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

examples/features/encryption/ALTS/client/main.go

@@ -0,0 +1,63 @@
+/*
+ *
+ * Copyright 2018 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.
+ *
+ */
+
+// Binary client demonstrates how to use ALTS credentials for secure
+// gRPC communication.
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"time"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/alts"
+	ecpb "google.golang.org/grpc/examples/features/proto/echo"
+)
+
+var addr = flag.String("addr", "localhost:50051", "the address to connect to")
+
+func callUnaryEcho(client ecpb.EchoClient, message string) {
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	resp, err := client.UnaryEcho(ctx, &ecpb.EchoRequest{Message: message})
+	if err != nil {
+		log.Fatalf("client.UnaryEcho(_) = _, %v: ", err)
+	}
+	fmt.Println("UnaryEcho: ", resp.Message)
+}
+
+func main() {
+	flag.Parse()
+
+	// Create alts based credential.
+	altsTC := alts.NewClientCreds(alts.DefaultClientOptions())
+
+	// Set up a connection to the server.
+	conn, err := grpc.NewClient(*addr, grpc.WithTransportCredentials(altsTC))
+	if err != nil {
+		log.Fatalf("did not connect: %v", err)
+	}
+	defer conn.Close()
+
+	// Make an echo client and send an RPC.
+	rgc := ecpb.NewEchoClient(conn)
+	callUnaryEcho(rgc, "hello world")
+}

examples/features/encryption/ALTS/server/main.go

@@ -0,0 +1,64 @@
+/*
+ *
+ * Copyright 2018 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.
+ *
+ */
+
+// Binary server demonstrates how to use ALTS credentials to secure gRPC
+// services.
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"net"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/alts"
+
+	pb "google.golang.org/grpc/examples/features/proto/echo"
+)
+
+var port = flag.Int("port", 50051, "the port to serve on")
+
+type ecServer struct {
+	pb.UnimplementedEchoServer
+}
+
+func (s *ecServer) UnaryEcho(_ context.Context, req *pb.EchoRequest) (*pb.EchoResponse, error) {
+	return &pb.EchoResponse{Message: req.Message}, nil
+}
+
+func main() {
+	flag.Parse()
+
+	lis, err := net.Listen("tcp", fmt.Sprintf(":%d", *port))
+	if err != nil {
+		log.Fatalf("failed to listen: %v", err)
+	}
+	// Create alts based credential.
+	altsTC := alts.NewServerCreds(alts.DefaultServerOptions())
+
+	s := grpc.NewServer(grpc.Creds(altsTC))
+
+	// Register EchoServer on the server.
+	pb.RegisterEchoServer(s, &ecServer{})
+
+	if err := s.Serve(lis); err != nil {
+		log.Fatalf("failed to serve: %v", err)
+	}
+}

examples/features/encryption/README.md

@@ -0,0 +1,119 @@
+# Encryption
+
+The example for encryption includes three individual examples for TLS, ALTS
+and mTLS encryption mechanism respectively.
+
+## Try it
+
+In each example's subdirectory:
+
+```
+go run server/main.go
+```
+
+```
+go run client/main.go
+```
+
+## Explanation
+
+### TLS
+
+TLS is a commonly used cryptographic protocol to provide end-to-end
+communication security. In the example, we show how to set up a server
+authenticated TLS connection to transmit RPC.
+
+In our `grpc/credentials` package, we provide several convenience methods to
+create grpc
+[`credentials.TransportCredentials`](https://godoc.org/google.golang.org/grpc/credentials#TransportCredentials)
+base on TLS. Refer to the
+[godoc](https://godoc.org/google.golang.org/grpc/credentials) for details.
+
+In our example, we use the public/private keys created ahead:
+* "server_cert.pem" contains the server certificate (public key).
+* "server_key.pem" contains the server private key.
+* "ca_cert.pem" contains the certificate (certificate authority)
+that can verify the server's certificate.
+
+On server side, we provide the paths to "server_cert.pem" and "server_key.pem" to
+configure TLS and create the server credential using
+[`credentials.NewServerTLSFromFile`](https://godoc.org/google.golang.org/grpc/credentials#NewServerTLSFromFile).
+
+On client side, we provide the path to the "ca_cert.pem" to configure TLS and create
+the client credential using
+[`credentials.NewClientTLSFromFile`](https://godoc.org/google.golang.org/grpc/credentials#NewClientTLSFromFile).
+Note that we override the server name with "x.test.example.com", as the server
+certificate is valid for *.test.example.com but not localhost. It is solely for
+the convenience of making an example.
+
+Once the credentials have been created at both sides, we can start the server
+with the just created server credential (by calling
+[`grpc.Creds`](https://godoc.org/google.golang.org/grpc#Creds)) and let client dial
+to the server with the created client credential (by calling
+[`grpc.WithTransportCredentials`](https://godoc.org/google.golang.org/grpc#WithTransportCredentials))
+
+And finally we make an RPC call over the created `grpc.ClientConn` to test the secure
+connection based upon TLS is successfully up.
+
+### ALTS
+NOTE: ALTS currently needs special early access permission on GCP. You can ask
+about the detailed process in https://groups.google.com/forum/#!forum/grpc-io.
+
+ALTS is the Google's Application Layer Transport Security, which supports mutual
+authentication and transport encryption. Note that ALTS is currently only
+supported on Google Cloud Platform, and therefore you can only run the example
+successfully in a GCP environment. In our example, we show how to initiate a
+secure connection that is based on ALTS.
+
+Unlike TLS, ALTS makes certificate/key management transparent to user. So it is
+easier to set up.
+
+On server side, first call
+[`alts.DefaultServerOptions`](https://godoc.org/google.golang.org/grpc/credentials/alts#DefaultServerOptions)
+to get the configuration for alts and then provide the configuration to
+[`alts.NewServerCreds`](https://godoc.org/google.golang.org/grpc/credentials/alts#NewServerCreds)
+to create the server credential based upon alts.
+
+On client side, first call
+[`alts.DefaultClientOptions`](https://godoc.org/google.golang.org/grpc/credentials/alts#DefaultClientOptions)
+to get the configuration for alts and then provide the configuration to
+[`alts.NewClientCreds`](https://godoc.org/google.golang.org/grpc/credentials/alts#NewClientCreds)
+to create the client credential based upon alts.
+
+Next, same as TLS, start the server with the server credential and let client
+dial to server with the client credential.
+
+Finally, make an RPC to test the secure connection based upon ALTS is
+successfully up.
+
+### mTLS
+
+In mutual TLS (mTLS), the client and the server authenticate each other. gRPC
+allows users to configure mutual TLS at the connection level.
+
+In this example, we use the following public/private keys created ahead of time:
+
+* "server_cert.pem" contains the server's certificate (public key).
+* "server_key.pem" contains the server's private key.
+* "ca_cert.pem" contains the certificate of the certificate authority that can
+  verify the server's certificate.
+* "client_cert.pem" contains the client's certificate (public key).
+* "client_key.pem" contains the client's private key.
+* "client_ca_cert.pem" contains the certificate of the certificate authority
+  that can verify the client's certificate.
+
+In normal TLS, the server is only concerned with presenting the server
+certificate for clients to verify. In mutual TLS, the server also loads in a
+list of trusted CA files for verifying the client's presented certificates.
+This is done by setting
+[`tls.Config.ClientCAs`](https://pkg.go.dev/crypto/tls#Config.ClientCAs)
+to the list of trusted CA files,
+and setting
+[`tls.config.ClientAuth`](https://pkg.go.dev/crypto/tls#Config.ClientAuth)
+to
+[`tls.RequireAndVerifyClientCert`](https://pkg.go.dev/crypto/tls#RequireAndVerifyClientCert).
+
+In normal TLS, the client is only concerned with authenticating the server by
+using one or more trusted CA file. In mutual TLS, the client also presents its
+client certificate to the server for authentication. This is done by setting
+[`tls.Config.Certificates`](https://pkg.go.dev/crypto/tls#Config.Certificates).

examples/features/encryption/TLS/client/main.go

@@ -0,0 +1,67 @@
+/*
+ *
+ * Copyright 2018 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.
+ *
+ */
+
+// Binary client demonstrates how to use TLS credentials for secure
+// gRPC communication.
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"time"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/examples/data"
+	ecpb "google.golang.org/grpc/examples/features/proto/echo"
+)
+
+var addr = flag.String("addr", "localhost:50051", "the address to connect to")
+
+func callUnaryEcho(client ecpb.EchoClient, message string) {
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	resp, err := client.UnaryEcho(ctx, &ecpb.EchoRequest{Message: message})
+	if err != nil {
+		log.Fatalf("client.UnaryEcho(_) = _, %v: ", err)
+	}
+	fmt.Println("UnaryEcho: ", resp.Message)
+}
+
+func main() {
+	flag.Parse()
+
+	// Create tls based credential.
+	creds, err := credentials.NewClientTLSFromFile(data.Path("x509/ca_cert.pem"), "x.test.example.com")
+	if err != nil {
+		log.Fatalf("failed to load credentials: %v", err)
+	}
+
+	// Set up a connection to the server.
+	conn, err := grpc.NewClient(*addr, grpc.WithTransportCredentials(creds))
+	if err != nil {
+		log.Fatalf("did not connect: %v", err)
+	}
+	defer conn.Close()
+
+	// Make an echo client and send an RPC.
+	rgc := ecpb.NewEchoClient(conn)
+	callUnaryEcho(rgc, "hello world")
+}

examples/features/encryption/TLS/server/main.go

@@ -0,0 +1,68 @@
+/*
+ *
+ * Copyright 2018 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.
+ *
+ */
+
+// Binary server demonstrates how to use TLS credentials to secure gRPC services.
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"net"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/examples/data"
+
+	pb "google.golang.org/grpc/examples/features/proto/echo"
+)
+
+var port = flag.Int("port", 50051, "the port to serve on")
+
+type ecServer struct {
+	pb.UnimplementedEchoServer
+}
+
+func (s *ecServer) UnaryEcho(_ context.Context, req *pb.EchoRequest) (*pb.EchoResponse, error) {
+	return &pb.EchoResponse{Message: req.Message}, nil
+}
+
+func main() {
+	flag.Parse()
+
+	lis, err := net.Listen("tcp", fmt.Sprintf(":%d", *port))
+	if err != nil {
+		log.Fatalf("failed to listen: %v", err)
+	}
+
+	// Create tls based credential.
+	creds, err := credentials.NewServerTLSFromFile(data.Path("x509/server_cert.pem"), data.Path("x509/server_key.pem"))
+	if err != nil {
+		log.Fatalf("failed to create credentials: %v", err)
+	}
+
+	s := grpc.NewServer(grpc.Creds(creds))
+
+	// Register EchoServer on the server.
+	pb.RegisterEchoServer(s, &ecServer{})
+
+	if err := s.Serve(lis); err != nil {
+		log.Fatalf("failed to serve: %v", err)
+	}
+}

examples/features/encryption/mTLS/client/main.go

@@ -0,0 +1,81 @@
+/*
+ *
+ * Copyright 2022 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.
+ *
+ */
+
+// Binary client is an example client which connects to the server using mTLS.
+package main
+
+import (
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"time"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/examples/data"
+	ecpb "google.golang.org/grpc/examples/features/proto/echo"
+)
+
+var addr = flag.String("addr", "localhost:50051", "the address to connect to")
+
+func callUnaryEcho(client ecpb.EchoClient, message string) {
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	resp, err := client.UnaryEcho(ctx, &ecpb.EchoRequest{Message: message})
+	if err != nil {
+		log.Fatalf("client.UnaryEcho(_) = _, %v: ", err)
+	}
+	fmt.Println("UnaryEcho: ", resp.Message)
+}
+
+func main() {
+	flag.Parse()
+
+	cert, err := tls.LoadX509KeyPair(data.Path("x509/client_cert.pem"), data.Path("x509/client_key.pem"))
+	if err != nil {
+		log.Fatalf("failed to load client cert: %v", err)
+	}
+
+	ca := x509.NewCertPool()
+	caFilePath := data.Path("x509/ca_cert.pem")
+	caBytes, err := os.ReadFile(caFilePath)
+	if err != nil {
+		log.Fatalf("failed to read ca cert %q: %v", caFilePath, err)
+	}
+	if ok := ca.AppendCertsFromPEM(caBytes); !ok {
+		log.Fatalf("failed to parse %q", caFilePath)
+	}
+
+	tlsConfig := &tls.Config{
+		ServerName:   "x.test.example.com",
+		Certificates: []tls.Certificate{cert},
+		RootCAs:      ca,
+	}
+
+	conn, err := grpc.NewClient(*addr, grpc.WithTransportCredentials(credentials.NewTLS(tlsConfig)))
+	if err != nil {
+		log.Fatalf("did not connect: %v", err)
+	}
+	defer conn.Close()
+
+	callUnaryEcho(ecpb.NewEchoClient(conn), "hello world")
+}

examples/features/encryption/mTLS/server/main.go

@@ -0,0 +1,82 @@
+/*
+ *
+ * Copyright 2022 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.
+ *
+ */
+
+// Binary server is an example server which authenticates clients using mTLS.
+package main
+
+import (
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"flag"
+	"fmt"
+	"log"
+	"net"
+	"os"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/examples/data"
+	pb "google.golang.org/grpc/examples/features/proto/echo"
+)
+
+var port = flag.Int("port", 50051, "the port to serve on")
+
+type ecServer struct {
+	pb.UnimplementedEchoServer
+}
+
+func (s *ecServer) UnaryEcho(_ context.Context, req *pb.EchoRequest) (*pb.EchoResponse, error) {
+	return &pb.EchoResponse{Message: req.Message}, nil
+}
+
+func main() {
+	flag.Parse()
+	log.Printf("server starting on port %d...\n", *port)
+
+	cert, err := tls.LoadX509KeyPair(data.Path("x509/server_cert.pem"), data.Path("x509/server_key.pem"))
+	if err != nil {
+		log.Fatalf("failed to load key pair: %s", err)
+	}
+
+	ca := x509.NewCertPool()
+	caFilePath := data.Path("x509/client_ca_cert.pem")
+	caBytes, err := os.ReadFile(caFilePath)
+	if err != nil {
+		log.Fatalf("failed to read ca cert %q: %v", caFilePath, err)
+	}
+	if ok := ca.AppendCertsFromPEM(caBytes); !ok {
+		log.Fatalf("failed to parse %q", caFilePath)
+	}
+
+	tlsConfig := &tls.Config{
+		ClientAuth:   tls.RequireAndVerifyClientCert,
+		Certificates: []tls.Certificate{cert},
+		ClientCAs:    ca,
+	}
+
+	s := grpc.NewServer(grpc.Creds(credentials.NewTLS(tlsConfig)))
+	pb.RegisterEchoServer(s, &ecServer{})
+	lis, err := net.Listen("tcp", fmt.Sprintf("localhost:%d", *port))
+	if err != nil {
+		log.Fatalf("failed to listen: %v", err)
+	}
+	if err := s.Serve(lis); err != nil {
+		log.Fatalf("failed to serve: %v", err)
+	}
+}