/// <summary>
/// Parses headers from message or mime entry.
/// </summary>
/// <param name="entryStrm">Stream from where to read headers.</param>
/// <returns>Returns header lines.</returns>
public static string ParseHeaders(Stream entryStrm)
{
/* Rfc 2822 3.1. GENERAL DESCRIPTION
* A message consists of header fields and, optionally, a body.
* The body is simply a sequence of lines containing ASCII charac-
* ters. It is separated from the headers by a null line (i.e., a
* line with nothing preceding the CRLF).
*/
byte[] crlf = new byte[] { (byte)'\r', (byte)'\n' };
MemoryStream msHeaders = new MemoryStream();
StreamLineReader r = new StreamLineReader(entryStrm);
byte[] lineData = r.ReadLine();
while (lineData != null)
{
if (lineData.Length == 0)
{
break;
}
msHeaders.Write(lineData, 0, lineData.Length);
msHeaders.Write(crlf, 0, crlf.Length);
lineData = r.ReadLine();
}
return(System.Text.Encoding.Default.GetString(msHeaders.ToArray()));
}
/// <summary>
/// Does period handling.
/// </summary>
/// <param name="strm">Input stream.</param>
/// <param name="add_Remove">If true add periods, else removes periods.</param>
/// <param name="setStrmPosTo0">If true sets stream position to 0.</param>
/// <returns></returns>
public static MemoryStream DoPeriodHandling(Stream strm, bool add_Remove, bool setStrmPosTo0)
{
MemoryStream replyData = new MemoryStream();
byte[] crlf = new byte[] { (byte)'\r', (byte)'\n' };
if (setStrmPosTo0)
{
strm.Position = 0;
}
StreamLineReader r = new StreamLineReader(strm);
byte[] line = r.ReadLine();
// Loop through all lines
while (line != null)
{
if (line.Length > 0)
{
if (line[0] == (byte)'.')
{
/* Add period Rfc 2821 4.5.2
* - Before sending a line of mail text, the SMTP client checks the
* first character of the line. If it is a period, one additional
* period is inserted at the beginning of the line.
*/
if (add_Remove)
{
replyData.WriteByte((byte)'.');
replyData.Write(line, 0, line.Length);
}
/* Remove period Rfc 2821 4.5.2
* If the first character is a period , the first characteris deleted.
*/
else
{
replyData.Write(line, 1, line.Length - 1);
}
}
else
{
replyData.Write(line, 0, line.Length);
}
}
replyData.Write(crlf, 0, crlf.Length);
// Read next line
line = r.ReadLine();
}
replyData.Position = 0;
return(replyData);
}
/// <summary>
/// Scans invalid CR or LF combination in stream. Returns true if contains invalid CR or LF combination.
/// </summary>
/// <param name="strm">Stream which to check.</param>
/// <returns>Returns true if contains invalid CR or LF combination.</returns>
public static bool ScanInvalid_CR_or_LF(Stream strm)
{
StreamLineReader lineReader = new StreamLineReader(strm);
byte[] line = lineReader.ReadLine();
while (line != null)
{
foreach (byte b in line)
{
// Contains CR or LF. It cannot conatian such sumbols, because CR must be paired with LF
// and we currently reading lines with CRLF combination.
if (b == 10 || b == 13)
{
return(true);
}
}
line = lineReader.ReadLine();
}
return(false);
}
