奇怪的SslStream缓冲问题

Question

我正在使用SslStream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，可能会给它提供一堆零字节，而不是真正的数据。下面是一个显示该问题的示例：

        // 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
        }

似乎客户端需要从流中读取的字节数与服务器仅在使用SslStream时写入的字节数完全相同。这不可能是对的这里我漏掉了什么？

Answer 1

这段代码

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

请求stream在buf中读取1到9个字节。它并不总是准确地读取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);