Support the new Go FIPS compiler which was upgraded inside Go 1.21.6

The release of Go 1.21.6 includes the new boring crypto when compiling
with FIPS enabled. See https://go.dev/doc/devel/release#go1.21.0 and
https://github.com/golang/go/issues/64717.

This new version of boring crypto allows the use of TLS v1.3 for the
first time, so we changed the Pinniped code to use TLS v1.3 where
appropriate when compiled with the FIPS compiler. It also changed the
allowed TLS v1.2 ciphers, so we updated those as well.

After this commit, the project must be compiled by at least Go v1.21.6
when compiling in fips mode. The hack/Dockerfile_fips was already
updated to use that version of Go in a previous commit.

Co-authored-by: Benjamin A. Petersen <ben@benjaminapetersen.me>

internal/testutil/tlsserver/tls13_ciphers.go

@@ -0,0 +1,31 @@
+// Copyright 2021-2024 the Pinniped contributors. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+//go:build !fips_strict
+
+package tlsserver
+
+import "crypto/tls"
+
+// GetExpectedTLS13Ciphers returns the expected TLS 1.3 cipher for a non-FIPS build.
+func GetExpectedTLS13Ciphers() []uint16 {
+	// TLS 1.3 ciphers are not configurable, so we can hard-code them here.
+	return []uint16{
+		tls.TLS_AES_128_GCM_SHA256,
+		tls.TLS_AES_256_GCM_SHA384,
+		tls.TLS_CHACHA20_POLY1305_SHA256,
+	}
+}
+
+// GetExpectedTLS13CipherNMapKeyExchangeInfoValue returns the expected key exchange info value
+// which is shown by nmap in parenthesis next to the cipher name for a non-FIPS build.
+func GetExpectedTLS13CipherNMapKeyExchangeInfoValue(cipher uint16) string {
+	switch cipher {
+	case tls.TLS_AES_128_GCM_SHA256,
+		tls.TLS_AES_256_GCM_SHA384,
+		tls.TLS_CHACHA20_POLY1305_SHA256:
+		return "ecdh_x25519"
+	default:
+		return "unknown key exchange value"
+	}
+}

internal/testutil/tlsserver/tls13_ciphers_fips.go

@@ -0,0 +1,30 @@
+// Copyright 2021-2024 the Pinniped contributors. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+//go:build fips_strict
+
+package tlsserver
+
+import "crypto/tls"
+
+// GetExpectedTLS13Ciphers returns the expected TLS 1.3 cipher for a FIPS build.
+func GetExpectedTLS13Ciphers() []uint16 {
+	// TLS 1.3 ciphers are not configurable, so we can hard-code them here.
+	return []uint16{
+		tls.TLS_AES_128_GCM_SHA256,
+		tls.TLS_AES_256_GCM_SHA384,
+		// tls.TLS_CHACHA20_POLY1305_SHA256 is not supported by boring crypto
+	}
+}
+
+// GetExpectedTLS13CipherNMapKeyExchangeInfoValue returns the expected key exchange info value
+// which is shown by nmap in parenthesis next to the cipher name for a FIPS build.
+func GetExpectedTLS13CipherNMapKeyExchangeInfoValue(cipher uint16) string {
+	switch cipher {
+	case tls.TLS_AES_128_GCM_SHA256,
+		tls.TLS_AES_256_GCM_SHA384:
+		return "secp256r1"
+	default:
+		return "unknown key exchange value"
+	}
+}

internal/testutil/tlsserver/tlsserver.go

@@ -1,4 +1,4 @@
-// Copyright 2021-2022 the Pinniped contributors. All Rights Reserved.
+// Copyright 2021-2024 the Pinniped contributors. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
 package tlsserver
@@ -18,6 +18,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"k8s.io/apimachinery/pkg/util/httpstream"
+	"k8s.io/apimachinery/pkg/util/sets"
 
 	"go.pinniped.dev/internal/crypto/ptls"
 )
@@ -66,7 +67,7 @@ func RecordTLSHello(server *httptest.Server) {
 	}
 }
 
-func AssertTLS(t *testing.T, r *http.Request, tlsConfigFunc ptls.ConfigFunc) {
+func AssertTLS(t *testing.T, r *http.Request, clientTLSConfigFunc ptls.ConfigFunc) {
 	t.Helper()
 
 	m, ok := getCtxMap(r.Context())
@@ -75,35 +76,55 @@ func AssertTLS(t *testing.T, r *http.Request, tlsConfigFunc ptls.ConfigFunc) {
 	h, ok := m.Load(helloKey)
 	require.True(t, ok)
 
-	info, ok := h.(*tls.ClientHelloInfo)
+	actualClientHello, ok := h.(*tls.ClientHelloInfo)
 	require.True(t, ok)
 
-	tlsConfig := tlsConfigFunc(nil)
+	clientTLSConfig := clientTLSConfigFunc(nil)
 
-	supportedVersions := []uint16{tlsConfig.MinVersion}
-	ciphers := tlsConfig.CipherSuites
+	var wantClientSupportedVersions []uint16
+	var wantClientSupportedCiphers []uint16
 
-	if secureTLSConfig := ptls.Secure(nil); tlsConfig.MinVersion != secureTLSConfig.MinVersion {
-		supportedVersions = append([]uint16{secureTLSConfig.MinVersion}, supportedVersions...)
-		ciphers = append(ciphers, secureTLSConfig.CipherSuites...)
+	switch {
+	// When the provided config only supports TLS 1.3, then set up the expected values for TLS 1.3.
+	case clientTLSConfig.MinVersion == tls.VersionTLS13:
+		wantClientSupportedVersions = []uint16{tls.VersionTLS13}
+		wantClientSupportedCiphers = GetExpectedTLS13Ciphers()
+	// When the provided config supports both TLS 1.2 and 1.3, then set up the expected values for both.
+	case clientTLSConfig.MinVersion == tls.VersionTLS12 && (clientTLSConfig.MaxVersion == 0 || clientTLSConfig.MaxVersion == tls.VersionTLS13):
+		wantClientSupportedVersions = []uint16{tls.VersionTLS13, tls.VersionTLS12}
+		wantClientSupportedCiphers = appendIfNotAlreadyIncluded(clientTLSConfig.CipherSuites, GetExpectedTLS13Ciphers())
+	default:
+		require.Fail(t, "incorrect test setup: clientTLSConfig supports an unexpected combination of TLS versions")
 	}
 
-	protos := tlsConfig.NextProtos
+	wantClientProtos := clientTLSConfig.NextProtos
 	if httpstream.IsUpgradeRequest(r) {
-		protos = tlsConfig.NextProtos[1:]
+		wantClientProtos = clientTLSConfig.NextProtos[1:]
 	}
 
 	// use assert instead of require to not break the http.Handler with a panic
-	ok1 := assert.Equal(t, supportedVersions, info.SupportedVersions)
-	ok2 := assert.Equal(t, cipherSuiteIDsToStrings(ciphers), cipherSuiteIDsToStrings(info.CipherSuites))
-	ok3 := assert.Equal(t, protos, info.SupportedProtos)
+	ok1 := assert.Equal(t, wantClientSupportedVersions, actualClientHello.SupportedVersions)
+	ok2 := assert.Equal(t, cipherSuiteIDsToStrings(wantClientSupportedCiphers), cipherSuiteIDsToStrings(actualClientHello.CipherSuites))
+	ok3 := assert.Equal(t, wantClientProtos, actualClientHello.SupportedProtos)
 
 	if all := ok1 && ok2 && ok3; !all {
-		t.Errorf("insecure TLS detected for %q %q %q upgrade=%v supportedVersions=%v ciphers=%v protos=%v",
+		t.Errorf("insecure TLS detected for %q %q %q upgrade=%v wantClientSupportedVersions=%v wantClientSupportedCiphers=%v wantClientProtos=%v",
 			r.Proto, r.Method, r.URL.String(), httpstream.IsUpgradeRequest(r), ok1, ok2, ok3)
 	}
 }
 
+// appendIfNotAlreadyIncluded only adds the newItems to the list if they are not already included
+// in this list. It returns the potentially updated list.
+func appendIfNotAlreadyIncluded(list []uint16, newItems []uint16) []uint16 {
+	originals := sets.New(list...)
+	for _, newItem := range newItems {
+		if !originals.Has(newItem) {
+			list = append(list, newItem)
+		}
+	}
+	return list
+}
+
 func cipherSuiteIDsToStrings(ids []uint16) []string {
 	cipherSuites := make([]string, 0, len(ids))
 	for _, id := range ids {