public static string Base64HeaderDecode(string line)
{
MemoryStream ms = null;
byte[] bytes = null;
string oStr = null;
string code = null;
string content = null;
Match m = Regex.Match(line, @"=\?([^?]+)\?[^?]+\?([^?]+)\?=");
while (m.Success)
{
ms = new MemoryStream();
oStr = m.Groups[0].ToString();
code = m.Groups[1].ToString();
content = m.Groups[2].ToString();
NntpUtil.Base64Decode(content, ms);
ms.Seek(0, SeekOrigin.Begin);
bytes = new byte[ms.Length];
ms.Read(bytes, 0, bytes.Length);
line = line.Replace(oStr, Encoding.GetEncoding(code).GetString(bytes));
m = m.NextMatch();
}
return(line);
}
public static MIMEPart DispatchMIMEContent(StreamReader sr, MIMEPart part, string seperator)
{
string line = null;
Match m = null;
MemoryStream ms;
byte[] bytes;
switch (part.ContentType.Substring(0, part.ContentType.IndexOf('/')).ToUpper())
{
case "MULTIPART":
MIMEPart newPart = null;
while ((line = sr.ReadLine()) != null && line != seperator && line != seperator + "--")
{
m = Regex.Match(line, @"CONTENT-TYPE: ""?([^""\s;]+)", RegexOptions.IgnoreCase);
if (!m.Success)
{
continue;
}
newPart = new MIMEPart();
newPart.ContentType = m.Groups[1].ToString();
newPart.Charset = "US-ASCII";
newPart.ContentTransferEncoding = "7BIT";
while (line != "")
{
m = Regex.Match(line, @"BOUNDARY=""?([^""\s;]+)", RegexOptions.IgnoreCase);
if (m.Success)
{
newPart.Boundary = m.Groups[1].ToString();
newPart.EmbeddedPartList = new ArrayList();
}
m = Regex.Match(line, @"CHARSET=""?([^""\s;]+)", RegexOptions.IgnoreCase);
if (m.Success)
{
newPart.Charset = m.Groups[1].ToString();
}
m = Regex.Match(line, @"CONTENT-TRANSFER-ENCODING: ""?([^""\s;]+)", RegexOptions.IgnoreCase);
if (m.Success)
{
newPart.ContentTransferEncoding = m.Groups[1].ToString();
}
m = Regex.Match(line, @"NAME=""?([^""\s;]+)", RegexOptions.IgnoreCase);
if (m.Success)
{
newPart.Filename = Base64HeaderDecode(m.Groups[1].ToString());
newPart.Filename = newPart.Filename.Substring(newPart.Filename.LastIndexOfAny(new char[] { '\\', '/' }) + 1);
}
line = sr.ReadLine();
}
part.EmbeddedPartList.Add(DispatchMIMEContent(sr, newPart, "--" + part.Boundary));
}
break;
case "TEXT":
ms = new MemoryStream();
bytes = null;
long pos;
StreamReader msr = new StreamReader(ms, Encoding.GetEncoding(part.Charset));
StringBuilder sb = new StringBuilder();
while ((line = sr.ReadLine()) != null && line != seperator && line != seperator + "--")
{
pos = ms.Position;
if (line != "")
{
switch (part.ContentTransferEncoding.ToUpper())
{
case "QUOTED-PRINTABLE":
NntpUtil.QuotedPrintableDecode(line, ms);
break;
case "BASE64":
if (line != null && line != "")
{
NntpUtil.Base64Decode(line, ms);
}
break;
case "UU":
if (line != null && line != "")
{
NntpUtil.UUDecode(line, ms);
}
break;
case "7BIT":
bytes = Encoding.ASCII.GetBytes(line);
ms.Write(bytes, 0, bytes.Length);
ms.WriteByte((byte)'\n');
break;
default:
bytes = Encoding.ASCII.GetBytes(line);
ms.Write(bytes, 0, bytes.Length);
ms.WriteByte((byte)'\n');
break;
}
}
ms.Position = pos;
if (part.ContentType.ToUpper() == "TEXT/HTML")
{
sb.Append(msr.ReadToEnd());
}
else
{
sb.Append(HttpUtility.HtmlEncode(msr.ReadToEnd()).Replace("\n", "<br>\n"));
}
}
part.Text = sb.ToString();
break;
default:
ms = new MemoryStream();
bytes = null;
while ((line = sr.ReadLine()) != null && line != seperator && line != seperator + "--")
{
if (line != "")
{
switch (part.ContentTransferEncoding.ToUpper())
{
case "QUOTED-PRINTABLE":
NntpUtil.QuotedPrintableDecode(line, ms);
break;
case "BASE64":
if (line != null && line != "")
{
NntpUtil.Base64Decode(line, ms);
}
break;
case "UU":
if (line != null && line != "")
{
NntpUtil.UUDecode(line, ms);
}
break;
default:
bytes = Encoding.ASCII.GetBytes(line);
ms.Write(bytes, 0, bytes.Length);
break;
}
}
}
ms.Seek(0, SeekOrigin.Begin);
part.BinaryData = new byte[ms.Length];
ms.Read(part.BinaryData, 0, (int)ms.Length);
break;
}
return(part);
}
