| /* BaseSignature.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.sig; |
| |
| import gnu.java.security.hash.IMessageDigest; |
| import gnu.java.security.prng.IRandom; |
| import gnu.java.security.prng.LimitReachedException; |
| import gnu.java.security.util.PRNG; |
| |
| import java.security.PrivateKey; |
| import java.security.PublicKey; |
| import java.util.Map; |
| import java.util.Random; |
| |
| /** |
| * A base abstract class to facilitate implementations of concrete Signatures. |
| */ |
| public abstract class BaseSignature |
| implements ISignature |
| { |
| /** The canonical name of this signature scheme. */ |
| protected String schemeName; |
| |
| /** The underlying message digest instance for this signature scheme. */ |
| protected IMessageDigest md; |
| |
| /** The public key to use when verifying signatures. */ |
| protected PublicKey publicKey; |
| |
| /** The private key to use when generating signatures (signing). */ |
| protected PrivateKey privateKey; |
| |
| /** The optional {@link Random} instance to use. */ |
| private Random rnd; |
| |
| /** The optional {@link IRandom} instance to use. */ |
| private IRandom irnd; |
| |
| /** Our default source of randomness. */ |
| private PRNG prng = null; |
| |
| /** |
| * Trivial constructor. |
| * |
| * @param schemeName the name of this signature scheme. |
| * @param md the underlying instance of the message digest algorithm. |
| * @throws IllegalArgumentException if the designated hash instance is |
| * <code>null</code>. |
| */ |
| protected BaseSignature(String schemeName, IMessageDigest md) |
| { |
| super(); |
| |
| this.schemeName = schemeName; |
| if (md == null) |
| throw new IllegalArgumentException("Message digest MUST NOT be null"); |
| |
| this.md = md; |
| } |
| |
| public String name() |
| { |
| return schemeName + "-" + md.name(); |
| } |
| |
| public void setupVerify(Map attributes) throws IllegalArgumentException |
| { |
| setup(attributes); |
| // do we have a public key? |
| PublicKey key = (PublicKey) attributes.get(VERIFIER_KEY); |
| if (key != null) |
| setupForVerification(key); |
| } |
| |
| public void setupSign(Map attributes) throws IllegalArgumentException |
| { |
| setup(attributes); |
| // do we have a private key? |
| PrivateKey key = (PrivateKey) attributes.get(SIGNER_KEY); |
| if (key != null) |
| setupForSigning(key); |
| } |
| |
| public void update(byte b) |
| { |
| if (md == null) |
| throw new IllegalStateException(); |
| |
| md.update(b); |
| } |
| |
| public void update(byte[] b, int off, int len) |
| { |
| if (md == null) |
| throw new IllegalStateException(); |
| |
| md.update(b, off, len); |
| } |
| |
| public Object sign() |
| { |
| if (md == null || privateKey == null) |
| throw new IllegalStateException(); |
| |
| return generateSignature(); |
| } |
| |
| public boolean verify(Object sig) |
| { |
| if (md == null || publicKey == null) |
| throw new IllegalStateException(); |
| |
| return verifySignature(sig); |
| } |
| |
| public abstract Object clone(); |
| |
| protected abstract void setupForVerification(PublicKey key) |
| throws IllegalArgumentException; |
| |
| protected abstract void setupForSigning(PrivateKey key) |
| throws IllegalArgumentException; |
| |
| protected abstract Object generateSignature() throws IllegalStateException; |
| |
| protected abstract boolean verifySignature(Object signature) |
| throws IllegalStateException; |
| |
| /** Initialises the internal fields of this instance. */ |
| protected void init() |
| { |
| md.reset(); |
| rnd = null; |
| irnd = null; |
| publicKey = null; |
| privateKey = null; |
| } |
| |
| /** |
| * Fills the designated byte array with random data. |
| * |
| * @param buffer the byte array to fill with random data. |
| */ |
| protected void nextRandomBytes(byte[] buffer) |
| { |
| if (rnd != null) |
| rnd.nextBytes(buffer); |
| else if (irnd != null) |
| try |
| { |
| irnd.nextBytes(buffer, 0, buffer.length); |
| } |
| catch (IllegalStateException x) |
| { |
| throw new RuntimeException("nextRandomBytes(): " + x); |
| } |
| catch (LimitReachedException x) |
| { |
| throw new RuntimeException("nextRandomBytes(): " + x); |
| } |
| else |
| getDefaultPRNG().nextBytes(buffer); |
| } |
| |
| private void setup(Map attributes) |
| { |
| init(); |
| // do we have a Random or SecureRandom, or should we use our own? |
| Object obj = attributes.get(SOURCE_OF_RANDOMNESS); |
| if (obj instanceof Random) |
| rnd = (Random) obj; |
| else if (obj instanceof IRandom) |
| irnd = (IRandom) obj; |
| } |
| |
| private PRNG getDefaultPRNG() |
| { |
| if (prng == null) |
| prng = PRNG.getInstance(); |
| |
| return prng; |
| } |
| } |