| /* |
| * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package java.net; |
| |
| import android.icu.text.IDNA; |
| |
| /** |
| * Provides methods to convert internationalized domain names (IDNs) between |
| * a normal Unicode representation and an ASCII Compatible Encoding (ACE) representation. |
| * Internationalized domain names can use characters from the entire range of |
| * Unicode, while traditional domain names are restricted to ASCII characters. |
| * ACE is an encoding of Unicode strings that uses only ASCII characters and |
| * can be used with software (such as the Domain Name System) that only |
| * understands traditional domain names. |
| * |
| * <p>Internationalized domain names are defined in <a href="http://www.ietf.org/rfc/rfc3490.txt">RFC 3490</a>. |
| * RFC 3490 defines two operations: ToASCII and ToUnicode. These 2 operations employ |
| * <a href="http://www.ietf.org/rfc/rfc3491.txt">Nameprep</a> algorithm, which is a |
| * profile of <a href="http://www.ietf.org/rfc/rfc3454.txt">Stringprep</a>, and |
| * <a href="http://www.ietf.org/rfc/rfc3492.txt">Punycode</a> algorithm to convert |
| * domain name string back and forth. |
| * |
| * <p>The behavior of aforementioned conversion process can be adjusted by various flags: |
| * <ul> |
| * <li>If the ALLOW_UNASSIGNED flag is used, the domain name string to be converted |
| * can contain code points that are unassigned in Unicode 3.2, which is the |
| * Unicode version on which IDN conversion is based. If the flag is not used, |
| * the presence of such unassigned code points is treated as an error. |
| * <li>If the USE_STD3_ASCII_RULES flag is used, ASCII strings are checked against <a href="http://www.ietf.org/rfc/rfc1122.txt">RFC 1122</a> and <a href="http://www.ietf.org/rfc/rfc1123.txt">RFC 1123</a>. |
| * It is an error if they don't meet the requirements. |
| * </ul> |
| * These flags can be logically OR'ed together. |
| * |
| * <p>The security consideration is important with respect to internationalization |
| * domain name support. For example, English domain names may be <i>homographed</i> |
| * - maliciously misspelled by substitution of non-Latin letters. |
| * <a href="http://www.unicode.org/reports/tr36/">Unicode Technical Report #36</a> |
| * discusses security issues of IDN support as well as possible solutions. |
| * Applications are responsible for taking adequate security measures when using |
| * international domain names. |
| * |
| * @author Edward Wang |
| * @since 1.6 |
| * |
| */ |
| public final class IDN { |
| /** |
| * Flag to allow processing of unassigned code points |
| */ |
| public static final int ALLOW_UNASSIGNED = 0x01; |
| |
| /** |
| * Flag to turn on the check against STD-3 ASCII rules |
| */ |
| public static final int USE_STD3_ASCII_RULES = 0x02; |
| |
| private IDN() { |
| } |
| |
| |
| /** |
| * Translates a string from Unicode to ASCII Compatible Encoding (ACE), |
| * as defined by the ToASCII operation of <a href="http://www.ietf.org/rfc/rfc3490.txt">RFC 3490</a>. |
| * |
| * <p>ToASCII operation can fail. ToASCII fails if any step of it fails. |
| * If ToASCII operation fails, an IllegalArgumentException will be thrown. |
| * In this case, the input string should not be used in an internationalized domain name. |
| * |
| * <p> A label is an individual part of a domain name. The original ToASCII operation, |
| * as defined in RFC 3490, only operates on a single label. This method can handle |
| * both label and entire domain name, by assuming that labels in a domain name are |
| * always separated by dots. The following characters are recognized as dots: |
| * \u002E (full stop), \u3002 (ideographic full stop), \uFF0E (fullwidth full stop), |
| * and \uFF61 (halfwidth ideographic full stop). if dots are |
| * used as label separators, this method also changes all of them to \u002E (full stop) |
| * in output translated string. |
| * |
| * @param input the string to be processed |
| * @param flag process flag; can be 0 or any logical OR of possible flags |
| * |
| * @return the translated <tt>String</tt> |
| * |
| * @throws IllegalArgumentException if the input string doesn't conform to RFC 3490 specification |
| */ |
| public static String toASCII(String input, int flag) { |
| try { |
| return IDNA.convertIDNToASCII(input, flag).toString(); |
| } catch (android.icu.text.StringPrepParseException e) { |
| throw new IllegalArgumentException("Invalid input to toASCII: " + input, e); |
| } |
| } |
| |
| |
| /** |
| * Translates a string from Unicode to ASCII Compatible Encoding (ACE), |
| * as defined by the ToASCII operation of <a href="http://www.ietf.org/rfc/rfc3490.txt">RFC 3490</a>. |
| * |
| * <p> This convenience method works as if by invoking the |
| * two-argument counterpart as follows: |
| * <blockquote><tt> |
| * {@link #toASCII(String, int) toASCII}(input, 0); |
| * </tt></blockquote> |
| * |
| * @param input the string to be processed |
| * |
| * @return the translated <tt>String</tt> |
| * |
| * @throws IllegalArgumentException if the input string doesn't conform to RFC 3490 specification |
| */ |
| public static String toASCII(String input) { |
| return toASCII(input, 0); |
| } |
| |
| |
| /** |
| * Translates a string from ASCII Compatible Encoding (ACE) to Unicode, |
| * as defined by the ToUnicode operation of <a href="http://www.ietf.org/rfc/rfc3490.txt">RFC 3490</a>. |
| * |
| * <p>ToUnicode never fails. In case of any error, the input string is returned unmodified. |
| * |
| * <p> A label is an individual part of a domain name. The original ToUnicode operation, |
| * as defined in RFC 3490, only operates on a single label. This method can handle |
| * both label and entire domain name, by assuming that labels in a domain name are |
| * always separated by dots. The following characters are recognized as dots: |
| * \u002E (full stop), \u3002 (ideographic full stop), \uFF0E (fullwidth full stop), |
| * and \uFF61 (halfwidth ideographic full stop). |
| * |
| * @param input the string to be processed |
| * @param flag process flag; can be 0 or any logical OR of possible flags |
| * |
| * @return the translated <tt>String</tt> |
| */ |
| public static String toUnicode(String input, int flag) { |
| try { |
| // ICU only translates separators to ASCII for toASCII. |
| // Java expects the translation for toUnicode too. |
| return convertFullStop(IDNA.convertIDNToUnicode(input, flag)).toString(); |
| } catch (android.icu.text.StringPrepParseException e) { |
| // The RI documentation explicitly states that if the conversion was unsuccessful |
| // the original string is returned. |
| return input; |
| } |
| } |
| |
| private static boolean isLabelSeperator(char c) { |
| return (c == '\u3002' || c == '\uff0e' || c == '\uff61'); |
| } |
| |
| private static StringBuffer convertFullStop(StringBuffer input) { |
| for (int i = 0; i < input.length(); i++) { |
| if (isLabelSeperator(input.charAt(i))) { |
| input.setCharAt(i, '.'); |
| } |
| } |
| return input; |
| } |
| |
| |
| /** |
| * Translates a string from ASCII Compatible Encoding (ACE) to Unicode, |
| * as defined by the ToUnicode operation of <a href="http://www.ietf.org/rfc/rfc3490.txt">RFC 3490</a>. |
| * |
| * <p> This convenience method works as if by invoking the |
| * two-argument counterpart as follows: |
| * <blockquote><tt> |
| * {@link #toUnicode(String, int) toUnicode}(input, 0); |
| * </tt></blockquote> |
| * |
| * @param input the string to be processed |
| * |
| * @return the translated <tt>String</tt> |
| */ |
| public static String toUnicode(String input) { |
| return toUnicode(input, 0); |
| } |
| } |
