private static string EncodeAndQuoteMime(string input)
{
string input1 = input;
bool flag = false;
if (ContentDispositionHeaderValue.IsQuoted((ReadOnlySpan <char>)input1))
{
input1 = input1.Substring(1, input1.Length - 2);
flag = true;
}
if (input1.Contains('"'))
{
throw new ArgumentException(SR.Format((IFormatProvider)CultureInfo.InvariantCulture, SR.net_http_headers_invalid_value, (object)input));
}
if (HeaderUtilities.ContainsNonAscii(input1))
{
flag = true;
input1 = ContentDispositionHeaderValue.EncodeMime(input1);
}
else if (!flag && HttpRuleParser.GetTokenLength(input1, 0) != input1.Length)
{
flag = true;
}
if (flag)
{
input1 = "\"" + input1 + "\"";
}
return(input1);
}
private static bool TryDecodeMime(string input, out string output)
{
output = (string)null;
string str = input;
if (!ContentDispositionHeaderValue.IsQuoted((ReadOnlySpan <char>)str) || str.Length < 10)
{
return(false);
}
string[] strArray = str.Split('?', StringSplitOptions.None);
if (strArray.Length == 5 && !(strArray[0] != "\"=") && !(strArray[4] != "=\""))
{
if (!(strArray[2].ToLowerInvariant() != "b"))
{
try
{
Encoding encoding = Encoding.GetEncoding(strArray[1]);
byte[] bytes = Convert.FromBase64String(strArray[3]);
output = encoding.GetString(bytes, 0, bytes.Length);
return(true);
}
catch (ArgumentException ex)
{
}
catch (FormatException ex)
{
}
return(false);
}
}
return(false);
}
private DateTimeOffset?GetDate(string parameter)
{
NameValueHeaderValue valueHeaderValue = NameValueHeaderValue.Find(this._parameters, parameter);
if (valueHeaderValue != null)
{
ReadOnlySpan <char> input = (ReadOnlySpan <char>)valueHeaderValue.Value;
if (ContentDispositionHeaderValue.IsQuoted(input))
{
input = input.Slice(1, input.Length - 2);
}
DateTimeOffset result;
if (HttpDateParser.TryStringToDate(input, out result))
{
return(new DateTimeOffset?(result));
}
}
return(new DateTimeOffset?());
}