Przemyslaw Szczepaniak | 8a7c160 | 2015-11-03 09:47:56 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one or more |
| 3 | * contributor license agreements. See the NOTICE file distributed with |
| 4 | * this work for additional information regarding copyright ownership. |
| 5 | * The ASF licenses this file to You under the Apache License, Version 2.0 |
| 6 | * (the "License"); you may not use this file except in compliance with |
| 7 | * the License. You may obtain a copy of the License at |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | * See the License for the specific language governing permissions and |
| 15 | * limitations under the License. |
| 16 | */ |
| 17 | |
| 18 | package android.util.jar; |
| 19 | |
| 20 | import java.io.ByteArrayOutputStream; |
| 21 | import java.io.IOException; |
| 22 | import java.nio.charset.StandardCharsets; |
| 23 | import java.util.HashMap; |
| 24 | import java.util.Map; |
| 25 | import java.util.jar.Attributes; |
| 26 | |
| 27 | /** |
| 28 | * Reads a JAR file manifest. The specification is here: |
| 29 | * http://java.sun.com/javase/6/docs/technotes/guides/jar/jar.html |
| 30 | */ |
| 31 | class StrictJarManifestReader { |
| 32 | // There are relatively few unique attribute names, |
| 33 | // but a manifest might have thousands of entries. |
| 34 | private final HashMap<String, Attributes.Name> attributeNameCache = new HashMap<String, Attributes.Name>(); |
| 35 | |
| 36 | private final ByteArrayOutputStream valueBuffer = new ByteArrayOutputStream(80); |
| 37 | |
| 38 | private final byte[] buf; |
| 39 | |
| 40 | private final int endOfMainSection; |
| 41 | |
| 42 | private int pos; |
| 43 | |
| 44 | private Attributes.Name name; |
| 45 | |
| 46 | private String value; |
| 47 | |
| 48 | private int consecutiveLineBreaks = 0; |
| 49 | |
| 50 | public StrictJarManifestReader(byte[] buf, Attributes main) throws IOException { |
| 51 | this.buf = buf; |
| 52 | while (readHeader()) { |
| 53 | main.put(name, value); |
| 54 | } |
| 55 | this.endOfMainSection = pos; |
| 56 | } |
| 57 | |
| 58 | public void readEntries(Map<String, Attributes> entries, Map<String, StrictJarManifest.Chunk> chunks) throws IOException { |
| 59 | int mark = pos; |
| 60 | while (readHeader()) { |
Tobias Thierer | 8a0845e | 2018-07-13 16:44:45 +0100 | [diff] [blame^] | 61 | if (!StrictJarManifest.ATTRIBUTE_NAME_NAME.equals(name)) { |
Przemyslaw Szczepaniak | 8a7c160 | 2015-11-03 09:47:56 +0000 | [diff] [blame] | 62 | throw new IOException("Entry is not named"); |
| 63 | } |
| 64 | String entryNameValue = value; |
| 65 | |
| 66 | Attributes entry = entries.get(entryNameValue); |
| 67 | if (entry == null) { |
| 68 | entry = new Attributes(12); |
| 69 | } |
| 70 | |
| 71 | while (readHeader()) { |
| 72 | entry.put(name, value); |
| 73 | } |
| 74 | |
| 75 | if (chunks != null) { |
| 76 | if (chunks.get(entryNameValue) != null) { |
| 77 | // TODO A bug: there might be several verification chunks for |
| 78 | // the same name. I believe they should be used to update |
| 79 | // signature in order of appearance; there are two ways to fix |
| 80 | // this: either use a list of chunks, or decide on used |
| 81 | // signature algorithm in advance and reread the chunks while |
| 82 | // updating the signature; for now a defensive error is thrown |
| 83 | throw new IOException("A jar verifier does not support more than one entry with the same name"); |
| 84 | } |
| 85 | chunks.put(entryNameValue, new StrictJarManifest.Chunk(mark, pos)); |
| 86 | mark = pos; |
| 87 | } |
| 88 | |
| 89 | entries.put(entryNameValue, entry); |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | public int getEndOfMainSection() { |
| 94 | return endOfMainSection; |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * Read a single line from the manifest buffer. |
| 99 | */ |
| 100 | private boolean readHeader() throws IOException { |
| 101 | if (consecutiveLineBreaks > 1) { |
| 102 | // break a section on an empty line |
| 103 | consecutiveLineBreaks = 0; |
| 104 | return false; |
| 105 | } |
| 106 | readName(); |
| 107 | consecutiveLineBreaks = 0; |
| 108 | readValue(); |
| 109 | // if the last line break is missed, the line |
| 110 | // is ignored by the reference implementation |
| 111 | return consecutiveLineBreaks > 0; |
| 112 | } |
| 113 | |
| 114 | private void readName() throws IOException { |
| 115 | int mark = pos; |
| 116 | |
| 117 | while (pos < buf.length) { |
| 118 | if (buf[pos++] != ':') { |
| 119 | continue; |
| 120 | } |
| 121 | |
| 122 | String nameString = new String(buf, mark, pos - mark - 1, StandardCharsets.US_ASCII); |
| 123 | |
| 124 | if (buf[pos++] != ' ') { |
| 125 | throw new IOException(String.format("Invalid value for attribute '%s'", nameString)); |
| 126 | } |
| 127 | |
| 128 | try { |
| 129 | name = attributeNameCache.get(nameString); |
| 130 | if (name == null) { |
| 131 | name = new Attributes.Name(nameString); |
| 132 | attributeNameCache.put(nameString, name); |
| 133 | } |
| 134 | } catch (IllegalArgumentException e) { |
| 135 | // new Attributes.Name() throws IllegalArgumentException but we declare IOException |
| 136 | throw new IOException(e.getMessage()); |
| 137 | } |
| 138 | return; |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | private void readValue() throws IOException { |
| 143 | boolean lastCr = false; |
| 144 | int mark = pos; |
| 145 | int last = pos; |
| 146 | valueBuffer.reset(); |
| 147 | while (pos < buf.length) { |
| 148 | byte next = buf[pos++]; |
| 149 | switch (next) { |
| 150 | case 0: |
| 151 | throw new IOException("NUL character in a manifest"); |
| 152 | case '\n': |
| 153 | if (lastCr) { |
| 154 | lastCr = false; |
| 155 | } else { |
| 156 | consecutiveLineBreaks++; |
| 157 | } |
| 158 | continue; |
| 159 | case '\r': |
| 160 | lastCr = true; |
| 161 | consecutiveLineBreaks++; |
| 162 | continue; |
| 163 | case ' ': |
| 164 | if (consecutiveLineBreaks == 1) { |
| 165 | valueBuffer.write(buf, mark, last - mark); |
| 166 | mark = pos; |
| 167 | consecutiveLineBreaks = 0; |
| 168 | continue; |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | if (consecutiveLineBreaks >= 1) { |
| 173 | pos--; |
| 174 | break; |
| 175 | } |
| 176 | last = pos; |
| 177 | } |
| 178 | |
| 179 | valueBuffer.write(buf, mark, last - mark); |
| 180 | // A bit frustrating that that Charset.forName will be called |
| 181 | // again. |
| 182 | value = valueBuffer.toString(StandardCharsets.UTF_8.name()); |
| 183 | } |
| 184 | } |