diff options
Diffstat (limited to 'libjava/classpath/gnu/javax/crypto/assembly/Cascade.java')
| -rw-r--r-- | libjava/classpath/gnu/javax/crypto/assembly/Cascade.java | 203 |
1 files changed, 74 insertions, 129 deletions
diff --git a/libjava/classpath/gnu/javax/crypto/assembly/Cascade.java b/libjava/classpath/gnu/javax/crypto/assembly/Cascade.java index 678a7e7308d..f790956a472 100644 --- a/libjava/classpath/gnu/javax/crypto/assembly/Cascade.java +++ b/libjava/classpath/gnu/javax/crypto/assembly/Cascade.java @@ -49,36 +49,31 @@ import java.util.Map; import java.util.Set; /** - * <p>A <i>Cascade</i> Cipher is the concatenation of two or more block ciphers + * 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> - * - * <p>In the simplest case, all stages in a <code>Cascade</code> have <i>k</i>-bit + * 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> - * - * <p>The term "block ciphers" used above refers to implementations of - * {@link gnu.crypto.mode.IMode}, including the {@link gnu.crypto.mode.ECB} - * mode which basically exposes a symmetric-key block cipher algorithm as a - * <i>Mode</i> of Operations.</p> - * - * <p>References:</p> - * + * 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> + * <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 { - - // Constants and variables - // ------------------------------------------------------------------------- - public static final String DIRECTION = "gnu.crypto.assembly.cascade.direction"; /** The map of Stages chained in this cascade. */ @@ -93,9 +88,6 @@ public class Cascade /** The curently set block-size for this instance. */ protected int blockSize; - // Constructor(s) - // ------------------------------------------------------------------------- - public Cascade() { super(); @@ -106,12 +98,9 @@ public class Cascade blockSize = 0; } - // Class methods - // ------------------------------------------------------------------------- - /** * 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>. @@ -123,18 +112,15 @@ public class Cascade return A.multiply(B).divide(A.gcd(B)).abs().intValue(); } - // Instance methods - // ------------------------------------------------------------------------- - /** * 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. + * @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 { @@ -143,13 +129,13 @@ public class Cascade /** * 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. + * @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 { @@ -159,62 +145,49 @@ public class Cascade /** * 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 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. + * <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(); - } + throw new IllegalArgumentException(); if (wired != null || stage == null) - { - throw new IllegalStateException(); - } - + throw new IllegalStateException(); if (index < 0 || index > size()) - { - throw new IndexOutOfBoundsException(); - } - + 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"); - } + 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"); - } + 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() @@ -226,18 +199,16 @@ public class Cascade * 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}. + * 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())); - } + result.addLast(stages.get(it.next())); return result.listIterator(); } @@ -245,9 +216,9 @@ public class Cascade * 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. + * + * @return a {@link Set} of supported block sizes common to all the stages of + * the chain. */ public Set blockSizes() { @@ -255,42 +226,33 @@ public class Cascade for (Iterator it = stages.values().iterator(); it.hasNext();) { Stage aStage = (Stage) it.next(); - if (result == null) - { // first time - result = new HashSet(aStage.blockSizes()); - } + if (result == null) // first time + result = new HashSet(aStage.blockSizes()); else - { - result.retainAll(aStage.blockSizes()); - } + 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. + * future behaviour of this instance. * @throws IllegalStateException if the chain, or any of its stages, is - * already initialised. + * already initialised. * @throws InvalidKeyException if the intialisation data provided with the - * stage is incorrect or causes an invalid key to be generated. + * 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(); - } + throw new IllegalStateException(); Direction flow = (Direction) attributes.get(DIRECTION); if (flow == null) - { - flow = Direction.FORWARD; - } - + flow = Direction.FORWARD; int optimalSize = 0; for (Iterator it = stageKeys.listIterator(); it.hasNext();) { @@ -300,30 +262,25 @@ public class Cascade 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); + : 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(); - } + throw new IllegalStateException(); return blockSize; } @@ -334,25 +291,21 @@ public class Cascade 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); - } + ((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). - * + * {@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. + * 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. @@ -360,23 +313,17 @@ public class Cascade public void update(byte[] in, int inOffset, byte[] out, int outOffset) { if (wired == null) - { - throw new IllegalStateException(); - } + 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); - } + stage.update(in, inOffset + j, out, outOffset + j); i--; if (i > 0) - { - System.arraycopy(out, outOffset, in, inOffset, blockSize); - } + System.arraycopy(out, outOffset, in, inOffset, blockSize); } } @@ -385,18 +332,16 @@ public class Cascade * 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. + * <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; - } + if (! ((Stage) stages.get(it.next())).selfTest()) + return false; } return true; } |
