package gnu.crypto.keyring; // -*- c-basic-offset: 3 -*-
// ---------------------------------------------------------------------------
// $Id: PasswordAuthenticatedEntry.java,v 1.10 2005/10/06 04:24:16 rsdio Exp $
//
// Copyright (C) 2003 Free Software Foundation, Inc.
//
// This file is part of GNU Crypto.
//
// GNU Crypto 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 Crypto 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 this program; 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.
//
// ---------------------------------------------------------------------------
import gnu.crypto.Registry;
import gnu.crypto.mac.IMac;
import gnu.crypto.mac.MacFactory;
import gnu.crypto.mac.MacInputStream;
import gnu.crypto.mac.MacOutputStream;
import gnu.crypto.prng.IPBE;
import gnu.crypto.prng.IRandom;
import gnu.crypto.prng.LimitReachedException;
import gnu.crypto.prng.PRNGFactory;
import gnu.crypto.util.PRNG;
import gnu.crypto.util.Util;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.security.InvalidKeyException;
import java.util.Arrays;
import java.util.Iterator;
import java.util.HashMap;
/**
* <p>An entry authenticated with a password-based MAC.</p>
*
* @version $Revision: 1.10 $
*/
public final class PasswordAuthenticatedEntry extends MaskableEnvelopeEntry
implements PasswordProtectedEntry, Registry {
// Constants and variables
// -------------------------------------------------------------------------
public static final int TYPE = 3;
// Constructor(s)
// -------------------------------------------------------------------------
public PasswordAuthenticatedEntry(String mac, int maclen, Properties properties) {
super(TYPE, properties);
if (mac == null || mac.length() == 0) {
throw new IllegalArgumentException("no MAC specified");
}
this.properties.put("mac", mac);
this.properties.put("maclen", String.valueOf(maclen));
setMasked(false);
}
private PasswordAuthenticatedEntry() {
super(TYPE);
setMasked(true);
}
// Class methods
// -------------------------------------------------------------------------
public static
PasswordAuthenticatedEntry decode(DataInputStream in, char[] password)
throws IOException {
PasswordAuthenticatedEntry entry = new PasswordAuthenticatedEntry();
entry.properties.decode(in);
IMac mac = entry.getMac(password);
int len = in.readInt() - mac.macSize();
MeteredInputStream min = new MeteredInputStream(in, len);
MacInputStream macin = new MacInputStream(min, mac);
DataInputStream in2 = new DataInputStream(macin);
entry.setMasked(false);
entry.decodeEnvelope(in2);
byte[] macValue = new byte[mac.macSize()];
in.readFully(macValue);
if (!Arrays.equals(macValue, mac.digest())) {
throw new MalformedKeyringException("MAC verification failed");
}
return entry;
}
public static PasswordAuthenticatedEntry decode(DataInputStream in)
throws IOException {
PasswordAuthenticatedEntry entry = new PasswordAuthenticatedEntry();
entry.defaultDecode(in);
if (!entry.properties.containsKey("mac")) {
throw new MalformedKeyringException("no MAC");
}
if (!entry.properties.containsKey("maclen")) {
throw new MalformedKeyringException("no MAC length");
}
if (!entry.properties.containsKey("salt")) {
throw new MalformedKeyringException("no salt");
}
return entry;
}
// Instance methods
// -------------------------------------------------------------------------
public void verify(char[] password) {
if (!isMasked() || payload == null) {
return;
}
IMac m = null;
try {
m = getMac(password);
} catch (Exception x) {
throw new IllegalArgumentException(x.toString());
}
m.update(payload, 0, payload.length - m.macSize());
byte[] macValue = new byte[m.macSize()];
System.arraycopy(payload, payload.length - macValue.length, macValue, 0, macValue.length);
if (!Arrays.equals(macValue, m.digest())) {
throw new IllegalArgumentException("MAC verification failed");
}
try {
DataInputStream in =
new DataInputStream(new ByteArrayInputStream(payload, 0, payload.length - m.macSize()));
decodeEnvelope(in);
} catch (IOException ioe) {
throw new IllegalArgumentException("malformed keyring fragment");
}
setMasked(false);
payload = null;
}
public void authenticate(char[] password) throws IOException {
if (isMasked()) {
throw new IllegalStateException("entry is masked");
}
byte[] salt = new byte[8];
PRNG.nextBytes(salt, 0, salt.length);
properties.put("salt", Util.toString(salt));
IMac m = getMac(password);
ByteArrayOutputStream bout = new ByteArrayOutputStream(1024);
MacOutputStream macout = new MacOutputStream(bout, m);
DataOutputStream out2 = new DataOutputStream(macout);
for (Iterator it = entries.iterator(); it.hasNext(); ) {
Entry entry = (Entry) it.next();
entry.encode(out2);
}
bout.write(m.digest());
payload = bout.toByteArray();
}
public void encode(DataOutputStream out, char[] password) throws IOException {
authenticate(password);
encode(out);
}
protected void encodePayload(DataOutputStream out) throws IOException {
if (payload == null) {
throw new IllegalStateException("mac not computed");
}
}
// Own methods.
// ------------------------------------------------------------------------
private IMac getMac(char[] password) throws MalformedKeyringException {
if (!properties.containsKey("salt")) {
throw new MalformedKeyringException("no salt");
}
byte[] salt = Util.toBytesFromString(properties.get("salt"));
IMac mac = MacFactory.getInstance(properties.get("mac"));
if (mac == null) {
throw new MalformedKeyringException("no such mac: " + properties.get("mac"));
}
int keylen = mac.macSize();
int maclen = 0;
if (!properties.containsKey("maclen")) {
throw new MalformedKeyringException("no MAC length");
}
try {
maclen = Integer.parseInt(properties.get("maclen"));
} catch (NumberFormatException nfe) {
throw new MalformedKeyringException("bad MAC length");
}
HashMap pbAttr = new HashMap();
pbAttr.put(IPBE.PASSWORD, password);
pbAttr.put(IPBE.SALT, salt);
pbAttr.put(IPBE.ITERATION_COUNT, ITERATION_COUNT);
IRandom kdf = PRNGFactory.getInstance("PBKDF2-HMAC-SHA");
kdf.init(pbAttr);
byte[] dk = new byte[keylen];
try {
kdf.nextBytes(dk, 0, keylen);
} catch (LimitReachedException shouldNotHappen) {
throw new Error(shouldNotHappen.toString());
}
HashMap macAttr = new HashMap();
macAttr.put(IMac.MAC_KEY_MATERIAL, dk);
macAttr.put(IMac.TRUNCATED_SIZE, new Integer(maclen));
try {
mac.init(macAttr);
} catch (InvalidKeyException shouldNotHappen) {
throw new Error(shouldNotHappen.toString());
}
return mac;
}
}