Set default TLS cipher suites if not configured

cmd/allocator/main.go

@@ -54,6 +54,7 @@ import (
 	"k8s.io/client-go/informers"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
+	cliflag "k8s.io/component-base/cli/flag"
 
 	"agones.dev/agones/pkg/util/httpserver"
 	"agones.dev/agones/pkg/util/runtime"
@@ -370,6 +371,19 @@ func runHTTP(listenCtx context.Context, workerCtx context.Context, h *serviceHan
 		cfg.VerifyPeerCertificate = h.verifyClientCertificate
 	}
 
+	if cfg.CipherSuites == nil {
+		// If no cipher suites are configured, use the default secure ones
+		// recommended by the TLS package, excluding those forbidden by RFC 7540.
+		// by https://datatracker.ietf.org/doc/html/rfc7540#appendix-A
+		preferredCiphers := cliflag.PreferredTLSCipherNames()
+		ciphersuites, err := cliflag.TLSCipherSuites(preferredCiphers)
+		if err != nil {
+			logger.WithError(err).Info("Failed to load TLS cipher suites")
+		} else {
+			cfg.CipherSuites = ciphersuites
+		}
+	}
+
 	// Create a Server instance to listen on the http port with the TLS config.
 	server := &http.Server{
 		Addr:      fmt.Sprintf(":%d", httpPort),

go.mod

@@ -77,6 +77,7 @@ require (
 	github.com/googleapis/gax-go/v2 v2.12.0 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
 	github.com/imdario/mergo v0.3.6 // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/jmespath/go-jmespath v0.4.0 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
@@ -93,6 +94,7 @@ require (
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	github.com/spf13/afero v1.9.2 // indirect
 	github.com/spf13/cast v1.3.0 // indirect
+	github.com/spf13/cobra v1.8.1 // indirect
 	github.com/spf13/jwalterweatherman v1.0.0 // indirect
 	github.com/subosito/gotenv v1.2.0 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
@@ -111,6 +113,7 @@ require (
 	gopkg.in/ini.v1 v1.51.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
+	k8s.io/component-base v0.31.0 // indirect
 	k8s.io/gengo v0.0.0-20230829151522-9cce18d56c01 // indirect
 	k8s.io/klog v1.0.0 // indirect
 	k8s.io/klog/v2 v2.130.1 // indirect

go.sum

@@ -100,6 +100,7 @@ github.com/coreos/etcd v3.3.13+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc
 github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
 github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
 github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f/go.mod h1:E3G3o1h8I7cfcXa63jLwjI0eiQQMgzzUDFVpN/nH/eA=
+github.com/cpuguy83/go-md2man/v2 v2.0.4/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -281,6 +282,8 @@ github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:
 github.com/ianlancetaylor/demangle v0.0.0-20200824232613-28f6c0f3b639/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/imdario/mergo v0.3.6 h1:xTNEAn+kxVO7dTZGu0CegyqKZmoWFI0rF8UxjlB2d28=
 github.com/imdario/mergo v0.3.6/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJh5FfA=
+github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
+github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/jmespath/go-jmespath v0.0.0-20160202185014-0b12d6b521d8/go.mod h1:Nht3zPeWKUH0NzdCt2Blrr5ys8VGpn0CEB0cQHVjt7k=
 github.com/jmespath/go-jmespath v0.4.0 h1:BEgLn5cpjn8UN1mAw4NjwDrS35OdebyEtFe+9YPoQUg=
 github.com/jmespath/go-jmespath v0.4.0/go.mod h1:T8mJZnbsbmF+m6zOOFylbeCJqk5+pHWvzYPziyZiYoo=
@@ -410,6 +413,8 @@ github.com/spf13/afero v1.9.2 h1:j49Hj62F0n+DaZ1dDCvhABaPNSGNkt32oRFxI33IEMw=
 github.com/spf13/afero v1.9.2/go.mod h1:iUV7ddyEEZPO5gA3zD4fJt6iStLlL+Lg4m2cihcDf8Y=
 github.com/spf13/cast v1.3.0 h1:oget//CVOEoFewqQxwr0Ej5yjygnqGkvggSE/gB35Q8=
 github.com/spf13/cast v1.3.0/go.mod h1:Qx5cxh0v+4UWYiBimWS+eyWzqEqokIECu5etghLkUJE=
+github.com/spf13/cobra v1.8.1 h1:e5/vxKd/rZsfSJMUX1agtjeTDf+qv1/JdBF8gg5k9ZM=
+github.com/spf13/cobra v1.8.1/go.mod h1:wHxEcudfqmLYa8iTfL+OuZPbBZkmvliBWKIezN3kD9Y=
 github.com/spf13/jwalterweatherman v1.0.0 h1:XHEdyB+EcvlqZamSM4ZOMGlc93t6AcsBEu9Gc1vn7yk=
 github.com/spf13/jwalterweatherman v1.0.0/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb68N+wFjFa4jdeBTo=
 github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
@@ -868,6 +873,8 @@ k8s.io/apimachinery v0.31.0 h1:m9jOiSr3FoSSL5WO9bjm1n6B9KROYYgNZOb4tyZ1lBc=
 k8s.io/apimachinery v0.31.0/go.mod h1:rsPdaZJfTfLsNJSQzNHQvYoTmxhoOEofxtOsF3rtsMo=
 k8s.io/client-go v0.31.0 h1:QqEJzNjbN2Yv1H79SsS+SWnXkBgVu4Pj3CJQgbx0gI8=
 k8s.io/client-go v0.31.0/go.mod h1:Y9wvC76g4fLjmU0BA+rV+h2cncoadjvjjkkIGoTLcGU=
+k8s.io/component-base v0.31.0 h1:/KIzGM5EvPNQcYgwq5NwoQBaOlVFrghoVGr8lG6vNRs=
+k8s.io/component-base v0.31.0/go.mod h1:TYVuzI1QmN4L5ItVdMSXKvH7/DtvIuas5/mm8YT3rTo=
 k8s.io/gengo v0.0.0-20201203183100-97869a43a9d9/go.mod h1:FiNAH4ZV3gBg2Kwh89tzAEV2be7d5xI0vBa/VySYy3E=
 k8s.io/gengo v0.0.0-20230829151522-9cce18d56c01 h1:pWEwq4Asjm4vjW7vcsmijwBhOr1/shsbSYiWXmNGlks=
 k8s.io/gengo v0.0.0-20230829151522-9cce18d56c01/go.mod h1:FiNAH4ZV3gBg2Kwh89tzAEV2be7d5xI0vBa/VySYy3E=