Save This Page
Home » openjdk-7 » com.sun.crypto » provider » [javadoc | source]
    1   /*
    2    * Copyright (c) 2003, 2007, 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.security.InvalidKeyException;
   29   
   30   /**
   31    * Implementation of the RC2(tm) algorithm as described in RFC 2268.
   32    *
   33    * RC2 is a 16-bit based algorithm and not particularly fast on 32/64 bit
   34    * architectures. Also, note that although the JVM has a 16-bit integer
   35    * type (short), all expressions are evaluated either in 32 or 64 bit
   36    * (int or long). Expression such as "s1 = s2 + s3" are implemented by
   37    * first promoting s2 and s3 to int, performing an int addition, and
   38    * then demoting the result back to short to store in s1. To avoid this
   39    * fairly slow process, we use the int type throughout and manually insert
   40    * "& 0xffff" where necessary.
   41    *
   42    * @since   1.5
   43    * @author  Andreas Sterbenz
   44    */
   45   final class RC2Crypt extends SymmetricCipher {
   46   
   47       // PITABLE from the RFC, used in key setup
   48       private final static int[] PI_TABLE = new int[] {
   49           0xd9, 0x78, 0xf9, 0xc4, 0x19, 0xdd, 0xb5, 0xed,
   50           0x28, 0xe9, 0xfd, 0x79, 0x4a, 0xa0, 0xd8, 0x9d,
   51           0xc6, 0x7e, 0x37, 0x83, 0x2b, 0x76, 0x53, 0x8e,
   52           0x62, 0x4c, 0x64, 0x88, 0x44, 0x8b, 0xfb, 0xa2,
   53           0x17, 0x9a, 0x59, 0xf5, 0x87, 0xb3, 0x4f, 0x13,
   54           0x61, 0x45, 0x6d, 0x8d, 0x09, 0x81, 0x7d, 0x32,
   55           0xbd, 0x8f, 0x40, 0xeb, 0x86, 0xb7, 0x7b, 0x0b,
   56           0xf0, 0x95, 0x21, 0x22, 0x5c, 0x6b, 0x4e, 0x82,
   57           0x54, 0xd6, 0x65, 0x93, 0xce, 0x60, 0xb2, 0x1c,
   58           0x73, 0x56, 0xc0, 0x14, 0xa7, 0x8c, 0xf1, 0xdc,
   59           0x12, 0x75, 0xca, 0x1f, 0x3b, 0xbe, 0xe4, 0xd1,
   60           0x42, 0x3d, 0xd4, 0x30, 0xa3, 0x3c, 0xb6, 0x26,
   61           0x6f, 0xbf, 0x0e, 0xda, 0x46, 0x69, 0x07, 0x57,
   62           0x27, 0xf2, 0x1d, 0x9b, 0xbc, 0x94, 0x43, 0x03,
   63           0xf8, 0x11, 0xc7, 0xf6, 0x90, 0xef, 0x3e, 0xe7,
   64           0x06, 0xc3, 0xd5, 0x2f, 0xc8, 0x66, 0x1e, 0xd7,
   65           0x08, 0xe8, 0xea, 0xde, 0x80, 0x52, 0xee, 0xf7,
   66           0x84, 0xaa, 0x72, 0xac, 0x35, 0x4d, 0x6a, 0x2a,
   67           0x96, 0x1a, 0xd2, 0x71, 0x5a, 0x15, 0x49, 0x74,
   68           0x4b, 0x9f, 0xd0, 0x5e, 0x04, 0x18, 0xa4, 0xec,
   69           0xc2, 0xe0, 0x41, 0x6e, 0x0f, 0x51, 0xcb, 0xcc,
   70           0x24, 0x91, 0xaf, 0x50, 0xa1, 0xf4, 0x70, 0x39,
   71           0x99, 0x7c, 0x3a, 0x85, 0x23, 0xb8, 0xb4, 0x7a,
   72           0xfc, 0x02, 0x36, 0x5b, 0x25, 0x55, 0x97, 0x31,
   73           0x2d, 0x5d, 0xfa, 0x98, 0xe3, 0x8a, 0x92, 0xae,
   74           0x05, 0xdf, 0x29, 0x10, 0x67, 0x6c, 0xba, 0xc9,
   75           0xd3, 0x00, 0xe6, 0xcf, 0xe1, 0x9e, 0xa8, 0x2c,
   76           0x63, 0x16, 0x01, 0x3f, 0x58, 0xe2, 0x89, 0xa9,
   77           0x0d, 0x38, 0x34, 0x1b, 0xab, 0x33, 0xff, 0xb0,
   78           0xbb, 0x48, 0x0c, 0x5f, 0xb9, 0xb1, 0xcd, 0x2e,
   79           0xc5, 0xf3, 0xdb, 0x47, 0xe5, 0xa5, 0x9c, 0x77,
   80           0x0a, 0xa6, 0x20, 0x68, 0xfe, 0x7f, 0xc1, 0xad,
   81       };
   82   
   83       // expanded key, 64 times 16-bit words
   84       private final int[] expandedKey;
   85   
   86       // effective key bits
   87       private int effectiveKeyBits;
   88   
   89       RC2Crypt() {
   90           expandedKey = new int[64];
   91       }
   92   
   93       int getBlockSize() {
   94           return 8;
   95       }
   96   
   97       int getEffectiveKeyBits() {
   98           return effectiveKeyBits;
   99       }
  100   
  101       /**
  102        * Initializes the effective key bit size. This method is a hook to
  103        * allow RC2Cipher to initialize the effective key size.
  104        */
  105       void initEffectiveKeyBits(int effectiveKeyBits) {
  106           this.effectiveKeyBits = effectiveKeyBits;
  107       }
  108   
  109       static void checkKey(String algorithm, int keyLength)
  110               throws InvalidKeyException {
  111           if (algorithm.equals("RC2") == false) {
  112               throw new InvalidKeyException("Key algorithm must be RC2");
  113           }
  114           if ((keyLength < 5) || (keyLength > 128)) {
  115               throw new InvalidKeyException
  116                   ("RC2 key length must be between 40 and 1024 bit");
  117           }
  118       }
  119   
  120       void init(boolean decrypting, String algorithm, byte[] key)
  121               throws InvalidKeyException {
  122           int keyLength = key.length;
  123           if (effectiveKeyBits == 0) {
  124               effectiveKeyBits = keyLength << 3;
  125           }
  126   
  127           checkKey(algorithm, keyLength);
  128   
  129           // key buffer, the L[] byte array from the spec
  130           byte[] expandedKeyBytes = new byte[128];
  131   
  132           // place key into key buffer
  133           System.arraycopy(key, 0, expandedKeyBytes, 0, keyLength);
  134   
  135           // first loop
  136           int t = expandedKeyBytes[keyLength - 1];
  137           for (int i = keyLength; i < 128; i++) {
  138               t = PI_TABLE[(t + expandedKeyBytes[i - keyLength]) & 0xff];
  139               expandedKeyBytes[i] = (byte)t;
  140           }
  141   
  142           int t8 = (effectiveKeyBits + 7) >> 3;
  143           int tm = 0xff >> (-effectiveKeyBits & 7);
  144   
  145           // second loop, reduce search space to effective key bits
  146           t = PI_TABLE[expandedKeyBytes[128 - t8] & tm];
  147           expandedKeyBytes[128 - t8] = (byte)t;
  148           for (int i = 127 - t8; i >= 0; i--) {
  149               t = PI_TABLE[t ^ (expandedKeyBytes[i + t8] & 0xff)];
  150               expandedKeyBytes[i] = (byte)t;
  151           }
  152   
  153           // byte to short conversion, little endian (copy into K[])
  154           for (int i = 0, j = 0; i < 64; i++, j += 2) {
  155               t =  (expandedKeyBytes[j    ] & 0xff)
  156                 + ((expandedKeyBytes[j + 1] & 0xff) << 8);
  157               expandedKey[i] = t;
  158           }
  159       }
  160   
  161       /**
  162        * Encrypt a single block. Note that in a few places we omit a "& 0xffff"
  163        * and allow variables to become larger than 16 bit. This still works
  164        * because there is never a 32 bit overflow.
  165        */
  166       void encryptBlock(byte[] in, int inOfs, byte[] out, int outOfs) {
  167           int R0 =  (in[inOfs    ] & 0xff)
  168                  + ((in[inOfs + 1] & 0xff) << 8);
  169           int R1 =  (in[inOfs + 2] & 0xff)
  170                  + ((in[inOfs + 3] & 0xff) << 8);
  171           int R2 =  (in[inOfs + 4] & 0xff)
  172                  + ((in[inOfs + 5] & 0xff) << 8);
  173           int R3 =  (in[inOfs + 6] & 0xff)
  174                  + ((in[inOfs + 7] & 0xff) << 8);
  175   
  176           // 5 mixing rounds
  177           for (int i = 0; i < 20; i += 4) {
  178               R0 = (R0 + expandedKey[i    ] + (R3 & R2) + (~R3 & R1)) & 0xffff;
  179               R0 = (R0 << 1) | (R0 >>> 15);
  180   
  181               R1 = (R1 + expandedKey[i + 1] + (R0 & R3) + (~R0 & R2)) & 0xffff;
  182               R1 = (R1 << 2) | (R1 >>> 14);
  183   
  184               R2 = (R2 + expandedKey[i + 2] + (R1 & R0) + (~R1 & R3)) & 0xffff;
  185               R2 = (R2 << 3) | (R2 >>> 13);
  186   
  187               R3 = (R3 + expandedKey[i + 3] + (R2 & R1) + (~R2 & R0)) & 0xffff;
  188               R3 = (R3 << 5) | (R3 >>> 11);
  189           }
  190   
  191           // 1 mashing round
  192           R0 += expandedKey[R3 & 0x3f];
  193           R1 += expandedKey[R0 & 0x3f];
  194           R2 += expandedKey[R1 & 0x3f];
  195           R3 += expandedKey[R2 & 0x3f];
  196   
  197           // 6 mixing rounds
  198           for (int i = 20; i < 44; i += 4) {
  199               R0 = (R0 + expandedKey[i    ] + (R3 & R2) + (~R3 & R1)) & 0xffff;
  200               R0 = (R0 << 1) | (R0 >>> 15);
  201   
  202               R1 = (R1 + expandedKey[i + 1] + (R0 & R3) + (~R0 & R2)) & 0xffff;
  203               R1 = (R1 << 2) | (R1 >>> 14);
  204   
  205               R2 = (R2 + expandedKey[i + 2] + (R1 & R0) + (~R1 & R3)) & 0xffff;
  206               R2 = (R2 << 3) | (R2 >>> 13);
  207   
  208               R3 = (R3 + expandedKey[i + 3] + (R2 & R1) + (~R2 & R0)) & 0xffff;
  209               R3 = (R3 << 5) | (R3 >>> 11);
  210           }
  211   
  212           // 1 mashing round
  213           R0 += expandedKey[R3 & 0x3f];
  214           R1 += expandedKey[R0 & 0x3f];
  215           R2 += expandedKey[R1 & 0x3f];
  216           R3 += expandedKey[R2 & 0x3f];
  217   
  218           // 5 mixing rounds
  219           for (int i = 44; i < 64; i += 4) {
  220               R0 = (R0 + expandedKey[i    ] + (R3 & R2) + (~R3 & R1)) & 0xffff;
  221               R0 = (R0 << 1) | (R0 >>> 15);
  222   
  223               R1 = (R1 + expandedKey[i + 1] + (R0 & R3) + (~R0 & R2)) & 0xffff;
  224               R1 = (R1 << 2) | (R1 >>> 14);
  225   
  226               R2 = (R2 + expandedKey[i + 2] + (R1 & R0) + (~R1 & R3)) & 0xffff;
  227               R2 = (R2 << 3) | (R2 >>> 13);
  228   
  229               R3 = (R3 + expandedKey[i + 3] + (R2 & R1) + (~R2 & R0)) & 0xffff;
  230               R3 = (R3 << 5) | (R3 >>> 11);
  231           }
  232   
  233           out[outOfs    ] = (byte)R0;
  234           out[outOfs + 1] = (byte)(R0 >> 8);
  235           out[outOfs + 2] = (byte)R1;
  236           out[outOfs + 3] = (byte)(R1 >> 8);
  237           out[outOfs + 4] = (byte)R2;
  238           out[outOfs + 5] = (byte)(R2 >> 8);
  239           out[outOfs + 6] = (byte)R3;
  240           out[outOfs + 7] = (byte)(R3 >> 8);
  241       }
  242   
  243       void decryptBlock(byte[] in, int inOfs, byte[] out, int outOfs) {
  244           int R0 =  (in[inOfs    ] & 0xff)
  245                  + ((in[inOfs + 1] & 0xff) << 8);
  246           int R1 =  (in[inOfs + 2] & 0xff)
  247                  + ((in[inOfs + 3] & 0xff) << 8);
  248           int R2 =  (in[inOfs + 4] & 0xff)
  249                  + ((in[inOfs + 5] & 0xff) << 8);
  250           int R3 =  (in[inOfs + 6] & 0xff)
  251                  + ((in[inOfs + 7] & 0xff) << 8);
  252   
  253           // 5 r-mixing rounds
  254           for(int i = 64; i > 44; i -= 4) {
  255               R3 = ((R3 << 11) | (R3 >>> 5)) & 0xffff;
  256               R3 = (R3 - expandedKey[i - 1] - (R2 & R1) - (~R2 & R0)) & 0xffff;
  257   
  258               R2 = ((R2 << 13) | (R2 >>> 3)) & 0xffff;
  259               R2 = (R2 - expandedKey[i - 2] - (R1 & R0) - (~R1 & R3)) & 0xffff;
  260   
  261               R1 = ((R1 << 14) | (R1 >>> 2)) & 0xffff;
  262               R1 = (R1 - expandedKey[i - 3] - (R0 & R3) - (~R0 & R2)) & 0xffff;
  263   
  264               R0 = ((R0 << 15) | (R0 >>> 1)) & 0xffff;
  265               R0 = (R0 - expandedKey[i - 4] - (R3 & R2) - (~R3 & R1)) & 0xffff;
  266           }
  267   
  268           // 1 r-mashing round
  269           R3 = (R3 - expandedKey[R2 & 0x3f]) & 0xffff;
  270           R2 = (R2 - expandedKey[R1 & 0x3f]) & 0xffff;
  271           R1 = (R1 - expandedKey[R0 & 0x3f]) & 0xffff;
  272           R0 = (R0 - expandedKey[R3 & 0x3f]) & 0xffff;
  273   
  274           // 6 r-mixing rounds
  275           for(int i = 44; i > 20; i -= 4) {
  276               R3 = ((R3 << 11) | (R3 >>> 5)) & 0xffff;
  277               R3 = (R3 - expandedKey[i - 1] - (R2 & R1) - (~R2 & R0)) & 0xffff;
  278   
  279               R2 = ((R2 << 13) | (R2 >>> 3)) & 0xffff;
  280               R2 = (R2 - expandedKey[i - 2] - (R1 & R0) - (~R1 & R3)) & 0xffff;
  281   
  282               R1 = ((R1 << 14) | (R1 >>> 2)) & 0xffff;
  283               R1 = (R1 - expandedKey[i - 3] - (R0 & R3) - (~R0 & R2)) & 0xffff;
  284   
  285               R0 = ((R0 << 15) | (R0 >>> 1)) & 0xffff;
  286               R0 = (R0 - expandedKey[i - 4] - (R3 & R2) - (~R3 & R1)) & 0xffff;
  287           }
  288   
  289           // 1 r-mashing round
  290           R3 = (R3 - expandedKey[R2 & 0x3f]) & 0xffff;
  291           R2 = (R2 - expandedKey[R1 & 0x3f]) & 0xffff;
  292           R1 = (R1 - expandedKey[R0 & 0x3f]) & 0xffff;
  293           R0 = (R0 - expandedKey[R3 & 0x3f]) & 0xffff;
  294   
  295           // 5 r-mixing rounds
  296           for(int i = 20; i > 0; i -= 4) {
  297               R3 = ((R3 << 11) | (R3 >>> 5)) & 0xffff;
  298               R3 = (R3 - expandedKey[i - 1] - (R2 & R1) - (~R2 & R0)) & 0xffff;
  299   
  300               R2 = ((R2 << 13) | (R2 >>> 3)) & 0xffff;
  301               R2 = (R2 - expandedKey[i - 2] - (R1 & R0) - (~R1 & R3)) & 0xffff;
  302   
  303               R1 = ((R1 << 14) | (R1 >>> 2)) & 0xffff;
  304               R1 = (R1 - expandedKey[i - 3] - (R0 & R3) - (~R0 & R2)) & 0xffff;
  305   
  306               R0 = ((R0 << 15) | (R0 >>> 1)) & 0xffff;
  307               R0 = (R0 - expandedKey[i - 4] - (R3 & R2) - (~R3 & R1)) & 0xffff;
  308           }
  309   
  310           out[outOfs    ] = (byte)R0;
  311           out[outOfs + 1] = (byte)(R0 >> 8);
  312           out[outOfs + 2] = (byte)R1;
  313           out[outOfs + 3] = (byte)(R1 >> 8);
  314           out[outOfs + 4] = (byte)R2;
  315           out[outOfs + 5] = (byte)(R2 >> 8);
  316           out[outOfs + 6] = (byte)R3;
  317           out[outOfs + 7] = (byte)(R3 >> 8);
  318       }
  319   
  320   }

Save This Page
Home » openjdk-7 » com.sun.crypto » provider » [javadoc | source]