c# - How to enable server side SSL for gRPC?

Question

New to gRPC and couldn't really find any example on how to enable SSL on the server side. I generated a key pair using openssl but it complains that the private key is invalid.

D0608 16:18:31.390303 Grpc.Core.Internal.UnmanagedLibrary Attempting to load native library "...grpc_csharp_ext.dll"
D0608 16:18:31.424331 Grpc.Core.Internal.NativeExtension gRPC native library loaded successfully.
E0608 16:18:43.307324 0 ..srccorelibsissl_transport_security.c:644: Invalid private key.
E0608 16:18:43.307824 0 ..srccorelibsecuritysecurity_connector.c:821: Handshaker factory creation failed with TSI_INVALID_ARGUMENT.
E0608 16:18:43.307824 0 ..srccoreextransportchttp2serversecureserver_secure_chttp2.c:188: Unable to create secure server with credentials of type Ssl.

Here's my code

var keypair = new KeyCertificatePair(
            File.ReadAllText(@"root-ca.pem"),
            File.ReadAllText(@"ssl-private.key"));
SslServerCredentials creds = new SslServerCredentials(new List<KeyCertificatePair>() {keypair});
Server server = new Server
{
    Services = { GrpcTest.BindService(new GrpcTestImpl()) },
    Ports = { new ServerPort("127.0.0.1", Port, creds) }
};

Answer 1

Here's what I did.

Using OpenSSL, generate certificates with the following:

@echo off
set OPENSSL_CONF=c:OpenSSL-Win64inopenssl.cfg   

echo Generate CA key:
openssl genrsa -passout pass:1111 -des3 -out ca.key 4096

echo Generate CA certificate:
openssl req -passin pass:1111 -new -x509 -days 365 -key ca.key -out ca.crt -subj  "/C=US/ST=CA/L=Cupertino/O=YourCompany/OU=YourApp/CN=MyRootCA"

echo Generate server key:
openssl genrsa -passout pass:1111 -des3 -out server.key 4096

echo Generate server signing request:
openssl req -passin pass:1111 -new -key server.key -out server.csr -subj  "/C=US/ST=CA/L=Cupertino/O=YourCompany/OU=YourApp/CN=%COMPUTERNAME%"

echo Self-sign server certificate:
openssl x509 -req -passin pass:1111 -days 365 -in server.csr -CA ca.crt -CAkey ca.key -set_serial 01 -out server.crt

echo Remove passphrase from server key:
openssl rsa -passin pass:1111 -in server.key -out server.key

echo Generate client key
openssl genrsa -passout pass:1111 -des3 -out client.key 4096

echo Generate client signing request:
openssl req -passin pass:1111 -new -key client.key -out client.csr -subj  "/C=US/ST=CA/L=Cupertino/O=YourCompany/OU=YourApp/CN=%CLIENT-COMPUTERNAME%"

echo Self-sign client certificate:
openssl x509 -passin pass:1111 -req -days 365 -in client.csr -CA ca.crt -CAkey ca.key -set_serial 01 -out client.crt

echo Remove passphrase from client key:
openssl rsa -passin pass:1111 -in client.key -out client.key

Change password 1111 to anything you like

Server:

var cacert = File.ReadAllText(@"ca.crt");
var servercert = File.ReadAllText(@"server.crt");
var serverkey = File.ReadAllText(@"server.key");
var keypair = new KeyCertificatePair(servercert, serverkey);
var sslCredentials = new SslServerCredentials(new List<KeyCertificatePair>() { keypair }, cacert, false);

var server = new Server
{
    Services = { GrpcTest.BindService(new GrpcTestImpl(writeToDisk)) },
    Ports = { new ServerPort("0.0.0.0", 555, sslCredentials) }
};
server.Start();

Client:

var cacert = File.ReadAllText(@"ca.crt");
var clientcert = File.ReadAllText(@"client.crt");
var clientkey = File.ReadAllText(@"client.key");
var ssl = new SslCredentials(cacert, new KeyCertificatePair(clientcert, clientkey));
channel = new Channel("localhost", 555, ssl);
client = new GrpcTest.GrpcTestClient(channel);

If "localhost" doesn't work, use the host name instead.