c# - 通过 ssl 套接字流式传输图像未正确显示

Question

我正在尝试在 2 台设备之间安全地传输文件，因此我正在使用附加到 TcpClient 的 SslStream。文档和文本文件看起来很好，但图像文件显示不正确。以下是服务端代码:

listener = new TcpListener(IPAddress.Any, 1337);
listener.Start();

while (true)
{
    TcpClient client = listener.AcceptTcpClient();

    SslStream sslStream = new SslStream(client.GetStream(), false, new RemoteCertificateValidationCallback(CertificateValidationCallback), new LocalCertificateSelectionCallback(CertificateSelectionCallback));
    var certificate = Connection.GetClientCertificate(((IPEndPoint)client.Client.RemoteEndPoint).Address.ToString());
    try
    {
        sslStream.AuthenticateAsServer(certificate, true, SslProtocols.Default, true);

        sslStream.ReadTimeout = 5000;
        sslStream.WriteTimeout = 5000;

        var messageData = ReadMessage(sslStream);

        var mode = messageData[0];
        var tokenBytes = messageData.Splice(1, 16);
        var fileNameBytes = messageData.Splice(17, 128);
        var fileBytes = messageData.Splice(146);

        var fileName = Encoding.ASCII.GetString(fileNameBytes).TrimEnd('\0');
        using (var tempFile = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.Write))
        {
            tempFile.Write(fileBytes, 0, fileBytes.Length);
            tempFile.Flush();
        }

        if (mode == 0)
            tempFiles.Add(fileName);

        Process.Start(fileName);
    }
    catch (AuthenticationException e)
    {
        MessageBox.Show("The other side failed to authenticate.");
    }
    finally
    {
        sslStream.Close();
        client.Close();
    }
}

而ReadMessage定义如下:

private static byte[] ReadMessage(SslStream sslStream)
{
    byte[] buffer = new byte[2048];
    MemoryStream stream = new MemoryStream();
    int bytes = -1;
    while (bytes != 0)
    {
        bytes = sslStream.Read(buffer, 0, buffer.Length);
        stream.Write(buffer, 0, bytes);
    }
    return stream.ToArray();
}

然后客户端代码是这样的:

TcpClient client = new TcpClient();
client.Connect(new IPEndPoint(IPAddress.Parse(ip), 1337));

SslStream sslStream = new SslStream(client.GetStream(), false, new RemoteCertificateValidationCallback(CertificateValidationCallback), new LocalCertificateSelectionCallback(CertificateSelectionCallback));
var certificate = Connection.GetClientCertificate(ip);
try
{
    sslStream.AuthenticateAsClient(ip, new X509CertificateCollection() { certificate }, SslProtocols.Default, false);

    sslStream.ReadTimeout = 5000;
    sslStream.WriteTimeout = 5000;
    sslStream.Write(data);
}
catch (AuthenticationException e)
{
    MessageBox.Show("The other side failed to authenticate.");
}
finally
{
    sslStream.Close();
    client.Close();
}

调用它的代码只是:

var fileBytes = File.ReadAllBytes(file);
var tokenBytes = Encoding.UTF8.GetBytes(token);
var fileNameBytes = Encoding.UTF8.GetBytes(Path.GetFileName(file));

var buffer = new byte[145 + fileBytes.Length];
buffer[0] = 1;
for (int i = 0; i < 16; i++)
{
    buffer[i + 1] = tokenBytes[i];
}

for (int i = 0; i < fileNameBytes.Length; i++)
{
    buffer[i + 17] = fileNameBytes[i];
}

for (int i = 0; i < fileBytes.Length; i++)
{
    buffer[i + 145] = fileBytes[i];
}

SocketConnection.Send(ip, buffer);

我正在做的事情是否存在本质上的错误，或者我是否需要对图像做一些不同的事情？

编辑:我已经更改它以反射(reflect)当前代码，而且，在对两端的原始字节进行转储之后，看起来由于某种原因，字节在通过网络传输时正在重新排列。有什么方法可以确保字节以原始顺序出现吗？

Answer 1

在 ReadMessage 中，您正在将 bytes.Length 字节写入流，而不管实际读取的字节数是多少。尝试:

private static byte[] ReadMessage(SslStream sslStream)
{
    byte[] buffer = new byte[2048];
    MemoryStream stream = new MemoryStream();
    int bytes = -1;
    while (bytes != 0)
    {
        bytes = sslStream.Read(buffer, 0, buffer.Length);
        // Use "bytes" instead of "buffer.Length" here
        stream.Write(buffer, 0, bytes);
    }
    return stream.ToArray();
}

根据您的后续行动，您还从缓冲区中的错误位置获取文件数据，因此您丢失了文件的第一个字节。

您的代码应该是:

var fileBytes = messageData.Splice(145); // File data starts at 145, not 146