com.novell.sasl.client.TokenParser Maven / Gradle / Ivy
/* **************************************************************************
* $OpenLDAP$
*
* Copyright (C) 2002 Novell, Inc. All Rights Reserved.
*
* THIS WORK IS SUBJECT TO U.S. AND INTERNATIONAL COPYRIGHT LAWS AND
* TREATIES. USE, MODIFICATION, AND REDISTRIBUTION OF THIS WORK IS SUBJECT
* TO VERSION 2.0.1 OF THE OPENLDAP PUBLIC LICENSE, A COPY OF WHICH IS
* AVAILABLE AT HTTP://WWW.OPENLDAP.ORG/LICENSE.HTML OR IN THE FILE "LICENSE"
* IN THE TOP-LEVEL DIRECTORY OF THE DISTRIBUTION. ANY USE OR EXPLOITATION
* OF THIS WORK OTHER THAN AS AUTHORIZED IN VERSION 2.0.1 OF THE OPENLDAP
* PUBLIC LICENSE, OR OTHER PRIOR WRITTEN CONSENT FROM NOVELL, COULD SUBJECT
* THE PERPETRATOR TO CRIMINAL AND CIVIL LIABILITY.
******************************************************************************/
package com.novell.sasl.client;
import com.novell.security.sasl.*;
/**
* The TokenParser class will parse individual tokens from a list of tokens that
* are a directive value for a DigestMD5 authentication.The tokens are separated
* commas.
*/
class TokenParser extends Object
{
private static final int STATE_LOOKING_FOR_FIRST_TOKEN = 1;
private static final int STATE_LOOKING_FOR_TOKEN = 2;
private static final int STATE_SCANNING_TOKEN = 3;
private static final int STATE_LOOKING_FOR_COMMA = 4;
private static final int STATE_PARSING_ERROR = 5;
private static final int STATE_DONE = 6;
private int m_curPos;
private int m_scanStart;
private int m_state;
private String m_tokens;
TokenParser(
String tokens)
{
m_tokens = tokens;
m_curPos = 0;
m_scanStart = 0;
m_state = STATE_LOOKING_FOR_FIRST_TOKEN;
}
/**
* This function parses the next token from the tokens string and returns
* it as a string. If there are no more tokens a null reference is returned.
*
* @return the parsed token or a null reference if there are no more
* tokens
*
* @exception SASLException if an error occurs while parsing
*/
String parseToken() throws SaslException
{
char currChar;
String token = null;
if (m_state == STATE_DONE)
return null;
while (m_curPos < m_tokens.length() && (token == null))
{
currChar = m_tokens.charAt(m_curPos);
switch (m_state)
{
case STATE_LOOKING_FOR_FIRST_TOKEN:
case STATE_LOOKING_FOR_TOKEN:
if (isWhiteSpace(currChar))
{
break;
}
else if (isValidTokenChar(currChar))
{
m_scanStart = m_curPos;
m_state = STATE_SCANNING_TOKEN;
}
else
{
m_state = STATE_PARSING_ERROR;
throw new SaslException("Invalid token character at position " + m_curPos);
}
break;
case STATE_SCANNING_TOKEN:
if (isValidTokenChar(currChar))
{
break;
}
else if (isWhiteSpace(currChar))
{
token = m_tokens.substring(m_scanStart, m_curPos);
m_state = STATE_LOOKING_FOR_COMMA;
}
else if (',' == currChar)
{
token = m_tokens.substring(m_scanStart, m_curPos);
m_state = STATE_LOOKING_FOR_TOKEN;
}
else
{
m_state = STATE_PARSING_ERROR;
throw new SaslException("Invalid token character at position " + m_curPos);
}
break;
case STATE_LOOKING_FOR_COMMA:
if (isWhiteSpace(currChar))
break;
else if (currChar == ',')
m_state = STATE_LOOKING_FOR_TOKEN;
else
{
m_state = STATE_PARSING_ERROR;
throw new SaslException("Expected a comma, found '" +
currChar + "' at postion " +
m_curPos);
}
break;
}
m_curPos++;
} /* end while loop */
if (token == null)
{ /* check the ending state */
switch (m_state)
{
case STATE_SCANNING_TOKEN:
token = m_tokens.substring(m_scanStart);
m_state = STATE_DONE;
break;
case STATE_LOOKING_FOR_FIRST_TOKEN:
case STATE_LOOKING_FOR_COMMA:
break;
case STATE_LOOKING_FOR_TOKEN:
throw new SaslException("Trialing comma");
}
}
return token;
}
/**
* This function returns TRUE if the character is a valid token character.
*
* token = 1*
*
* separators = "(" | ")" | "<" | ">" | "@"
* | "," | ";" | ":" | "\" | <">
* | "/" | "[" | "]" | "?" | "="
* | "{" | "}" | SP | HT
*
* CTL =
*
* CHAR =
*
* @param c character to be validated
*
* @return True if character is valid Token character else it returns
* false
*/
boolean isValidTokenChar(
char c)
{
if ( ( (c >= '\u0000') && (c <='\u0020') ) ||
( (c >= '\u003a') && (c <= '\u0040') ) ||
( (c >= '\u005b') && (c <= '\u005d') ) ||
('\u002c' == c) ||
('\u0025' == c) ||
('\u0028' == c) ||
('\u0029' == c) ||
('\u007b' == c) ||
('\u007d' == c) ||
('\u007f' == c) )
return false;
return true;
}
/**
* This function returns TRUE if the character is linear white space (LWS).
* LWS = [CRLF] 1*( SP | HT )
*
* @param c character to be validated
*
* @return True if character is liner whitespace else it returns false
*/
boolean isWhiteSpace(
char c)
{
if ( ('\t' == c) || // HORIZONTAL TABULATION.
('\n' == c) || // LINE FEED.
('\r' == c) || // CARRIAGE RETURN.
('\u0020' == c) )
return true;
return false;
}
}