feat(istio): add configurable TLS version

- Introduced support for configuring the minimum TLS version for UDS Core.
- Added 'supportTLSV1_2' boolean flag in values file to allow selection between TLS 1.2 and TLS 1.3.
- Updated Helm templates to conditionally set 'minProtocolVersion' based on 'supportTLSV1_2' value.
- Ensured backward compatibility by defaulting to TLS 1.3.
- Commented and documented the new configuration option for clarity.

Closes #599

Signed-off-by: jamestexas <[email protected]>

src/istio/chart/templates/gateway.yaml

@@ -32,7 +32,7 @@ spec:
         mode: {{ $server.mode }}
         {{- if ne $server.mode "PASSTHROUGH" }}
         credentialName: gateway-tls
-        minProtocolVersion: TLSV1_3
+        minProtocolVersion: {{ if .Values.tls.supportTLSV1_2 }}TLSV1_2{{ else }}TLSV1_3{{ end }}
         {{- end }}
     {{ end }}
 {{ end }}

src/istio/chart/values.yaml

@@ -24,3 +24,5 @@ domain: "###ZARF_VAR_DOMAIN###"
 #       # Hosts to add to this gateway
 #       hosts:
 #         - "*"
+#   # Whether to support TLS 1.2 (if false, only TLS 1.3 will be supported)
+#   supportTLSV1_2: false