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| 1 | +/* |
| 2 | + * Copyright (c) 2021, Oracle and/or its affiliates. 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. 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 com.sun.crypto.provider; |
| 27 | + |
| 28 | +import java.util.Arrays; |
| 29 | +import java.security.*; |
| 30 | +import java.security.spec.*; |
| 31 | +import javax.crypto.*; |
| 32 | +import javax.crypto.spec.*; |
| 33 | +import static com.sun.crypto.provider.KWUtil.*; |
| 34 | + |
| 35 | +/** |
| 36 | + * This class implement the AES KeyWrap mode of operation as defined in |
| 37 | + * <a href=https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-38F.pdf> |
| 38 | + * "Recommendation for Block Cipher Modes of Operation: Methods for Key Wrapping"</a> |
| 39 | + * and represents AES cipher in KW mode. |
| 40 | + */ |
| 41 | +class AESKeyWrap extends FeedbackCipher { |
| 42 | + |
| 43 | + // default integrity check value (icv) if iv is not supplied |
| 44 | + private static final byte[] ICV1 = { // SEMI_BLKSIZE long |
| 45 | + (byte) 0xA6, (byte) 0xA6, (byte) 0xA6, (byte) 0xA6, |
| 46 | + (byte) 0xA6, (byte) 0xA6, (byte) 0xA6, (byte) 0xA6 |
| 47 | + }; |
| 48 | + |
| 49 | + AESKeyWrap() { |
| 50 | + super(new AESCrypt()); |
| 51 | + } |
| 52 | + |
| 53 | + /** |
| 54 | + * Gets the name of this feedback mode. |
| 55 | + * |
| 56 | + * @return the string <code>KW</code> |
| 57 | + */ |
| 58 | + @Override |
| 59 | + String getFeedback() { |
| 60 | + return "KW"; |
| 61 | + } |
| 62 | + |
| 63 | + /** |
| 64 | + * Save the current content of this cipher. |
| 65 | + */ |
| 66 | + @Override |
| 67 | + void save() { |
| 68 | + throw new UnsupportedOperationException("save not supported"); |
| 69 | + }; |
| 70 | + |
| 71 | + /** |
| 72 | + * Restores the content of this cipher to the previous saved one. |
| 73 | + */ |
| 74 | + @Override |
| 75 | + void restore() { |
| 76 | + throw new UnsupportedOperationException("restore not supported"); |
| 77 | + }; |
| 78 | + |
| 79 | + /** |
| 80 | + * Initializes the cipher in the specified mode with the given key |
| 81 | + * and iv. |
| 82 | + * |
| 83 | + * @param decrypting flag indicating encryption or decryption |
| 84 | + * @param algorithm the algorithm name |
| 85 | + * @param key the key |
| 86 | + * @param iv the iv |
| 87 | + * |
| 88 | + * @exception InvalidKeyException if the given key is inappropriate for |
| 89 | + * initializing this cipher |
| 90 | + * @exception InvalidAlgorithmParameterException if the given iv is |
| 91 | + * non-null and not the right length |
| 92 | + */ |
| 93 | + @Override |
| 94 | + void init(boolean decrypting, String algorithm, byte[] key, byte[] iv) |
| 95 | + throws InvalidKeyException, InvalidAlgorithmParameterException { |
| 96 | + if (key == null) { |
| 97 | + throw new InvalidKeyException("Invalid null key"); |
| 98 | + } |
| 99 | + if (iv != null && iv.length != SEMI_BLKSIZE) { |
| 100 | + throw new InvalidAlgorithmParameterException("Invalid IV"); |
| 101 | + } |
| 102 | + embeddedCipher.init(decrypting, algorithm, key); |
| 103 | + // iv is retrieved from IvParameterSpec.getIV() which is already cloned |
| 104 | + this.iv = (iv == null? ICV1 : iv); |
| 105 | + } |
| 106 | + |
| 107 | + /** |
| 108 | + * Resets the iv to its original value. |
| 109 | + * This is used when doFinal is called in the Cipher class, so that the |
| 110 | + * cipher can be reused (with its original iv). |
| 111 | + */ |
| 112 | + @Override |
| 113 | + void reset() { |
| 114 | + throw new UnsupportedOperationException("reset not supported"); |
| 115 | + }; |
| 116 | + |
| 117 | + |
| 118 | + // no support for multi-part encryption |
| 119 | + @Override |
| 120 | + int encrypt(byte[] pt, int ptOfs, int ptLen, byte[] ct, int ctOfs) { |
| 121 | + throw new UnsupportedOperationException("multi-part not supported"); |
| 122 | + }; |
| 123 | + |
| 124 | + // no support for multi-part decryption |
| 125 | + @Override |
| 126 | + int decrypt(byte[] ct, int ctOfs, int ctLen, byte[] pt, int ptOfs) { |
| 127 | + throw new UnsupportedOperationException("multi-part not supported"); |
| 128 | + }; |
| 129 | + |
| 130 | + /** |
| 131 | + * Performs single-part encryption operation. |
| 132 | + * |
| 133 | + * <p>The input <code>pt</code>, starting at <code>0</code> |
| 134 | + * and ending at <code>ptLen-1</code>, is encrypted. |
| 135 | + * The result is stored in place into <code>pt</code>, starting at |
| 136 | + * <code>0</code>. |
| 137 | + * |
| 138 | + * <p>The subclass that implements Cipher should ensure that |
| 139 | + * <code>init</code> has been called before this method is called. |
| 140 | + * |
| 141 | + * @param pt the input buffer with the data to be encrypted |
| 142 | + * @param dummy1 the offset in <code>pt</code> which is always 0 |
| 143 | + * @param ptLen the length of the input data |
| 144 | + * @param dummy2 the output buffer for the encryption which is always pt |
| 145 | + * @param dummy3 the offset in the output buffer which is always 0 |
| 146 | + * @return the number of bytes placed into <code>pt</code> |
| 147 | + */ |
| 148 | + @Override |
| 149 | + int encryptFinal(byte[] pt, int dummy1, int ptLen, byte[] dummy2, |
| 150 | + int dummy3) throws IllegalBlockSizeException { |
| 151 | + // adjust the min value since pt contains the first semi-block |
| 152 | + if (ptLen < MIN_INPUTLEN || (ptLen % SEMI_BLKSIZE) != 0) { |
| 153 | + throw new IllegalBlockSizeException("data should" + |
| 154 | + " be at least 16 bytes and multiples of 8"); |
| 155 | + } |
| 156 | + return W(iv, pt, ptLen, embeddedCipher); |
| 157 | + } |
| 158 | + |
| 159 | + /** |
| 160 | + * Performs single-part decryption operation. |
| 161 | + * |
| 162 | + * <p>The input <code>ct</code>, starting at <code>0</code> |
| 163 | + * and ending at <code>ctLen-1</code>, is decrypted. |
| 164 | + * The result is stored in place into <code>ct</code>, starting at |
| 165 | + * <code>0</code>. |
| 166 | + * |
| 167 | + * <p>NOTE: Purpose of this special impl is for minimizing array |
| 168 | + * copying, those unused arguments are named as dummyN. |
| 169 | + * |
| 170 | + * <p>The subclass that implements Cipher should ensure that |
| 171 | + * <code>init</code> has been called before this method is called. |
| 172 | + * |
| 173 | + * @param ct the input buffer with the data to be decrypted |
| 174 | + * @param dummy1 the offset in <code>ct</code> which is always 0 |
| 175 | + * @param ctLen the length of the input data |
| 176 | + * @param dummy2 the output buffer for the decryption which is always ct |
| 177 | + * @param dummy3 the offset in the output buffer which is always 0 |
| 178 | + * @return the number of bytes placed into <code>ct</code> |
| 179 | + */ |
| 180 | + @Override |
| 181 | + int decryptFinal(byte[] ct, int dummy1, int ctLen, byte[] dummy2, |
| 182 | + int dummy3) throws IllegalBlockSizeException { |
| 183 | + if (ctLen < MIN_INPUTLEN || (ctLen % SEMI_BLKSIZE) != 0) { |
| 184 | + throw new IllegalBlockSizeException |
| 185 | + ("data should be at least 24 bytes and multiples of 8"); |
| 186 | + } |
| 187 | + byte[] ivOut = new byte[SEMI_BLKSIZE]; |
| 188 | + ctLen = W_INV(ct, ctLen, ivOut, embeddedCipher); |
| 189 | + |
| 190 | + // check against icv and fail if not match |
| 191 | + if (!MessageDigest.isEqual(ivOut, this.iv)) { |
| 192 | + throw new IllegalBlockSizeException("Integrity check failed"); |
| 193 | + } |
| 194 | + return ctLen; |
| 195 | + } |
| 196 | +} |
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