diff options
Diffstat (limited to 'gcc-4.4.3/libjava/classpath/gnu/java/security/prng/IRandom.java')
| -rw-r--r-- | gcc-4.4.3/libjava/classpath/gnu/java/security/prng/IRandom.java | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/gcc-4.4.3/libjava/classpath/gnu/java/security/prng/IRandom.java b/gcc-4.4.3/libjava/classpath/gnu/java/security/prng/IRandom.java new file mode 100644 index 000000000..66ad6d224 --- /dev/null +++ b/gcc-4.4.3/libjava/classpath/gnu/java/security/prng/IRandom.java @@ -0,0 +1,174 @@ +/* IRandom.java -- + Copyright (C) 2001, 2002, 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.java.security.prng; + +import java.util.Map; + +/** + * The basic visible methods of any pseudo-random number generator. + * <p> + * The [HAC] defines a PRNG (as implemented in this library) as follows: + * <ul> + * <li>"5.6 Definition: A pseudorandom bit generator (PRBG) is said to pass the + * <em>next-bit test</em> if there is no polynomial-time algorithm which, on + * input of the first <code>L</code> bits of an output sequence <code>S</code>, + * can predict the <code>(L+1)</code><sup>st</sup> bit of <code>S</code> with a + * probability significantly greater than <code>1/2</code>."</li> + * <li>"5.8 Definition: A PRBG that passes the <em>next-bit test</em> + * (possibly under some plausible but unproved mathematical assumption such as + * the intractability of factoring integers) is called a <em>cryptographically + * secure pseudorandom bit generator</em> (CSPRBG)."</li> + * </ul> + * <p> + * <b>IMPLEMENTATION NOTE</b>: Although all the concrete classes in this + * package implement the {@link Cloneable} interface, it is important to note + * here that such an operation, for those algorithms that use an underlying + * symmetric key block cipher, <b>DOES NOT</b> clone any session key material + * that may have been used in initialising the source PRNG (the instance to be + * cloned). Instead a clone of an already initialised PRNG, that uses an + * underlying symmetric key block cipher, is another instance with a clone of + * the same cipher that operates with the <b>same block size</b> but without + * any knowledge of neither key material nor key size. + * <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 interface IRandom + extends Cloneable +{ + /** + * Returns the canonical name of this instance. + * + * @return the canonical name of this instance. + */ + String name(); + + /** + * Initialises the pseudo-random number generator scheme with the appropriate + * attributes. + * + * @param attributes a set of name-value pairs that describe the desired + * future instance behaviour. + * @exception IllegalArgumentException if at least one of the defined name/ + * value pairs contains invalid data. + */ + void init(Map attributes); + + /** + * Returns the next 8 bits of random data generated from this instance. + * + * @return the next 8 bits of random data generated from this instance. + * @exception IllegalStateException if the instance is not yet initialised. + * @exception LimitReachedException if this instance has reached its + * theoretical limit for generating non-repetitive pseudo-random + * data. + */ + byte nextByte() throws IllegalStateException, LimitReachedException; + + /** + * Fills the designated byte array, starting from byte at index + * <code>offset</code>, for a maximum of <code>length</code> bytes with + * the output of this generator instance. + * + * @param out the placeholder to contain the generated random bytes. + * @param offset the starting index in <i>out</i> to consider. This method + * does nothing if this parameter is not within <code>0</code> and + * <code>out.length</code>. + * @param length the maximum number of required random bytes. This method does + * nothing if this parameter is less than <code>1</code>. + * @exception IllegalStateException if the instance is not yet initialised. + * @exception LimitReachedException if this instance has reached its + * theoretical limit for generating non-repetitive pseudo-random + * data. + */ + void nextBytes(byte[] out, int offset, int length) + throws IllegalStateException, LimitReachedException; + + /** + * Supplement, or possibly replace, the random state of this PRNG with a + * random byte. + * <p> + * Implementations are not required to implement this method in any meaningful + * way; this may be a no-operation, and implementations may throw an + * {@link UnsupportedOperationException}. + * + * @param b The byte to add. + */ + void addRandomByte(byte b); + + /** + * Supplement, or possibly replace, the random state of this PRNG with a + * sequence of new random bytes. + * <p> + * Implementations are not required to implement this method in any meaningful + * way; this may be a no-operation, and implementations may throw an + * {@link UnsupportedOperationException}. + * + * @param in The buffer of new random bytes to add. + */ + void addRandomBytes(byte[] in); + + /** + * Supplement, or possibly replace, the random state of this PRNG with a + * sequence of new random bytes. + * <p> + * Implementations are not required to implement this method in any meaningful + * way; this may be a no-operation, and implementations may throw an + * {@link UnsupportedOperationException}. + * + * @param in The buffer of new random bytes to add. + * @param offset The offset from whence to begin reading random bytes. + * @param length The number of random bytes to add. + * @exception IndexOutOfBoundsException If <i>offset</i>, <i>length</i>, or + * <i>offset</i>+<i>length</i> is out of bounds. + */ + void addRandomBytes(byte[] in, int offset, int length); + + /** + * Returns a clone copy of this instance. + * + * @return a clone copy of this instance. + */ + Object clone() throws CloneNotSupportedException; +} |