grpc-swift/Tests/GRPCTests/ClientTLSTests.swift

import Foundation
import GRPC
import GRPCSampleData
import EchoModel
import EchoImplementation
import NIO
import NIOSSL
import XCTest

class ClientTLSHostnameOverrideTests: GRPCTestCase {
  var eventLoopGroup: EventLoopGroup!
  var server: Server!
  var connection: ClientConnection!

  override func setUp() {
    super.setUp()
    self.eventLoopGroup = MultiThreadedEventLoopGroup(numberOfThreads: 1)
  }

  override func tearDown() {
    super.tearDown()
    XCTAssertNoThrow(try self.server.close().wait())
    XCTAssertNoThrow(try connection.close().wait())
    XCTAssertNoThrow(try self.eventLoopGroup.syncShutdownGracefully())
  }

  func makeEchoServer(tls: Server.Configuration.TLS) throws -> Server {
    let configuration: Server.Configuration = .init(
      target: .hostAndPort("localhost", 0),
      eventLoopGroup: self.eventLoopGroup,
      serviceProviders: [EchoProvider()],
      tls: tls
    )

    return try Server.start(configuration: configuration).wait()
  }

  func makeConnection(port: Int, tls: ClientConnection.Configuration.TLS) -> ClientConnection {
    let configuration: ClientConnection.Configuration = .init(
      target: .hostAndPort("localhost", port),
      eventLoopGroup: self.eventLoopGroup,
      tls: tls
    )

    return ClientConnection(configuration: configuration)
  }

  func doTestUnary() throws {
    let client = Echo_EchoServiceClient(connection: self.connection)
    let get = client.get(.with { $0.text = "foo" })

    let response = try get.response.wait()
    XCTAssertEqual(response.text, "Swift echo get: foo")

    let status = try get.status.wait()
    XCTAssertEqual(status.code, .ok)
  }

  func testTLSWithHostnameOverride() throws {
    // Run a server presenting a certificate for example.com on localhost.
    let serverTLS: Server.Configuration.TLS = .init(
      certificateChain: [.certificate(SampleCertificate.exampleServer.certificate)],
      privateKey: .privateKey(SamplePrivateKey.exampleServer),
      trustRoots: .certificates([SampleCertificate.ca.certificate])
    )

    self.server = try makeEchoServer(tls: serverTLS)
    guard let port = self.server.channel.localAddress?.port else {
      XCTFail("could not get server port")
      return
    }

    let clientTLS: ClientConnection.Configuration.TLS = .init(
      trustRoots: .certificates([SampleCertificate.ca.certificate]),
      hostnameOverride: "example.com"
    )

    self.connection = self.makeConnection(port: port, tls: clientTLS)
    try self.doTestUnary()
  }

  func testTLSWithoutHostnameOverride() throws {
    // Run a server presenting a certificate for localhost on localhost.
    let serverTLS: Server.Configuration.TLS = .init(
      certificateChain: [.certificate(SampleCertificate.server.certificate)],
      privateKey: .privateKey(SamplePrivateKey.server),
      trustRoots: .certificates([SampleCertificate.ca.certificate])
    )

    self.server = try makeEchoServer(tls: serverTLS)
    guard let port = self.server.channel.localAddress?.port else {
      XCTFail("could not get server port")
      return
    }

    let clientTLS: ClientConnection.Configuration.TLS = .init(
      trustRoots: .certificates([SampleCertificate.ca.certificate])
    )

    self.connection = self.makeConnection(port: port, tls: clientTLS)
    try self.doTestUnary()
  }
}