c# - 奇怪的 SslStream 缓冲问题

Question

我正在使用 SslStream 来加密客户端和服务器之间的 TCP 连接。问题是当客户端读取数据时，可能会得到一堆零字节而不是真正的数据。这是显示问题的示例:

        // Server
        using (NetworkStream tcpStream = client.GetStream())
        {
            Stream stream = tcpStream;
            if (ssl)
            {
                SslStream sslStream = new SslStream(tcpStream, true);
                sslStream.AuthenticateAsServer(cert, false, SslProtocols.Default, false);
                stream = sslStream;
            }

            byte[] buf = new byte[] {0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02};
            stream.Write(buf, 0, buf.Length);

            buf = new byte[] {0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03};
            stream.Write(buf, 0, buf.Length);
        }



        // Client
        using (NetworkStream tcpStream = client.GetStream())
        {
            Stream stream = tcpStream;
            if (ssl)
            {
                SslStream sslStream = new SslStream(
                    tcpStream, 
                    true, 
                    delegate { return true; }
                );
                sslStream.AuthenticateAsClient(
                    "localhost",
                    null,
                    SslProtocols.Default,
                    false
                    );
                stream = sslStream;
            }

            byte[] buf = new byte[7];
            stream.Read(buf, 0, buf.Length);
            // buf is 01010101010101 as expected

            buf = new byte[9];
            stream.Read(buf, 0, buf.Length);
            // buf is 020000000000000000 instead of the expected 020303030303030303
            // a subsequent read of 8 bytes will get me 0303030303030303
            // if the ssl bool is set to false, then the expected data is received without the need for a third read
        }

似乎只有在使用 SslStream 时，客户端才需要从流中读取与服务器写入的字节数完全相同的字节数。这不可能是对的。我在这里缺少什么？

Answer 1

这段代码

buf = new byte[9];
stream.Read(buf, 0, buf.Length);

请求 stream 将 1 到 9 个字节读入 buf。它并不总是准确读取 9 个字节。

Read Method返回实际读取的字节数。

试试这个:

byte[] buffer = new byte[9];
int offset = 0;
int count = buffer.Length;

do
{
    int bytesRead = stream.Read(buffer, offset, count);
    if (bytesRead == 0)
        break; // end of stream
    offset += bytesRead;
    count -= bytesRead;
}
while (count > 0);