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Diffstat (limited to 'gcc-4.4.3/libjava/classpath/gnu/javax/crypto/assembly/Cascade.java')
| -rw-r--r-- | gcc-4.4.3/libjava/classpath/gnu/javax/crypto/assembly/Cascade.java | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/gcc-4.4.3/libjava/classpath/gnu/javax/crypto/assembly/Cascade.java b/gcc-4.4.3/libjava/classpath/gnu/javax/crypto/assembly/Cascade.java new file mode 100644 index 000000000..f790956a4 --- /dev/null +++ b/gcc-4.4.3/libjava/classpath/gnu/javax/crypto/assembly/Cascade.java @@ -0,0 +1,348 @@ +/* Cascade.java -- + Copyright (C) 2003, 2006 Free Software Foundation, Inc. + +This file is a part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2 of the License, or (at +your option) any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; if not, write to the Free Software +Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 +USA + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package gnu.javax.crypto.assembly; + +import java.math.BigInteger; +import java.security.InvalidKeyException; +import java.util.Collections; +import java.util.HashMap; +import java.util.HashSet; +import java.util.Iterator; +import java.util.LinkedList; +import java.util.Map; +import java.util.Set; + +/** + * A <i>Cascade</i> Cipher is the concatenation of two or more block ciphers + * each with independent keys. Plaintext is input to the first stage; the output + * of stage <code>i</code> is input to stage <code>i + 1</code>; and the + * output of the last stage is the <i>Cascade</i>'s ciphertext output. + * <p> + * In the simplest case, all stages in a <code>Cascade</code> have <i>k</i>-bit + * keys, and the stage inputs and outputs are all n-bit quantities. The stage + * ciphers may differ (general cascade of ciphers), or all be identical (cascade + * of identical ciphers). + * <p> + * The term "block ciphers" used above refers to implementations of + * {@link gnu.javax.crypto.mode.IMode}, including the + * {@link gnu.javax.crypto.mode.ECB} mode which basically exposes a + * symmetric-key block cipher algorithm as a <i>Mode</i> of Operations. + * <p> + * References: + * <ol> + * <li><a href="http://www.cacr.math.uwaterloo.ca/hac">[HAC]</a>: Handbook of + * Applied Cryptography.<br> + * CRC Press, Inc. ISBN 0-8493-8523-7, 1997<br> + * Menezes, A., van Oorschot, P. and S. Vanstone.</li> + * </ol> + */ +public class Cascade +{ + public static final String DIRECTION = "gnu.crypto.assembly.cascade.direction"; + + /** The map of Stages chained in this cascade. */ + protected HashMap stages; + + /** The ordered list of Stage UIDs to their attribute maps. */ + protected LinkedList stageKeys; + + /** The current operational direction of this instance. */ + protected Direction wired; + + /** The curently set block-size for this instance. */ + protected int blockSize; + + public Cascade() + { + super(); + + stages = new HashMap(3); + stageKeys = new LinkedList(); + wired = null; + blockSize = 0; + } + + /** + * Returns the Least Common Multiple of two integers. + * + * @param a the first integer. + * @param b the second integer. + * @return the LCM of <code>abs(a)</code> and <code>abs(b)</code>. + */ + private static final int lcm(int a, int b) + { + BigInteger A = BigInteger.valueOf(a * 1L); + BigInteger B = BigInteger.valueOf(b * 1L); + return A.multiply(B).divide(A.gcd(B)).abs().intValue(); + } + + /** + * Adds to the end of the current chain, a designated {@link Stage}. + * + * @param stage the {@link Stage} to append to the chain. + * @return a unique identifier for this stage, within this cascade. + * @throws IllegalStateException if the instance is already initialised. + * @throws IllegalArgumentException if the designated stage is already in the + * chain, or it has incompatible characteristics with the current + * elements already in the chain. + */ + public Object append(Stage stage) throws IllegalArgumentException + { + return insert(size(), stage); + } + + /** + * Adds to the begining of the current chain, a designated {@link Stage}. + * + * @param stage the {@link Stage} to prepend to the chain. + * @return a unique identifier for this stage, within this cascade. + * @throws IllegalStateException if the instance is already initialised. + * @throws IllegalArgumentException if the designated stage is already in the + * chain, or it has incompatible characteristics with the current + * elements already in the chain. + */ + public Object prepend(Stage stage) throws IllegalArgumentException + { + return insert(0, stage); + } + + /** + * Inserts a {@link Stage} into the current chain, at the specified index + * (zero-based) position. + * + * @param stage the {@link Stage} to insert into the chain. + * @return a unique identifier for this stage, within this cascade. + * @throws IllegalArgumentException if the designated stage is already in the + * chain, or it has incompatible characteristics with the current + * elements already in the chain. + * @throws IllegalStateException if the instance is already initialised. + * @throws IndexOutOfBoundsException if <code>index</code> is less than + * <code>0</code> or greater than the current size of this + * cascade. + */ + public Object insert(int index, Stage stage) throws IllegalArgumentException, + IndexOutOfBoundsException + { + if (stages.containsValue(stage)) + throw new IllegalArgumentException(); + if (wired != null || stage == null) + throw new IllegalStateException(); + if (index < 0 || index > size()) + throw new IndexOutOfBoundsException(); + // check that there is a non-empty set of common block-sizes + Set set = stage.blockSizes(); + if (stages.isEmpty()) + { + if (set.isEmpty()) + throw new IllegalArgumentException("1st stage with no block sizes"); + } + else + { + Set common = this.blockSizes(); + common.retainAll(set); + if (common.isEmpty()) + throw new IllegalArgumentException("no common block sizes found"); + } + Object result = new Object(); + stageKeys.add(index, result); + stages.put(result, stage); + return result; + } + + /** + * Returns the current number of stages in this chain. + * + * @return the current count of stages in this chain. + */ + public int size() + { + return stages.size(); + } + + /** + * Returns an {@link Iterator} over the stages contained in this instance. + * Each element of this iterator is a concrete implementation of a {@link + * Stage}. + * + * @return an {@link Iterator} over the stages contained in this instance. + * Each element of the returned iterator is a concrete instance of a + * {@link Stage}. + */ + public Iterator stages() + { + LinkedList result = new LinkedList(); + for (Iterator it = stageKeys.listIterator(); it.hasNext();) + result.addLast(stages.get(it.next())); + return result.listIterator(); + } + + /** + * Returns the {@link Set} of supported block sizes for this + * <code>Cascade</code> that are common to all of its chained stages. Each + * element in the returned {@link Set} is an instance of {@link Integer}. + * + * @return a {@link Set} of supported block sizes common to all the stages of + * the chain. + */ + public Set blockSizes() + { + HashSet result = null; + for (Iterator it = stages.values().iterator(); it.hasNext();) + { + Stage aStage = (Stage) it.next(); + if (result == null) // first time + result = new HashSet(aStage.blockSizes()); + else + result.retainAll(aStage.blockSizes()); + } + return result == null ? Collections.EMPTY_SET : result; + } + + /** + * Initialises the chain for operation with specific characteristics. + * + * @param attributes a set of name-value pairs that describes the desired + * future behaviour of this instance. + * @throws IllegalStateException if the chain, or any of its stages, is + * already initialised. + * @throws InvalidKeyException if the intialisation data provided with the + * stage is incorrect or causes an invalid key to be generated. + * @see Direction#FORWARD + * @see Direction#REVERSED + */ + public void init(Map attributes) throws InvalidKeyException + { + if (wired != null) + throw new IllegalStateException(); + Direction flow = (Direction) attributes.get(DIRECTION); + if (flow == null) + flow = Direction.FORWARD; + int optimalSize = 0; + for (Iterator it = stageKeys.listIterator(); it.hasNext();) + { + Object id = it.next(); + Map attr = (Map) attributes.get(id); + attr.put(Stage.DIRECTION, flow); + Stage stage = (Stage) stages.get(id); + stage.init(attr); + optimalSize = optimalSize == 0 ? stage.currentBlockSize() + : lcm(optimalSize, + stage.currentBlockSize()); + } + if (flow == Direction.REVERSED) // reverse order + Collections.reverse(stageKeys); + wired = flow; + blockSize = optimalSize; + } + + /** + * Returns the currently set block size for the chain. + * + * @return the current block size for the chain. + * @throws IllegalStateException if the instance is not initialised. + */ + public int currentBlockSize() + { + if (wired == null) + throw new IllegalStateException(); + return blockSize; + } + + /** + * Resets the chain for re-initialisation and use with other characteristics. + * This method always succeeds. + */ + public void reset() + { + for (Iterator it = stageKeys.listIterator(); it.hasNext();) + ((Stage) stages.get(it.next())).reset(); + if (wired == Direction.REVERSED) // reverse it back + Collections.reverse(stageKeys); + wired = null; + blockSize = 0; + } + + /** + * Processes exactly one block of <i>plaintext</i> (if initialised in the + * {@link Direction#FORWARD} state) or <i>ciphertext</i> (if initialised in + * the {@link Direction#REVERSED} state). + * + * @param in the plaintext. + * @param inOffset index of <code>in</code> from which to start considering + * data. + * @param out the ciphertext. + * @param outOffset index of <code>out</code> from which to store result. + * @throws IllegalStateException if the instance is not initialised. + */ + public void update(byte[] in, int inOffset, byte[] out, int outOffset) + { + if (wired == null) + throw new IllegalStateException(); + int stageBlockSize, j, i = stages.size(); + for (Iterator it = stageKeys.listIterator(); it.hasNext();) + { + Stage stage = (Stage) stages.get(it.next()); + stageBlockSize = stage.currentBlockSize(); + for (j = 0; j < blockSize; j += stageBlockSize) + stage.update(in, inOffset + j, out, outOffset + j); + i--; + if (i > 0) + System.arraycopy(out, outOffset, in, inOffset, blockSize); + } + } + + /** + * Conducts a simple <i>correctness</i> test that consists of basic symmetric + * encryption / decryption test(s) for all supported block and key sizes of + * underlying block cipher(s) wrapped by Mode leafs. The test also includes + * one (1) variable key Known Answer Test (KAT) for each block cipher. + * + * @return <code>true</code> if the implementation passes simple + * <i>correctness</i> tests. Returns <code>false</code> otherwise. + */ + public boolean selfTest() + { + for (Iterator it = stageKeys.listIterator(); it.hasNext();) + { + if (! ((Stage) stages.get(it.next())).selfTest()) + return false; + } + return true; + } +} |