我需要连接到 SMTP 服务器，但无法打开连接。握手失败(缺少身份验证)是我到达这里最远的地方。我打开了到普通服务器的套接字，但未能在此处这样做以发送电子邮件。

    private func connect() throws {
        var input: InputStream? = nil
        var output: OutputStream? = nil

        Stream.getStreamsToHost(withName: server, port: port, inputStream: &input, outputStream: &output)

        guard let inputSafe = input, let outputSafe = output else {
            throw FailerError.unableToConnectToHost
        }

        self.inputStream = inputSafe
        self.outputStream = outputSafe

        // TODO: Authentication using login

        // Enable SSL/TLS on the streams
//        inputStream!.setProperty(kCFStreamSocketSecurityLevelNegotiatedSSL, forKey: Stream.PropertyKey(rawValue: kCFStreamPropertySocketSecurityLevel as String))
//        outputStream!.setProperty(kCFStreamSocketSecurityLevelNegotiatedSSL, forKey: Stream.PropertyKey(rawValue: kCFStreamPropertySocketSecurityLevel as String))
//        
//        // Define custom SSL/TLS settings
//        let sslSettings: [NSString : Any] = [
//             NSStream automatically sets up the socket, the streams and creates a trust object and evaulates it before you even get a chance to check the trust yourself. Only proper SSL certificates will work with this method. If you have a self signed certificate like I do, you need to disable the trust check here and evaulate the trust against your custom root CA yourself.
//            NSString(format: kCFStreamSSLValidatesCertificateChain): kCFBooleanFalse,
//            //
//            NSString(format: kCFStreamSSLPeerName): kCFNull,
//            // We are an SSL/TLS client, not a server
//            NSString(format: kCFStreamSSLIsServer): kCFBooleanFalse,
//            
//            NSString(format: kCFStreamSocketSecurityLevelNegotiatedSSL): kCFBooleanTrue
//        ]
//        
//        // Set the SSL/TLS settingson the streams
//        inputStream!.setProperty(sslSettings, forKey: Stream.PropertyKey(rawValue: kCFStreamPropertySSLSettings as String))
//        outputStream!.setProperty(sslSettings, forKey: Stream.PropertyKey(rawValue: kCFStreamPropertySSLSettings as String))


        inputStream.delegate = self
        outputStream.delegate = self

        inputStream.schedule(in: .main, forMode: .commonModes)
        outputStream.schedule(in: .main, forMode: .commonModes)

        inputStream.open()
        outputStream.open()
    }

评论部分显示我试图设置一些东西，但真的不知道那里应该有什么。有人有什么想法吗？

澄清一下，这是针对使用 SMTP 接收数据的设计糟糕的 API(不是我的想法但必须使用它)所以请不要建议 MessageUI 否则该应用会因为直接发送电子邮件而被拒绝:)

如果有人感兴趣，可以在这里查看 Playground 的完整要点: https://gist.github.com/rafiki270/c004b92deca437934f702efd3508bd83

最佳答案

@Ondrej 根据 Apple 文档“Cocoa 流编程指南简介”，提到 NSStream (Objective C)/Stream (Swift) 类不支持连接到 iOS 上的远程主机。您的替代方案是通过利用 CFStream 和 NSStream 之间的免费桥梁将您的 CFStreams 转换为 NSStreams 来使用 CFStream。

下面是关于如何使用 CFStream 执行此操作的示例。

CFReadStreamRef readStream;
CFWriteStreamRef writeStream;
CFStreamCreatePairWithSocketToHost(NULL, (CFStringRef)[website host], 80, &readStream, &writeStream);

NSInputStream *inputStream = (__bridge_transfer NSInputStream *)readStream;
NSOutputStream *outputStream = (__bridge_transfer NSOutputStream *)writeStream;
[inputStream setDelegate:self];
[outputStream setDelegate:self];
[inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[inputStream open];
[outputStream open];

希望这对您有所帮助。

关于ios - 在 Swift 3 中使用 Stream 打开与 SMTP 服务器的套接字连接，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/45404050/