/*
* Copyright (c) 2012, 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 sun.security.util;
import java.security.Key;
import java.security.PrivilegedAction;
import java.security.AccessController;
import java.security.interfaces.ECKey;
import java.security.interfaces.RSAKey;
import java.security.interfaces.DSAKey;
import javax.crypto.SecretKey;
import javax.crypto.interfaces.DHKey;
/**
* A utility class to get key length
*/
public final class KeyLength {
/**
* Returns the key size of the given key object in bits.
*
* @param key the key object, cannot be null
* @return the key size of the given key object in bits, or -1 if the
* key size is not accessible
*/
final public static int getKeySize(Key key) {
int size = -1;
if (key instanceof Length) {
try {
Length ruler = (Length)key;
size = ruler.length();
} catch (UnsupportedOperationException usoe) {
// ignore the exception
}
if (size >= 0) {
return size;
}
}
// try to parse the length from key specification
if (key instanceof SecretKey) {
SecretKey sk = (SecretKey)key;
String format = sk.getFormat();
if ("RAW".equals(format) && sk.getEncoded() != null) {
size = (sk.getEncoded().length * 8);
} // Otherwise, it may be a unextractable key of PKCS#11, or
// a key we are not able to handle.
} else if (key instanceof RSAKey) {
RSAKey pubk = (RSAKey)key;
size = pubk.getModulus().bitLength();
} else if (key instanceof ECKey) {
ECKey pubk = (ECKey)key;
size = pubk.getParams().getOrder().bitLength();
} else if (key instanceof DSAKey) {
DSAKey pubk = (DSAKey)key;
size = pubk.getParams().getP().bitLength();
} else if (key instanceof DHKey) {
DHKey pubk = (DHKey)key;
size = pubk.getParams().getP().bitLength();
} // Otherwise, it may be a unextractable key of PKCS#11, or
// a key we are not able to handle.
return size;
}
}