/// <summary>
/// Splits a string without the use of a regex, which could split either by isDot() or %2e
/// @param input the input string that will be split by dot
/// @return an array of strings that is a partition of the original string split by dot
/// </summary>
/// <param name="input"></param>
/// <returns></returns>
public static string[] SplitByDot(string input)
{
var splitList = new List <string>();
var section = new StringBuilder();
if (string.IsNullOrEmpty(input))
{
return(new[] { "" });
}
var reader = new InputTextReader(input);
while (!reader.Eof())
{
var curr = reader.Read();
if (IsDot(curr))
{
splitList.Add(section.ToString());
section.Length = 0;
}
else if (curr == '%' && reader.CanReadChars(2) && reader.Peek(2).Equals("2e", StringComparison.InvariantCultureIgnoreCase))
{
reader.Read();
reader.Read(); //advance past the 2e
splitList.Add(section.ToString());
section.Length = 0;
}
else
{
section.Append(curr);
}
}
splitList.Add(section.ToString());
return(splitList.ToArray());
}
/// <summary>
/// The default input reader which looks for specific flags to start detecting the url.
/// </summary>
private void ReadDefault()
{
//Keeps track of the number of characters read to be able to later cut out the domain name.
var length = 0;
// keep track of how many times each character in each index of the raw input has been read
var contentReadByIndexCount = new byte[_reader.ContentLength];
//until end of string read the contents
while (!_reader.Eof())
{
// We want to ensure that backtracking and looping on content is limited from infinite-loops, so
// we take the hit and track each time an element in the input is read, and if its been hit too
// many times, we step forwards until we find an element that has NOT been read too many times
var currentIndex = _reader.GetPosition();
contentReadByIndexCount[currentIndex] += 1;
while (contentReadByIndexCount[currentIndex] >= ContentReadByIndexMaximum)
{
// Forcably step to the next character in the input, so we jump out of infinite loops
_reader.Read();
currentIndex = _reader.GetPosition();
}
// Read the next char to process.
var curr = _reader.Read();
switch (curr)
{
case ' ':
//space was found, check if it's a valid single level domain.
if (_options.HasFlag(UrlDetectorOptions.ALLOW_SINGLE_LEVEL_DOMAIN) && _buffer.Length > 0 && _hasScheme)
{
_reader.GoBack();
if (!ReadDomainName(_buffer.ToString().Substring(length)))
{
ReadEnd(ReadEndState.InvalidUrl);
}
;
}
_buffer.Append(curr);
ReadEnd(ReadEndState.InvalidUrl);
length = 0;
break;
case '%':
if (_reader.CanReadChars(2))
{
if (_reader.Peek(2).Equals("3a", StringComparison.InvariantCultureIgnoreCase))
{
_buffer.Append(curr);
_buffer.Append(_reader.Read());
_buffer.Append(_reader.Read());
length = ProcessColon(length);
}
else if (CharUtils.IsHex(_reader.PeekChar(0)) && CharUtils.IsHex(_reader.PeekChar(1)))
{
_buffer.Append(curr);
_buffer.Append(_reader.Read());
_buffer.Append(_reader.Read());
if (!ReadDomainName(_buffer.ToString().Substring(length)))
{
ReadEnd(ReadEndState.InvalidUrl);
}
length = 0;
}
}
break;
case '\u3002': //non-standard dots
case '\uFF0E':
case '\uFF61':
case '.': //"." was found, read the domain name using the start from length.
_buffer.Append(curr);
if (!ReadDomainName(_buffer.ToString().Substring(length)))
{
ReadEnd(ReadEndState.InvalidUrl);
}
length = 0;
break;
case '@': //Check the domain name after a username
if (_buffer.Length > 0)
{
_currentUrlMarker.SetIndex(UrlPart.USERNAME_PASSWORD, length);
_buffer.Append(curr);
if (!ReadDomainName(null))
{
ReadEnd(ReadEndState.InvalidUrl);
}
length = 0;
}
break;
case '[':
if (_dontMatchIpv6)
{
//Check if we need to match characters. If we match characters and this is a start or stop of range,
//either way reset the world and start processing again.
if (CheckMatchingCharacter(curr) != CharacterMatch.CharacterNotMatched)
{
ReadEnd(ReadEndState.InvalidUrl);
length = 0;
}
}
var beginning = _reader.GetPosition();
//if it doesn't have a scheme, clear the buffer.
if (!_hasScheme)
{
_buffer.Remove(0, _buffer.Length);
}
_buffer.Append(curr);
if (!ReadDomainName(_buffer.ToString().Substring(length)))
{
//if we didn't find an ipv6 address, then check inside the brackets for urls
ReadEnd(ReadEndState.InvalidUrl);
_reader.Seek(beginning);
_dontMatchIpv6 = true;
}
length = 0;
break;
case '/':
// "/" was found, then we either read a scheme, or if we already read a scheme, then
// we are reading a url in the format http://123123123/asdf
if (_hasScheme || _options.HasFlag(UrlDetectorOptions.ALLOW_SINGLE_LEVEL_DOMAIN) && _buffer.Length > 1)
{
//we already have the scheme, so then we already read:
//http://something/ <- if something is all numeric then its a valid url.
//OR we are searching for single level domains. We have buffer length > 1 condition
//to weed out infinite backtrack in cases of html5 roots
//unread this "/" and continue to check the domain name starting from the beginning of the domain
_reader.GoBack();
if (!ReadDomainName(_buffer.ToString().Substring(length)))
{
ReadEnd(ReadEndState.InvalidUrl);
}
length = 0;
}
else
{
//we don't have a scheme already, then clear state, then check for html5 root such as: "//google.com/"
// remember the state of the quote when clearing state just in case its "//google.com" so its not cleared.
ReadEnd(ReadEndState.InvalidUrl);
_buffer.Append(curr);
_hasScheme = ReadHtml5Root();
length = _buffer.Length;
}
break;
case ':':
//add the ":" to the url and check for scheme/username
_buffer.Append(curr);
length = ProcessColon(length);
break;
default:
//Check if we need to match characters. If we match characters and this is a start or stop of range,
//either way reset the world and start processing again.
if (CheckMatchingCharacter(curr) != CharacterMatch.CharacterNotMatched)
{
ReadEnd(ReadEndState.InvalidUrl);
length = 0;
}
else
{
_buffer.Append(curr);
}
break;
}
}
if (_options.HasFlag(UrlDetectorOptions.ALLOW_SINGLE_LEVEL_DOMAIN) && _buffer.Length > 0 && _hasScheme)
{
if (!ReadDomainName(_buffer.ToString().Substring(length)))
{
ReadEnd(ReadEndState.InvalidUrl);
}
}
}
/// <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));
}
