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Java example source code file (KeyUtil.java)
The KeyUtil.java Java example source code/* * 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. * * 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.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; } } Other Java examples (source code examples)Here is a short list of links related to this Java KeyUtil.java source code file: |
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