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Diffstat (limited to 'libjava/classpath/javax/crypto/spec/PBEKeySpec.java')
-rw-r--r-- | libjava/classpath/javax/crypto/spec/PBEKeySpec.java | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/libjava/classpath/javax/crypto/spec/PBEKeySpec.java b/libjava/classpath/javax/crypto/spec/PBEKeySpec.java new file mode 100644 index 000000000..f0ffa379a --- /dev/null +++ b/libjava/classpath/javax/crypto/spec/PBEKeySpec.java @@ -0,0 +1,281 @@ +/* PBEKeySpec.java -- Wrapper for password-based keys. + Copyright (C) 2004, 2006 Free Software Foundation, Inc. + +This file is 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, 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; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, 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 javax.crypto.spec; + +import java.security.spec.KeySpec; + +/** + * A wrapper for a password-based key, used for password-based + * encryption (PBE). + * + * <p>Examples of password-based encryption algorithms include: + * + * <ul> + * <li><a href="http://www.rsasecurity.com/rsalabs/pkcs/pkcs-5/">PKCS #5 + * - Password-Based Cryptography Standard</a></li> + * <li><a href="http://www.rsasecurity.com/rsalabs/pkcs/pkcs-12/">PKCS + * #12 - Personal Information Exchange Syntax Standard</a></li> + * </ul> + * + * @author Casey Marshall (csm@gnu.org) + * @since 1.4 + * @see javax.crypto.SecretKeyFactory + * @see PBEParameterSpec + */ +public class PBEKeySpec implements KeySpec +{ + + // Fields. + // ------------------------------------------------------------------------ + + /** The iteration count. */ + private int iterationCount; + + /** The generated key length. */ + private int keyLength; + + /** The password. */ + private char[] password; + + /** The salt. */ + private byte[] salt; + + /** The password state */ + private boolean passwordValid = true; + + // Constructors. + // ------------------------------------------------------------------------ + + /** + * Create a new PBE key spec with just a password. + * <p> + * A copy of the password argument is stored instead of the argument itself. + * + * @param password The password char array. + */ + public PBEKeySpec(char[] password) + { + setPassword(password); + + // load the default values for unspecified variables. + salt = null; + iterationCount = 0; + keyLength = 0; + } + + /** + * Create a PBE key spec with a password, salt, and iteration count. + * <p> + * A copy of the password and salt arguments are stored instead of the + * arguments themselves. + * + * @param password The password char array. + * @param salt The salt bytes. + * @param iterationCount The iteration count. + * @throws NullPointerException If salt is null + * @throws IllegalArgumentException If salt is an empty array, or + * iterationCount is negative + */ + public PBEKeySpec(char[] password, byte[] salt, int iterationCount) + { + setPassword(password); + setSalt(salt); + setIterationCount(iterationCount); + + // load default values into unspecified variables. + keyLength = 0; + } + + /** + * Create a PBE key spec with a password, salt, iteration count, and key + * length. + * <p> + * A copy of the password and salt arguments are stored instead of the + * arguments themselves. + * + * @param password The password char array. + * @param salt The salt bytes. + * @param iterationCount The iteration count. + * @param keyLength The generated key length. + * @throws NullPointerException If salt is null + * @throws IllegalArgumentException If salt is an empty array, if + * iterationCount or keyLength is negative + */ + public PBEKeySpec(char[] password, byte[] salt, int iterationCount, + int keyLength) + { + setPassword(password); + setSalt(salt); + setIterationCount(iterationCount); + setKeyLength(keyLength); + } + + // Instance methods. + // ------------------------------------------------------------------------ + + /** + * Clear the password array by filling it with null characters. + * <p> + * This clears the stored copy of the password, not the original char array + * used to create the password. + */ + public final void clearPassword() + { + if (password == null) + return; + for (int i = 0; i < password.length; i++) + password[i] = '\u0000'; + + // since the password is cleared, it is no longer valid + passwordValid = false; + } + + /** + * Get the iteration count, or 0 if it has not been specified. + * + * @return The iteration count, or 0 if it has not been specified. + */ + public final int getIterationCount() + { + return iterationCount; + } + + /** + * Get the generated key length, or 0 if it has not been specified. + * + * @return The key length, or 0 if it has not been specified. + */ + public final int getKeyLength() + { + return keyLength; + } + + /** + * Get the password character array copy. + * <p> + * This returns a copy of the password, not the password itself. + * + * @return a clone of the password. + * @throws IllegalStateException If {@link #clearPassword()} has already been + * called. + */ + public final char[] getPassword() + { + if (! passwordValid) + throw new IllegalStateException("clearPassword() has been called, the " + + "password is no longer valid"); + return (char[]) password.clone(); + } + + /** + * Get the salt bytes array copy. + * <p> + * This returns a copy of the salt, not the salt itself. + * + * @return The salt. + */ + public final byte[] getSalt() + { + if (salt != null) + return (byte[]) salt.clone(); + return null; + } + + /** + * Set the password char array. + * <p> + * A copy of the password argument is stored instead of the argument itself. + * + * @param password The password to be set + */ + private void setPassword(char[] password) + { + if (password != null) + this.password = (char[]) password.clone(); + else + this.password = new char[0]; + + passwordValid = true; + } + + /** + * Set the salt byte array. + * <p> + * A copy of the salt arguments is stored instead of the argument itself. + * + * @param salt The salt to be set. + * @throws NullPointerException If the salt is null. + * @throws IllegalArgumentException If the salt is an empty array. + */ + private void setSalt(byte[] salt) + { + if (salt.length == 0) + throw new IllegalArgumentException("salt MUST NOT be an empty byte array"); + + this.salt = (byte[]) salt.clone(); + } + + /** + * Set the iterationCount. + * + * @param iterationCount The iteration count to be set. + * @throws IllegalArgumentException If the iterationCount is negative. + */ + private void setIterationCount(int iterationCount) + { + if (iterationCount < 0) + throw new IllegalArgumentException("iterationCount MUST be positive"); + + this.iterationCount = iterationCount; + } + + /** + * Set the keyLength. + * + * @param keyLength The keyLength to be set. + * @throws IllegalArgumentException if the keyLength is negative. + */ + private void setKeyLength(int keyLength) + { + if (keyLength < 0) + throw new IllegalArgumentException("keyLength MUST be positive"); + + this.keyLength = keyLength; + } +} |