage   65.81%   65.79%   -0.02%     
==========================================
  Files         200      200              
  Lines       24177    24190      +13     
==========================================
+ Hits        15911    15917       +6     
- Misses       7129     7134       +5     
- Partials     1137     1139       +2     

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[guydc]

Following yesterday's community meeting, some additional industry context.

Currently, Mozilla's SSL config generator recommends disabling stateless resumption (session tickets) for nginx, apache and haproxy for security reasons.

• https://ssl-config.mozilla.org/#server=apache&version=2.4.41&config=modern&openssl=1.1.1k&guideline=5.7
• https://ssl-config.mozilla.org/#server=haproxy&version=2.1&config=modern&openssl=1.1.1k&guideline=5.7
• https://ssl-config.mozilla.org/#server=nginx&version=1.17.7&config=modern&openssl=1.1.1k&guideline=5.7

This is mostly due to insufficient rotation of session ticket encryption keys in these projects. There is an ongoing discussion on changing the recommendation for newer versions of nginx where keys are rotated: mozilla/server-side-tls#135.

BoringSSL rotates encryption keys by default every 48 hours: https://commondatastorage.googleapis.com/chromium-boringssl-docs/ssl.h.html#Session-tickets. Envoy doesn't change this behavior or make the rotation schedule configurable. Industry leaders like cloudflare rotate session ticket encryption keys every hour: https://blog.cloudflare.com/keyless-ssl-the-nitty-gritty-technical-details/.

There is no security recommendation to disable stateful session resumption. However:

• Stateful resumption is no longer supported in TLSv1.3: https://www.wolfssl.com/tls-1-3-performance-resumption/
• Envoy has a well-known issue that can only be mitigated by disabling stateful session resumption: https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/route/v3/route_components.proto#config-route-v3-routematch-tlscontextmatchoptions
• There is no way to synchronize session caches across proxy instances. The effort to support synchronization is significant: RFC: Enable TLS external session cache envoy#14553

nginx ingress by default disables stateful and stateless session resumption, but makes it possible to opt-in:

• https://github.com/kubernetes/ingress-nginx/blob/a9c9a9d51e48f50edd5e8e3084a5c485366ba6c4/rootfs/etc/nginx/template/nginx.tmpl#L426
• https://github.com/kubernetes/ingress-nginx/blob/a9c9a9d51e48f50edd5e8e3084a5c485366ba6c4/rootfs/etc/nginx/template/nginx.tmpl#L432

I propose that we change the current behavior and disable both resumption methods by default, but allow users to opt-in similar to nginx ingress.

[zirain]

need to record how this is generated for future maintenance.

[arkodg]

prefer SessionResumption

[zirain]

can we use following structure?

session:
  timeout:
  resumption:

if there're more than 1 property with session prefix, prefer to move them into a struct.

[zhaohuabing]

Should the timeout be part of the sessionResumption setting?

• https://www.envoyproxy.io/docs/envoy/latest/api-v3/extensions/transport_sockets/tls/v3/tls.proto#envoy-v3-api-msg-extensions-transport-sockets-tls-v3-downstreamtlscontext
• https://datatracker.ietf.org/doc/html/rfc5077#section-5.6

[guydc]

Well, it seems that different implementations have different meanings for session timeout.

BoringSSL seems to treat this as a hard timeout after which a new handshake is required:

This is how long we are willing to use the secret to encrypt traffic without fresh key material.

In envoy, this is also used as a hint on session tickets.

OpenSSL seems to treat this as a soft timeout after which resumption cannot occur, but an active session may still continue (?):

Whenever a new session is negotiated, it is assigned a timeout value, after which it will not be accepted for session reuse.

@arkodg requested that we leave sessionTimeout out of this PR. I will change the API to @zirain's proposal, to support for future addition of session-related settings that are not specific to resumption.

[arkodg]

Suggested change

	// Session defines setting related to TLS session management.
	// Session defines settings related to TLS session management.

[arkodg]

Suggested change

	// Resumption determine the proxy's supported TLS session resumption option.
	// Resumption determines the proxy's supported TLS session resumption option.

[arkodg]

sessionTimeout clean up needed here

[zirain]

require user-faced doc.

[zhaohuabing]

LGTM, Thanks.