J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Portions Copyright 2003-2005 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | /* |
| 27 | ******************************************************************************* |
| 28 | * (C) Copyright IBM Corp. 1996-2005 - All Rights Reserved * |
| 29 | * * |
| 30 | * The original version of this source code and documentation is copyrighted * |
| 31 | * and owned by IBM, These materials are provided under terms of a License * |
| 32 | * Agreement between IBM and Sun. This technology is protected by multiple * |
| 33 | * US and International patents. This notice and attribution to IBM may not * |
| 34 | * to removed. * |
| 35 | ******************************************************************************* |
| 36 | */ |
| 37 | |
| 38 | package sun.text.normalizer; |
| 39 | |
| 40 | import java.io.InputStream; |
| 41 | import java.io.DataInputStream; |
| 42 | import java.io.IOException; |
| 43 | import java.util.Arrays; |
| 44 | |
| 45 | public final class ICUBinary |
| 46 | { |
| 47 | // public inner interface ------------------------------------------------ |
| 48 | |
| 49 | /** |
| 50 | * Special interface for data authentication |
| 51 | */ |
| 52 | public static interface Authenticate |
| 53 | { |
| 54 | /** |
| 55 | * Method used in ICUBinary.readHeader() to provide data format |
| 56 | * authentication. |
| 57 | * @param version version of the current data |
| 58 | * @return true if dataformat is an acceptable version, false otherwise |
| 59 | */ |
| 60 | public boolean isDataVersionAcceptable(byte version[]); |
| 61 | } |
| 62 | |
| 63 | // public methods -------------------------------------------------------- |
| 64 | |
| 65 | /** |
| 66 | * <p>ICU data header reader method. |
| 67 | * Takes a ICU generated big-endian input stream, parse the ICU standard |
| 68 | * file header and authenticates them.</p> |
| 69 | * <p>Header format: |
| 70 | * <ul> |
| 71 | * <li> Header size (char) |
| 72 | * <li> Magic number 1 (byte) |
| 73 | * <li> Magic number 2 (byte) |
| 74 | * <li> Rest of the header size (char) |
| 75 | * <li> Reserved word (char) |
| 76 | * <li> Big endian indicator (byte) |
| 77 | * <li> Character set family indicator (byte) |
| 78 | * <li> Size of a char (byte) for c++ and c use |
| 79 | * <li> Reserved byte (byte) |
| 80 | * <li> Data format identifier (4 bytes), each ICU data has its own |
| 81 | * identifier to distinguish them. [0] major [1] minor |
| 82 | * [2] milli [3] micro |
| 83 | * <li> Data version (4 bytes), the change version of the ICU data |
| 84 | * [0] major [1] minor [2] milli [3] micro |
| 85 | * <li> Unicode version (4 bytes) this ICU is based on. |
| 86 | * </ul> |
| 87 | * </p> |
| 88 | * <p> |
| 89 | * Example of use:<br> |
| 90 | * <pre> |
| 91 | * try { |
| 92 | * FileInputStream input = new FileInputStream(filename); |
| 93 | * If (Utility.readICUDataHeader(input, dataformat, dataversion, |
| 94 | * unicode) { |
| 95 | * System.out.println("Verified file header, this is a ICU data file"); |
| 96 | * } |
| 97 | * } catch (IOException e) { |
| 98 | * System.out.println("This is not a ICU data file"); |
| 99 | * } |
| 100 | * </pre> |
| 101 | * </p> |
| 102 | * @param inputStream input stream that contains the ICU data header |
| 103 | * @param dataFormatIDExpected Data format expected. An array of 4 bytes |
| 104 | * information about the data format. |
| 105 | * E.g. data format ID 1.2.3.4. will became an array of |
| 106 | * {1, 2, 3, 4} |
| 107 | * @param authenticate user defined extra data authentication. This value |
| 108 | * can be null, if no extra authentication is needed. |
| 109 | * @exception IOException thrown if there is a read error or |
| 110 | * when header authentication fails. |
| 111 | * @draft 2.1 |
| 112 | */ |
| 113 | public static final byte[] readHeader(InputStream inputStream, |
| 114 | byte dataFormatIDExpected[], |
| 115 | Authenticate authenticate) |
| 116 | throws IOException |
| 117 | { |
| 118 | DataInputStream input = new DataInputStream(inputStream); |
| 119 | char headersize = input.readChar(); |
| 120 | int readcount = 2; |
| 121 | //reading the header format |
| 122 | byte magic1 = input.readByte(); |
| 123 | readcount ++; |
| 124 | byte magic2 = input.readByte(); |
| 125 | readcount ++; |
| 126 | if (magic1 != MAGIC1 || magic2 != MAGIC2) { |
| 127 | throw new IOException(MAGIC_NUMBER_AUTHENTICATION_FAILED_); |
| 128 | } |
| 129 | |
| 130 | input.readChar(); // reading size |
| 131 | readcount += 2; |
| 132 | input.readChar(); // reading reserved word |
| 133 | readcount += 2; |
| 134 | byte bigendian = input.readByte(); |
| 135 | readcount ++; |
| 136 | byte charset = input.readByte(); |
| 137 | readcount ++; |
| 138 | byte charsize = input.readByte(); |
| 139 | readcount ++; |
| 140 | input.readByte(); // reading reserved byte |
| 141 | readcount ++; |
| 142 | |
| 143 | byte dataFormatID[] = new byte[4]; |
| 144 | input.readFully(dataFormatID); |
| 145 | readcount += 4; |
| 146 | byte dataVersion[] = new byte[4]; |
| 147 | input.readFully(dataVersion); |
| 148 | readcount += 4; |
| 149 | byte unicodeVersion[] = new byte[4]; |
| 150 | input.readFully(unicodeVersion); |
| 151 | readcount += 4; |
| 152 | if (headersize < readcount) { |
| 153 | throw new IOException("Internal Error: Header size error"); |
| 154 | } |
| 155 | input.skipBytes(headersize - readcount); |
| 156 | |
| 157 | if (bigendian != BIG_ENDIAN_ || charset != CHAR_SET_ |
| 158 | || charsize != CHAR_SIZE_ |
| 159 | || !Arrays.equals(dataFormatIDExpected, dataFormatID) |
| 160 | || (authenticate != null |
| 161 | && !authenticate.isDataVersionAcceptable(dataVersion))) { |
| 162 | throw new IOException(HEADER_AUTHENTICATION_FAILED_); |
| 163 | } |
| 164 | return unicodeVersion; |
| 165 | } |
| 166 | |
| 167 | // private variables ------------------------------------------------- |
| 168 | |
| 169 | /** |
| 170 | * Magic numbers to authenticate the data file |
| 171 | */ |
| 172 | private static final byte MAGIC1 = (byte)0xda; |
| 173 | private static final byte MAGIC2 = (byte)0x27; |
| 174 | |
| 175 | /** |
| 176 | * File format authentication values |
| 177 | */ |
| 178 | private static final byte BIG_ENDIAN_ = 1; |
| 179 | private static final byte CHAR_SET_ = 0; |
| 180 | private static final byte CHAR_SIZE_ = 2; |
| 181 | |
| 182 | /** |
| 183 | * Error messages |
| 184 | */ |
| 185 | private static final String MAGIC_NUMBER_AUTHENTICATION_FAILED_ = |
| 186 | "ICU data file error: Not an ICU data file"; |
| 187 | private static final String HEADER_AUTHENTICATION_FAILED_ = |
| 188 | "ICU data file error: Header authentication failed, please check if you have a valid ICU data file"; |
| 189 | } |