use P256 as the default curve for fips140 mode

Why not?

.github/workflows/smoke.yml

@@ -25,39 +25,19 @@ jobs:
         go-version: '1.26'
         check-latest: true
 
-    - name: build
-      run: make bin-docker CGO_ENABLED=1 BUILD_ARGS=-race
+    - name: Smoke Docker
+      run: make smoke-docker
 
-    - name: setup docker image
-      working-directory: ./.github/workflows/smoke
-      run: ./build.sh
+    - name: Smoke Docker IPv6 overlay
+      run: make smoke-docker-ipv6
 
-    - name: run smoke
-      working-directory: ./.github/workflows/smoke
-      run: ./smoke.sh
+    - name: Smoke Relay Docker
+      run: make smoke-relay-docker
 
-    - name: setup docker image ipv6
-      working-directory: ./.github/workflows/smoke
-      run: SMOKE_OVERLAY_IPV6=1 ./build.sh
+    - name: Smoke Docker boringcrypto
+      run: make boringcrypto smoke-docker
 
-    - name: run smoke ipv6
-      working-directory: ./.github/workflows/smoke
-      run: SMOKE_OVERLAY_IPV6=1 ./smoke.sh
-
-    - name: setup relay docker image
-      working-directory: ./.github/workflows/smoke
-      run: ./build-relay.sh
-
-    - name: run smoke relay
-      working-directory: ./.github/workflows/smoke
-      run: ./smoke-relay.sh
-
-    - name: setup docker image for P256
-      working-directory: ./.github/workflows/smoke
-      run: NAME="smoke-p256" CURVE=P256 ./build.sh
-
-    - name: run smoke-p256
-      working-directory: ./.github/workflows/smoke
-      run: NAME="smoke-p256" ./smoke.sh
+    - name: Smoke Docker fips140
+      run: make fips140-all GOALS=smoke-docker
 
     timeout-minutes: 10

.github/workflows/test.yml

@@ -58,9 +58,14 @@ jobs:
           e2e-cmd: make e2evv
         - name: linux-boringcrypto
           os: ubuntu-latest
-          build-cmd: make bin-boringcrypto
-          test-cmd: make test-boringcrypto
-          e2e-cmd: make e2e GOEXPERIMENT=boringcrypto CGO_ENABLED=1 TEST_ENV="TEST_LOGS=1" TEST_FLAGS="-v -ldflags -checklinkname=0"
+          build-cmd: make boringcrypto
+          test-cmd: make boringcrypto test
+          e2e-cmd: make boringcrypto e2evv
+        - name: linux-fips140
+          os: ubuntu-latest
+          build-cmd: make fips140-all
+          test-cmd: make fips140-all GOALS=test
+          e2e-cmd: make fips140-all GOALS=e2evv
         - name: linux-pkcs11
           os: ubuntu-latest
           build-cmd: make bin-pkcs11

CHANGELOG.md

@@ -7,88 +7,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-## [1.11.0] - 2026-07-23
-
-See the [v1.11.0](https://github.com/slackhq/nebula/milestone/25?closed=1) milestone for a complete list of changes.
-
-### Breaking
-
-- Logging has switched from logrus to Go's structured `slog`. Log output changes: levels are upper case
-  (`level=INFO`), trace prints as `level=DEBUG-4`, timestamps are always RFC3339Nano and `logging.timestamp_format`
-  is ignored, and some messages were reworded. Review any log parsing before upgrading. This is also an API break
-  for embedders, as constructors now take a `*slog.Logger`. (#1672, #1734, #1621)
-- `firewall.inbound_action` and `firewall.outbound_action` (used to set reject vs. drop policy) were each being
-  applied to the opposite direction, that is now corrected. This only affects how blocked packets are answered, not
-  which packets the firewall allows or denies. If you set either of these you are getting the behavior of the other
-  one today and likely want to swap them before upgrading. (#1798)
-- On Windows, Nebula now installs WFP PERMIT filters for the nebula adapter and the listener port by default. WFP
-  sits below Windows Defender Firewall, so any WDF inbound rules you rely on for either will no longer apply. Set
-  `tun.windows_bypass_wdf` and `listen.windows_bypass_wdf` to false to leave WDF in charge. (#1710)
-- On Windows, the nebula device is now set to the `private` network category instead of whatever Windows decided,
-  which is usually `Public`. This makes the host firewall less restrictive on the overlay. Set
-  `tun.network_category` to `unset` to keep the old behavior. (#1710)
-- Reject packets for non-TCP now use ICMP code 13, communication administratively prohibited, instead of code 3,
-  port unreachable. Anything keying off the old code needs updating. (#1766, #1768)
-- The SSH debug server's profiling commands are now confined to `sshd.sandbox_dir`, which defaults to
-  `$TMP/nebula-debug`. Relative paths resolve inside it and absolute paths outside it are rejected, so anything
-  scripting `start-cpu-profile`, `save-heap-profile`, or `save-mutex-profile` with a path elsewhere needs the
-  directory set. The directory is not created for you. (#1622)
-
-### Added
-
-- Sign the Windows release binaries. (#1718)
-- Generate IPv6 reject packets, matching the existing IPv4 behavior. (#1766, #1767, #1768)
-- Accept `-` in `nebula-cert` to read from stdin or write to stdout. (#1714)
-- Search for both `config.yml` and `config.yaml` in service and command line modes. (#1717)
-- Add version labels to the Docker/OCI images. (#1772)
-- Rebind the listener and re-query lighthouses on macOS when the underlay network changes, so devices moving
-  between wifi and wired or between networks recover without waiting for dead tunnel detection. Controlled by
-  `listen.rebind_on_network_change` (default `true`, not reloadable). (#1816)
-
-### Changed
-
-- Reload the firewall when the unsafe networks in the certificate change. (#1719)
-- Reconfigure, start, and stop the stats listener on a config reload instead of requiring a restart. (#1670)
-- Update a static host's addresses when they change on reload. (#1713)
-- Don't require a port on ICMP firewall rules. (#1609)
-- Connection track ICMP traffic. (#1602)
-- Return `NODATA` instead of `NXDOMAIN` from the DNS server for a name that exists but has no record of the
-  requested type, so clients that query `AAAA` first (busybox/Alpine) fall through to `A`. (#1668)
-- Record the local host's details in the DNS server. (#1716)
-- Install Windows unsafe routes as link routes. (#1709)
-- Reduce relay handshake log spam, and only log a handshake send error at error level when the remote list
-  changes. (#1733, #1765, #1810)
-- Start, stop, and reload subsystems (DNS, stats, conntrack, ssh, punchy) cleanly without leaking goroutines. (#1640, #1654, #1661, #1667, #1669, #1708, #1806, #1815)
-- `Control` is now safe to stop and wait on from any lifecycle state, and a new `Control.Wait` blocks until nebula
-  has fully stopped and returns the first fatal reader error. Failed starts release the udp sockets and tun fd
-  instead of leaking them. (#1794)
-- Trigger an immediate lighthouse update when reconnecting to or adding a lighthouse instead of waiting for the next update tick. (#1645)
-- Bring the Darwin and OpenBSD tun implementations in line with the other BSDs. (#1703)
-- Update to build against go v1.26. (#1818)
-- Various dependency updates. (#1586, #1587, #1604, #1617, #1618, #1627, #1628, #1629, #1652, #1664, #1665, #1697, #1721, #1732, #1742, #1743, #1750, #1763, #1771, #1782, #1800, #1807)
-
-### Fixed
-
-- Fix a data race on a host's remote address that could send packets to the wrong address during a roam. (#1773)
-- Fix tunnels that could permanently escape connection manager monitoring. (#1752)
-- Fix a crash when reloading the SSH server's trusted keys. (#1787)
-- Fix hostmap corruption when a host has multiple overlay addresses. Each address now gets its own list instead of
-  a single shared chain, which also fixes two latent bugs on the add and makePrimary paths. (#1788, #1790)
-- Apply `remote_allow_list` IPv4 rules to 4-in-6 mapped addresses. (#1786)
-- Don't panic in the DNS server on a short or empty query name. (#1635)
-- Advance the replay window on relayed packets so a relay drops replayed frames instead of re-forwarding them. (#1751)
-- Fix a race in relay state handling. (#1753)
-- Lock replay window updates so concurrent readers can't corrupt it. (#1802)
-- Reject malformed handshakes more reliably, including invalid ed25519 key lengths. (#1601, #1756)
-- Properly handle `closetunnel` packets. (#1638)
-- Fix an IPv6 extension-header length overflow that could make the firewall parse the wrong protocol and ports. (#1789)
-- Fix relay re-establishment when a handshake arrives over a relay entry that a one-sided teardown left
-  `Disestablished`, which silently dropped every send until dead tunnel detection forced a re-handshake. (#1805)
-- Don't build new relay state on a tunnel that was just discarded. (#1796)
-- Don't delete the wrong pending hostinfo in the handshake manager. (#1811)
-- Don't call the packet reader after a UDP error on Darwin. (#1755)
-- Open the FreeBSD tun device non blocking. (#1666)
-
 ## [1.10.3] - 2026-02-06
 
 ### Security

Makefile

@@ -72,6 +72,17 @@ ALL_CROSS_LINUX_ARM   = linux-arm-5 linux-arm-6 linux-arm-7 linux-arm64
 ALL_CROSS_LINUX_MIPS  = linux-mips linux-mipsle linux-mips64 linux-mips64le linux-mips-softfloat
 ALL_CROSS_LINUX_OTHER = linux-386 linux-ppc64le linux-riscv64 linux-loong64
 
+# Based on section 2.2 of the Go Cryptographic Module CVMP Security Policy #5247
+ALL_FIPS140 = linux-amd64-fips140 \
+	linux-arm64-fips140 \
+	windows-amd64-fips140 \
+	windows-arm64-fips140 \
+	darwin-arm64-fips140 \
+	freebsd-amd64-fips140 \
+	linux-arm-7-fips140 \
+	linux-mips64-fips140 \
+	linux-ppc64le-fips140
+
 e2e:
 	$(TEST_ENV) go test -tags=e2e_testing -count=1 $(TEST_FLAGS) ./e2e
 
@@ -137,6 +148,8 @@ release-netbsd: $(ALL_NETBSD:%=build/nebula-%.tar.gz)
 
 release-boringcrypto: build/nebula-linux-$(shell go env GOARCH)-boringcrypto.tar.gz
 
+release-fips140: $(ALL_FIPS140:%=build/nebula-%.tar.gz)
+
 BUILD_ARGS += -trimpath
 
 bin-windows: build/windows-amd64/nebula.exe build/windows-amd64/nebula-cert.exe
@@ -157,17 +170,20 @@ bin-freebsd-arm64: build/freebsd-arm64/nebula build/freebsd-arm64/nebula-cert
 bin-boringcrypto: build/linux-$(shell go env GOARCH)-boringcrypto/nebula build/linux-$(shell go env GOARCH)-boringcrypto/nebula-cert
 	mv $? .
 
+bin-fips140: build/linux-$(shell go env GOARCH)-fips140/nebula build/linux-$(shell go env GOARCH)-fips140/nebula-cert
+	mv $? .
+
 bin-pkcs11: BUILD_ARGS += -tags pkcs11
 bin-pkcs11: CGO_ENABLED = 1
 bin-pkcs11: bin
 
 bin:
-	go build $(BUILD_ARGS) -ldflags "$(LDFLAGS)" -o ./nebula${NEBULA_CMD_SUFFIX} ${NEBULA_CMD_PATH}
-	go build $(BUILD_ARGS) -ldflags "$(LDFLAGS)" -o ./nebula-cert${NEBULA_CMD_SUFFIX} ./cmd/nebula-cert
+	$(GOENV) go build $(BUILD_ARGS) -ldflags "$(LDFLAGS)" -o ./nebula${NEBULA_CMD_SUFFIX} ${NEBULA_CMD_PATH}
+	$(GOENV) go build $(BUILD_ARGS) -ldflags "$(LDFLAGS)" -o ./nebula-cert${NEBULA_CMD_SUFFIX} ./cmd/nebula-cert
 
 install:
-	go install $(BUILD_ARGS) -ldflags "$(LDFLAGS)" ${NEBULA_CMD_PATH}
-	go install $(BUILD_ARGS) -ldflags "$(LDFLAGS)" ./cmd/nebula-cert
+	$(GOENV) go install $(BUILD_ARGS) -ldflags "$(LDFLAGS)" ${NEBULA_CMD_PATH}
+	$(GOENV) go install $(BUILD_ARGS) -ldflags "$(LDFLAGS)" ./cmd/nebula-cert
 
 build/linux-arm-%: GOENV += GOARM=$(word 3, $(subst -, ,$*))
 build/linux-mips-%: GOENV += GOMIPS=$(word 3, $(subst -, ,$*))
@@ -178,8 +194,11 @@ build/linux-mips-softfloat/%: LDFLAGS += -s -w
 # boringcrypto
 build/linux-amd64-boringcrypto/%: GOENV += GOEXPERIMENT=boringcrypto CGO_ENABLED=1
 build/linux-arm64-boringcrypto/%: GOENV += GOEXPERIMENT=boringcrypto CGO_ENABLED=1
-build/linux-amd64-boringcrypto/%: LDFLAGS += -checklinkname=0
-build/linux-arm64-boringcrypto/%: LDFLAGS += -checklinkname=0
+
+# fips140
+FIPSVERSION = v1.0.0
+$(foreach _rule, $(ALL_FIPS140), build/$(_rule)/%): GOENV += GOFIPS140=$(FIPSVERSION)
+$(foreach _rule, $(ALL_FIPS140), build/$(_rule)/%): BUILD_ARGS += -tags fips140enforce
 
 build/%/nebula: .FORCE
 	GOOS=$(firstword $(subst -, , $*)) \
@@ -210,10 +229,7 @@ vet:
 	go vet $(VET_FLAGS) -v ./...
 
 test:
-	go test -v ./...
-
-test-boringcrypto:
-	GOEXPERIMENT=boringcrypto CGO_ENABLED=1 go test -ldflags "-checklinkname=0" -v ./...
+	$(TEST_ENV) go test $(TEST_FLAGS) -v ./...
 
 test-pkcs11:
 	CGO_ENABLED=1 go test -v -tags pkcs11 ./...
@@ -256,29 +272,72 @@ ifeq ($(words $(MAKECMDGOALS)),1)
 	@$(MAKE) service ${.DEFAULT_GOAL} --no-print-directory
 endif
 
+# Useful to chain together, like:
+# - make fips140 e2evv
+# - make fips140 smoke-docker
+# Use `release-fips140` to build release binaries
+fips140:
+	@echo > $(NULL_FILE)
+ifeq ($(strip $(GOFIPS140)),)
+	$(eval GOFIPS140 = $(FIPSVERSION))
+endif
+	$(eval GOENV += GOFIPS140=$(GOFIPS140))
+	$(eval BUILD_ARGS += -tags fips140enforce)
+	$(eval TEST_ENV += $(GOENV))
+	$(eval CURVE = P256)
+ifeq ($(words $(MAKECMDGOALS)),1)
+	@$(MAKE) fips140 GOFIPS140=$(GOFIPS140) ${.DEFAULT_GOAL} --no-print-directory
+endif
+
+# To test the future pending module, use like `make fips140-latest test`
+ALL_GOFIPS140 = v1.0.0 v1.26.0 latest
+define FIPS140_rule
+fips140-$(1): GOFIPS140 = $(1)
+fips140-$(1): fips140
+endef
+$(foreach _rule, $(ALL_GOFIPS140), $(eval $(call FIPS140_rule,$(_rule))))
+
+# Iterate and run the goals for all fips versions, like `make fips140-all GOALS=test`
+fips140-all:
+	@$(foreach _v,$(ALL_GOFIPS140),$(MAKE) fips140-$(_v) $(GOALS) &&) true
+
+# Useful to chain together, like:
+# - make boringcrypto e2evv
+# - make boringcrypto smoke-docker
+# Use `release-boringcrypto` or `bin-boringcrypto` to build release binaries
+boringcrypto:
+	@echo > $(NULL_FILE)
+	$(eval GOENV += GOEXPERIMENT=boringcrypto CGO_ENABLED=1)
+	$(eval TEST_ENV += $(GOENV))
+	$(eval CURVE = P256)
+ifeq ($(words $(MAKECMDGOALS)),1)
+	@$(MAKE) boringcrypto ${.DEFAULT_GOAL} --no-print-directory
+endif
+
 bin-docker: bin build/linux-amd64/nebula build/linux-amd64/nebula-cert
 
+smoke-docker: BUILD_ARGS += -race
+smoke-docker: GOENV += CGO_ENABLED=1
 smoke-docker: bin-docker
-	cd .github/workflows/smoke/ && ./build.sh
-	cd .github/workflows/smoke/ && ./smoke.sh
-	cd .github/workflows/smoke/ && NAME="smoke-p256" CURVE="P256" ./build.sh
-	cd .github/workflows/smoke/ && NAME="smoke-p256" ./smoke.sh
+	# This is so we can limit `fips140` smoke test to just P256 curve.
+	if [ "$(CURVE)" != "P256" ]; then cd .github/workflows/smoke/ && $(GOENV) ./build.sh; fi
+	if [ "$(CURVE)" != "P256" ]; then cd .github/workflows/smoke/ && $(GOENV) ./smoke.sh; fi
+	cd .github/workflows/smoke/ && $(GOENV) NAME="smoke-p256" CURVE="P256" ./build.sh
+	cd .github/workflows/smoke/ && $(GOENV) NAME="smoke-p256" ./smoke.sh
 
+smoke-relay-docker: BUILD_ARGS += -race
+smoke-relay-docker: GOENV += CGO_ENABLED=1
 smoke-relay-docker: bin-docker
-	cd .github/workflows/smoke/ && ./build-relay.sh
-	cd .github/workflows/smoke/ && ./smoke-relay.sh
+	cd .github/workflows/smoke/ && $(GOENV) ./build-relay.sh
+	cd .github/workflows/smoke/ && $(GOENV) ./smoke-relay.sh
 
 smoke-docker-ipv6: export SMOKE_OVERLAY_IPV6 = 1
 smoke-docker-ipv6: smoke-docker
 
-smoke-docker-race: BUILD_ARGS = -race
-smoke-docker-race: CGO_ENABLED = 1
-smoke-docker-race: smoke-docker
-
 smoke-vagrant/%: bin-docker build/%/nebula
 	cd .github/workflows/smoke/ && ./build.sh $*
 	cd .github/workflows/smoke/ && ./smoke-vagrant.sh $*
 
 .FORCE:
-.PHONY: all all-linux all-freebsd all-openbsd all-netbsd all-darwin all-windows all-cross-linux all-cross-linux-arm all-cross-linux-mips all-cross-linux-other all-cross-darwin all-cross-windows bench bench-cpu bench-cpu-long bin build-test-mobile e2e e2ev e2evv e2evvv e2evvvv proto release service smoke-docker smoke-docker-race test test-cov-html smoke-vagrant/%
+.PHONY: all all-linux all-freebsd all-openbsd all-netbsd all-darwin all-windows all-cross-linux all-cross-linux-arm all-cross-linux-mips all-cross-linux-other all-cross-darwin all-cross-windows bench bench-cpu bench-cpu-long bin bin-windows bin-windows-arm64 bin-darwin bin-freebsd bin-freebsd-arm64 bin-boringcrypto bin-fips140 bin-pkcs11 bin-docker boringcrypto build-test-mobile docker e2e e2ev e2evv e2evvv e2evvvv e2e-bench fips140 fips140-all $(ALL_GOFIPS140:%=fips140-%) install proto release release-linux release-freebsd release-openbsd release-netbsd release-boringcrypto release-fips140 service smoke-docker smoke-relay-docker smoke-docker-ipv6 test test-pkcs11 test-cov-html vet smoke-vagrant/%
 .DEFAULT_GOAL := bin

README.md

@@ -145,17 +145,27 @@ To build nebula for a specific platform (ex, Windows):
 
 See the [Makefile](Makefile) for more details on build targets
 
-## Curve P256 and BoringCrypto
+## Curve P256 and FIPS 140-3 mode
 
 The default curve used for cryptographic handshakes and signatures is Curve25519. This is the recommended setting for most users. If your deployment has certain compliance requirements, you have the option of creating your CA using `nebula-cert ca -curve P256` to use NIST Curve P256. The CA will then sign certificates using ECDSA P256, and any hosts using these certificates will use P256 for ECDH handshakes.
 
-In addition, Nebula can be built using the [BoringCrypto GOEXPERIMENT](https://github.com/golang/go/blob/go1.20/src/crypto/internal/boring/README.md) by running either of the following make targets:
+Nebula can be built to support the [FIPS 140-3](https://go.dev/doc/security/fips140) mode of Go by running either of the following make targets. (This sets GOFIPS140=v1.0.0, which must be done at compile time so that the correct AES-GCM can be used for FIPS 140-3 enforcement mode).
+
+```sh
+make fips140
+make fips140 test
+make release-fips140
+```
+
+Nebula can also be built using the [BoringCrypto GOEXPERIMENT](https://github.com/golang/go/blob/go1.20/src/crypto/internal/boring/README.md) by running either of the following make targets.
 
 ```sh
 make bin-boringcrypto
 make release-boringcrypto
 ```
 
+NOTE: boringcrypto support is deprecated and will be removed in the next release. Users should migrate to the native FIPS 140-3 mode described above.
+
 This is not the recommended default deployment, but may be useful based on your compliance requirements.
 
 ## Credits

cmd/nebula-cert/ca.go

@@ -3,6 +3,7 @@ package main
 import (
 	"crypto/ecdsa"
 	"crypto/elliptic"
+	"crypto/fips140"
 	"crypto/rand"
 	"flag"
 	"fmt"
@@ -43,6 +44,13 @@ type caFlags struct {
 	subnets *string
 }
 
+func defaultCurve() string {
+	if fips140.Enforced() {
+		return "P256"
+	}
+	return "25519"
+}
+
 func newCaFlags() *caFlags {
 	cf := caFlags{set: flag.NewFlagSet("ca", flag.ContinueOnError)}
 	cf.set.Usage = func() {}
@@ -59,7 +67,7 @@ func newCaFlags() *caFlags {
 	cf.argonParallelism = cf.set.Uint("argon-parallelism", 4, "Optional: Argon2 parallelism parameter used for encrypted private key passphrase")
 	cf.argonIterations = cf.set.Uint("argon-iterations", 1, "Optional: Argon2 iterations parameter used for encrypted private key passphrase")
 	cf.encryption = cf.set.Bool("encrypt", false, "Optional: prompt for passphrase and write out-key in an encrypted format")
-	cf.curve = cf.set.String("curve", "25519", "EdDSA/ECDSA Curve (25519, P256)")
+	cf.curve = cf.set.String("curve", defaultCurve(), "EdDSA/ECDSA Curve (25519, P256)")
 	cf.p11url = p11Flag(cf.set)
 
 	cf.ips = cf.set.String("ips", "", "Deprecated, see -networks")

cmd/nebula-cert/fips140enforce.go

@@ -0,0 +1,5 @@
+//go:build fips140enforce
+
+//go:debug fips140=only
+
+package main

cmd/nebula-cert/keygen.go

@@ -24,7 +24,7 @@ func newKeygenFlags() *keygenFlags {
 	cf.set.Usage = func() {}
 	cf.outPubPath = cf.set.String("out-pub", "", "Required: path to write the public key to")
 	cf.outKeyPath = cf.set.String("out-key", "", "Required: path to write the private key to")
-	cf.curve = cf.set.String("curve", "25519", "ECDH Curve (25519, P256)")
+	cf.curve = cf.set.String("curve", defaultCurve(), "ECDH Curve (25519, P256)")
 	cf.p11url = p11Flag(cf.set)
 	return &cf
 }

cmd/nebula-service/fips140enforce.go

@@ -0,0 +1,5 @@
+//go:build fips140enforce
+
+//go:debug fips140=only
+
+package main

cmd/nebula/fips140enforce.go

@@ -0,0 +1,5 @@
+//go:build fips140enforce
+
+//go:debug fips140=only
+
+package main

e2e/recovery_timing_test.go

@@ -1,136 +0,0 @@
-//go:build e2e_testing
-// +build e2e_testing
-
-package e2e
-
-import (
-	"testing"
-	"time"
-
-	"github.com/slackhq/nebula"
-	"github.com/slackhq/nebula/cert"
-	"github.com/slackhq/nebula/cert_test"
-	"github.com/slackhq/nebula/e2e/router"
-	"github.com/slackhq/nebula/udp"
-)
-
-// TestRecoveryTiming measures how long a tunnel takes to come back after the peer stops accepting our traffic,
-// which is what a laptop waking on a new network looks like from the peer's side: its NAT has no state for where
-// we are now, so everything we send disappears.
-//
-// It is a measurement, not a pass/fail assertion. Recovery is timed to the moment the peer punches back at us,
-// since that is when its NAT opens and the tunnel is usable again.
-//
-//	go test -tags e2e_testing -v -run TestRecoveryTiming ./e2e/
-func TestRecoveryTiming(t *testing.T) {
-	for _, tc := range []struct {
-		name   string
-		rebind bool
-	}{
-		{"no trigger", false},
-		{"rebind counter", true},
-	} {
-		t.Run(tc.name, func(t *testing.T) {
-			d, lost := measureRecovery(t, tc.rebind)
-			t.Logf("RESULT %-16s recovered in %-9v (%d packets lost)", tc.name, d.Round(time.Millisecond), lost)
-		})
-	}
-}
-
-// measureRecovery returns how long until the peer punched back, and how many of our packets died meanwhile. When
-// rebind is true we call RebindUDPServer once the tunnel goes dark, which is what the darwin network change
-// monitor does and what iOS has always done. When false, nothing tells nebula anything is wrong.
-func measureRecovery(t *testing.T, rebind bool) (time.Duration, int) {
-	t.Helper()
-	ca, _, caKey, _ := cert_test.NewTestCaCert(cert.Version2, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
-
-	lhControl, lhVpnIpNet, lhUdpAddr, _ := newSimpleServer(cert.Version2, ca, caKey, "lh", "10.128.0.1/24", m{
-		"lighthouse": m{"am_lighthouse": true},
-	})
-
-	peerCfg := m{
-		"lighthouse": m{
-			"hosts":    []any{lhVpnIpNet[0].Addr().String()},
-			"interval": 600,
-			"local_allow_list": m{
-				"10.0.0.0/24": true,
-				"::/0":        false,
-			},
-		},
-		"static_host_map": m{
-			lhVpnIpNet[0].Addr().String(): []any{lhUdpAddr.String()},
-		},
-	}
-
-	myControl, myVpnIpNet, myUdpAddr, _ := newSimpleServer(cert.Version2, ca, caKey, "me", "10.128.0.2/24", peerCfg)
-	theirControl, theirVpnIpNet, theirUdpAddr, _ := newSimpleServer(cert.Version2, ca, caKey, "them", "10.128.0.3/24", peerCfg)
-
-	r := router.NewR(t, lhControl, myControl, theirControl)
-	defer r.RenderFlow()
-	defer func() {
-		lhControl.Stop()
-		myControl.Stop()
-		theirControl.Stop()
-	}()
-
-	lhControl.Start()
-	myControl.Start()
-	theirControl.Start()
-	r.RouteFor(time.Millisecond * 500)
-
-	myControl.InjectLightHouseAddr(theirVpnIpNet[0].Addr(), theirUdpAddr)
-	theirControl.InjectLightHouseAddr(myVpnIpNet[0].Addr(), myUdpAddr)
-
-	myControl.InjectTunPacket(BuildTunUDPPacket(theirVpnIpNet[0].Addr(), 80, myVpnIpNet[0].Addr(), 80, []byte("establish")))
-	r.RouteFor(time.Second)
-	if myControl.GetHostInfoByVpnAddr(theirVpnIpNet[0].Addr(), false) == nil {
-		t.Fatal("failed to establish the tunnel we are measuring")
-	}
-	r.RouteFor(time.Millisecond * 500)
-
-	// From here the peer's NAT has no state for us, everything we send it disappears
-	start := time.Now()
-	blackholed := 0
-	var recovered time.Duration
-
-	if rebind {
-		myControl.RebindUDPServer()
-	}
-
-	// Keep the tun busy the way someone retrying a stalled connection would
-	stop := make(chan struct{})
-	defer close(stop)
-	go func() {
-		tick := time.NewTicker(time.Millisecond * 200)
-		defer tick.Stop()
-		for {
-			select {
-			case <-stop:
-				return
-			case <-tick.C:
-				myControl.InjectTunPacket(BuildTunUDPPacket(
-					theirVpnIpNet[0].Addr(), 80, myVpnIpNet[0].Addr(), 80, []byte("retry")))
-			}
-		}
-	}()
-
-	r.RouteForAllExitFuncOrTimeout(time.Second*30, func(p *udp.Packet, c *nebula.Control) router.ExitType {
-		if c == theirControl && p.From == myControl.GetUDPAddr() {
-			blackholed++
-			return router.Drop
-		}
-
-		// The peer reaching us directly is the moment its NAT opened, whether that is a punch or a handshake
-		if c == myControl && p.From == theirUdpAddr {
-			recovered = time.Since(start)
-			return router.RouteAndExit
-		}
-
-		return router.KeepRouting
-	})
-
-	if recovered == 0 {
-		t.Fatalf("no recovery within 30s (%d packets blackholed)", blackholed)
-	}
-	return recovered, blackholed
-}

e2e/router/router.go

@@ -153,9 +153,6 @@ const (
 	ExitNow ExitType = 1
 	// RouteAndExit routes this packet and exits immediately afterwards
 	RouteAndExit ExitType = 2
-	// Drop discards this packet without delivering it and keeps routing. Use it to simulate a blackhole, such as
-	// a restrictive NAT refusing traffic from an address it has not seen.
-	Drop ExitType = 3
 )
 
 type ExitFunc func(packet *udp.Packet, receiver *nebula.Control) ExitType
@@ -166,9 +163,7 @@ type ExitFunc func(packet *udp.Packet, receiver *nebula.Control) ExitType
 func NewR(t testing.TB, controls ...*nebula.Control) *R {
 	ctx, cancel := context.WithCancel(context.Background())
 
-	// t.Name() contains a slash for subtests, so the flow log can land in a nested directory
-	fn := filepath.Join("mermaid", fmt.Sprintf("%s.md", t.Name()))
-	if err := os.MkdirAll(filepath.Dir(fn), 0755); err != nil {
+	if err := os.MkdirAll("mermaid", 0755); err != nil {
 		panic(err)
 	}
 
@@ -179,7 +174,7 @@ func NewR(t testing.TB, controls ...*nebula.Control) *R {
 		outNat:       make(map[outNatKey]netip.AddrPort),
 		flow:         []flowEntry{},
 		ignoreFlows:  []ignoreFlow{},
-		fn:           fn,
+		fn:           filepath.Join("mermaid", fmt.Sprintf("%s.md", t.Name())),
 		t:            t,
 		cancelRender: cancel,
 	}
@@ -692,10 +687,6 @@ func (r *R) RouteExitFunc(sender *nebula.Control, whatDo ExitFunc) {
 			p.Release()
 			return
 
-		case Drop:
-			// Record it so the flow log shows the attempt, but never hand it to the receiver
-			r.unlockedInjectFlow(sender, receiver, p, false)
-
 		case KeepRouting:
 			fp := r.unlockedInjectFlow(sender, receiver, p, false)
 			receiver.InjectUDPPacket(p)
@@ -788,10 +779,6 @@ func (r *R) RouteForAllExitFuncOrTimeout(timeout time.Duration, whatDo ExitFunc)
 			p.Release()
 			return true
 
-		case Drop:
-			// Record it so the flow log shows the attempt, but never hand it to the receiver
-			r.unlockedInjectFlow(cm[x], receiver, p, false)
-
 		case KeepRouting:
 			fp := r.unlockedInjectFlow(cm[x], receiver, p, false)
 			receiver.InjectUDPPacket(p)
@@ -897,10 +884,6 @@ func (r *R) RouteForAllExitFunc(whatDo ExitFunc) {
 			p.Release()
 			return
 
-		case Drop:
-			// Record it so the flow log shows the attempt, but never hand it to the receiver
-			r.unlockedInjectFlow(cm[x], receiver, p, false)
-
 		case KeepRouting:
 			fp := r.unlockedInjectFlow(cm[x], receiver, p, false)
 			receiver.InjectUDPPacket(p)

go.mod

@@ -23,7 +23,7 @@ require (
 	github.com/stretchr/testify v1.11.1
 	github.com/vishvananda/netlink v1.3.1
 	go.uber.org/goleak v1.3.0
-	go.yaml.in/yaml/v3 v3.0.5
+	go.yaml.in/yaml/v3 v3.0.4
 	golang.org/x/crypto v0.54.0
 	golang.org/x/exp v0.0.0-20230725093048-515e97ebf090
 	golang.org/x/net v0.57.0

go.sum

@@ -155,8 +155,8 @@ go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
 go.yaml.in/yaml/v2 v2.4.2 h1:DzmwEr2rDGHl7lsFgAHxmNz/1NlQ7xLIrlN2h5d1eGI=
 go.yaml.in/yaml/v2 v2.4.2/go.mod h1:081UH+NErpNdqlCXm3TtEran0rJZGxAYx9hb/ELlsPU=
-go.yaml.in/yaml/v3 v3.0.5 h1:N6y/pJk8buWs9NY5ERU2HSMfm+IuD/OtfdAnq6kESPw=
-go.yaml.in/yaml/v3 v3.0.5/go.mod h1:HVTZu1O7/Vkt2N+BFy8Zza+lnLsABggaTM2ZpNIGuKg=
+go.yaml.in/yaml/v3 v3.0.4 h1:tfq32ie2Jv2UxXFdLJdh3jXuOzWiL1fo0bu/FbuKpbc=
+go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=

interface.go

@@ -2,6 +2,7 @@ package nebula
 
 import (
 	"context"
+	"crypto/fips140"
 	"errors"
 	"fmt"
 	"io"
@@ -238,6 +239,9 @@ func (f *Interface) activate() error {
 		"build", f.version,
 		"udpAddr", addr,
 		"boringcrypto", boringEnabled(),
+		"fips140Version", fips140.Version(),
+		"fips140Enabled", fips140.Enabled(),
+		"fips140Enforced", fips140.Enforced(),
 	)
 
 	if f.routines > 1 {

noiseutil/boring.go

@@ -4,77 +4,16 @@
 package noiseutil
 
 import (
-	"crypto/aes"
-	"crypto/cipher"
-	"encoding/binary"
-
-	// unsafe needed for go:linkname
-	_ "unsafe"
+	"crypto/boring"
 
 	"github.com/flynn/noise"
 )
 
+var CipherAESGCM noise.CipherFunc = CipherAESGCMFIPS140
+
 // EncryptLockNeeded indicates if calls to Encrypt need a lock
 // This is true for boringcrypto because the Seal function verifies that the
 // nonce is strictly increasing.
 const EncryptLockNeeded = true
 
-// NewGCMTLS is no longer exposed in go1.19+, so we need to link it in
-// See: https://github.com/golang/go/issues/56326
-//
-// NewGCMTLS is the internal method used with boringcrypto that provides a
-// validated mode of AES-GCM which enforces the nonce is strictly
-// monotonically increasing.  This is the TLS 1.2 specification for nonce
-// generation (which also matches the method used by the Noise Protocol)
-//
-// - https://github.com/golang/go/blob/go1.19/src/crypto/tls/cipher_suites.go#L520-L522
-// - https://github.com/golang/go/blob/go1.19/src/crypto/internal/boring/aes.go#L235-L237
-// - https://github.com/golang/go/blob/go1.19/src/crypto/internal/boring/aes.go#L250
-// - https://github.com/google/boringssl/blob/ae223d6138807a13006342edfeef32e813246b39/include/openssl/aead.h#L379-L381
-// - https://github.com/google/boringssl/blob/ae223d6138807a13006342edfeef32e813246b39/crypto/fipsmodule/cipher/e_aes.c#L1082-L1093
-//
-//go:linkname newGCMTLS crypto/internal/boring.NewGCMTLS
-func newGCMTLS(c cipher.Block) (cipher.AEAD, error)
-
-type cipherFn struct {
-	fn   func([32]byte) noise.Cipher
-	name string
-}
-
-func (c cipherFn) Cipher(k [32]byte) noise.Cipher { return c.fn(k) }
-func (c cipherFn) CipherName() string             { return c.name }
-
-// CipherAESGCM is the AES256-GCM AEAD cipher (using NewGCMTLS when GoBoring is present)
-var CipherAESGCM noise.CipherFunc = cipherFn{cipherAESGCMBoring, "AESGCM"}
-
-func cipherAESGCMBoring(k [32]byte) noise.Cipher {
-	c, err := aes.NewCipher(k[:])
-	if err != nil {
-		panic(err)
-	}
-	gcm, err := newGCMTLS(c)
-	if err != nil {
-		panic(err)
-	}
-	return aeadCipher{
-		gcm,
-		func(n uint64) []byte {
-			var nonce [12]byte
-			binary.BigEndian.PutUint64(nonce[4:], n)
-			return nonce[:]
-		},
-	}
-}
-
-type aeadCipher struct {
-	cipher.AEAD
-	nonce func(uint64) []byte
-}
-
-func (c aeadCipher) Encrypt(out []byte, n uint64, ad, plaintext []byte) []byte {
-	return c.Seal(out, c.nonce(n), plaintext, ad)
-}
-
-func (c aeadCipher) Decrypt(out []byte, n uint64, ad, ciphertext []byte) ([]byte, error) {
-	return c.Open(out, c.nonce(n), ciphertext, ad)
-}
+var boringEnabled = boring.Enabled()

noiseutil/boring_test.go

@@ -4,8 +4,6 @@
 package noiseutil
 
 import (
-	"crypto/boring"
-	"encoding/hex"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -14,33 +12,3 @@ import (
 func TestEncryptLockNeeded(t *testing.T) {
 	assert.True(t, EncryptLockNeeded)
 }
-
-// Ensure NewGCMTLS validates the nonce is non-repeating
-func TestNewGCMTLS(t *testing.T) {
-	assert.True(t, boring.Enabled())
-
-	// Test Case 16 from GCM Spec:
-	//  - (now dead link): http://csrc.nist.gov/groups/ST/toolkit/BCM/documents/proposedmodes/gcm/gcm-spec.pdf
-	//  - as listed in boringssl tests: https://github.com/google/boringssl/blob/fips-20220613/crypto/cipher_extra/test/cipher_tests.txt#L412-L418
-	key, _ := hex.DecodeString("feffe9928665731c6d6a8f9467308308feffe9928665731c6d6a8f9467308308")
-	iv, _ := hex.DecodeString("cafebabefacedbaddecaf888")
-	plaintext, _ := hex.DecodeString("d9313225f88406e5a55909c5aff5269a86a7a9531534f7da2e4c303d8a318a721c3c0c95956809532fcf0e2449a6b525b16aedf5aa0de657ba637b39")
-	aad, _ := hex.DecodeString("feedfacedeadbeeffeedfacedeadbeefabaddad2")
-	expected, _ := hex.DecodeString("522dc1f099567d07f47f37a32a84427d643a8cdcbfe5c0c97598a2bd2555d1aa8cb08e48590dbb3da7b08b1056828838c5f61e6393ba7a0abcc9f662")
-	expectedTag, _ := hex.DecodeString("76fc6ece0f4e1768cddf8853bb2d551b")
-
-	expected = append(expected, expectedTag...)
-
-	var keyArray [32]byte
-	copy(keyArray[:], key)
-	c := CipherAESGCM.Cipher(keyArray)
-	aead := c.(aeadCipher).AEAD
-
-	dst := aead.Seal([]byte{}, iv, plaintext, aad)
-	assert.Equal(t, expected, dst)
-
-	// We expect this to fail since we are re-encrypting with a repeat IV
-	assert.PanicsWithError(t, "boringcrypto: EVP_AEAD_CTX_seal failed", func() {
-		dst = aead.Seal([]byte{}, iv, plaintext, aad)
-	})
-}

noiseutil/cipher_state.go

@@ -29,8 +29,11 @@ type CipherState interface {
 // NewCipherState wraps the post-handshake noise.CipherState in the per-cipher type that matches cipherFunc.
 // cipherFunc must be the same cipher used to build the noise CipherSuite that produced s.
 func NewCipherState(s *noise.CipherState, cipherFunc noise.CipherFunc) CipherState {
+	if cs, ok := s.Cipher().(CipherState); ok {
+		return cs
+	}
 	switch cipherFunc.CipherName() {
-	case CipherAESGCM.CipherName():
+	case noise.CipherAESGCM.CipherName():
 		return NewCipherStateAESGCM(s)
 	case noise.CipherChaChaPoly.CipherName():
 		return NewCipherStateChaChaPoly(s)

noiseutil/cipher_state_test.go

@@ -1,6 +1,7 @@
 package noiseutil
 
 import (
+	"crypto/fips140"
 	"testing"
 
 	"github.com/flynn/noise"
@@ -10,24 +11,30 @@ import (
 
 func TestCipherStateAESGCMRoundtrip(t *testing.T) {
 	enc, dec := buildCipherStates(t, CipherAESGCM)
-	roundtrip(t, NewCipherStateAESGCM(enc), NewCipherStateAESGCM(dec))
+	roundtrip(t, NewCipherState(enc, CipherAESGCM), NewCipherState(dec, CipherAESGCM))
 }
 
 func TestCipherStateChaChaPolyRoundtrip(t *testing.T) {
 	enc, dec := buildCipherStates(t, noise.CipherChaChaPoly)
-	roundtrip(t, NewCipherStateChaChaPoly(enc), NewCipherStateChaChaPoly(dec))
+	roundtrip(t, NewCipherState(enc, noise.CipherChaChaPoly), NewCipherState(dec, noise.CipherChaChaPoly))
 }
 
 func TestNewCipherStateDispatch(t *testing.T) {
 	encA, _ := buildCipherStates(t, CipherAESGCM)
 	encC, _ := buildCipherStates(t, noise.CipherChaChaPoly)
 
-	assert.IsType(t, &CipherStateAESGCM{}, NewCipherState(encA, CipherAESGCM))
+	if !boringEnabled && !fips140.Enabled() {
+		assert.IsType(t, &CipherStateAESGCM{}, NewCipherState(encA, CipherAESGCM))
+	} else {
+		// fips140
+		assert.IsType(t, encA.Cipher(), NewCipherState(encA, CipherAESGCM))
+	}
+
 	assert.IsType(t, &CipherStateChaChaPoly{}, NewCipherState(encC, noise.CipherChaChaPoly))
 }
 
 func TestNewCipherStateUnsupportedPanics(t *testing.T) {
-	enc, _ := buildCipherStates(t, CipherAESGCM)
+	enc, _ := buildCipherStates(t, noise.CipherChaChaPoly)
 	assert.Panics(t, func() {
 		NewCipherState(enc, fakeCipher{})
 	})

noiseutil/fips140.go

@@ -0,0 +1,179 @@
+package noiseutil
+
+import (
+	"bytes"
+	"crypto/cipher"
+	"crypto/fips140"
+	"encoding/binary"
+	"fmt"
+	"reflect"
+	"runtime"
+	"unsafe"
+
+	// unsafe needed for go:linkname
+	_ "crypto/tls"
+	_ "unsafe"
+
+	"github.com/flynn/noise"
+)
+
+// TODO: Use NewGCMWithCounterNonce or NewGCMForQUIC once available:
+// - https://github.com/golang/go/issues/73110
+// - https://github.com/golang/go/issues/79219
+// Using tls.aeadAESGCMTLS13 gives us the TLS 1.3 GCM, which also verifies
+// that the nonce is strictly increasing. This works for both boringcrypto
+// and fips140.
+//
+//go:linkname aeadAESGCMTLS13 crypto/tls.aeadAESGCMTLS13
+func aeadAESGCMTLS13(key, noncePrefix []byte) cipher.AEAD
+
+type cipherFn struct {
+	fn   func([32]byte) noise.Cipher
+	name string
+}
+
+func (c cipherFn) Cipher(k [32]byte) noise.Cipher { return c.fn(k) }
+func (c cipherFn) CipherName() string             { return c.name }
+
+// CipherAESGCMFIPS140 is the AES256-GCM AEAD cipher (using tls.aeadAESGCMTLS13, for both boringcrypto and fips140)
+var CipherAESGCMFIPS140 noise.CipherFunc = cipherFn{cipherAESGCMFIPS140, "AESGCM"}
+
+// tls.aeadAESGCMTLS13 uses a 4 byte static prefix and an 8 byte XOR mask
+var emptyNonce = []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
+
+func cipherAESGCMFIPS140(k [32]byte) noise.Cipher {
+	gcm := aeadAESGCMTLS13(k[:], emptyNonce)
+	gcm = extractFIPSAEAD(gcm)
+	return &aeadGCMFIPS140Cipher{
+		AEAD: gcm,
+	}
+}
+
+type aeadGCMFIPS140Cipher struct {
+	cipher.AEAD
+	ready bool
+}
+
+// Extract the internal FIPS GCM implementation from the tls wrapper. The TLS
+// wrapper is not thread safe around Open, so instead of locking around it we
+// can grab the internal implementation that is thread safe. This is the FIPS
+// module implementation: `crypto/internal/fips140/aes/gcm.GCMWithXORCounterNonce`
+//
+// - https://github.com/golang/go/blob/go1.26.4/src/crypto/internal/fips140/aes/gcm/gcm_nonces.go#L212-L287
+//
+// The wrapper is struct `crypto/tls.xorNonceAEAD` , with field `aead`:
+//
+// - https://github.com/golang/go/blob/go1.26.4/src/crypto/tls/cipher_suites.go#L482-L487
+//
+// This can be cleaned up once these FIPS implementations are exposed directly:
+//
+// - https://github.com/golang/go/issues/73110
+func extractFIPSAEAD(xorNonceAEAD cipher.AEAD) cipher.AEAD {
+	r := reflect.ValueOf(xorNonceAEAD)
+	v := r.Elem().FieldByName("aead")
+	if !v.IsValid() {
+		// The internal crypto/tls.xorNonceAEAD struct no longer has an `aead`
+		// field. This can only happen on a Go version this code was not built
+		// against; the package init() self-test guards against ever reaching
+		// this at runtime, so this is a defensive fail-fast.
+		panic(fmt.Sprintf("noiseutil: could not extract FIPS AEAD from %T on %s: no `aead` field (incompatible Go version)", xorNonceAEAD, runtime.Version()))
+	}
+	v2 := reflect.NewAt(v.Type(), unsafe.Pointer(v.UnsafeAddr())).Elem()
+	aead, ok := v2.Interface().(cipher.AEAD)
+	if !ok {
+		panic(fmt.Sprintf("noiseutil: extracted FIPS `aead` field is %s, not a cipher.AEAD, on %s (incompatible Go version)", v2.Type(), runtime.Version()))
+	}
+	return aead
+}
+
+func (c *aeadGCMFIPS140Cipher) init(nonce []byte) {
+	// GCMWithXORCounterNonce expects that the first call to Seal
+	// is with a counter of `0`, this is how it extracts the nonce mask.
+	// We can clean this up in the future when NewGCMWithCounterNonce or
+	// NewGCMForQUIC are available:
+	if !bytes.Equal(emptyNonce, nonce) {
+		c.AEAD.Seal([]byte{}, emptyNonce, []byte{}, []byte{})
+	}
+	c.ready = true
+}
+
+func (c *aeadGCMFIPS140Cipher) Seal(dst, nonce, plaintext, additionalData []byte) []byte {
+	if !c.ready {
+		c.init(nonce)
+	}
+	return c.AEAD.Seal(dst, nonce, plaintext, additionalData)
+}
+
+func (c *aeadGCMFIPS140Cipher) Encrypt(out []byte, n uint64, ad, plaintext []byte) []byte {
+	return c.Seal(out, aeadGCMFIPS140CipherNonce(n), plaintext, ad)
+}
+
+func (c *aeadGCMFIPS140Cipher) Decrypt(out []byte, n uint64, ad, ciphertext []byte) ([]byte, error) {
+	return c.Open(out, aeadGCMFIPS140CipherNonce(n), ciphertext, ad)
+}
+
+func (c *aeadGCMFIPS140Cipher) EncryptDanger(out, ad, plaintext []byte, n uint64, nb []byte) ([]byte, error) {
+	binary.BigEndian.PutUint64(nb[4:], n)
+	out = c.Seal(out, nb, plaintext, ad)
+	return out, nil
+}
+
+func (c *aeadGCMFIPS140Cipher) DecryptDanger(out, ad, ciphertext []byte, n uint64, nb []byte) ([]byte, error) {
+	binary.BigEndian.PutUint64(nb[4:], n)
+	return c.Open(out, nb, ciphertext, ad)
+}
+
+func aeadGCMFIPS140CipherNonce(n uint64) []byte {
+	// GCMWithXORCounterNonce uses a 4 byte static prefix and an 8 byte nonce
+	var nonce [12]byte
+	binary.BigEndian.PutUint64(nonce[4:], n)
+	return nonce[:]
+}
+
+// init validates the go:linkname + reflection extraction and the nonce-reuse
+// protection at startup, in every build. cipherAESGCMFIPS140 relies on unexported
+// crypto/tls and crypto/internal/fips140 internals; if a future Go version changes
+// those, this fails fast with a clear message instead of panicking per-handshake
+// (or, worse, silently losing the strictly-increasing nonce check that is the whole
+// point of using this cipher). Because this file has no build tag, this self-test
+// runs even in non-FIPS builds, so the default CI lane catches an incompatible Go.
+func init() {
+	var key [32]byte
+	c := cipherAESGCMFIPS140(key)
+
+	// Verify the extracted AEAD produces a working encrypt/decrypt roundtrip.
+	plaintext := []byte("nebula fips140 self-test")
+	ad := []byte("ad")
+	ct := c.Encrypt(nil, 1, ad, plaintext)
+	pt, err := c.Decrypt(nil, 1, ad, ct)
+	if err != nil {
+		panic(fmt.Sprintf("noiseutil: FIPS AES-GCM self-test roundtrip failed on %s: %v", runtime.Version(), err))
+	}
+	if !bytes.Equal(pt, plaintext) {
+		panic(fmt.Sprintf("noiseutil: FIPS AES-GCM self-test roundtrip returned wrong plaintext on %s", runtime.Version()))
+	}
+
+	// Verify the nonce-reuse protection still fires: re-encrypting with the same
+	// counter must panic. This is the guarantee we depend on for nonce safety, so
+	// if the extraction ever silently yields an AEAD without it, refuse to start.
+	// The strictly-increasing nonce check only exists under boringcrypto/fips140;
+	// in a plain build aeadAESGCMTLS13 wraps a standard GCM that does not enforce
+	// it (and CipherAESGCMFIPS140 is unused there anyway), so only assert it when
+	// one of those modes is active.
+	if (boringEnabled || fips140.Enabled()) && !reusePanics(c) {
+		panic(fmt.Sprintf("noiseutil: FIPS AES-GCM self-test did not reject a reused nonce on %s; nonce-reuse protection is missing (incompatible Go version)", runtime.Version()))
+	}
+}
+
+// reusePanics reports whether re-encrypting with an already-used counter panics,
+// as GCMWithXORCounterNonce is expected to.
+func reusePanics(c noise.Cipher) (panicked bool) {
+	c.Encrypt(nil, 2, nil, nil)
+	defer func() {
+		if recover() != nil {
+			panicked = true
+		}
+	}()
+	c.Encrypt(nil, 2, nil, nil)
+	return false
+}

noiseutil/fips140_test.go

@@ -0,0 +1,48 @@
+package noiseutil
+
+import (
+	"crypto/cipher"
+	"crypto/fips140"
+	"encoding/hex"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// Ensure NewAESGCM validates the nonce is non-repeating
+func TestNewAESGCM(t *testing.T) {
+	if !boringEnabled && !fips140.Enabled() {
+		t.Skip("TestNewAESGCM is only for fips140/boringcrypto")
+	}
+
+	key, _ := hex.DecodeString("feffe9928665731c6d6a8f9467308308feffe9928665731c6d6a8f9467308308")
+	iv, _ := hex.DecodeString("00000000facedbaddecaf888")
+	plaintext, _ := hex.DecodeString("d9313225f88406e5a55909c5aff5269a86a7a9531534f7da2e4c303d8a318a721c3c0c95956809532fcf0e2449a6b525b16aedf5aa0de657ba637b39")
+	aad, _ := hex.DecodeString("feedfacedeadbeeffeedfacedeadbeefabaddad2")
+	expected, _ := hex.DecodeString("6a65c2edd45bd63c7e29f40e3d2ed8ba2b99f4c83135383d5676652f255059ceb24863ff10afb1089db701245da87fb88d3acd5f9dd0770cac220c3c04145caf25e190aeb775e7080401c628")
+
+	var keyArray [32]byte
+	copy(keyArray[:], key)
+	c := CipherAESGCM.Cipher(keyArray)
+	aead := c.(cipher.AEAD)
+
+	dst := aead.Seal([]byte{}, iv, plaintext, aad)
+	t.Logf("%x", dst)
+	assert.Equal(t, expected, dst)
+
+	// We expect this to fail since we are re-encrypting with a repeat IV
+	switch {
+	case boringEnabled:
+		assert.PanicsWithError(t, "boringcrypto: EVP_AEAD_CTX_seal failed", func() {
+			dst = aead.Seal([]byte{}, iv, plaintext, aad)
+		})
+	case fips140.Version() == "v1.0.0":
+		assert.PanicsWithValue(t, "crypto/cipher: counter decreased", func() {
+			dst = aead.Seal([]byte{}, iv, plaintext, aad)
+		})
+	default:
+		assert.PanicsWithValue(t, "crypto/cipher: counter decreased or remained the same", func() {
+			dst = aead.Seal([]byte{}, iv, plaintext, aad)
+		})
+	}
+}

noiseutil/fips140enforce.go

@@ -0,0 +1,13 @@
+//go:build fips140enforce
+
+package noiseutil
+
+import (
+	"crypto/fips140"
+)
+
+func init() {
+	if !fips140.Enforced() {
+		panic("Nebula compiled with fips140 expects FIPS140 to be enforced. Do not set GODEBUG=fips140, or if you do it must be set as GODEBUG=fips140=only")
+	}
+}

noiseutil/notboring.go

@@ -1,14 +1,25 @@
 //go:build !boringcrypto
-// +build !boringcrypto
 
 package noiseutil
 
 import (
+	"crypto/fips140"
+
 	"github.com/flynn/noise"
 )
 
 // EncryptLockNeeded indicates if calls to Encrypt need a lock
-const EncryptLockNeeded = false
+var EncryptLockNeeded = fips140.Enabled()
 
-// CipherAESGCM is the standard noise.CipherAESGCM when boringcrypto is not enabled
-var CipherAESGCM noise.CipherFunc = noise.CipherAESGCM
+var CipherAESGCM noise.CipherFunc = initAESGCM()
+
+func initAESGCM() noise.CipherFunc {
+	if fips140.Enabled() {
+		return CipherAESGCMFIPS140
+	} else {
+		return noise.CipherAESGCM
+	}
+
+}
+
+var boringEnabled = false

noiseutil/notboring_test.go

@@ -1,14 +0,0 @@
-//go:build !boringcrypto
-// +build !boringcrypto
-
-package noiseutil
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestEncryptLockNeeded(t *testing.T) {
-	assert.False(t, EncryptLockNeeded)
-}

pki.go

@@ -1,6 +1,7 @@
 package nebula
 
 import (
+	"crypto/fips140"
 	"encoding/binary"
 	"encoding/json"
 	"errors"
@@ -237,10 +238,17 @@ func (cs *CertState) getCertificate(v cert.Version) cert.Certificate {
 	return nil
 }
 
-func newCipherSuite(curve cert.Curve, pkcs11backed bool, cipher string) (noise.CipherSuite, error) {
+// newCipherSuite builds the noise.CipherSuite for the given curve and cipher.
+// When fips140Enforced is true (FIPS 140-only mode), non-approved algorithms
+// (Curve25519 and ChaChaPoly) are rejected with an error. Callers pass
+// fips140.Enforced() for fips140Enforced.
+func newCipherSuite(curve cert.Curve, pkcs11backed bool, cipher string, fips140Enforced bool) (noise.CipherSuite, error) {
 	var dhFunc noise.DHFunc
 	switch curve {
 	case cert.Curve_CURVE25519:
+		if fips140Enforced {
+			return nil, errors.New("pki: use of Curve25519 is not allowed in FIPS 140-only mode")
+		}
 		dhFunc = noise.DH25519
 	case cert.Curve_P256:
 		if pkcs11backed {
@@ -253,6 +261,9 @@ func newCipherSuite(curve cert.Curve, pkcs11backed bool, cipher string) (noise.C
 	}
 
 	if cipher == "chachapoly" {
+		if fips140Enforced {
+			return nil, errors.New("pki: use of ChaChaPoly is not allowed in FIPS 140-only mode")
+		}
 		return noise.NewCipherSuite(dhFunc, noise.CipherChaChaPoly, noise.HashSHA256), nil
 	}
 	return noise.NewCipherSuite(dhFunc, noiseutil.CipherAESGCM, noise.HashSHA256), nil
@@ -326,6 +337,10 @@ func newCertStateFromConfig(c *config.C, cipher string) (*CertState, error) {
 			return nil, err
 		}
 
+		if fips140.Enforced() && crt.Curve() != cert.Curve_P256 {
+			return nil, fmt.Errorf("pki: use of %s is not allowed in FIPS 140-only mode", crt.Curve())
+		}
+
 		switch crt.Version() {
 		case cert.Version1:
 			if v1 != nil {
@@ -405,7 +420,7 @@ func newCertState(dv cert.Version, v1, v2 cert.Certificate, pkcs11backed bool, p
 			//NOTE: We do not currently have a method to verify a public private key pair when the private key is in an hsm
 		} else {
 			if err := v1.VerifyPrivateKey(privateKeyCurve, privateKey); err != nil {
-				return nil, fmt.Errorf("private key is not a pair with public key in nebula cert")
+				return nil, fmt.Errorf("private key is not a pair with public key in nebula cert: %w", err)
 			}
 		}
 
@@ -413,7 +428,7 @@ func newCertState(dv cert.Version, v1, v2 cert.Certificate, pkcs11backed bool, p
 		if err != nil {
 			return nil, fmt.Errorf("error marshalling v1 certificate for handshake: %w", err)
 		}
-		ncs, err := newCipherSuite(v1.Curve(), pkcs11backed, cipher)
+		ncs, err := newCipherSuite(v1.Curve(), pkcs11backed, cipher, fips140.Enforced())
 		if err != nil {
 			return nil, err
 		}
@@ -430,7 +445,7 @@ func newCertState(dv cert.Version, v1, v2 cert.Certificate, pkcs11backed bool, p
 			//NOTE: We do not currently have a method to verify a public private key pair when the private key is in an hsm
 		} else {
 			if err := v2.VerifyPrivateKey(privateKeyCurve, privateKey); err != nil {
-				return nil, fmt.Errorf("private key is not a pair with public key in nebula cert")
+				return nil, fmt.Errorf("private key is not a pair with public key in nebula cert: %w", err)
 			}
 		}
 
@@ -438,7 +453,7 @@ func newCertState(dv cert.Version, v1, v2 cert.Certificate, pkcs11backed bool, p
 		if err != nil {
 			return nil, fmt.Errorf("error marshalling v2 certificate for handshake: %w", err)
 		}
-		ncs, err := newCipherSuite(v2.Curve(), pkcs11backed, cipher)
+		ncs, err := newCipherSuite(v2.Curve(), pkcs11backed, cipher, fips140.Enforced())
 		if err != nil {
 			return nil, err
 		}

pki_test.go

@@ -0,0 +1,94 @@
+package nebula
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/slackhq/nebula/cert"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewCipherSuite(t *testing.T) {
+	tests := []struct {
+		name            string
+		curve           cert.Curve
+		cipher          string
+		fips140Enforced bool
+		wantErr         string
+		// wantName is the full expected CipherSuite name (<DH>_<Cipher>_<Hash>),
+		// only checked when wantErr is empty. Asserting the whole name makes both
+		// the curve and cipher selection load-bearing.
+		wantName string
+	}{
+		{
+			name:     "curve25519 aesgcm, not enforced",
+			curve:    cert.Curve_CURVE25519,
+			cipher:   "aesgcm",
+			wantName: "25519_AESGCM_SHA256",
+		},
+		{
+			name:     "curve25519 chachapoly, not enforced",
+			curve:    cert.Curve_CURVE25519,
+			cipher:   "chachapoly",
+			wantName: "25519_ChaChaPoly_SHA256",
+		},
+		{
+			name:     "p256 aesgcm, not enforced",
+			curve:    cert.Curve_P256,
+			cipher:   "aesgcm",
+			wantName: "P256_AESGCM_SHA256",
+		},
+		{
+			name:            "p256 aesgcm, enforced is allowed",
+			curve:           cert.Curve_P256,
+			cipher:          "aesgcm",
+			fips140Enforced: true,
+			wantName:        "P256_AESGCM_SHA256",
+		},
+		{
+			name:            "curve25519 rejected when enforced",
+			curve:           cert.Curve_CURVE25519,
+			cipher:          "aesgcm",
+			fips140Enforced: true,
+			wantErr:         "pki: use of Curve25519 is not allowed in FIPS 140-only mode",
+		},
+		{
+			name:            "chachapoly rejected when enforced",
+			curve:           cert.Curve_P256,
+			cipher:          "chachapoly",
+			fips140Enforced: true,
+			wantErr:         "pki: use of ChaChaPoly is not allowed in FIPS 140-only mode",
+		},
+		{
+			// Curve is checked before cipher, so a Curve25519+ChaChaPoly
+			// request reports the Curve25519 rejection.
+			name:            "curve25519 chachapoly rejected on curve when enforced",
+			curve:           cert.Curve_CURVE25519,
+			cipher:          "chachapoly",
+			fips140Enforced: true,
+			wantErr:         "pki: use of Curve25519 is not allowed in FIPS 140-only mode",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cs, err := newCipherSuite(tt.curve, false, tt.cipher, tt.fips140Enforced)
+			if tt.wantErr != "" {
+				require.EqualError(t, err, tt.wantErr)
+				assert.Nil(t, cs)
+				return
+			}
+			require.NoError(t, err)
+			require.NotNil(t, cs)
+			assert.Equal(t, tt.wantName, string(cs.Name()))
+		})
+	}
+}
+
+func TestNewCipherSuiteUnsupportedCurve(t *testing.T) {
+	cs, err := newCipherSuite(cert.Curve(99), false, "aesgcm", false)
+	require.Error(t, err)
+	assert.True(t, strings.HasPrefix(err.Error(), "unsupported curve:"), "got: %v", err)
+	assert.Nil(t, cs)
+}

stats.go

@@ -2,6 +2,7 @@ package nebula
 
 import (
 	"context"
+	"crypto/fips140"
 	"errors"
 	"fmt"
 	"log/slog"
@@ -288,9 +289,12 @@ func (s *statsServer) buildRuntime(cfg statsConfig) ([]func(), *http.Server) {
 			Name:      "info",
 			Help:      "Version information for the Nebula binary",
 			ConstLabels: prometheus.Labels{
-				"version":      s.buildVersion,
-				"goversion":    runtime.Version(),
-				"boringcrypto": strconv.FormatBool(boringEnabled()),
+				"version":         s.buildVersion,
+				"goversion":       runtime.Version(),
+				"boringcrypto":    strconv.FormatBool(boringEnabled()),
+				"fips140Version":  fips140.Version(),
+				"fips140Enabled":  strconv.FormatBool(fips140.Enabled()),
+				"fips140Enforced": strconv.FormatBool(fips140.Enforced()),
 			},
 		})
 		pr.MustRegister(g)