/* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.crypto.provider; import java.io.ObjectStreamException; import java.nio.ByteBuffer; import java.nio.CharBuffer; import java.nio.charset.Charset; import java.util.Arrays; import java.security.KeyRep; import java.security.GeneralSecurityException; import java.security.NoSuchAlgorithmException; import java.security.NoSuchProviderException; import java.security.spec.InvalidKeySpecException; import javax.crypto.Mac; import javax.crypto.SecretKey; import javax.crypto.spec.PBEKeySpec; /** * This class represents a PBE key derived using PBKDF2 defined * in PKCS#5 v2.0. meaning that * 1) the password must consist of characters which will be converted * to bytes using UTF-8 character encoding. * 2) salt, iteration count, and to be derived key length are supplied * * @author Valerie Peng * */ final class PBKDF2KeyImpl implements javax.crypto.interfaces.PBEKey { static final long serialVersionUID = -2234868909660948157L; private char[] passwd; private byte[] salt; private int iterCount; private byte[] key; private Mac prf; private static byte[] getPasswordBytes(char[] passwd) { Charset utf8 = Charset.forName("UTF-8"); CharBuffer cb = CharBuffer.wrap(passwd); ByteBuffer bb = utf8.encode(cb); int len = bb.limit(); byte[] passwdBytes = new byte[len]; bb.get(passwdBytes, 0, len); return passwdBytes; } /** * Creates a PBE key from a given PBE key specification. * * @param key the given PBE key specification */ PBKDF2KeyImpl(PBEKeySpec keySpec, String prfAlgo) throws InvalidKeySpecException { char[] passwd = keySpec.getPassword(); if (passwd == null) { // Should allow an empty password. this.passwd = new char[0]; } else { this.passwd = passwd.clone(); } // Convert the password from char[] to byte[] byte[] passwdBytes = getPasswordBytes(this.passwd); this.salt = keySpec.getSalt(); if (salt == null) { throw new InvalidKeySpecException("Salt not found"); } this.iterCount = keySpec.getIterationCount(); if (iterCount == 0) { throw new InvalidKeySpecException("Iteration count not found"); } else if (iterCount < 0) { throw new InvalidKeySpecException("Iteration count is negative"); } int keyLength = keySpec.getKeyLength(); if (keyLength == 0) { throw new InvalidKeySpecException("Key length not found"); } else if (keyLength == 0) { throw new InvalidKeySpecException("Key length is negative"); } try { this.prf = Mac.getInstance(prfAlgo, "SunJCE"); } catch (NoSuchAlgorithmException nsae) { // not gonna happen; re-throw just in case InvalidKeySpecException ike = new InvalidKeySpecException(); ike.initCause(nsae); throw ike; } catch (NoSuchProviderException nspe) { // Again, not gonna happen; re-throw just in case InvalidKeySpecException ike = new InvalidKeySpecException(); ike.initCause(nspe); throw ike; } this.key = deriveKey(prf, passwdBytes, salt, iterCount, keyLength); } private static byte[] deriveKey(final Mac prf, final byte[] password, byte[] salt, int iterCount, int keyLengthInBit) { int keyLength = keyLengthInBit/8; byte[] key = new byte[keyLength]; try { int hlen = prf.getMacLength(); int intL = (keyLength + hlen - 1)/hlen; // ceiling int intR = keyLength - (intL - 1)*hlen; // residue byte[] ui = new byte[hlen]; byte[] ti = new byte[hlen]; // SecretKeySpec cannot be used, since password can be empty here. SecretKey macKey = new SecretKey() { @Override public String getAlgorithm() { return prf.getAlgorithm(); } @Override public String getFormat() { return "RAW"; } @Override public byte[] getEncoded() { return password; } @Override public int hashCode() { return Arrays.hashCode(password) * 41 + prf.getAlgorithm().toLowerCase().hashCode(); } @Override public boolean equals(Object obj) { if (this == obj) return true; if (this.getClass() != obj.getClass()) return false; SecretKey sk = (SecretKey)obj; return prf.getAlgorithm().equalsIgnoreCase( sk.getAlgorithm()) && Arrays.equals(password, sk.getEncoded()); } }; prf.init(macKey); byte[] ibytes = new byte[4]; for (int i = 1; i <= intL; i++) { prf.update(salt); ibytes[3] = (byte) i; ibytes[2] = (byte) ((i >> 8) & 0xff); ibytes[1] = (byte) ((i >> 16) & 0xff); ibytes[0] = (byte) ((i >> 24) & 0xff); prf.update(ibytes); prf.doFinal(ui, 0); System.arraycopy(ui, 0, ti, 0, ui.length); for (int j = 2; j <= iterCount; j++) { prf.update(ui); prf.doFinal(ui, 0); // XOR the intermediate Ui's together. for (int k = 0; k < ui.length; k++) { ti[k] ^= ui[k]; } } if (i == intL) { System.arraycopy(ti, 0, key, (i-1)*hlen, intR); } else { System.arraycopy(ti, 0, key, (i-1)*hlen, hlen); } } } catch (GeneralSecurityException gse) { throw new RuntimeException("Error deriving PBKDF2 keys"); } return key; } public byte[] getEncoded() { return (byte[]) key.clone(); } public String getAlgorithm() { return "PBKDF2With" + prf.getAlgorithm(); } public int getIterationCount() { return iterCount; } public char[] getPassword() { return (char[]) passwd.clone(); } public byte[] getSalt() { return salt.clone(); } public String getFormat() { return "RAW"; } /** * Calculates a hash code value for the object. * Objects that are equal will also have the same hashcode. */ public int hashCode() { int retval = 0; for (int i = 1; i < this.key.length; i++) { retval += this.key[i] * i; } return(retval ^= getAlgorithm().toLowerCase().hashCode()); } public boolean equals(Object obj) { if (obj == this) return true; if (!(obj instanceof SecretKey)) return false; SecretKey that = (SecretKey) obj; if (!(that.getAlgorithm().equalsIgnoreCase(getAlgorithm()))) return false; if (!(that.getFormat().equalsIgnoreCase("RAW"))) return false; byte[] thatEncoded = that.getEncoded(); boolean ret = Arrays.equals(key, that.getEncoded()); java.util.Arrays.fill(thatEncoded, (byte)0x00); return ret; } /** * Replace the PBE key to be serialized. * * @return the standard KeyRep object to be serialized * * @throws ObjectStreamException if a new object representing * this PBE key could not be created */ private Object writeReplace() throws ObjectStreamException { return new KeyRep(KeyRep.Type.SECRET, getAlgorithm(), getFormat(), getEncoded()); } /** * Ensures that the password bytes of this key are * erased when there are no more references to it. */ protected void finalize() throws Throwable { try { if (this.passwd != null) { java.util.Arrays.fill(this.passwd, (char) '0'); this.passwd = null; } if (this.key != null) { java.util.Arrays.fill(this.key, (byte)0x00); this.key = null; } } finally { super.finalize(); } } }