Facebook聊天PLAIN身份验证问题Windows Phone

Question

I'am trying to write simple library for facebook chat, but I've encountered an issue at the very beginning. I do not know why chat.facebook.com sends me "<" after sending auth element. Having searched through the Internet I found nothing that colud help me. Related code is at a very end of following code block.

public const string BEGIN_AUTH_PLAIN = @"<auth xmlns='urn:ietf:params:xml:ns:xmpp-     sasl' mechanism='PLAIN'>";
public const string END_AUTH = @"</auth>";

public static string GetPlainAuth(string email, string password)
{
    byte[] plain = System.Text.Encoding.UTF8.GetBytes((char)0+email+(char)0+password);
    string credentials = System.Convert.ToBase64String(plain);
    return String.Format("{0}{1}{2}", BEGIN_AUTH_PLAIN, credentials, END_AUTH);
}

//////////////////////////////////////////////////////////////////////////////
public async Task<bool> NegotiateStream()
{
    if (!connected)
        return false;

    writer.WriteString(XmlConstants.BEGIN_STREAM);
    await writer.StoreAsync();
    await reader.LoadAsync(4096);
    string resp = reader.ReadString(reader.UnconsumedBufferLength);
    //check if response is stream and offers plaintext mechanism
    if (!resp.Contains("stream:stream") || !resp.Contains("<mechanism>PLAIN"))
        return false;
    writer.WriteString(XmlConstants.START_TLS);
    await writer.StoreAsync();
    await reader.LoadAsync(4096);
    resp = reader.ReadString(reader.UnconsumedBufferLength);
    if (!resp.Contains("proceed"))
        return false;
    //now upgrate to tls connection
    await socket.UpgradeToSslAsync(SocketProtectionLevel.Ssl, HostName);
    //now try to login 
    writer.WriteString(XmlConstants.BEGIN_STREAM);
    await writer.StoreAsync();
    await reader.LoadAsync(4096);
    resp = reader.ReadString(reader.UnconsumedBufferLength);
    if (!resp.Contains("stream:stream") || !resp.Contains("<mechanism>PLAIN"))
        return false;
    //now send auth
    string xx = XmlConstants.GetPlainAuth(Email, Password);
    writer.WriteString(xx);
    await writer.StoreAsync();
    await reader.LoadAsync(4096);
    resp = reader.ReadString(reader.UnconsumedBufferLength);
    //could not login
    if (!resp.Contains("success"))
        return false;

    return true;     



}

Answer 1

I had to do a hack like this(do/while). But I would recommend you to use a library. Here is as far as I got trying to convert the php example into C#. http://pastebin.com/jst7qkrh Here is the thread on SO: Send message via Facebook Chat API (XMPP) C#

public string SendWihSsl(string dataToSend)
{
    Byte[] data = System.Text.Encoding.UTF8.GetBytes(dataToSend);

    ssl.Write(data, 0, data.Length);
    ssl.Flush();
    data = new Byte[2048];

    int myBytesRead = 0;
    StringBuilder myResponseAsSB = new StringBuilder();
    do
    {
        myBytesRead = ssl.Read(data, 0, data.Length);
        myResponseAsSB.Append(System.Text.Encoding.UTF8.GetString(data, 0, myBytesRead));
        if (myResponseAsSB.ToString().IndexOf("</") != -1)
        {
            break;
        }
    } while (myBytesRead != 0);

    return myResponseAsSB.ToString();
}