introduce build tags to optionally override some TLS settings

Dockerfile

@@ -21,6 +21,9 @@ ENV KUBE_GIT_VERSION=$KUBE_GIT_VERSION
 ARG TARGETOS
 ARG TARGETARCH
 
+# If provided, must be a comma-separated list of Go build tags.
+ARG ADDITIONAL_BUILD_TAGS
+
 # Build the statically linked (CGO_ENABLED=0) binary.
 # Mount source, build cache, and module cache for performance reasons.
 # See https://www.docker.com/blog/faster-multi-platform-builds-dockerfile-cross-compilation-guide/
@@ -29,8 +32,8 @@ RUN \
   --mount=type=cache,target=/cache/gocache \
   --mount=type=cache,target=/cache/gomodcache \
   export GOCACHE=/cache/gocache GOMODCACHE=/cache/gomodcache CGO_ENABLED=0 GOOS=$TARGETOS GOARCH=$TARGETARCH && \
-  go build -v -trimpath -ldflags "$(hack/get-ldflags.sh) -w -s" -o /usr/local/bin/pinniped-concierge-kube-cert-agent ./cmd/pinniped-concierge-kube-cert-agent/... && \
+  go build -tags $ADDITIONAL_BUILD_TAGS -v -trimpath -ldflags "$(hack/get-ldflags.sh) -w -s" -o /usr/local/bin/pinniped-concierge-kube-cert-agent ./cmd/pinniped-concierge-kube-cert-agent/... && \
-  go build -v -trimpath -ldflags "$(hack/get-ldflags.sh) -w -s" -o /usr/local/bin/pinniped-server ./cmd/pinniped-server/... && \
+  go build -tags $ADDITIONAL_BUILD_TAGS -v -trimpath -ldflags "$(hack/get-ldflags.sh) -w -s" -o /usr/local/bin/pinniped-server ./cmd/pinniped-server/... && \
   ln -s /usr/local/bin/pinniped-server /usr/local/bin/pinniped-concierge && \
   ln -s /usr/local/bin/pinniped-server /usr/local/bin/pinniped-supervisor && \
   ln -s /usr/local/bin/pinniped-server /usr/local/bin/local-user-authenticator

hack/Dockerfile_fips

@@ -35,6 +35,9 @@ ENV KUBE_GIT_VERSION=$KUBE_GIT_VERSION
 ARG TARGETOS
 ARG TARGETARCH
 
+# If provided, must be a comma-separated list of Go build tags.
+ARG ADDITIONAL_BUILD_TAGS
+
 # Build the executable binary (CGO_ENABLED=1 is required for go boring).
 # Even though we need cgo to call the boring crypto C functions, these
 # functions are statically linked into the binary.  We also want to statically
@@ -59,8 +62,8 @@ RUN \
   --mount=type=cache,target=/cache/gocache \
   --mount=type=cache,target=/cache/gomodcache \
   export GOCACHE=/cache/gocache GOMODCACHE=/cache/gomodcache CGO_ENABLED=1 GOOS=$TARGETOS GOARCH=$TARGETARCH GOEXPERIMENT=boringcrypto && \
-  go build -tags fips_strict,osusergo,netgo -v -trimpath -ldflags "$(hack/get-ldflags.sh) -w -linkmode=external -extldflags -static" -o /usr/local/bin/pinniped-concierge-kube-cert-agent ./cmd/pinniped-concierge-kube-cert-agent/... && \
+  go build -tags fips_strict,osusergo,netgo,$ADDITIONAL_BUILD_TAGS -v -trimpath -ldflags "$(hack/get-ldflags.sh) -w -linkmode=external -extldflags -static" -o /usr/local/bin/pinniped-concierge-kube-cert-agent ./cmd/pinniped-concierge-kube-cert-agent/... && \
-  go build -tags fips_strict,osusergo,netgo -v -trimpath -ldflags "$(hack/get-ldflags.sh) -w -linkmode=external -extldflags -static" -o /usr/local/bin/pinniped-server ./cmd/pinniped-server/... && \
+  go build -tags fips_strict,osusergo,netgo,$ADDITIONAL_BUILD_TAGS -v -trimpath -ldflags "$(hack/get-ldflags.sh) -w -linkmode=external -extldflags -static" -o /usr/local/bin/pinniped-server ./cmd/pinniped-server/... && \
   ln -s /usr/local/bin/pinniped-server /usr/local/bin/pinniped-concierge && \
   ln -s /usr/local/bin/pinniped-server /usr/local/bin/pinniped-supervisor && \
   ln -s /usr/local/bin/pinniped-server /usr/local/bin/local-user-authenticator

internal/crypto/ptls/default_profile_max_tls_version_for_fips_13.go

@@ -0,0 +1,10 @@
+// Copyright 2024 the Pinniped contributors. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+//go:build fips_enable_tls13_max_for_default_profile
+
+package ptls
+
+import "crypto/tls"
+
+const DefaultProfileMaxTLSVersionForFIPS = tls.VersionTLS13

internal/crypto/ptls/default_profile_max_tls_version_for_fips_default_value.go

@@ -0,0 +1,10 @@
+// Copyright 2024 the Pinniped contributors. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+//go:build !fips_enable_tls13_max_for_default_profile
+
+package ptls
+
+import "crypto/tls"
+
+const DefaultProfileMaxTLSVersionForFIPS = tls.VersionTLS12

internal/crypto/ptls/profiles.go

@@ -86,12 +86,10 @@ func init() { //nolint:gochecknoinits
 	// this init runs before we have parsed our config to determine our log level
 	// thus we must use a log statement that will always print instead of conditionally print
 	plog.Always("this server was not compiled in FIPS-only mode",
-		"go version", runtime.Version())
+		"go version", runtime.Version(),
+		"SecureProfileMinTLSVersionForNonFIPS", tls.VersionName(SecureProfileMinTLSVersionForNonFIPS))
 }
 
-// SecureTLSConfigMinTLSVersion is the minimum tls version in the format expected by tls.Config.
-const SecureTLSConfigMinTLSVersion = tls.VersionTLS13
-
 // Default TLS profile should be used by:
 // A. servers whose clients are outside our control and who may reasonably wish to use TLS 1.2, and
 // B. clients who need to interact with servers that might not support TLS 1.3.
@@ -127,8 +125,12 @@ func Secure(rootCAs *x509.CertPool) *tls.Config {
 	// - Safari 12.1
 	// https://ssl-config.mozilla.org/#server=go&version=1.17.2&config=modern&guideline=5.6
 	c := Default(rootCAs)
-	c.MinVersion = SecureTLSConfigMinTLSVersion // max out the security
+	// Max out the security by requiring TLS 1.3 by default. Allow it to be overridden by a build tag.
-	c.CipherSuites = nil                        // TLS 1.3 ciphers are not configurable
+	c.MinVersion = SecureProfileMinTLSVersionForNonFIPS
+	if c.MinVersion == tls.VersionTLS13 {
+		// Go ignores this setting for TLS 1.3 anyway, so set this to nil just to be explicit when only supporting TLS 1.3.
+		c.CipherSuites = nil
+	}
 	return c
 }
 

internal/crypto/ptls/profiles_fips_strict.go

@@ -62,21 +62,18 @@ func init() {
 	// this init runs before we have parsed our config to determine our log level
 	// thus we must use a log statement that will always print instead of conditionally print
 	plog.Always("this server was compiled to use boring crypto in FIPS-only mode",
-		"go version", runtime.Version())
+		"go version", runtime.Version(),
+		"DefaultProfileMaxTLSVersionForFIPS", tls.VersionName(DefaultProfileMaxTLSVersionForFIPS))
 }
 
-// SecureTLSConfigMinTLSVersion: see comment in profiles.go.
-// Until goboring supports TLS 1.3, use TLS 1.2.
-const SecureTLSConfigMinTLSVersion = tls.VersionTLS12
-
 // Default: see comment in profiles.go.
 // This chooses different cipher suites and/or TLS versions compared to non-FIPS mode.
 // In FIPS mode, this will use the union of the secureCipherSuiteIDs, additionalSecureCipherSuiteIDsOnlyForLDAPClients,
 // and insecureCipherSuiteIDs values defined above.
 func Default(rootCAs *x509.CertPool) *tls.Config {
 	config := buildTLSConfig(rootCAs, allHardcodedAllowedCipherSuites(), getUserConfiguredAllowedCipherSuitesForTLSOneDotTwo())
-	// Until goboring supports TLS 1.3, make the max version 1.2.
+	// Until goboring supports TLS 1.3, make the max version 1.2 by default. Allow it to be overridden by a build tag.
-	config.MaxVersion = tls.VersionTLS12
+	config.MaxVersion = DefaultProfileMaxTLSVersionForFIPS
 	return config
 }
 

internal/crypto/ptls/secure_profile_min_tls_version_for_nonfips_12.go

@@ -0,0 +1,10 @@
+// Copyright 2024 the Pinniped contributors. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+//go:build nonfips_enable_tls12_min_for_secure_profile
+
+package ptls
+
+import "crypto/tls"
+
+const SecureProfileMinTLSVersionForNonFIPS = tls.VersionTLS12

internal/crypto/ptls/secure_profile_min_tls_version_for_nonfips_default_value.go

@@ -0,0 +1,10 @@
+// Copyright 2024 the Pinniped contributors. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+//go:build !nonfips_enable_tls12_min_for_secure_profile
+
+package ptls
+
+import "crypto/tls"
+
+const SecureProfileMinTLSVersionForNonFIPS = tls.VersionTLS13

test/integration/supervisor_discovery_test.go

@@ -34,7 +34,6 @@ import (
 	idpv1alpha1 "go.pinniped.dev/generated/latest/apis/supervisor/idp/v1alpha1"
 	supervisorclientset "go.pinniped.dev/generated/latest/client/supervisor/clientset/versioned"
 	"go.pinniped.dev/internal/certauthority"
-	"go.pinniped.dev/internal/crypto/ptls"
 	"go.pinniped.dev/internal/here"
 	"go.pinniped.dev/test/testlib"
 )
@@ -866,7 +865,7 @@ func newHTTPClient(t *testing.T, caBundle []byte, dnsOverrides map[string]string
 		caCertPool.AppendCertsFromPEM(caBundle)
 		c.Transport = &http.Transport{
 			DialContext:     overrideDialContext,
-			TLSClientConfig: &tls.Config{MinVersion: ptls.SecureTLSConfigMinTLSVersion, RootCAs: caCertPool}, //nolint:gosec // this seems to be a false flag, min tls version is 1.3 in normal mode or 1.2 in fips mode
+			TLSClientConfig: &tls.Config{MinVersion: tls.VersionTLS12, RootCAs: caCertPool},
 		}
 	} else {
 		c.Transport = &http.Transport{