| /* |
| * Copyright (C) 2014 The Android Open Source Project |
| * Copyright (c) 2005, 2013, 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; |
| |
| |
| /** |
| * 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 {@code String} |
| * |
| * @throws IllegalArgumentException if the input string doesn't conform to RFC 3490 specification |
| */ |
| public static String toASCII(String input, int flag) { |
| // BEGIN Android-changed: Use ICU4J implementation |
| try { |
| return IDNA.convertIDNToASCII(input, flag).toString(); |
| } catch (android.icu.text.StringPrepParseException e) { |
| // b/113787610: "." is a valid IDN but is rejected by ICU. |
| // Usage is relatively uncommon, so only check for it if ICU throws. |
| if (".".equals(input)) { |
| return input; |
| } |
| throw new IllegalArgumentException("Invalid input to toASCII: " + input, e); |
| } |
| // END Android-changed: Use ICU4J implementation |
| } |
| |
| |
| /** |
| * 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> |
| * {@link #toASCII(String, int) toASCII}(input, 0); |
| * </blockquote> |
| * |
| * @param input the string to be processed |
| * |
| * @return the translated {@code String} |
| * |
| * @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 {@code String} |
| */ |
| public static String toUnicode(String input, int flag) { |
| // BEGIN Android-changed: Use ICU4J implementation |
| 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; |
| } |
| // END Android-changed: Use ICU4J implementation |
| } |
| |
| // BEGIN Android-added: Use ICU4J implementation |
| 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; |
| } |
| // END Android-added: Use ICU4J implementation |
| |
| /** |
| * 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> |
| * {@link #toUnicode(String, int) toUnicode}(input, 0); |
| * </blockquote> |
| * |
| * @param input the string to be processed |
| * |
| * @return the translated {@code String} |
| */ |
| public static String toUnicode(String input) { |
| return toUnicode(input, 0); |
| } |
| |
| |
| /* ---------------- Private members -------------- */ |
| |
| // Android-removed: Private helper methods, unused because we use ICU. |
| /* |
| // ACE Prefix is "xn--" |
| private static final String ACE_PREFIX = "xn--"; |
| private static final int ACE_PREFIX_LENGTH = ACE_PREFIX.length(); |
| |
| private static final int MAX_LABEL_LENGTH = 63; |
| |
| // single instance of nameprep |
| private static StringPrep namePrep = null; |
| |
| static { |
| InputStream stream = null; |
| |
| try { |
| final String IDN_PROFILE = "uidna.spp"; |
| if (System.getSecurityManager() != null) { |
| stream = AccessController.doPrivileged(new PrivilegedAction<InputStream>() { |
| public InputStream run() { |
| return StringPrep.class.getResourceAsStream(IDN_PROFILE); |
| } |
| }); |
| } else { |
| stream = StringPrep.class.getResourceAsStream(IDN_PROFILE); |
| } |
| |
| namePrep = new StringPrep(stream); |
| stream.close(); |
| } catch (IOException e) { |
| // should never reach here |
| assert false; |
| } |
| } |
| */ |
| |
| /* ---------------- Private operations -------------- */ |
| |
| |
| // |
| // to suppress the default zero-argument constructor |
| // |
| private IDN() {} |
| |
| // Android-removed: Private helper methods, unused because we use ICU. |
| /* |
| // |
| // toASCII operation; should only apply to a single label |
| // |
| private static String toASCIIInternal(String label, int flag) |
| { |
| // step 1 |
| // Check if the string contains code points outside the ASCII range 0..0x7c. |
| boolean isASCII = isAllASCII(label); |
| StringBuffer dest; |
| |
| // step 2 |
| // perform the nameprep operation; flag ALLOW_UNASSIGNED is used here |
| if (!isASCII) { |
| UCharacterIterator iter = UCharacterIterator.getInstance(label); |
| try { |
| dest = namePrep.prepare(iter, flag); |
| } catch (java.text.ParseException e) { |
| throw new IllegalArgumentException(e); |
| } |
| } else { |
| dest = new StringBuffer(label); |
| } |
| |
| // step 8, move forward to check the smallest number of the code points |
| // the length must be inside 1..63 |
| if (dest.length() == 0) { |
| throw new IllegalArgumentException( |
| "Empty label is not a legal name"); |
| } |
| |
| // step 3 |
| // Verify the absence of non-LDH ASCII code points |
| // 0..0x2c, 0x2e..0x2f, 0x3a..0x40, 0x5b..0x60, 0x7b..0x7f |
| // Verify the absence of leading and trailing hyphen |
| boolean useSTD3ASCIIRules = ((flag & USE_STD3_ASCII_RULES) != 0); |
| if (useSTD3ASCIIRules) { |
| for (int i = 0; i < dest.length(); i++) { |
| int c = dest.charAt(i); |
| if (isNonLDHAsciiCodePoint(c)) { |
| throw new IllegalArgumentException( |
| "Contains non-LDH ASCII characters"); |
| } |
| } |
| |
| if (dest.charAt(0) == '-' || |
| dest.charAt(dest.length() - 1) == '-') { |
| |
| throw new IllegalArgumentException( |
| "Has leading or trailing hyphen"); |
| } |
| } |
| |
| if (!isASCII) { |
| // step 4 |
| // If all code points are inside 0..0x7f, skip to step 8 |
| if (!isAllASCII(dest.toString())) { |
| // step 5 |
| // verify the sequence does not begin with ACE prefix |
| if(!startsWithACEPrefix(dest)){ |
| |
| // step 6 |
| // encode the sequence with punycode |
| try { |
| dest = Punycode.encode(dest, null); |
| } catch (java.text.ParseException e) { |
| throw new IllegalArgumentException(e); |
| } |
| |
| dest = toASCIILower(dest); |
| |
| // step 7 |
| // prepend the ACE prefix |
| dest.insert(0, ACE_PREFIX); |
| } else { |
| throw new IllegalArgumentException("The input starts with the ACE Prefix"); |
| } |
| |
| } |
| } |
| |
| // step 8 |
| // the length must be inside 1..63 |
| if (dest.length() > MAX_LABEL_LENGTH) { |
| throw new IllegalArgumentException("The label in the input is too long"); |
| } |
| |
| return dest.toString(); |
| } |
| |
| // |
| // toUnicode operation; should only apply to a single label |
| // |
| private static String toUnicodeInternal(String label, int flag) { |
| boolean[] caseFlags = null; |
| StringBuffer dest; |
| |
| // step 1 |
| // find out if all the codepoints in input are ASCII |
| boolean isASCII = isAllASCII(label); |
| |
| if(!isASCII){ |
| // step 2 |
| // perform the nameprep operation; flag ALLOW_UNASSIGNED is used here |
| try { |
| UCharacterIterator iter = UCharacterIterator.getInstance(label); |
| dest = namePrep.prepare(iter, flag); |
| } catch (Exception e) { |
| // toUnicode never fails; if any step fails, return the input string |
| return label; |
| } |
| } else { |
| dest = new StringBuffer(label); |
| } |
| |
| // step 3 |
| // verify ACE Prefix |
| if(startsWithACEPrefix(dest)) { |
| |
| // step 4 |
| // Remove the ACE Prefix |
| String temp = dest.substring(ACE_PREFIX_LENGTH, dest.length()); |
| |
| try { |
| // step 5 |
| // Decode using punycode |
| StringBuffer decodeOut = Punycode.decode(new StringBuffer(temp), null); |
| |
| // step 6 |
| // Apply toASCII |
| String toASCIIOut = toASCII(decodeOut.toString(), flag); |
| |
| // step 7 |
| // verify |
| if (toASCIIOut.equalsIgnoreCase(dest.toString())) { |
| // step 8 |
| // return output of step 5 |
| return decodeOut.toString(); |
| } |
| } catch (Exception ignored) { |
| // no-op |
| } |
| } |
| |
| // just return the input |
| return label; |
| } |
| |
| |
| // |
| // LDH stands for "letter/digit/hyphen", with characters restricted to the |
| // 26-letter Latin alphabet <A-Z a-z>, the digits <0-9>, and the hyphen |
| // <->. |
| // Non LDH refers to characters in the ASCII range, but which are not |
| // letters, digits or the hypen. |
| // |
| // non-LDH = 0..0x2C, 0x2E..0x2F, 0x3A..0x40, 0x5B..0x60, 0x7B..0x7F |
| // |
| private static boolean isNonLDHAsciiCodePoint(int ch){ |
| return (0x0000 <= ch && ch <= 0x002C) || |
| (0x002E <= ch && ch <= 0x002F) || |
| (0x003A <= ch && ch <= 0x0040) || |
| (0x005B <= ch && ch <= 0x0060) || |
| (0x007B <= ch && ch <= 0x007F); |
| } |
| |
| // |
| // search dots in a string and return the index of that character; |
| // or if there is no dots, return the length of input string |
| // dots might be: \u002E (full stop), \u3002 (ideographic full stop), \uFF0E (fullwidth full stop), |
| // and \uFF61 (halfwidth ideographic full stop). |
| // |
| private static int searchDots(String s, int start) { |
| int i; |
| for (i = start; i < s.length(); i++) { |
| if (isLabelSeparator(s.charAt(i))) { |
| break; |
| } |
| } |
| |
| return i; |
| } |
| |
| // |
| // to check if a string is a root label, ".". |
| // |
| private static boolean isRootLabel(String s) { |
| return (s.length() == 1 && isLabelSeparator(s.charAt(0))); |
| } |
| |
| // |
| // to check if a character is a label separator, i.e. a dot character. |
| // |
| private static boolean isLabelSeparator(char c) { |
| return (c == '.' || c == '\u3002' || c == '\uFF0E' || c == '\uFF61'); |
| } |
| |
| // |
| // to check if a string only contains US-ASCII code point |
| // |
| private static boolean isAllASCII(String input) { |
| boolean isASCII = true; |
| for (int i = 0; i < input.length(); i++) { |
| int c = input.charAt(i); |
| if (c > 0x7F) { |
| isASCII = false; |
| break; |
| } |
| } |
| return isASCII; |
| } |
| |
| // |
| // to check if a string starts with ACE-prefix |
| // |
| private static boolean startsWithACEPrefix(StringBuffer input){ |
| boolean startsWithPrefix = true; |
| |
| if(input.length() < ACE_PREFIX_LENGTH){ |
| return false; |
| } |
| for(int i = 0; i < ACE_PREFIX_LENGTH; i++){ |
| if(toASCIILower(input.charAt(i)) != ACE_PREFIX.charAt(i)){ |
| startsWithPrefix = false; |
| } |
| } |
| return startsWithPrefix; |
| } |
| |
| private static char toASCIILower(char ch){ |
| if('A' <= ch && ch <= 'Z'){ |
| return (char)(ch + 'a' - 'A'); |
| } |
| return ch; |
| } |
| |
| private static StringBuffer toASCIILower(StringBuffer input){ |
| StringBuffer dest = new StringBuffer(); |
| for(int i = 0; i < input.length();i++){ |
| dest.append(toASCIILower(input.charAt(i))); |
| } |
| return dest; |
| } |
| */ |
| } |
