Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 1 | /* |
Shubham Ajmera | 2b41a21 | 2016-07-19 17:31:13 +0100 | [diff] [blame] | 2 | * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved. |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 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. Oracle designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| 22 | * or visit www.oracle.com if you need additional information or have any |
| 23 | * questions. |
| 24 | */ |
| 25 | |
| 26 | package javax.crypto; |
| 27 | |
Shubham Ajmera | 2b41a21 | 2016-07-19 17:31:13 +0100 | [diff] [blame] | 28 | import java.io.InputStream; |
| 29 | import java.io.FilterInputStream; |
| 30 | import java.io.IOException; |
| 31 | import javax.crypto.BadPaddingException; |
| 32 | import javax.crypto.IllegalBlockSizeException; |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 33 | |
| 34 | /** |
| 35 | * A CipherInputStream is composed of an InputStream and a Cipher so |
| 36 | * that read() methods return data that are read in from the |
| 37 | * underlying InputStream but have been additionally processed by the |
| 38 | * Cipher. The Cipher must be fully initialized before being used by |
| 39 | * a CipherInputStream. |
| 40 | * |
| 41 | * <p> For example, if the Cipher is initialized for decryption, the |
| 42 | * CipherInputStream will attempt to read in data and decrypt them, |
| 43 | * before returning the decrypted data. |
| 44 | * |
| 45 | * <p> This class adheres strictly to the semantics, especially the |
| 46 | * failure semantics, of its ancestor classes |
| 47 | * java.io.FilterInputStream and java.io.InputStream. This class has |
| 48 | * exactly those methods specified in its ancestor classes, and |
| 49 | * overrides them all. Moreover, this class catches all exceptions |
| 50 | * that are not thrown by its ancestor classes. In particular, the |
| 51 | * <code>skip</code> method skips, and the <code>available</code> |
| 52 | * method counts only data that have been processed by the encapsulated Cipher. |
| 53 | * |
| 54 | * <p> It is crucial for a programmer using this class not to use |
| 55 | * methods that are not defined or overriden in this class (such as a |
| 56 | * new method or constructor that is later added to one of the super |
| 57 | * classes), because the design and implementation of those methods |
| 58 | * are unlikely to have considered security impact with regard to |
| 59 | * CipherInputStream. |
| 60 | * |
| 61 | * @author Li Gong |
| 62 | * @see java.io.InputStream |
| 63 | * @see java.io.FilterInputStream |
| 64 | * @see javax.crypto.Cipher |
| 65 | * @see javax.crypto.CipherOutputStream |
| 66 | * |
| 67 | * @since 1.4 |
| 68 | */ |
| 69 | |
| 70 | public class CipherInputStream extends FilterInputStream { |
| 71 | |
| 72 | // the cipher engine to use to process stream data |
| 73 | private Cipher cipher; |
| 74 | |
| 75 | // the underlying input stream |
| 76 | private InputStream input; |
| 77 | |
| 78 | /* the buffer holding data that have been read in from the |
| 79 | underlying stream, but have not been processed by the cipher |
| 80 | engine. the size 512 bytes is somewhat randomly chosen */ |
| 81 | private byte[] ibuffer = new byte[512]; |
| 82 | |
| 83 | // having reached the end of the underlying input stream |
| 84 | private boolean done = false; |
| 85 | |
| 86 | /* the buffer holding data that have been processed by the cipher |
| 87 | engine, but have not been read out */ |
| 88 | private byte[] obuffer; |
| 89 | // the offset pointing to the next "new" byte |
| 90 | private int ostart = 0; |
| 91 | // the offset pointing to the last "new" byte |
| 92 | private int ofinish = 0; |
Shubham Ajmera | 2b41a21 | 2016-07-19 17:31:13 +0100 | [diff] [blame] | 93 | // stream status |
| 94 | private boolean closed = false; |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 95 | |
| 96 | /** |
| 97 | * private convenience function. |
| 98 | * |
| 99 | * Entry condition: ostart = ofinish |
| 100 | * |
| 101 | * Exit condition: ostart <= ofinish |
| 102 | * |
| 103 | * return (ofinish-ostart) (we have this many bytes for you) |
| 104 | * return 0 (no data now, but could have more later) |
| 105 | * return -1 (absolutely no more data) |
Shubham Ajmera | 2b41a21 | 2016-07-19 17:31:13 +0100 | [diff] [blame] | 106 | * |
| 107 | * Note: Exceptions are only thrown after the stream is completely read. |
| 108 | * For AEAD ciphers a read() of any length will internally cause the |
| 109 | * whole stream to be read fully and verify the authentication tag before |
| 110 | * returning decrypted data or exceptions. |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 111 | */ |
| 112 | private int getMoreData() throws IOException { |
Shubham Ajmera | e115d42 | 2016-11-15 14:03:33 +0000 | [diff] [blame] | 113 | // Android-changed: The method was creating a new object every time update(byte[], int, int) |
| 114 | // or doFinal() was called resulting in the old object being GCed. With do(byte[], int) and |
| 115 | // update(byte[], int, int, byte[], int), we use already initialized obuffer. |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 116 | if (done) return -1; |
Shubham Ajmera | e115d42 | 2016-11-15 14:03:33 +0000 | [diff] [blame] | 117 | ofinish = 0; |
| 118 | ostart = 0; |
| 119 | int expectedOutputSize = cipher.getOutputSize(ibuffer.length); |
| 120 | if (obuffer == null || expectedOutputSize > obuffer.length) { |
| 121 | obuffer = new byte[expectedOutputSize]; |
| 122 | } |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 123 | int readin = input.read(ibuffer); |
| 124 | if (readin == -1) { |
| 125 | done = true; |
| 126 | try { |
Shubham Ajmera | e115d42 | 2016-11-15 14:03:33 +0000 | [diff] [blame] | 127 | // doFinal resets the cipher and it is the final call that is made. If there isn't |
| 128 | // any more byte available, it returns 0. In case of any exception is raised, |
| 129 | // obuffer will get reset and therefore, it is equivalent to no bytes returned. |
| 130 | ofinish = cipher.doFinal(obuffer, 0); |
Shubham Ajmera | 2b41a21 | 2016-07-19 17:31:13 +0100 | [diff] [blame] | 131 | } catch (IllegalBlockSizeException | BadPaddingException e) { |
| 132 | obuffer = null; |
| 133 | throw new IOException(e); |
Shubham Ajmera | e115d42 | 2016-11-15 14:03:33 +0000 | [diff] [blame] | 134 | } catch (ShortBufferException e) { |
| 135 | obuffer = null; |
| 136 | throw new IllegalStateException("ShortBufferException is not expected", e); |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 137 | } |
Shubham Ajmera | e115d42 | 2016-11-15 14:03:33 +0000 | [diff] [blame] | 138 | } else { |
| 139 | // update returns number of bytes stored in obuffer. |
| 140 | try { |
| 141 | ofinish = cipher.update(ibuffer, 0, readin, obuffer, 0); |
| 142 | } catch (IllegalStateException e) { |
| 143 | obuffer = null; |
| 144 | throw e; |
| 145 | } catch (ShortBufferException e) { |
| 146 | // Should not reset the value of ofinish as the cipher is still not invalidated. |
| 147 | obuffer = null; |
| 148 | throw new IllegalStateException("ShortBufferException is not expected", e); |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 149 | } |
| 150 | } |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 151 | return ofinish; |
| 152 | } |
| 153 | |
| 154 | /** |
| 155 | * Constructs a CipherInputStream from an InputStream and a |
| 156 | * Cipher. |
| 157 | * <br>Note: if the specified input stream or cipher is |
| 158 | * null, a NullPointerException may be thrown later when |
| 159 | * they are used. |
| 160 | * @param is the to-be-processed input stream |
| 161 | * @param c an initialized Cipher object |
| 162 | */ |
| 163 | public CipherInputStream(InputStream is, Cipher c) { |
| 164 | super(is); |
| 165 | input = is; |
| 166 | cipher = c; |
| 167 | } |
| 168 | |
| 169 | /** |
| 170 | * Constructs a CipherInputStream from an InputStream without |
| 171 | * specifying a Cipher. This has the effect of constructing a |
| 172 | * CipherInputStream using a NullCipher. |
| 173 | * <br>Note: if the specified input stream is null, a |
| 174 | * NullPointerException may be thrown later when it is used. |
| 175 | * @param is the to-be-processed input stream |
| 176 | */ |
| 177 | protected CipherInputStream(InputStream is) { |
| 178 | super(is); |
| 179 | input = is; |
| 180 | cipher = new NullCipher(); |
| 181 | } |
| 182 | |
| 183 | /** |
| 184 | * Reads the next byte of data from this input stream. The value |
| 185 | * byte is returned as an <code>int</code> in the range |
| 186 | * <code>0</code> to <code>255</code>. If no byte is available |
| 187 | * because the end of the stream has been reached, the value |
| 188 | * <code>-1</code> is returned. This method blocks until input data |
| 189 | * is available, the end of the stream is detected, or an exception |
| 190 | * is thrown. |
| 191 | * <p> |
| 192 | * |
| 193 | * @return the next byte of data, or <code>-1</code> if the end of the |
| 194 | * stream is reached. |
| 195 | * @exception IOException if an I/O error occurs. |
| 196 | * @since JCE1.2 |
| 197 | */ |
| 198 | public int read() throws IOException { |
| 199 | if (ostart >= ofinish) { |
| 200 | // we loop for new data as the spec says we are blocking |
| 201 | int i = 0; |
| 202 | while (i == 0) i = getMoreData(); |
| 203 | if (i == -1) return -1; |
| 204 | } |
| 205 | return ((int) obuffer[ostart++] & 0xff); |
| 206 | }; |
| 207 | |
| 208 | /** |
| 209 | * Reads up to <code>b.length</code> bytes of data from this input |
| 210 | * stream into an array of bytes. |
| 211 | * <p> |
| 212 | * The <code>read</code> method of <code>InputStream</code> calls |
| 213 | * the <code>read</code> method of three arguments with the arguments |
| 214 | * <code>b</code>, <code>0</code>, and <code>b.length</code>. |
| 215 | * |
| 216 | * @param b the buffer into which the data is read. |
| 217 | * @return the total number of bytes read into the buffer, or |
| 218 | * <code>-1</code> is there is no more data because the end of |
| 219 | * the stream has been reached. |
| 220 | * @exception IOException if an I/O error occurs. |
| 221 | * @see java.io.InputStream#read(byte[], int, int) |
| 222 | * @since JCE1.2 |
| 223 | */ |
| 224 | public int read(byte b[]) throws IOException { |
| 225 | return read(b, 0, b.length); |
| 226 | } |
| 227 | |
| 228 | /** |
| 229 | * Reads up to <code>len</code> bytes of data from this input stream |
| 230 | * into an array of bytes. This method blocks until some input is |
| 231 | * available. If the first argument is <code>null,</code> up to |
| 232 | * <code>len</code> bytes are read and discarded. |
| 233 | * |
| 234 | * @param b the buffer into which the data is read. |
| 235 | * @param off the start offset in the destination array |
| 236 | * <code>buf</code> |
| 237 | * @param len the maximum number of bytes read. |
| 238 | * @return the total number of bytes read into the buffer, or |
| 239 | * <code>-1</code> if there is no more data because the end of |
| 240 | * the stream has been reached. |
| 241 | * @exception IOException if an I/O error occurs. |
| 242 | * @see java.io.InputStream#read() |
| 243 | * @since JCE1.2 |
| 244 | */ |
| 245 | public int read(byte b[], int off, int len) throws IOException { |
| 246 | if (ostart >= ofinish) { |
| 247 | // we loop for new data as the spec says we are blocking |
| 248 | int i = 0; |
| 249 | while (i == 0) i = getMoreData(); |
| 250 | if (i == -1) return -1; |
| 251 | } |
| 252 | if (len <= 0) { |
| 253 | return 0; |
| 254 | } |
| 255 | int available = ofinish - ostart; |
| 256 | if (len < available) available = len; |
| 257 | if (b != null) { |
| 258 | System.arraycopy(obuffer, ostart, b, off, available); |
| 259 | } |
| 260 | ostart = ostart + available; |
| 261 | return available; |
| 262 | } |
| 263 | |
| 264 | /** |
| 265 | * Skips <code>n</code> bytes of input from the bytes that can be read |
| 266 | * from this input stream without blocking. |
| 267 | * |
| 268 | * <p>Fewer bytes than requested might be skipped. |
| 269 | * The actual number of bytes skipped is equal to <code>n</code> or |
| 270 | * the result of a call to |
Shubham Ajmera | 2b41a21 | 2016-07-19 17:31:13 +0100 | [diff] [blame] | 271 | * {@link #available() available}, |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 272 | * whichever is smaller. |
| 273 | * If <code>n</code> is less than zero, no bytes are skipped. |
| 274 | * |
| 275 | * <p>The actual number of bytes skipped is returned. |
| 276 | * |
| 277 | * @param n the number of bytes to be skipped. |
| 278 | * @return the actual number of bytes skipped. |
| 279 | * @exception IOException if an I/O error occurs. |
| 280 | * @since JCE1.2 |
| 281 | */ |
| 282 | public long skip(long n) throws IOException { |
| 283 | int available = ofinish - ostart; |
| 284 | if (n > available) { |
| 285 | n = available; |
| 286 | } |
| 287 | if (n < 0) { |
| 288 | return 0; |
| 289 | } |
| 290 | ostart += n; |
| 291 | return n; |
| 292 | } |
| 293 | |
| 294 | /** |
| 295 | * Returns the number of bytes that can be read from this input |
| 296 | * stream without blocking. The <code>available</code> method of |
| 297 | * <code>InputStream</code> returns <code>0</code>. This method |
| 298 | * <B>should</B> be overridden by subclasses. |
| 299 | * |
| 300 | * @return the number of bytes that can be read from this input stream |
| 301 | * without blocking. |
| 302 | * @exception IOException if an I/O error occurs. |
| 303 | * @since JCE1.2 |
| 304 | */ |
| 305 | public int available() throws IOException { |
| 306 | return (ofinish - ostart); |
| 307 | } |
| 308 | |
| 309 | /** |
| 310 | * Closes this input stream and releases any system resources |
| 311 | * associated with the stream. |
| 312 | * <p> |
| 313 | * The <code>close</code> method of <code>CipherInputStream</code> |
| 314 | * calls the <code>close</code> method of its underlying input |
| 315 | * stream. |
| 316 | * |
| 317 | * @exception IOException if an I/O error occurs. |
| 318 | * @since JCE1.2 |
| 319 | */ |
| 320 | public void close() throws IOException { |
Shubham Ajmera | 2b41a21 | 2016-07-19 17:31:13 +0100 | [diff] [blame] | 321 | if (closed) { |
| 322 | return; |
| 323 | } |
| 324 | |
| 325 | closed = true; |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 326 | input.close(); |
Shubham Ajmera | 2b41a21 | 2016-07-19 17:31:13 +0100 | [diff] [blame] | 327 | |
Adam Vartanian | b1fb0c2 | 2017-02-22 15:50:26 +0000 | [diff] [blame] | 328 | // Android-removed: Removed a now-inaccurate comment |
Shubham Ajmera | 2b41a21 | 2016-07-19 17:31:13 +0100 | [diff] [blame] | 329 | if (!done) { |
| 330 | try { |
| 331 | cipher.doFinal(); |
| 332 | } |
| 333 | catch (BadPaddingException | IllegalBlockSizeException ex) { |
Adam Vartanian | b1fb0c2 | 2017-02-22 15:50:26 +0000 | [diff] [blame] | 334 | // Android-changed: Added throw if bad tag is seen. See b/31590622. |
| 335 | if (ex instanceof AEADBadTagException) { |
| 336 | throw new IOException(ex); |
| 337 | } |
Shubham Ajmera | 2b41a21 | 2016-07-19 17:31:13 +0100 | [diff] [blame] | 338 | } |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 339 | } |
| 340 | ostart = 0; |
| 341 | ofinish = 0; |
| 342 | } |
| 343 | |
| 344 | /** |
| 345 | * Tests if this input stream supports the <code>mark</code> |
| 346 | * and <code>reset</code> methods, which it does not. |
| 347 | * |
| 348 | * @return <code>false</code>, since this class does not support the |
| 349 | * <code>mark</code> and <code>reset</code> methods. |
| 350 | * @see java.io.InputStream#mark(int) |
| 351 | * @see java.io.InputStream#reset() |
| 352 | * @since JCE1.2 |
| 353 | */ |
| 354 | public boolean markSupported() { |
| 355 | return false; |
| 356 | } |
| 357 | } |