/* * Copyright (c) 1998, 2016, 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 javax.crypto; import java.util.*; import java.security.*; import java.security.Provider.Service; import java.security.spec.AlgorithmParameterSpec; import java.nio.ByteBuffer; import sun.security.util.Debug; import sun.security.jca.*; import sun.security.jca.GetInstance.Instance; /** * This class provides the functionality of a "Message Authentication Code" * (MAC) algorithm. * *
A MAC provides a way to check * the integrity of information transmitted over or stored in an unreliable * medium, based on a secret key. Typically, message * authentication codes are used between two parties that share a secret * key in order to validate information transmitted between these * parties. * *
A MAC mechanism that is based on cryptographic hash functions is * referred to as HMAC. HMAC can be used with any cryptographic hash function, * e.g., MD5 or SHA-1, in combination with a secret shared key. HMAC is * specified in RFC 2104. * *
Every implementation of the Java platform is required to support * the following standard {@code Mac} algorithms: *
This is the same name that was specified in one of the * {@code getInstance} calls that created this * {@code Mac} object. * * @return the algorithm name of this {@code Mac} object. */ public final String getAlgorithm() { return this.algorithm; } /** * Returns a {@code Mac} object that implements the * specified MAC algorithm. * *
This method traverses the list of registered security Providers, * starting with the most preferred Provider. * A new Mac object encapsulating the * MacSpi implementation from the first * Provider that supports the specified algorithm is returned. * *
Note that the list of registered providers may be retrieved via
* the {@link Security#getProviders() Security.getProviders()} method.
*
* @implNote
* The JDK Reference Implementation additionally uses the
* {@code jdk.security.provider.preferred}
* {@link Security#getProperty(String) Security} property to determine
* the preferred provider order for the specified algorithm. This
* may be different than the order of providers returned by
* {@link Security#getProviders() Security.getProviders()}.
*
* @param algorithm the standard name of the requested MAC algorithm.
* See the Mac section in the
* Java Cryptography Architecture Standard Algorithm Name Documentation
* for information about standard algorithm names.
*
* @return the new {@code Mac} object
*
* @throws NoSuchAlgorithmException if no {@code Provider} supports a
* {@code MacSpi} implementation for the specified algorithm
*
* @throws NullPointerException if {@code algorithm} is {@code null}
*
* @see java.security.Provider
*/
public static final Mac getInstance(String algorithm)
throws NoSuchAlgorithmException {
List A new Mac object encapsulating the
* MacSpi implementation from the specified provider
* is returned. The specified provider must be registered
* in the security provider list.
*
* Note that the list of registered providers may be retrieved via
* the {@link Security#getProviders() Security.getProviders()} method.
*
* @param algorithm the standard name of the requested MAC algorithm.
* See the Mac section in the
* Java Cryptography Architecture Standard Algorithm Name Documentation
* for information about standard algorithm names.
*
* @param provider the name of the provider.
*
* @return the new {@code Mac} object
*
* @throws IllegalArgumentException if the {@code provider}
* is {@code null} or empty
*
* @throws NoSuchAlgorithmException if a {@code MacSpi}
* implementation for the specified algorithm is not
* available from the specified provider
*
* @throws NoSuchProviderException if the specified provider is not
* registered in the security provider list
*
* @throws NullPointerException if {@code algorithm} is {@code null}
*
* @see java.security.Provider
*/
public static final Mac getInstance(String algorithm, String provider)
throws NoSuchAlgorithmException, NoSuchProviderException {
Instance instance = JceSecurity.getInstance
("Mac", MacSpi.class, algorithm, provider);
return new Mac((MacSpi)instance.impl, instance.provider, algorithm);
}
/**
* Returns a {@code Mac} object that implements the
* specified MAC algorithm.
*
* A new Mac object encapsulating the
* MacSpi implementation from the specified Provider
* object is returned. Note that the specified Provider object
* does not have to be registered in the provider list.
*
* @param algorithm the standard name of the requested MAC algorithm.
* See the Mac section in the
* Java Cryptography Architecture Standard Algorithm Name Documentation
* for information about standard algorithm names.
*
* @param provider the provider.
*
* @return the new {@code Mac} object
*
* @throws IllegalArgumentException if the {@code provider} is
* {@code null}
*
* @throws NoSuchAlgorithmException if a {@code MacSpi}
* implementation for the specified algorithm is not available
* from the specified {@code Provider} object
*
* @throws NullPointerException if {@code algorithm} is {@code null}
*
* @see java.security.Provider
*/
public static final Mac getInstance(String algorithm, Provider provider)
throws NoSuchAlgorithmException {
Instance instance = JceSecurity.getInstance
("Mac", MacSpi.class, algorithm, provider);
return new Mac((MacSpi)instance.impl, instance.provider, algorithm);
}
// max number of debug warnings to print from chooseFirstProvider()
private static int warnCount = 10;
/**
* Choose the Spi from the first provider available. Used if
* delayed provider selection is not possible because init()
* is not the first method called.
*/
void chooseFirstProvider() {
if ((spi != null) || (serviceIterator == null)) {
return;
}
synchronized (lock) {
if (spi != null) {
return;
}
if (debug != null) {
int w = --warnCount;
if (w >= 0) {
debug.println("Mac.init() not first method "
+ "called, disabling delayed provider selection");
if (w == 0) {
debug.println("Further warnings of this type will "
+ "be suppressed");
}
new Exception("Call trace").printStackTrace();
}
}
Exception lastException = null;
while ((firstService != null) || serviceIterator.hasNext()) {
Service s;
if (firstService != null) {
s = firstService;
firstService = null;
} else {
s = serviceIterator.next();
}
if (JceSecurity.canUseProvider(s.getProvider()) == false) {
continue;
}
try {
Object obj = s.newInstance(null);
if (obj instanceof MacSpi == false) {
continue;
}
spi = (MacSpi)obj;
provider = s.getProvider();
// not needed any more
firstService = null;
serviceIterator = null;
return;
} catch (NoSuchAlgorithmException e) {
lastException = e;
}
}
ProviderException e = new ProviderException
("Could not construct MacSpi instance");
if (lastException != null) {
e.initCause(lastException);
}
throw e;
}
}
private void chooseProvider(Key key, AlgorithmParameterSpec params)
throws InvalidKeyException, InvalidAlgorithmParameterException {
synchronized (lock) {
if (spi != null) {
spi.engineInit(key, params);
return;
}
Exception lastException = null;
while ((firstService != null) || serviceIterator.hasNext()) {
Service s;
if (firstService != null) {
s = firstService;
firstService = null;
} else {
s = serviceIterator.next();
}
// if provider says it does not support this key, ignore it
if (s.supportsParameter(key) == false) {
continue;
}
if (JceSecurity.canUseProvider(s.getProvider()) == false) {
continue;
}
try {
MacSpi spi = (MacSpi)s.newInstance(null);
spi.engineInit(key, params);
provider = s.getProvider();
this.spi = spi;
firstService = null;
serviceIterator = null;
return;
} catch (Exception e) {
// NoSuchAlgorithmException from newInstance()
// InvalidKeyException from init()
// RuntimeException (ProviderException) from init()
if (lastException == null) {
lastException = e;
}
}
}
// no working provider found, fail
if (lastException instanceof InvalidKeyException) {
throw (InvalidKeyException)lastException;
}
if (lastException instanceof InvalidAlgorithmParameterException) {
throw (InvalidAlgorithmParameterException)lastException;
}
if (lastException instanceof RuntimeException) {
throw (RuntimeException)lastException;
}
String kName = (key != null) ? key.getClass().getName() : "(null)";
throw new InvalidKeyException
("No installed provider supports this key: "
+ kName, lastException);
}
}
/**
* Returns the provider of this {@code Mac} object.
*
* @return the provider of this {@code Mac} object.
*/
public final Provider getProvider() {
chooseFirstProvider();
return this.provider;
}
/**
* Returns the length of the MAC in bytes.
*
* @return the MAC length in bytes.
*/
public final int getMacLength() {
chooseFirstProvider();
return spi.engineGetMacLength();
}
/**
* Initializes this {@code Mac} object with the given key.
*
* @param key the key.
*
* @exception InvalidKeyException if the given key is inappropriate for
* initializing this MAC.
*/
public final void init(Key key) throws InvalidKeyException {
try {
if (spi != null) {
spi.engineInit(key, null);
} else {
chooseProvider(key, null);
}
} catch (InvalidAlgorithmParameterException e) {
throw new InvalidKeyException("init() failed", e);
}
initialized = true;
if (!skipDebug && pdebug != null) {
pdebug.println("Mac." + algorithm + " algorithm from: " +
this.provider.getName());
}
}
/**
* Initializes this {@code Mac} object with the given key and
* algorithm parameters.
*
* @param key the key.
* @param params the algorithm parameters.
*
* @exception InvalidKeyException if the given key is inappropriate for
* initializing this MAC.
* @exception InvalidAlgorithmParameterException if the given algorithm
* parameters are inappropriate for this MAC.
*/
public final void init(Key key, AlgorithmParameterSpec params)
throws InvalidKeyException, InvalidAlgorithmParameterException {
if (spi != null) {
spi.engineInit(key, params);
} else {
chooseProvider(key, params);
}
initialized = true;
if (!skipDebug && pdebug != null) {
pdebug.println("Mac." + algorithm + " algorithm from: " +
this.provider.getName());
}
}
/**
* Processes the given byte.
*
* @param input the input byte to be processed.
*
* @exception IllegalStateException if this {@code Mac} has not been
* initialized.
*/
public final void update(byte input) throws IllegalStateException {
chooseFirstProvider();
if (initialized == false) {
throw new IllegalStateException("MAC not initialized");
}
spi.engineUpdate(input);
}
/**
* Processes the given array of bytes.
*
* @param input the array of bytes to be processed.
*
* @exception IllegalStateException if this {@code Mac} has not been
* initialized.
*/
public final void update(byte[] input) throws IllegalStateException {
chooseFirstProvider();
if (initialized == false) {
throw new IllegalStateException("MAC not initialized");
}
if (input != null) {
spi.engineUpdate(input, 0, input.length);
}
}
/**
* Processes the first {@code len} bytes in {@code input},
* starting at {@code offset} inclusive.
*
* @param input the input buffer.
* @param offset the offset in {@code input} where the input starts.
* @param len the number of bytes to process.
*
* @exception IllegalStateException if this {@code Mac} has not been
* initialized.
*/
public final void update(byte[] input, int offset, int len)
throws IllegalStateException {
chooseFirstProvider();
if (initialized == false) {
throw new IllegalStateException("MAC not initialized");
}
if (input != null) {
if ((offset < 0) || (len > (input.length - offset)) || (len < 0))
throw new IllegalArgumentException("Bad arguments");
spi.engineUpdate(input, offset, len);
}
}
/**
* Processes {@code input.remaining()} bytes in the ByteBuffer
* {@code input}, starting at {@code input.position()}.
* Upon return, the buffer's position will be equal to its limit;
* its limit will not have changed.
*
* @param input the ByteBuffer
*
* @exception IllegalStateException if this {@code Mac} has not been
* initialized.
* @since 1.5
*/
public final void update(ByteBuffer input) {
chooseFirstProvider();
if (initialized == false) {
throw new IllegalStateException("MAC not initialized");
}
if (input == null) {
throw new IllegalArgumentException("Buffer must not be null");
}
spi.engineUpdate(input);
}
/**
* Finishes the MAC operation.
*
* A call to this method resets this {@code Mac} object to the
* state it was in when previously initialized via a call to
* {@code init(Key)} or
* {@code init(Key, AlgorithmParameterSpec)}.
* That is, the object is reset and available to generate another MAC from
* the same key, if desired, via new calls to {@code update} and
* {@code doFinal}.
* (In order to reuse this {@code Mac} object with a different key,
* it must be reinitialized via a call to {@code init(Key)} or
* {@code init(Key, AlgorithmParameterSpec)}.
*
* @return the MAC result.
*
* @exception IllegalStateException if this {@code Mac} has not been
* initialized.
*/
public final byte[] doFinal() throws IllegalStateException {
chooseFirstProvider();
if (initialized == false) {
throw new IllegalStateException("MAC not initialized");
}
byte[] mac = spi.engineDoFinal();
spi.engineReset();
return mac;
}
/**
* Finishes the MAC operation.
*
* A call to this method resets this {@code Mac} object to the
* state it was in when previously initialized via a call to
* {@code init(Key)} or
* {@code init(Key, AlgorithmParameterSpec)}.
* That is, the object is reset and available to generate another MAC from
* the same key, if desired, via new calls to {@code update} and
* {@code doFinal}.
* (In order to reuse this {@code Mac} object with a different key,
* it must be reinitialized via a call to {@code init(Key)} or
* {@code init(Key, AlgorithmParameterSpec)}.
*
* The MAC result is stored in {@code output}, starting at
* {@code outOffset} inclusive.
*
* @param output the buffer where the MAC result is stored
* @param outOffset the offset in {@code output} where the MAC is
* stored
*
* @exception ShortBufferException if the given output buffer is too small
* to hold the result
* @exception IllegalStateException if this {@code Mac} has not been
* initialized.
*/
public final void doFinal(byte[] output, int outOffset)
throws ShortBufferException, IllegalStateException
{
chooseFirstProvider();
if (initialized == false) {
throw new IllegalStateException("MAC not initialized");
}
int macLen = getMacLength();
if (output == null || output.length-outOffset < macLen) {
throw new ShortBufferException
("Cannot store MAC in output buffer");
}
byte[] mac = doFinal();
System.arraycopy(mac, 0, output, outOffset, macLen);
return;
}
/**
* Processes the given array of bytes and finishes the MAC operation.
*
* A call to this method resets this {@code Mac} object to the
* state it was in when previously initialized via a call to
* {@code init(Key)} or
* {@code init(Key, AlgorithmParameterSpec)}.
* That is, the object is reset and available to generate another MAC from
* the same key, if desired, via new calls to {@code update} and
* {@code doFinal}.
* (In order to reuse this {@code Mac} object with a different key,
* it must be reinitialized via a call to {@code init(Key)} or
* {@code init(Key, AlgorithmParameterSpec)}.
*
* @param input data in bytes
* @return the MAC result.
*
* @exception IllegalStateException if this {@code Mac} has not been
* initialized.
*/
public final byte[] doFinal(byte[] input) throws IllegalStateException
{
chooseFirstProvider();
if (initialized == false) {
throw new IllegalStateException("MAC not initialized");
}
update(input);
return doFinal();
}
/**
* Resets this {@code Mac} object.
*
* A call to this method resets this {@code Mac} object to the
* state it was in when previously initialized via a call to
* {@code init(Key)} or
* {@code init(Key, AlgorithmParameterSpec)}.
* That is, the object is reset and available to generate another MAC from
* the same key, if desired, via new calls to {@code update} and
* {@code doFinal}.
* (In order to reuse this {@code Mac} object with a different key,
* it must be reinitialized via a call to {@code init(Key)} or
* {@code init(Key, AlgorithmParameterSpec)}.
*/
public final void reset() {
chooseFirstProvider();
spi.engineReset();
}
/**
* Returns a clone if the provider implementation is cloneable.
*
* @return a clone if the provider implementation is cloneable.
*
* @exception CloneNotSupportedException if this is called on a
* delegate that does not support {@code Cloneable}.
*/
public final Object clone() throws CloneNotSupportedException {
chooseFirstProvider();
Mac that = (Mac)super.clone();
that.spi = (MacSpi)this.spi.clone();
return that;
}
}