/// <summary>
/// Reads the Dns and returns the next state the state machine should take in throwing this out, or continue processing
/// if this is a valid domain name.
/// @return The next state to take.
/// </summary>
public ReaderNextState ReadDomainName()
{
//Read the current, and if its bad, just return.
if (ReadCurrent() == ReaderNextState.InvalidDomainName)
{
return(ReaderNextState.InvalidDomainName);
}
//If this is the first domain part, check if it's ip address in is hexa
//similar to what is done on 'readCurrent' method
bool isAllHexSoFar = (_current == null || _current.Equals("")) &&
_reader.CanReadChars(3) &&
("0x".Equals(_reader.Peek(2), StringComparison.InvariantCultureIgnoreCase));
if (isAllHexSoFar)
{
//Append hexa radix symbol characters (0x)
_buffer.Append(_reader.Read());
_buffer.Append(_reader.Read());
_currentLabelLength += 2;
_topLevelLength = _currentLabelLength;
}
//while not done and not end of string keep reading.
var done = false;
while (!done && !_reader.Eof())
{
var curr = _reader.Read();
if (curr == '/')
{
//continue by reading the path
return(CheckDomainNameValid(ReaderNextState.ReadPath, curr));
}
if (curr == ':' && (!_seenBracket || _seenCompleteBracketSet))
{
//Don't check for a port if it's in the middle of an ipv6 address
//continue by reading the port.
return(CheckDomainNameValid(ReaderNextState.ReadPort, curr));
}
if (curr == '?')
{
//continue by reading the query string
return(CheckDomainNameValid(ReaderNextState.ReadQueryString, curr));
}
if (curr == '#')
{
//continue by reading the fragment
return(CheckDomainNameValid(ReaderNextState.ReadFragment, curr));
}
else if (curr == '@')
{
//this may not have been a domain after all, but rather a username/password instead
_reader.GoBack();
return(ReaderNextState.ReadUserPass);
}
else if (CharUtils.IsDot(curr) ||
curr == '%' && _reader.CanReadChars(2) && _reader.Peek(2).Equals(HEX_ENCODED_DOT, StringComparison.InvariantCultureIgnoreCase))
{
//if the current character is a dot or a urlEncodedDot
//handles the case: hello..
if (_currentLabelLength < 1)
{
done = true;
}
else
{
//append the "." to the domain name
_buffer.Append(curr);
//if it was not a normal dot, then it is url encoded
//read the next two chars, which are the hex representation
if (!CharUtils.IsDot(curr))
{
_buffer.Append(_reader.Read());
_buffer.Append(_reader.Read());
}
//increment the dots only if it's not part of the zone index and reset the last length.
if (!_zoneIndex)
{
_dots++;
_currentLabelLength = 0;
}
//if the length of the last section is longer than or equal to 64, it's too long to be a valid domain
if (_currentLabelLength >= MAX_LABEL_LENGTH)
{
return(ReaderNextState.InvalidDomainName);
}
}
}
else if (_seenBracket && (CharUtils.IsHex(curr) || curr == ':' || curr == '[' || curr == ']' || curr == '%') &&
!_seenCompleteBracketSet)
{
//if this is an ipv6 address.
switch (curr)
{
case ':':
_currentLabelLength = 0;
break;
case '[':
// if we read another '[', we need to restart by re-reading from this bracket instead.
_reader.GoBack();
return(ReaderNextState.InvalidDomainName);
case ']':
_seenCompleteBracketSet = true; //means that we already have a complete ipv6 address.
_zoneIndex = false; //set this back off so that we can keep counting dots after ipv6 is over.
break;
case '%': //set flag to subtract subsequent dots because it's part of the zone index
_zoneIndex = true;
break;
default:
_currentLabelLength++;
break;
}
_numeric = false;
_buffer.Append(curr);
}
else if (CharUtils.IsAlphaNumeric(curr) || curr == '-' || curr >= INTERNATIONAL_CHAR_START)
{
//Valid domain name character. Either a-z, A-Z, 0-9, -, or international character
if (_seenCompleteBracketSet)
{
//covers case of [fe80::]www.google.com
_reader.GoBack();
done = true;
}
else
{
if (isAllHexSoFar && !CharUtils.IsHex(curr))
{
_numeric = false;
}
//if its not numeric, remember that;
if (!isAllHexSoFar && !CharUtils.IsNumeric(curr))
{
_numeric = false;
}
//append to the states.
_buffer.Append(curr);
_currentLabelLength++;
_topLevelLength = _currentLabelLength;
}
}
else if (curr == '[' && !_seenBracket)
{
_seenBracket = true;
_numeric = false;
_buffer.Append(curr);
}
else if (curr == '[' && _seenCompleteBracketSet)
{
//Case where [::][ ...
_reader.GoBack();
done = true;
}
else if (curr == '%' && _reader.CanReadChars(2) && CharUtils.IsHex(_reader.PeekChar(0)) &&
CharUtils.IsHex(_reader.PeekChar(1)))
{
//append to the states.
_buffer.Append(curr);
_buffer.Append(_reader.Read());
_buffer.Append(_reader.Read());
_currentLabelLength += 3;
_topLevelLength = _currentLabelLength;
}
else
{
//called to increment the count of matching characters
//_characterHandler.addCharacter(curr);
_characterHandler(curr);
//invalid character, we are done.
done = true;
}
}
//Check the domain name to make sure its ok.
return(CheckDomainNameValid(ReaderNextState.ValidDomainName, null));
}
/// <summary>
/// Try to read the port of the url.
/// </summary>
/// <returns>True if a valid port was read.</returns>
private bool ReadPort()
{
_currentUrlMarker.SetIndex(UrlPart.PORT, _buffer.Length);
//The length of the port read.
var portLen = 0;
while (!_reader.Eof())
{
//read the next one and remember the length
var curr = _reader.Read();
portLen++;
if (curr == '/')
{
//continue to read path
_buffer.Append(curr);
return(ReadPath());
}
if (curr == '?')
{
//continue to read query string
_buffer.Append(curr);
return(ReadQueryString());
}
if (curr == '#')
{
//continue to read fragment.
_buffer.Append(curr);
return(ReadFragment());
}
if (CheckMatchingCharacter(curr) == CharacterMatch.CharacterMatchStop || !CharUtils.IsNumeric(curr))
{
//if we got here, then what we got so far is a valid url. don't append the current character.
_reader.GoBack();
//no port found; it was something like google.com:hello.world
if (portLen == 1)
{
//remove the ":" from the end.
_buffer.Remove(_buffer.Length - 1, 1);
}
_currentUrlMarker.UnsetIndex(UrlPart.PORT);
return(ReadEnd(ReadEndState.ValidUrl));
}
//this is a valid character in the port string.
_buffer.Append(curr);
}
//found a correct url
return(ReadEnd(ReadEndState.ValidUrl));
}
/// <summary>
/// Reads and parses the current string to make sure the domain name started where it was supposed to,
/// and the current domain name is correct.
/// @return The next state to use after reading the current.
/// </summary>
private ReaderNextState ReadCurrent()
{
if (_current != null)
{
//Handles the case where the string is ".hello"
if (_current.Length == 1 && CharUtils.IsDot(_current[0]))
{
return(ReaderNextState.InvalidDomainName);
}
if (_current.Length == 3 && _current.Equals("%" + HEX_ENCODED_DOT, StringComparison.InvariantCultureIgnoreCase))
{
return(ReaderNextState.InvalidDomainName);
}
//The location where the domain name started.
_startDomainName = _buffer.Length - _current.Length;
//flag that the domain is currently all numbers and/or dots.
_numeric = true;
//If an invalid char is found, we can just restart the domain from there.
var newStart = 0;
var currArray = _current.ToCharArray();
var length = currArray.Length;
//hex special case
var isAllHexSoFar = length > 2 && currArray[0] == '0' && (currArray[1] == 'x' || currArray[1] == 'X');
var index = isAllHexSoFar ? 2 : 0;
var done = false;
while (index < length && !done)
{
//get the current character and update length counts.
var curr = currArray[index];
_currentLabelLength++;
_topLevelLength = _currentLabelLength;
//Is the length of the last part > 64 (plus one since we just incremented)
if (_currentLabelLength > MAX_LABEL_LENGTH)
{
return(ReaderNextState.InvalidDomainName);
}
if (CharUtils.IsDot(curr))
{
//found a dot. Increment dot count, and reset last length
_dots++;
_currentLabelLength = 0;
}
else if (curr == '[')
{
_seenBracket = true;
_numeric = false;
}
else if (curr == '%' && index + 2 < length && CharUtils.IsHex(currArray[index + 1]) &&
CharUtils.IsHex(currArray[index + 2]))
{
//handle url encoded dot
if (currArray[index + 1] == '2' && currArray[index + 2] == 'e')
{
_dots++;
_currentLabelLength = 0;
}
else
{
_numeric = false;
}
index += 2;
}
else if (isAllHexSoFar)
{
//if it's a valid character in the domain that is not numeric
if (!CharUtils.IsHex(curr))
{
_numeric = false;
isAllHexSoFar = false;
index--; //backtrack to rerun last character knowing it isn't hex.
}
}
else if (CharUtils.IsAlpha(curr) || curr == '-' || curr >= INTERNATIONAL_CHAR_START)
{
_numeric = false;
}
else if (!CharUtils.IsNumeric(curr) && !_options.HasFlag(UrlDetectorOptions.ALLOW_SINGLE_LEVEL_DOMAIN))
{
//if its not _numeric and not alphabetical, then restart searching for a domain from this point.
newStart = index + 1;
_currentLabelLength = 0;
_topLevelLength = 0;
_numeric = true;
_dots = 0;
done = true;
}
index++;
}
//An invalid character for the domain was found somewhere in the current buffer.
//cut the first part of the domain out. For example:
// http://asdf%asdf.google.com <- asdf.google.com is still valid, so restart from the %
if (newStart > 0)
{
//make sure the location is not at the end. Otherwise the thing is just invalid.
if (newStart < _current.Length)
{
_buffer.Clear();
_buffer.Append(_current.Substring(newStart));
//_buffer.Replace(0, _buffer.Length(), _current.javaSubstring(newStart));
//cut out the previous part, so now the domain name has to be from here.
_startDomainName = 0;
}
//now after cutting if the buffer is just "." newStart > current (last character in current is invalid)
if (newStart >= _current.Length || _buffer.ToString().Equals("."))
{
return(ReaderNextState.InvalidDomainName);
}
}
}
else
{
_startDomainName = _buffer.Length;
}
//all else is good, return OK
return(ReaderNextState.ValidDomainName);
}