/*
* Copyright (c) 2012, 2013, 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.
*
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package sun.security.util;
import java.security.Key;
import java.security.PrivilegedAction;
import java.security.AccessController;
import java.security.InvalidKeyException;
import java.security.interfaces.ECKey;
import java.security.interfaces.RSAKey;
import java.security.interfaces.DSAKey;
import java.security.spec.KeySpec;
import javax.crypto.SecretKey;
import javax.crypto.interfaces.DHKey;
import javax.crypto.interfaces.DHPublicKey;
import javax.crypto.spec.DHParameterSpec;
import javax.crypto.spec.DHPublicKeySpec;
import java.math.BigInteger;
/**
* A utility class to get key length, valiate keys, etc.
*/
public final class KeyUtil {
/**
* 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
*/
public static final 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;
}
/**
* Returns whether the key is valid or not.
* <P>
* Note that this method is only apply to DHPublicKey at present.
*
* @param publicKey
* the key object, cannot be null
*
* @throws NullPointerException if {@code publicKey} is null
* @throws InvalidKeyException if {@code publicKey} is invalid
*/
public static final void validate(Key key)
throws InvalidKeyException {
if (key == null) {
throw new NullPointerException(
"The key to be validated cannot be null");
}
if (key instanceof DHPublicKey) {
validateDHPublicKey((DHPublicKey)key);
}
}
/**
* Returns whether the key spec is valid or not.
* <P>
* Note that this method is only apply to DHPublicKeySpec at present.
*
* @param keySpec
* the key spec object, cannot be null
*
* @throws NullPointerException if {@code keySpec} is null
* @throws InvalidKeyException if {@code keySpec} is invalid
*/
public static final void validate(KeySpec keySpec)
throws InvalidKeyException {
if (keySpec == null) {
throw new NullPointerException(
"The key spec to be validated cannot be null");
}
if (keySpec instanceof DHPublicKeySpec) {
validateDHPublicKey((DHPublicKeySpec)keySpec);
}
}
/**
* Returns whether the specified provider is Oracle provider or not.
* <P>
* Note that this method is only apply to SunJCE and SunPKCS11 at present.
*
* @param providerName
* the provider name
* @return true if, and only if, the provider of the specified
* {@code providerName} is Oracle provider
*/
public static final boolean isOracleJCEProvider(String providerName) {
return providerName != null && (providerName.equals("SunJCE") ||
providerName.startsWith("SunPKCS11"));
}
/**
* Returns whether the Diffie-Hellman public key is valid or not.
*
* Per RFC 2631 and NIST SP800-56A, the following algorithm is used to
* validate Diffie-Hellman public keys:
* 1. Verify that y lies within the interval [2,p-1]. If it does not,
* the key is invalid.
* 2. Compute y^q mod p. If the result == 1, the key is valid.
* Otherwise the key is invalid.
*/
private static void validateDHPublicKey(DHPublicKey publicKey)
throws InvalidKeyException {
DHParameterSpec paramSpec = publicKey.getParams();
BigInteger p = paramSpec.getP();
BigInteger g = paramSpec.getG();
BigInteger y = publicKey.getY();
validateDHPublicKey(p, g, y);
}
private static void validateDHPublicKey(DHPublicKeySpec publicKeySpec)
throws InvalidKeyException {
validateDHPublicKey(publicKeySpec.getP(),
publicKeySpec.getG(), publicKeySpec.getY());
}
private static void validateDHPublicKey(BigInteger p,
BigInteger g, BigInteger y) throws InvalidKeyException {
// For better interoperability, the interval is limited to [2, p-2].
BigInteger leftOpen = BigInteger.ONE;
BigInteger rightOpen = p.subtract(BigInteger.ONE);
if (y.compareTo(leftOpen) <= 0) {
throw new InvalidKeyException(
"Diffie-Hellman public key is too small");
}
if (y.compareTo(rightOpen) >= 0) {
throw new InvalidKeyException(
"Diffie-Hellman public key is too large");
}
// Don't bother to check against the y^q mod p if safe primes are used.
}
/**
* Trim leading (most significant) zeroes from the result.
*
* @throws NullPointerException if {@code b} is null
*/
public static byte[] trimZeroes(byte[] b) {
int i = 0;
while ((i < b.length - 1) && (b[i] == 0)) {
i++;
}
if (i == 0) {
return b;
}
byte[] t = new byte[b.length - i];
System.arraycopy(b, i, t, 0, t.length);
return t;
}
}