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Diffstat (limited to 'libjava/classpath/gnu/javax/crypto/assembly/Stage.java')
| -rw-r--r-- | libjava/classpath/gnu/javax/crypto/assembly/Stage.java | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/libjava/classpath/gnu/javax/crypto/assembly/Stage.java b/libjava/classpath/gnu/javax/crypto/assembly/Stage.java new file mode 100644 index 000000000..5d0ab5353 --- /dev/null +++ b/libjava/classpath/gnu/javax/crypto/assembly/Stage.java @@ -0,0 +1,202 @@ +/* Stage.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 gnu.javax.crypto.mode.IMode; + +import java.security.InvalidKeyException; +import java.util.Map; +import java.util.Set; + +/** + * A <i>Stage</i> in a Cascade Cipher. + * <p> + * Each stage may be either an implementation of a Block Cipher Mode of + * Operation ({@link IMode}) or another Cascade Cipher ({@link Cascade}). + * Each stage has also a <i>natural</i> operational direction when constructed + * for inclusion within a {@link Cascade}. This <i>natural</i> direction + * dictates how data flows from one stage into another when stages are chained + * together in a cascade. One can think of a stage and its natural direction as + * the specification of how to wire the stage into the chain. The following + * diagrams may help understand the paradigme. The first shows two stages + * chained each with a {@link Direction#FORWARD} direction. + * + * <pre> + * FORWARD FORWARD + * +------+ +-------+ + * | | | | + * | +--in --+ | +--in --+ + * ---+ | Stage | | | Stage | +--- + * +--out--+ | +--out--+ | + * | | | | + * +-------+ +------+ + * </pre> + * + * <p> + * The second diagram shows two stages, one in a {@link Direction#FORWARD} + * direction, while the other is wired in a {@link Direction#REVERSED} + * direction. + * + * <pre> + * FORWARD REVERSED + * +------+ +------+ + * | | | | + * | +--in --+ +--in --+ | + * ---+ | Stage | | Stage | +--- + * +--out--+ +--out--+ + * | | + * +---------------+ + * </pre> + * + * @see ModeStage + * @see CascadeStage + */ +public abstract class Stage +{ + public static final String DIRECTION = "gnu.crypto.assembly.stage.direction"; + + protected Direction forward; + + protected Direction wired; + + protected Stage(Direction forwardDirection) + { + super(); + + this.forward = forwardDirection; + this.wired = null; + } + + public static final Stage getInstance(IMode mode, Direction forwardDirection) + { + return new ModeStage(mode, forwardDirection); + } + + public static final Stage getInstance(Cascade cascade, + Direction forwardDirection) + { + return new CascadeStage(cascade, forwardDirection); + } + + /** + * Returns the {@link Set} of supported block sizes for this + * <code>Stage</code>. Each element in the returned {@link Set} is an + * instance of {@link Integer}. + * + * @return a {@link Set} of supported block sizes. + */ + public abstract Set blockSizes(); + + /** + * Initialises the stage 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 instance is already initialised. + * @throws InvalidKeyException if the key data is invalid. + */ + 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; + attributes.put(DIRECTION, flow); + } + initDelegate(attributes); + wired = flow; + } + + /** + * Returns the currently set block size for the stage. + * + * @return the current block size for this stage. + * @throws IllegalStateException if the instance is not initialised. + */ + public abstract int currentBlockSize() throws IllegalStateException; + + /** + * Resets the stage for re-initialisation and use with other characteristics. + * This method always succeeds. + */ + public void reset() + { + resetDelegate(); + wired = null; + } + + /** + * 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(); + updateDelegate(in, inOffset, out, outOffset); + } + + /** + * 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 abstract boolean selfTest(); + + abstract void initDelegate(Map attributes) throws InvalidKeyException; + + abstract void resetDelegate(); + + abstract void updateDelegate(byte[] in, int inOffset, byte[] out, + int outOffset); +} |