Nuevo en gRPC y realmente no pude encontrar ningún ejemplo sobre cómo habilitar SSL en el lado del servidor. Generé un par de claves usando openssl pero se queja de que la clave privada no es válida.

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 ..\src\core\lib\tsi\ssl_transport_security.c:644: Invalid private key.
E0608 16:18:43.307824 0 ..\src\core\lib\security\security_connector.c:821: Handshaker factory creation failed with TSI_INVALID_ARGUMENT.
E0608 16:18:43.307824 0 ..\src\core\ext\transport\chttp2\server\secure\server_secure_chttp2.c:188: Unable to create secure server with credentials of type Ssl.

Aquí está mi código

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) }
};