Add support for configurable SSL curves in HAProxy configuration

[richardsonnick]

To support new PQC key exchanges add option to set default ssl curves.

Adds a new environment variable ROUTER_CURVES.

This is a colon delimited set of curves to use for ECDHE.
Uses HAProxy's ssl-default-bind-curves to configure openssl's supported groups (https://docs.haproxy.org/3.1/configuration.html#ssl-default-bind-curves).

Tested via local cluster:

haproxy/conf should reflect curves in $ROUTER_POD

With default (no ROUTER_CURVES set)

nr@redd:~/forks/router$ oc exec -n router-test $ROUTER_POD -- grep "ssl-default-bind-curves" /var/lib/haproxy/conf/haproxy.config
  ssl-default-bind-curves X25519:P-256:P-384:P-521

Test with ROUTER_CURVES == X25519MLKEM768

nr@redd: oc set env deployment/custom-router-test -n router-test ROUTER_CURVES='X25519MLKEM768'
nr@redd: ~/forks/router$ oc exec -n router-test $ROUTER_POD -- grep "ssl-default-bind-curves" /var/lib/haproxy/conf/haproxy.config
  ssl-default-bind-curves X25519MLKEM768

Test with ROUTER_CURVES == X25519MLKEM768:P-256

nr@redd:~/forks/router$ oc set env deployment/custom-router-test -n router-test ROUTER_CURVES='X25519MLKEM768:P-256'
nr@redd:~/forks/router$ oc exec -n router-test $ROUTER_POD -- grep "ssl-default-bind-curves" /var/lib/haproxy/conf/haproxy.config
  ssl-default-bind-curves X25519MLKEM768:P-256

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[richardsonnick]

/test all

[richardsonnick]

/test all

[richardsonnick]

/retest-required

[richardsonnick]

/retest-required

[openshift-ci]

@richardsonnick: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
ci/prow/e2e-metal-ipi-ovn-dualstack	f033f21	link	false	/test e2e-metal-ipi-ovn-dualstack
ci/prow/e2e-aws-serial	f033f21	link	true	/test e2e-aws-serial
ci/prow/okd-scos-e2e-aws-ovn	f033f21	link	false	/test okd-scos-e2e-aws-ovn
ci/prow/e2e-metal-ipi-ovn-router	f033f21	link	false	/test e2e-metal-ipi-ovn-router

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