/// <summary>
/// Is the position in the string the start of an encoded-word
/// </summary>
/// <param name="InString">String to examine</param>
/// <param name="InBx">Position in string</param>
/// <returns></returns>
public static bool IsStartOfEncodedWord(string InString, int InBx)
{
bool isEncodedWord = true;
if (AcCommon.PullString(InString, InBx, 2, null) != "=?")
{
isEncodedWord = false;
}
else
{
isEncodedWord = CrackEncodedWord(InString, InBx).a;
}
return(isEncodedWord);
}
// ------------------- CalcMessageShowCodes ---------------------------
// return the message string in a form that shows the cr, lf, and tab codes
private string CalcMessageShowCodes( )
{
string msg = Message;
StringBuilder sb = new StringBuilder(msg.Length);
for (int Ix = 0; Ix < msg.Length; ++Ix)
{
char ch1 = msg[Ix];
if (ch1 == '\t')
{
sb.Append("<TAB>");
}
// a crlf followed by a space in a message header is a FOLD. mail agents
// interpret folds as whitespace.
else if ((ch1 == '\r') &&
(AcCommon.PullString(msg, Ix, 3, null) == "\r\n "))
{
sb.Append("<FOLD>");
Ix += 2;
}
else if ((ch1 == '\r') &&
(AcCommon.PullString(msg, Ix, 2, null) == NetworkConstants.CrLf))
{
sb.Append("<CRLF>");
++Ix;
}
else if (ch1 == '\r')
{
sb.Append("<CR>");
}
else if (ch1 == '\n')
{
sb.Append("<LF>");
}
else
{
sb.Append(ch1);
}
}
return(sb.ToString( ));
}
/// <summary>
/// Decode the quoted-printable encoded string.
/// Note: use DecodeLines to decode lines of text that include the QP line
/// continuation character ( "=" ).
/// </summary>
/// <param name="InString"></param>
/// <returns></returns>
public static string DecodeString(string InString)
{
StringBuilder sb = new StringBuilder(InString.Length);
for (int Ix = 0; Ix < InString.Length; ++Ix)
{
char ch1 = InString[Ix];
if (ch1 != '=')
{
sb.Append(ch1);
}
else
{
string hex = AcCommon.PullString(InString, Ix + 1, 2, " ");
// note: not an error if a lone "=" in a QP encoded string.
if (AcCommon.IsHexExternalForm(hex) == false)
{
sb.Append(ch1);
}
else
{
// sb.Append( (char) Convert.ToInt32( hex, 16 )) ;
// Ix += 2 ;
byte singleByte = System.Convert.ToByte(hex, 16);
byte[] bytes = AcCommon.ToByteArray(singleByte);
string hexChar = System.Text.Encoding.ASCII.GetString(bytes);
sb.Append(hexChar);
Ix += 2;
}
}
}
return(sb.ToString( ));
}
/// <summary>
/// Crack the component parts of the encoded-word string starting at InBx
/// in the string. Return an object pair. pair.a is a bool set to false if the
/// encoded-word string is not correctly formed. pair.b is a MimeEncodedWord object
/// containing the component parts of the cracked word.
/// </summary>
/// <param name="InString"></param>
/// <param name="InBx"></param>
/// <returns></returns>
public static BoolObjectPair CrackEncodedWord(string InString, int InBx)
{
int Fx, Ix, Lx, RemLx;
string ws = null;
MimeEncodedWord ew = new MimeEncodedWord( );
bool isEncodedWord = true;
try
{
// isolate the next 80 chars from the string as a workspace ( encoded words are
// limited to 75 chars or less )
ew.Bx = InBx;
ws = AcCommon.PullString(InString, InBx, 80, null).ToLower( );
Ix = 0;
// isolate the charset name
Ix = 2;
if (isEncodedWord == true)
{
RemLx = ws.Length - Ix;
if (RemLx <= 3)
{
isEncodedWord = false;
}
else
{
Fx = ws.IndexOf("?q?", Ix);
if (Fx == -1)
{
isEncodedWord = false;
}
else
{
Lx = Fx - Ix;
ew.CharSet = InString.Substring(InBx + Ix, Lx);
Ix = Fx + 3;
}
}
}
// quoted-printable encoded text runs until "?="
if (isEncodedWord == true)
{
RemLx = ws.Length - Ix;
if (RemLx <= 2)
{
isEncodedWord = false;
}
else
{
Fx = ws.IndexOf("?=", Ix);
if (Fx == -1)
{
isEncodedWord = false;
}
else
{
Lx = Fx - Ix;
string qpEncoded = InString.Substring(InBx + Ix, Lx);
ew.DecodedValue = QuotedPrintable.DecodeString(qpEncoded);
ew.Lx = Fx + 2;
}
}
}
}
catch (Exception)
{
isEncodedWord = false;
}
return(new BoolObjectPair(isEncodedWord, ew));
}
