feat: add support for mDTLS

Signed-off-by: Felix Gateru <felix.gateru@gmail.com>

Author: felixgateru

.env

@@ -103,4 +103,14 @@ MGATE_COAP_WITH_DTLS_TARGET_PORT=5683
 MGATE_COAP_WITH_DTLS_CERT_FILE=ssl/certs/server.crt
 MGATE_COAP_WITH_DTLS_KEY_FILE=ssl/certs/server.key
 MGATE_COAP_WITH_DTLS_SERVER_CA_FILE=ssl/certs/ca.crt
-MGATE_COAP_WITH_DTLS_CLIENT_CA_FILE=ssl/certs/ca.crt
+
+MGATE_COAP_WITH_MDTLS_HOST=
+MGATE_COAP_WITH_MDTLS_PORT=5685
+MGATE_COAP_WITH_MDTLS_TARGET_HOST=localhost
+MGATE_COAP_WITH_MDTLS_TARGET_PORT=5683
+MGATE_COAP_WITH_MDTLS_CERT_FILE=ssl/certs/server.crt
+MGATE_COAP_WITH_MDTLS_KEY_FILE=ssl/certs/server.key
+MGATE_COAP_WITH_MDTLS_SERVER_CA_FILE=ssl/certs/ca.crt
+MGATE_COAP_WITH_MDTLS_CLIENT_CA_FILE=ssl/certs/ca.crt
+MGATE_COAP_WITH_MDTLS_CERT_VERIFICATION_METHODS=ocsp
+MGATE_COAP_WITH_MDTLS_OCSP_RESPONDER_URL=http://localhost:8880/ocsp

cmd/main.go

@@ -38,6 +38,7 @@ const (
 
 	coapWithoutDTLS = "MGATE_COAP_WITHOUT_DTLS_"
 	coapWithDTLS    = "MGATE_COAP_WITH_DTLS_"
+	coapWithmDTLS   = "MGATE_COAP_WITH_MDTLS_"
 )
 
 func main() {
@@ -200,6 +201,18 @@ func main() {
 		return coapDTLSProxy.Listen(ctx)
 	})
 
+	// mGate server Configuration for CoAP with mDTLS
+	coapmDTLSConfig, err := mgate.NewConfig(env.Options{Prefix: coapWithmDTLS})
+	if err != nil {
+		panic(err)
+	}
+
+	// mGate server for CoAP with mDTLS
+	coapmDTLSProxy := coap.NewProxy(coapmDTLSConfig, handler, logger)
+	g.Go(func() error {
+		return coapmDTLSProxy.Listen(ctx)
+	})
+
 	g.Go(func() error {
 		return StopSignalHandler(ctx, cancel, logger)
 	})

pkg/coap/coap.go

@@ -120,7 +120,7 @@ func (p *Proxy) Listen(ctx context.Context) error {
 	}
 
 	status := mptls.SecurityStatus(p.config.DTLSConfig)
-	p.logger.Info(fmt.Sprintf("COAP proxy server started at %s  with %s", net.JoinHostPort(p.config.Host, p.config.Port), status))
+	p.logger.Info(fmt.Sprintf("COAP proxy server started at %s with %s", net.JoinHostPort(p.config.Host, p.config.Port), status))
 
 	if err := g.Wait(); err != nil {
 		p.logger.Info(fmt.Sprintf("COAP proxy server at %s exiting with errors", net.JoinHostPort(p.config.Host, p.config.Port)), slog.String("error", err.Error()))

pkg/tls/tls.go

@@ -143,7 +143,12 @@ func SecurityStatus[sc TLSConfig](s sc) string {
 		}
 		return ret
 	case *dtls.Config:
-		return "DTLS"
+		ret := "DTLS"
+
+		if c.ClientCAs != nil {
+			ret += " and " + toClientAuthString(c.ClientAuth)
+		}
+		return ret
 	default:
 		return "no TLS"
 	}
@@ -155,3 +160,20 @@ func loadCertFile(certFile string) ([]byte, error) {
 	}
 	return []byte{}, nil
 }
+
+func toClientAuthString(cat dtls.ClientAuthType) string {
+	switch cat {
+	case dtls.NoClientCert:
+		return "NoClientCert"
+	case dtls.RequestClientCert:
+		return "RequestClientCert"
+	case dtls.RequireAnyClientCert:
+		return "RequestAnyClientCert"
+	case dtls.VerifyClientCertIfGiven:
+		return "VerifyClientCertIfGiven"
+	case dtls.RequireAndVerifyClientCert:
+		return "RequireAndVerifyClientCert"
+	default:
+		return ""
+	}
+}