private void OnHandleMultipartCommand(IncommingMail context, string commandLine)
{
if (context.IsMultipart && (commandLine == "--" + context.Boundary))
{
context.State = SmtpState.Data;
}
}
private void OnHandleControlCommand(Socket client, IncommingMail context, string commandLine)
{
if (commandLine.StartsWith("QUIT", StringComparison.InvariantCultureIgnoreCase))
{
Send(client, "221 Closing channel");
client.Close();
return;
}
if (commandLine.StartsWith("EHLO", StringComparison.InvariantCultureIgnoreCase))
{
Send(client, "250-AUTH LOGIN");
Send(client, "250 OK");
return;
}
if (commandLine.StartsWith("HELO", StringComparison.InvariantCultureIgnoreCase))
{
Send(client, "250 OK");
return;
}
if (commandLine.StartsWith("AUTH", StringComparison.InvariantCultureIgnoreCase))
{
context.State = SmtpState.Authentication1;
Send(client, "334 " + Convert.ToBase64String(Encoding.ASCII.GetBytes("useless")));
return;
}
if (commandLine.StartsWith("RCPT TO", StringComparison.InvariantCultureIgnoreCase))
{
var addr = new Regex(@".*\<([a-zA-Z0-9\.\@_-]+)\>.*").Match(commandLine.Substring(7));
if (addr.Success)
{
context.Message.To.Add(addr.Groups[1].Value);
}
Send(client, "250 OK");
return;
}
if (commandLine.StartsWith("MAIL FROM", StringComparison.InvariantCultureIgnoreCase))
{
var addr = new Regex(@".*\<([a-zA-Z0-9\.\@]+)\>.*").Match(commandLine.Substring(7));
if (addr.Success)
{
context.Message.From = new MailAddress(addr.Groups[1].Value);
}
Send(client, "250 OK");
return;
}
if (commandLine.StartsWith("DATA", StringComparison.InvariantCultureIgnoreCase))
{
context.State = SmtpState.Data;
Send(client, "354 Start mail input");
}
}
private void OnHandleBodyCommand(Socket client, IncommingMail context, string commandLine)
{
// handle mail body
if (context.IsMultipart && commandLine.StartsWith("--" + context.Boundary))
{
if (context.PartDisposition.Contains("attachment"))
{
ContentType contentType = null;
try
{
if (!string.IsNullOrEmpty(context.PartContentType))
{
contentType = new ContentType(context.PartContentType);
}
}
catch (Exception ex)
{
Trace.TraceWarning("Invalid ContentType '" + context.PartContentType + "' ignored: " + ex.Message);
}
var data = new MemoryStream(GetBytes(context.Body, context.PartContentEncoding));
var attachment = (contentType != null) ? new Attachment(data, contentType) : new Attachment(data, context.PartName);
if ((attachment.Name == null) && !string.IsNullOrEmpty(context.PartName))
{
attachment.Name = context.PartName;
}
context.Message.Attachments.Add(attachment);
}
else
{
context.Message.BodyEncoding = null;
context.Message.Body = Encoding.UTF8.GetString(GetBytes(context.Body, context.PartContentEncoding));
context.Message.IsBodyHtml = context.PartContentType.ToLower().Contains("html");
if (context.Message.IsBodyHtml)
{
context.Message.BodyEncoding = DetectHtmlEncoding(context.Message.Body);
}
}
context.PartContentType = string.Empty;
context.PartContentEncoding = string.Empty;
context.PartName = string.Empty;
context.PartDisposition = string.Empty;
context.Body = string.Empty;
context.State = SmtpState.Data;
return;
}
if (commandLine == ".")
{
//message has successfully been received
if (!context.IsMultipart)
{
context.Message.BodyEncoding = null;
context.Message.Body = Encoding.UTF8.GetString(GetBytes(context.Body, context.ContentEncoding));
context.Message.IsBodyHtml = context.ContentType.ToLower().Contains("html");
if (context.Message.IsBodyHtml)
{
context.Message.BodyEncoding = DetectHtmlEncoding(context.Message.Body);
}
}
OnNewMail(context.Message);
Send(client, "250 OK");
return;
}
context.Body += commandLine;
}
private void OnHandleDataCommand(IncommingMail context, string commandLine)
{
// parse header data here
if (commandLine == string.Empty)
{
context.State = SmtpState.Body;
return;
}
if (commandLine.StartsWith("Subject:", StringComparison.InvariantCultureIgnoreCase))
{
context.Message.Subject = commandLine.Substring(8).Trim();
if (context.Message.Subject.StartsWith("=") && context.Message.Subject.EndsWith("="))
{
var decoder = new QuotedPrintable();
var iso = Encoding.GetEncoding("ISO-8859-1");
context.Message.Subject = iso.GetString(decoder.Decode(context.Message.Subject));
}
context.RecentLine = commandLine;
return;
}
if (commandLine.StartsWith("Content-Type:", StringComparison.InvariantCultureIgnoreCase))
{
var contentType = commandLine.Substring(13).Trim();
if (context.IsMultipart)
{
context.PartContentType = contentType;
if (contentType.Contains("name="))
{
var name = contentType.IndexOf("name=", StringComparison.InvariantCultureIgnoreCase);
context.PartName = contentType.Substring(name + 5).Trim();
}
if (string.IsNullOrEmpty(context.PartName) && contentType.Contains("file="))
{
var file = contentType.IndexOf("file=", StringComparison.InvariantCultureIgnoreCase);
context.PartName = contentType.Substring(file + 5).Trim();
}
if (string.IsNullOrEmpty(context.PartName) && contentType.Contains("filename="))
{
var filename = context.PartDisposition.IndexOf("filename=", StringComparison.InvariantCultureIgnoreCase);
context.PartName = context.PartDisposition.Substring(filename + 9).Trim();
}
}
else
{
context.ContentType = contentType;
if (contentType.Contains("multipart") && contentType.Contains("boundary="))
{
var boundary = contentType.IndexOf("boundary=", StringComparison.InvariantCultureIgnoreCase);
context.Boundary = contentType.Substring(boundary + 9).Trim();
}
}
if (context.IsMultipart && commandLine.Contains("boundary="))
{
var boundary = commandLine.IndexOf("boundary=", StringComparison.InvariantCultureIgnoreCase);
context.Boundary = commandLine.Substring(boundary + 9).Trim();
}
context.RecentLine = commandLine;
return;
}
if (commandLine.StartsWith("Content-Disposition:", StringComparison.InvariantCultureIgnoreCase))
{
var disposition = commandLine.Substring(20).Trim();
context.PartDisposition = disposition;
context.RecentLine = commandLine;
return;
}
if (commandLine.StartsWith("Content-Transfer-Encoding:", StringComparison.InvariantCultureIgnoreCase))
{
var encoding = commandLine.Substring(26).Trim();
if (context.IsMultipart)
{
context.PartContentEncoding = encoding;
}
else
{
context.ContentEncoding = encoding;
}
context.RecentLine = commandLine;
}
}
private void OnHandleAuthentication2Command(Socket client, IncommingMail context)
{
context.State = SmtpState.Control;
Send(client, "235 Authentication successful.");
}
private void OnHandleAuthentication1Command(Socket client, IncommingMail context)
{
context.State = SmtpState.Authentication2;
Send(client, "334 " + Convert.ToBase64String(Encoding.ASCII.GetBytes("useless")));
}
