From d438db50012b7abeeda0829c373abb0a41f0306e Mon Sep 17 00:00:00 2001
From: Viktor Liu <viktor@netbird.io>
Date: Tue, 14 Jul 2026 14:32:34 +0200
Subject: [PATCH] Run Rosenpass in permissive mode on the embedded proxy

---
 client/embed/embed.go               |  7 ++++++
 proxy/internal/roundtrip/netbird.go | 33 +++++++++++++++++++++++------
 2 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/client/embed/embed.go b/client/embed/embed.go
index 99a6b8229..e3815eb3a 100644
--- a/client/embed/embed.go
+++ b/client/embed/embed.go
@@ -85,6 +85,11 @@ type Options struct {
 	DisableIPv6 bool
 	// BlockInbound blocks all inbound connections from peers
 	BlockInbound bool
+	// EnableRosenpass enables the Rosenpass post-quantum key exchange.
+	EnableRosenpass bool
+	// RosenpassPermissive lets a Rosenpass-enabled peer still connect to peers
+	// that do not run Rosenpass (falling back to the plain WireGuard PSK).
+	RosenpassPermissive bool
 	// BlockLANAccess blocks the embedded peer from reaching the host's
 	// LAN (RFC 1918, link-local, loopback) when it's used as a routing
 	// peer. Mirrors profilemanager.ConfigInput.BlockLANAccess. Useful
@@ -203,6 +208,8 @@ func New(opts Options) (*Client, error) {
 		DisableIPv6:         &opts.DisableIPv6,
 		BlockInbound:        &opts.BlockInbound,
 		BlockLANAccess:      &opts.BlockLANAccess,
+		RosenpassEnabled:    &opts.EnableRosenpass,
+		RosenpassPermissive: &opts.RosenpassPermissive,
 		WireguardPort:       opts.WireguardPort,
 		MTU:                 opts.MTU,
 		DNSLabels:           parsedLabels,
diff --git a/proxy/internal/roundtrip/netbird.go b/proxy/internal/roundtrip/netbird.go
index cb2e7f930..ae3308a3e 100644
--- a/proxy/internal/roundtrip/netbird.go
+++ b/proxy/internal/roundtrip/netbird.go
@@ -30,6 +30,12 @@ import (
 
 const deviceNamePrefix = "ingress-proxy-"
 
+// envProxyRosenpass toggles Rosenpass (permissive) on the embedded proxy client. Defaults to on.
+const envProxyRosenpass = "NB_PROXY_ROSENPASS" //nolint:gosec // env var name, not a credential
+
+// envProxyClientLogLevel sets the embedded NetBird client's log level.
+const envProxyClientLogLevel = "NB_PROXY_CLIENT_LOG_LEVEL"
+
 const clientStopTimeout = 30 * time.Second
 
 const createProxyPeerTimeout = 30 * time.Second
@@ -353,11 +359,11 @@ func (n *NetBird) createClientEntry(ctx context.Context, accountID types.Account
 	// NB_PROXY_CLIENT_LOG_LEVEL (e.g. "trace") to surface the embedded NetBird
 	// client's relay / signal / handshake detail for local debugging.
 	clientLogLevel := log.WarnLevel.String()
-	if v := strings.TrimSpace(os.Getenv("NB_PROXY_CLIENT_LOG_LEVEL")); v != "" {
+	if v := strings.TrimSpace(os.Getenv(envProxyClientLogLevel)); v != "" {
 		if lvl, err := log.ParseLevel(v); err == nil {
 			clientLogLevel = lvl.String()
 		} else {
-			n.logger.Warnf("invalid NB_PROXY_CLIENT_LOG_LEVEL %q, using %q: %v", v, clientLogLevel, err)
+			n.logger.Warnf("invalid %s %q, using %q: %v", envProxyClientLogLevel, v, clientLogLevel, err)
 		}
 	}
 
@@ -367,15 +373,26 @@ func (n *NetBird) createClientEntry(ctx context.Context, accountID types.Account
 		}
 	})
 
+	// Rosenpass runs in permissive mode by default so the embedded proxy can
+	// establish connections with Rosenpass-enabled peers (which otherwise fail
+	// on a PSK mismatch) while still falling back to plain WireGuard for peers
+	// that do not run Rosenpass. Set NB_PROXY_ROSENPASS=false to disable it.
+	rosenpassEnabled := true
+	if v, ok := envBool(envProxyRosenpass, n.logger); ok {
+		rosenpassEnabled = v
+	}
+
 	// Create embedded NetBird client with the generated private key.
 	// The peer has already been created via CreateProxyPeer RPC with the public key.
 	wgPort := int(n.clientCfg.WGPort)
 	embedOpts := embed.Options{
-		DeviceName:    deviceNamePrefix + n.proxyID,
-		ManagementURL: n.clientCfg.MgmtAddr,
-		PrivateKey:    privateKey.String(),
-		LogLevel:      clientLogLevel,
-		BlockInbound:  n.clientCfg.BlockInbound,
+		DeviceName:          deviceNamePrefix + n.proxyID,
+		ManagementURL:       n.clientCfg.MgmtAddr,
+		PrivateKey:          privateKey.String(),
+		LogLevel:            clientLogLevel,
+		BlockInbound:        n.clientCfg.BlockInbound,
+		EnableRosenpass:     rosenpassEnabled,
+		RosenpassPermissive: rosenpassEnabled,
 		// The embedded proxy peer must never be a stepping stone into
 		// the proxy host's LAN: it only exists to reach NetBird mesh
 		// targets or, when direct_upstream is set, the host network
@@ -899,6 +916,8 @@ func logEmbedOptions(logger *log.Logger, accountID types.AccountID, serviceID ty
 		"mtu":                   mtu,
 		"block_inbound":         opts.BlockInbound,
 		"block_lan_access":      opts.BlockLANAccess,
+		"rosenpass_enabled":     opts.EnableRosenpass,
+		"rosenpass_permissive":  opts.RosenpassPermissive,
 		"disable_ipv6":          opts.DisableIPv6,
 		"disable_client_routes": opts.DisableClientRoutes,
 		"no_userspace":          opts.NoUserspace,