snapshot of https://github.com/grpc/grpc-go.git (master, 2026-09-15; blobs > 131072B omitted)

security/advancedtls/examples/credential_reloading_from_files/server/main.go

@@ -0,0 +1,112 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// The server demonstrates how to use the credential reloading feature in
+// advancedtls to serve mTLS connections from the client.
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"net"
+	"time"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/tls/certprovider/pemfile"
+	"google.golang.org/grpc/keepalive"
+	"google.golang.org/grpc/security/advancedtls"
+	"google.golang.org/grpc/security/advancedtls/testdata"
+
+	pb "google.golang.org/grpc/examples/helloworld/helloworld"
+)
+
+var port = ":50051"
+
+// Intervals that set to monitor the credential updates.
+const credRefreshingInterval = 1 * time.Minute
+
+type greeterServer struct {
+	pb.UnimplementedGreeterServer
+}
+
+// sayHello is a simple implementation of the pb.GreeterServer SayHello method.
+func (greeterServer) SayHello(_ context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
+	return &pb.HelloReply{Message: "Hello " + in.Name}, nil
+}
+
+func main() {
+	flag.Parse()
+	fmt.Printf("server starting on port %s...\n", port)
+
+	identityOptions := pemfile.Options{
+		CertFile:        testdata.Path("server_cert_1.pem"),
+		KeyFile:         testdata.Path("server_key_1.pem"),
+		RefreshDuration: credRefreshingInterval,
+	}
+	identityProvider, err := pemfile.NewProvider(identityOptions)
+	if err != nil {
+		log.Fatalf("pemfile.NewProvider(%v) failed: %v", identityOptions, err)
+	}
+	defer identityProvider.Close()
+	rootOptions := pemfile.Options{
+		RootFile:        testdata.Path("server_trust_cert_1.pem"),
+		RefreshDuration: credRefreshingInterval,
+	}
+	rootProvider, err := pemfile.NewProvider(rootOptions)
+	if err != nil {
+		log.Fatalf("pemfile.NewProvider(%v) failed: %v", rootOptions, err)
+	}
+	defer rootProvider.Close()
+
+	// Start a server and create a client using advancedtls API with Provider.
+	options := &advancedtls.Options{
+		IdentityOptions: advancedtls.IdentityCertificateOptions{
+			IdentityProvider: identityProvider,
+		},
+		RootOptions: advancedtls.RootCertificateOptions{
+			RootProvider: rootProvider,
+		},
+		RequireClientCert: true,
+		AdditionalPeerVerification: func(params *advancedtls.HandshakeVerificationInfo) (*advancedtls.PostHandshakeVerificationResults, error) {
+			// This message is to show the certificate under the hood is actually reloaded.
+			fmt.Printf("Client common name: %s.\n", params.Leaf.Subject.CommonName)
+			return &advancedtls.PostHandshakeVerificationResults{}, nil
+		},
+		VerificationType: advancedtls.CertVerification,
+	}
+	serverTLSCreds, err := advancedtls.NewServerCreds(options)
+	if err != nil {
+		log.Fatalf("advancedtls.NewServerCreds(%v) failed: %v", options, err)
+	}
+	s := grpc.NewServer(grpc.Creds(serverTLSCreds), grpc.KeepaliveParams(keepalive.ServerParameters{
+		// Set the max connection time to be 0.5 s to force the client to
+		// re-establish the connection, and hence re-invoke the verification
+		// callback.
+		MaxConnectionAge: 500 * time.Millisecond,
+	}))
+	lis, err := net.Listen("tcp", port)
+	if err != nil {
+		log.Fatalf("failed to listen: %v", err)
+	}
+	pb.RegisterGreeterServer(s, greeterServer{})
+	if err := s.Serve(lis); err != nil {
+		log.Fatalf("failed to serve: %v", err)
+	}
+}