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Diffstat (limited to 'gcc-4.4.3/libjava/classpath/gnu/javax/crypto/mac/IMac.java')
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1 files changed, 181 insertions, 0 deletions
diff --git a/gcc-4.4.3/libjava/classpath/gnu/javax/crypto/mac/IMac.java b/gcc-4.4.3/libjava/classpath/gnu/javax/crypto/mac/IMac.java new file mode 100644 index 000000000..a9da9eefb --- /dev/null +++ b/gcc-4.4.3/libjava/classpath/gnu/javax/crypto/mac/IMac.java @@ -0,0 +1,181 @@ +/* IMac.java -- + Copyright (C) 2001, 2002, 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.mac; + +import java.security.InvalidKeyException; +import java.util.Map; + +/** + * The basic visible methods of any MAC (Message Authentication Code) algorithm. + * <p> + * A <i>MAC</i> provides a way to check the integrity of information + * transmitted over, or stored in, an unreliable medium, based on a secret key. + * Typically, <i>MAC</i>s are used between two parties, that share a common + * secret key, in order to validate information transmitted between them. + * <p> + * When a <i>MAC</i> algorithm is based on a cryptographic hash function, it is + * then called to a <i>HMAC</i> (Hashed Message Authentication Code) --see <a + * href="http://www.ietf.org/rfc/rfc-2104.txt">RFC-2104</a>. + * <p> + * Another type of <i>MAC</i> algorithms exist: UMAC or <i>Universal Message + * Authentication Code</i>, described in <a + * href="http://www.ietf.org/internet-drafts/draft-krovetz-umac-01.txt"> + * draft-krovetz-umac-01.txt</a>. + * <p> + * With <i>UMAC</i>s, the sender and receiver share a common secret key (the + * <i>MAC</i> key) which determines: + * <ul> + * <li>The key for a <i>universal hash function</i>. This hash function is + * <i>non-cryptographic</i>, in the sense that it does not need to have any + * cryptographic <i>hardness</i> property. Rather, it needs to satisfy some + * combinatorial property, which can be proven to hold without relying on + * unproven hardness assumptions.</li> + * <li>The key for a <i>pseudorandom function</i>. This is where one needs a + * cryptographic hardness assumption. The pseudorandom function may be obtained + * from a <i>block cipher</i> or a <i>cryptographic hash function</i>. </li> + * </ul> + * <p> + * References: + * <ol> + * <li><a href="http://www.ietf.org/rfc/rfc-2104.txt">RFC 2104</a>HMAC: + * Keyed-Hashing for Message Authentication.<br> + * H. Krawczyk, M. Bellare, and R. Canetti.</li> + * <li><a href="http://www.ietf.org/internet-drafts/draft-krovetz-umac-01.txt"> + * UMAC</a>: Message Authentication Code using Universal Hashing.<br> + * T. Krovetz, J. Black, S. Halevi, A. Hevia, H. Krawczyk, and P. Rogaway.</li> + * </ol> + */ +public interface IMac +{ + /** + * Property name of the user-supplied key material. The value associated to + * this property name is taken to be a byte array. + */ + String MAC_KEY_MATERIAL = "gnu.crypto.mac.key.material"; + /** + * Property name of the desired truncated output size in bytes. The value + * associated to this property name is taken to be an integer. If no value is + * specified in the attributes map at initialisation time, then all bytes of + * the underlying hash algorithm's output are emitted. + * <p> + * This implementation, follows the recommendation of the <i>RFC 2104</i> + * authors; specifically: + * <pre> + * We recommend that the output length t be not less than half the + * length of the hash output (to match the birthday attack bound) + * and not less than 80 bits (a suitable lower bound on the number + * of bits that need to be predicted by an attacker). + * </pre> + */ + String TRUNCATED_SIZE = "gnu.crypto.mac.truncated.size"; + + /** + * Returns the canonical name of this algorithm. + * + * @return the canonical name of this algorithm. + */ + String name(); + + /** + * Returns the output length in bytes of this <i>MAC</i> algorithm. + * + * @return the output length in bytes of this <i>MAC</i> algorithm. + */ + int macSize(); + + /** + * Initialises the algorithm with designated attributes. Permissible names and + * values are described in the class documentation above. + * + * @param attributes a set of name-value pairs that describe the desired + * future instance behaviour. + * @exception InvalidKeyException if the key data is invalid. + * @exception IllegalStateException if the instance is already initialised. + * @see #MAC_KEY_MATERIAL + */ + void init(Map attributes) throws InvalidKeyException, IllegalStateException; + + /** + * Continues a <i>MAC</i> operation using the input byte. + * + * @param b the input byte to digest. + */ + void update(byte b); + + /** + * Continues a <i>MAC</i> operation, by filling the buffer, processing data + * in the algorithm's MAC_SIZE-bit block(s), updating the context and count, + * and buffering the remaining bytes in buffer for the next operation. + * + * @param in the input block. + * @param offset start of meaningful bytes in input block. + * @param length number of bytes, in input block, to consider. + */ + void update(byte[] in, int offset, int length); + + /** + * Completes the <i>MAC</i> by performing final operations such as padding + * and resetting the instance. + * + * @return the array of bytes representing the <i>MAC</i> value. + */ + byte[] digest(); + + /** + * Resets the algorithm instance for re-initialisation and use with other + * characteristics. This method always succeeds. + */ + void reset(); + + /** + * A basic test. Ensures that the MAC of a pre-determined message is equal to + * a known pre-computed value. + * + * @return <code>true</code> if the implementation passes a basic self-test. + * Returns <code>false</code> otherwise. + */ + boolean selfTest(); + + /** + * Returns a clone copy of this instance. + * + * @return a clone copy of this instance. + */ + Object clone() throws CloneNotSupportedException; +} |