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/* * Copyright 2005-2010 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * https://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.springframework.security.ldap; import org.springframework.ldap.BadLdapGrammarException; /** * Helper class to encode and decode ldap names and values. * * <p> * NOTE: This is a copy from Spring LDAP so that both Spring LDAP 1.x and 2.x can be * supported without reflection. * </p> * * @author Adam Skogman * @author Mattias Hellborg Arthursson */ final class LdapEncoder { private static final int HEX = 16; private static String[] NAME_ESCAPE_TABLE = new String[96]; private static String[] FILTER_ESCAPE_TABLE = new String['\\' + 1]; static { // Name encoding table ------------------------------------- // all below 0x20 (control chars) for (char c = 0; c < ' '; c++) { NAME_ESCAPE_TABLE[c] = "\\" + toTwoCharHex(c); } NAME_ESCAPE_TABLE['#'] = "\\#"; NAME_ESCAPE_TABLE[','] = "\\,"; NAME_ESCAPE_TABLE[';'] = "\\;"; NAME_ESCAPE_TABLE['='] = "\\="; NAME_ESCAPE_TABLE['+'] = "\\+"; NAME_ESCAPE_TABLE['<'] = "\\<"; NAME_ESCAPE_TABLE['>'] = "\\>"; NAME_ESCAPE_TABLE['\"'] = "\\\""; NAME_ESCAPE_TABLE['\\'] = "\\\\"; // Filter encoding table ------------------------------------- // fill with char itself for (char c = 0; c < FILTER_ESCAPE_TABLE.length; c++) { FILTER_ESCAPE_TABLE[c] = String.valueOf(c); } // escapes (RFC2254) FILTER_ESCAPE_TABLE['*'] = "\\2a"; FILTER_ESCAPE_TABLE['('] = "\\28"; FILTER_ESCAPE_TABLE[')'] = "\\29"; FILTER_ESCAPE_TABLE['\\'] = "\\5c"; FILTER_ESCAPE_TABLE[0] = "\\00"; } /** * All static methods - not to be instantiated. */ private LdapEncoder() { } protected static String toTwoCharHex(char c) { String raw = Integer.toHexString(c).toUpperCase(); if (raw.length() > 1) { return raw; } else { return "0" + raw; } } /** * Escape a value for use in a filter. * * @param value the value to escape. * @return a properly escaped representation of the supplied value. */ public static String filterEncode(String value) { if (value == null) { return null; } // make buffer roomy StringBuilder encodedValue = new StringBuilder(value.length() * 2); int length = value.length(); for (int i = 0; i < length; i++) { char c = value.charAt(i); if (c < FILTER_ESCAPE_TABLE.length) { encodedValue.append(FILTER_ESCAPE_TABLE[c]); } else { // default: add the char encodedValue.append(c); } } return encodedValue.toString(); } /** * LDAP Encodes a value for use with a DN. Escapes for LDAP, not JNDI! * * <br/> * Escapes:<br/> * ' ' [space] - "\ " [if first or last] <br/> * '#' [hash] - "\#" <br/> * ',' [comma] - "\," <br/> * ';' [semicolon] - "\;" <br/> * '= [equals] - "\=" <br/> * '+' [plus] - "\+" <br/> * '<' [less than] - "\<" <br/> * '>' [greater than] - "\>" <br/> * '"' [double quote] - "\"" <br/> * '\' [backslash] - "\\" <br/> * * @param value the value to escape. * @return The escaped value. */ public static String nameEncode(String value) { if (value == null) { return null; } // make buffer roomy StringBuilder encodedValue = new StringBuilder(value.length() * 2); int length = value.length(); int last = length - 1; for (int i = 0; i < length; i++) { char c = value.charAt(i); // space first or last if (c == ' ' && (i == 0 || i == last)) { encodedValue.append("\\ "); continue; } if (c < NAME_ESCAPE_TABLE.length) { // check in table for escapes String esc = NAME_ESCAPE_TABLE[c]; if (esc != null) { encodedValue.append(esc); continue; } } // default: add the char encodedValue.append(c); } return encodedValue.toString(); } /** * Decodes a value. Converts escaped chars to ordinary chars. * * @param value Trimmed value, so no leading an trailing blanks, except an escaped * space last. * @return The decoded value as a string. * @throws BadLdapGrammarException */ static public String nameDecode(String value) throws BadLdapGrammarException { if (value == null) { return null; } // make buffer same size StringBuilder decoded = new StringBuilder(value.length()); int i = 0; while (i < value.length()) { char currentChar = value.charAt(i); if (currentChar == '\\') { if (value.length() <= i + 1) { // Ending with a single backslash is not allowed throw new BadLdapGrammarException("Unexpected end of value " + "unterminated '\\'"); } else { char nextChar = value.charAt(i + 1); if (nextChar == ',' || nextChar == '=' || nextChar == '+' || nextChar == '<' || nextChar == '>' || nextChar == '#' || nextChar == ';' || nextChar == '\\' || nextChar == '\"' || nextChar == ' ') { // Normal backslash escape decoded.append(nextChar); i += 2; } else { if (value.length() <= i + 2) { throw new BadLdapGrammarException("Unexpected end of value " + "expected special or hex, found '" + nextChar + "'"); } else { // This should be a hex value String hexString = "" + nextChar + value.charAt(i + 2); decoded.append((char) Integer.parseInt(hexString, HEX)); i += 3; } } } } else { // This character wasn't escaped - just append it decoded.append(currentChar); i++; } } return decoded.toString(); } }