/*
* Copyright (c) 1997, 2007, 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,
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*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package javax.crypto;
import java.util.*;
import java.util.regex.*;
import static java.util.Locale.ENGLISH;
import java.security.*;
import java.security.Provider.Service;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.InvalidParameterSpecException;
import java.security.cert.Certificate;
import java.security.cert.X509Certificate;
import javax.crypto.spec.*;
import java.nio.ByteBuffer;
import java.nio.ReadOnlyBufferException;
import sun.security.util.Debug;
import sun.security.jca.*;
import sun.security.jca.GetInstance.Instance;
/**
* This class provides the functionality of a cryptographic cipher for
* encryption and decryption. It forms the core of the Java Cryptographic
* Extension (JCE) framework.
*
* <p>In order to create a Cipher object, the application calls the
* Cipher's <code>getInstance</code> method, and passes the name of the
* requested <i>transformation</i> to it. Optionally, the name of a provider
* may be specified.
*
* <p>A <i>transformation</i> is a string that describes the operation (or
* set of operations) to be performed on the given input, to produce some
* output. A transformation always includes the name of a cryptographic
* algorithm (e.g., <i>DES</i>), and may be followed by a feedback mode and
* padding scheme.
*
* <p> A transformation is of the form:<p>
*
* <ul>
* <li>"<i>algorithm/mode/padding</i>" or
* <p>
* <li>"<i>algorithm</i>"
* </ul>
*
* <P> (in the latter case,
* provider-specific default values for the mode and padding scheme are used).
* For example, the following is a valid transformation:<p>
*
* <pre>
* Cipher c = Cipher.getInstance("<i>DES/CBC/PKCS5Padding</i>");
* </pre>
*
* Using modes such as <code>CFB</code> and <code>OFB<code>, block
* ciphers can encrypt data in units smaller than the cipher's actual
* block size. When requesting such a mode, you may optionally specify
* the number of bits to be processed at a time by appending this number
* to the mode name as shown in the "<code>DES/CFB8/NoPadding</code>" and
* "<code>DES/OFB32/PKCS5Padding</code>" transformations. If no such
* number is specified, a provider-specific default is used. (For
* example, the SunJCE provider uses a default of 64 bits for DES.)
* Thus, block ciphers can be turned into byte-oriented stream ciphers by
* using an 8 bit mode such as CFB8 or OFB8.
*
* @author Jan Luehe
* @see KeyGenerator
* @see SecretKey
* @since 1.4
*/
public class Cipher {
private static final Debug debug =
Debug.getInstance("jca", "Cipher");
/**
* Constant used to initialize cipher to encryption mode.
*/
public static final int ENCRYPT_MODE = 1;
/**
* Constant used to initialize cipher to decryption mode.
*/
public static final int DECRYPT_MODE = 2;
/**
* Constant used to initialize cipher to key-wrapping mode.
*/
public static final int WRAP_MODE = 3;
/**
* Constant used to initialize cipher to key-unwrapping mode.
*/
public static final int UNWRAP_MODE = 4;
/**
* Constant used to indicate the to-be-unwrapped key is a "public key".
*/
public static final int PUBLIC_KEY = 1;
/**
* Constant used to indicate the to-be-unwrapped key is a "private key".
*/
public static final int PRIVATE_KEY = 2;
/**
* Constant used to indicate the to-be-unwrapped key is a "secret key".
*/
public static final int SECRET_KEY = 3;
// The provider
private Provider provider;
// The provider implementation (delegate)
private CipherSpi spi;
// The transformation
private String transformation;
// Crypto permission representing the maximum allowable cryptographic
// strength that this Cipher object can be used for. (The cryptographic
// strength is a function of the keysize and algorithm parameters encoded
// in the crypto permission.)
private CryptoPermission cryptoPerm;
// The exemption mechanism that needs to be enforced
private ExemptionMechanism exmech;
// Flag which indicates whether or not this cipher has been initialized
private boolean initialized = false;
// The operation mode - store the operation mode after the
// cipher has been initialized.
private int opmode = 0;
// The OID for the KeyUsage extension in an X.509 v3 certificate
private static final String KEY_USAGE_EXTENSION_OID = "2.5.29.15";
// next SPI to try in provider selection
// null once provider is selected
private CipherSpi firstSpi;
// next service to try in provider selection
// null once provider is selected
private Service firstService;
// remaining services to try in provider selection
// null once provider is selected
private Iterator serviceIterator;
// list of transform Strings to lookup in the provider
private List transforms;
private final Object lock;
/**
* Creates a Cipher object.
*
* @param cipherSpi the delegate
* @param provider the provider
* @param transformation the transformation
*/
protected Cipher(CipherSpi cipherSpi,
Provider provider,
String transformation) {
// See bug 4341369 & 4334690 for more info.
// If the caller is trusted, then okey.
// Otherwise throw a NullPointerException.
if (!JceSecurityManager.INSTANCE.isCallerTrusted()) {
throw new NullPointerException();
}
this.spi = cipherSpi;
this.provider = provider;
this.transformation = transformation;
this.cryptoPerm = CryptoAllPermission.INSTANCE;
this.lock = null;
}
/**
* Creates a Cipher object. Called internally and by NullCipher.
*
* @param cipherSpi the delegate
* @param transformation the transformation
*/
Cipher(CipherSpi cipherSpi, String transformation) {
this.spi = cipherSpi;
this.transformation = transformation;
this.cryptoPerm = CryptoAllPermission.INSTANCE;
this.lock = null;
}
private Cipher(CipherSpi firstSpi, Service firstService,
Iterator serviceIterator, String transformation, List transforms) {
this.firstSpi = firstSpi;
this.firstService = firstService;
this.serviceIterator = serviceIterator;
this.transforms = transforms;
this.transformation = transformation;
this.lock = new Object();
}
private static String[] tokenizeTransformation(String transformation)
throws NoSuchAlgorithmException {
if (transformation == null) {
throw new NoSuchAlgorithmException("No transformation given");
}
/*
* array containing the components of a Cipher transformation:
*
* index 0: algorithm component (e.g., DES)
* index 1: feedback component (e.g., CFB)
* index 2: padding component (e.g., PKCS5Padding)
*/
String[] parts = new String[3];
int count = 0;
StringTokenizer parser = new StringTokenizer(transformation, "/");
try {
while (parser.hasMoreTokens() && count < 3) {
parts[count++] = parser.nextToken().trim();
}
if (count == 0 || count == 2 || parser.hasMoreTokens()) {
throw new NoSuchAlgorithmException("Invalid transformation"
+ " format:" +
transformation);
}
} catch (NoSuchElementException e) {
throw new NoSuchAlgorithmException("Invalid transformation " +
"format:" + transformation);
}
if ((parts[0] == null) || (parts[0].length() == 0)) {
throw new NoSuchAlgorithmException("Invalid transformation:" +
"algorithm not specified-"
+ transformation);
}
return parts;
}
// Provider attribute name for supported chaining mode
private final static String ATTR_MODE = "SupportedModes";
// Provider attribute name for supported padding names
private final static String ATTR_PAD = "SupportedPaddings";
// constants indicating whether the provider supports
// a given mode or padding
private final static int S_NO = 0; // does not support
private final static int S_MAYBE = 1; // unable to determine
private final static int S_YES = 2; // does support
/**
* Nested class to deal with modes and paddings.
*/
private static class Transform {
// transform string to lookup in the provider
final String transform;
// the mode/padding suffix in upper case. for example, if the algorithm
// to lookup is "DES/CBC/PKCS5Padding" suffix is "/CBC/PKCS5PADDING"
// if loopup is "DES", suffix is the empty string
// needed because aliases prevent straight transform.equals()
final String suffix;
// value to pass to setMode() or null if no such call required
final String mode;
// value to pass to setPadding() or null if no such call required
final String pad;
Transform(String alg, String suffix, String mode, String pad) {
this.transform = alg + suffix;
this.suffix = suffix.toUpperCase(Locale.ENGLISH);
this.mode = mode;
this.pad = pad;
}
// set mode and padding for the given SPI
void setModePadding(CipherSpi spi) throws NoSuchAlgorithmException,
NoSuchPaddingException {
if (mode != null) {
spi.engineSetMode(mode);
}
if (pad != null) {
spi.engineSetPadding(pad);
}
}
// check whether the given services supports the mode and
// padding described by this Transform
int supportsModePadding(Service s) {
int smode = supportsMode(s);
if (smode == S_NO) {
return smode;
}
int spad = supportsPadding(s);
// our constants are defined so that Math.min() is a tri-valued AND
return Math.min(smode, spad);
}
// separate methods for mode and padding
// called directly by Cipher only to throw the correct exception
int supportsMode(Service s) {
return supports(s, ATTR_MODE, mode);
}
int supportsPadding(Service s) {
return supports(s, ATTR_PAD, pad);
}
private static int supports(Service s, String attrName, String value) {
if (value == null) {
return S_YES;
}
String regexp = s.getAttribute(attrName);
if (regexp == null) {
return S_MAYBE;
}
return matches(regexp, value) ? S_YES : S_NO;
}
// Map<String,Pattern> for previously compiled patterns
// XXX use ConcurrentHashMap once available
private final static Map patternCache =
Collections.synchronizedMap(new HashMap());
private static boolean matches(String regexp, String str) {
Pattern pattern = (Pattern)patternCache.get(regexp);
if (pattern == null) {
pattern = Pattern.compile(regexp);
patternCache.put(regexp, pattern);
}
return pattern.matcher(str.toUpperCase(Locale.ENGLISH)).matches();
}
}
private static List getTransforms(String transformation)
throws NoSuchAlgorithmException {
String[] parts = tokenizeTransformation(transformation);
String alg = parts[0];
String mode = parts[1];
String pad = parts[2];
if ((mode != null) && (mode.length() == 0)) {
mode = null;
}
if ((pad != null) && (pad.length() == 0)) {
pad = null;
}
if ((mode == null) && (pad == null)) {
// DES
Transform tr = new Transform(alg, "", null, null);
return Collections.singletonList(tr);
} else { // if ((mode != null) && (pad != null)) {
// DES/CBC/PKCS5Padding
List list = new ArrayList(4);
list.add(new Transform(alg, "/" + mode + "/" + pad, null, null));
list.add(new Transform(alg, "/" + mode, null, pad));
list.add(new Transform(alg, "//" + pad, mode, null));
list.add(new Transform(alg, "", mode, pad));
return list;
}
}
// get the transform matching the specified service
private static Transform getTransform(Service s, List transforms) {
String alg = s.getAlgorithm().toUpperCase(Locale.ENGLISH);
for (Iterator t = transforms.iterator(); t.hasNext(); ) {
Transform tr = (Transform)t.next();
if (alg.endsWith(tr.suffix)) {
return tr;
}
}
return null;
}
/**
* Returns a <code>Cipher</code> object that implements the specified
* transformation.
*
* <p> This method traverses the list of registered security Providers,
* starting with the most preferred Provider.
* A new Cipher object encapsulating the
* CipherSpi implementation from the first
* Provider that supports the specified algorithm is returned.
*
* <p> Note that the list of registered providers may be retrieved via
* the {@link Security#getProviders() Security.getProviders()} method.
*
* @param transformation the name of the transformation, e.g.,
* <i>DES/CBC/PKCS5Padding</i>.
* See Appendix A in the
* <a href=
* "{@docRoot}/../technotes/guides/security/crypto/CryptoSpec.html#AppA">
* Java Cryptography Architecture Reference Guide</a>
* for information about standard transformation names.
*
* @return a cipher that implements the requested transformation.
*
* @exception NoSuchAlgorithmException if <code>transformation</code>
* is null, empty, in an invalid format,
* or if no Provider supports a CipherSpi implementation for the
* specified algorithm.
*
* @exception NoSuchPaddingException if <code>transformation</code>
* contains a padding scheme that is not available.
*
* @see java.security.Provider
*/
public static final Cipher getInstance(String transformation)
throws NoSuchAlgorithmException, NoSuchPaddingException
{
List transforms = getTransforms(transformation);
List cipherServices = new ArrayList(transforms.size());
for (Iterator t = transforms.iterator(); t.hasNext(); ) {
Transform transform = (Transform)t.next();
cipherServices.add(new ServiceId("Cipher", transform.transform));
}
List services = GetInstance.getServices(cipherServices);
// make sure there is at least one service from a signed provider
// and that it can use the specified mode and padding
Iterator t = services.iterator();
Exception failure = null;
while (t.hasNext()) {
Service s = (Service)t.next();
if (JceSecurity.canUseProvider(s.getProvider()) == false) {
continue;
}
Transform tr = getTransform(s, transforms);
if (tr == null) {
// should never happen
continue;
}
int canuse = tr.supportsModePadding(s);
if (canuse == S_NO) {
// does not support mode or padding we need, ignore
continue;
}
if (canuse == S_YES) {
return new Cipher(null, s, t, transformation, transforms);
} else { // S_MAYBE, try out if it works
try {
CipherSpi spi = (CipherSpi)s.newInstance(null);
tr.setModePadding(spi);
return new Cipher(spi, s, t, transformation, transforms);
} catch (Exception e) {
failure = e;
}
}
}
throw new NoSuchAlgorithmException
("Cannot find any provider supporting " + transformation, failure);
}
/**
* Returns a <code>Cipher</code> object that implements the specified
* transformation.
*
* <p> A new Cipher object encapsulating the
* CipherSpi implementation from the specified provider
* is returned. The specified provider must be registered
* in the security provider list.
*
* <p> Note that the list of registered providers may be retrieved via
* the {@link Security#getProviders() Security.getProviders()} method.
*
* @param transformation the name of the transformation,
* e.g., <i>DES/CBC/PKCS5Padding</i>.
* See Appendix A in the
* <a href=
* "{@docRoot}/../technotes/guides/security/crypto/CryptoSpec.html#AppA">
* Java Cryptography Architecture Reference Guide</a>
* for information about standard transformation names.
*
* @param provider the name of the provider.
*
* @return a cipher that implements the requested transformation.
*
* @exception NoSuchAlgorithmException if <code>transformation</code>
* is null, empty, in an invalid format,
* or if a CipherSpi implementation for the specified algorithm
* is not available from the specified provider.
*
* @exception NoSuchProviderException if the specified provider is not
* registered in the security provider list.
*
* @exception NoSuchPaddingException if <code>transformation</code>
* contains a padding scheme that is not available.
*
* @exception IllegalArgumentException if the <code>provider</code>
* is null or empty.
*
* @see java.security.Provider
*/
public static final Cipher getInstance(String transformation,
String provider)
throws NoSuchAlgorithmException, NoSuchProviderException,
NoSuchPaddingException
{
if ((provider == null) || (provider.length() == 0)) {
throw new IllegalArgumentException("Missing provider");
}
Provider p = Security.getProvider(provider);
if (p == null) {
throw new NoSuchProviderException("No such provider: " +
provider);
}
return getInstance(transformation, p);
}
/**
* Returns a <code>Cipher</code> object that implements the specified
* transformation.
*
* <p> A new Cipher object encapsulating the
* CipherSpi 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 transformation the name of the transformation,
* e.g., <i>DES/CBC/PKCS5Padding</i>.
* See Appendix A in the
* <a href=
* "{@docRoot}/../technotes/guides/security/crypto/CryptoSpec.html#AppA">
* Java Cryptography Architecture Reference Guide</a>
* for information about standard transformation names.
*
* @param provider the provider.
*
* @return a cipher that implements the requested transformation.
*
* @exception NoSuchAlgorithmException if <code>transformation</code>
* is null, empty, in an invalid format,
* or if a CipherSpi implementation for the specified algorithm
* is not available from the specified Provider object.
*
* @exception NoSuchPaddingException if <code>transformation</code>
* contains a padding scheme that is not available.
*
* @exception IllegalArgumentException if the <code>provider</code>
* is null.
*
* @see java.security.Provider
*/
public static final Cipher getInstance(String transformation,
Provider provider)
throws NoSuchAlgorithmException, NoSuchPaddingException
{
if (provider == null) {
throw new IllegalArgumentException("Missing provider");
}
Exception failure = null;
List transforms = getTransforms(transformation);
boolean providerChecked = false;
String paddingError = null;
for (Iterator t = transforms.iterator(); t.hasNext();) {
Transform tr = (Transform)t.next();
Service s = provider.getService("Cipher", tr.transform);
if (s == null) {
continue;
}
if (providerChecked == false) {
// for compatibility, first do the lookup and then verify
// the provider. this makes the difference between a NSAE
// and a SecurityException if the
// provider does not support the algorithm.
Exception ve = JceSecurity.getVerificationResult(provider);
if (ve != null) {
String msg = "JCE cannot authenticate the provider "
+ provider.getName();
throw new SecurityException(msg, ve);
}
providerChecked = true;
}
if (tr.supportsMode(s) == S_NO) {
continue;
}
if (tr.supportsPadding(s) == S_NO) {
paddingError = tr.pad;
continue;
}
try {
CipherSpi spi = (CipherSpi)s.newInstance(null);
tr.setModePadding(spi);
Cipher cipher = new Cipher(spi, transformation);
cipher.provider = s.getProvider();
cipher.initCryptoPermission();
return cipher;
} catch (Exception e) {
failure = e;
}
}
// throw NoSuchPaddingException if the problem is with padding
if (failure instanceof NoSuchPaddingException) {
throw (NoSuchPaddingException)failure;
}
if (paddingError != null) {
throw new NoSuchPaddingException
("Padding not supported: " + paddingError);
}
throw new NoSuchAlgorithmException
("No such algorithm: " + transformation, failure);
}
// If the requested crypto service is export-controlled,
// determine the maximum allowable keysize.
private void initCryptoPermission() throws NoSuchAlgorithmException {
if (JceSecurity.isRestricted() == false) {
cryptoPerm = CryptoAllPermission.INSTANCE;
exmech = null;
return;
}
cryptoPerm = getConfiguredPermission(transformation);
// Instantiate the exemption mechanism (if required)
String exmechName = cryptoPerm.getExemptionMechanism();
if (exmechName != null) {
exmech = ExemptionMechanism.getInstance(exmechName);
}
}
// 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) {
return;
}
synchronized (lock) {
if (spi != null) {
return;
}
if (debug != null) {
int w = --warnCount;
if (w >= 0) {
debug.println("Cipher.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;
CipherSpi thisSpi;
if (firstService != null) {
s = firstService;
thisSpi = firstSpi;
firstService = null;
firstSpi = null;
} else {
s = (Service)serviceIterator.next();
thisSpi = null;
}
if (JceSecurity.canUseProvider(s.getProvider()) == false) {
continue;
}
Transform tr = getTransform(s, transforms);
if (tr == null) {
// should never happen
continue;
}
if (tr.supportsModePadding(s) == S_NO) {
continue;
}
try {
if (thisSpi == null) {
Object obj = s.newInstance(null);
if (obj instanceof CipherSpi == false) {
continue;
}
thisSpi = (CipherSpi)obj;
}
tr.setModePadding(thisSpi);
initCryptoPermission();
spi = thisSpi;
provider = s.getProvider();
// not needed any more
firstService = null;
serviceIterator = null;
transforms = null;
return;
} catch (Exception e) {
lastException = e;
}
}
ProviderException e = new ProviderException
("Could not construct CipherSpi instance");
if (lastException != null) {
e.initCause(lastException);
}
throw e;
}
}
private final static int I_KEY = 1;
private final static int I_PARAMSPEC = 2;
private final static int I_PARAMS = 3;
private final static int I_CERT = 4;
private void implInit(CipherSpi thisSpi, int type, int opmode, Key key,
AlgorithmParameterSpec paramSpec, AlgorithmParameters params,
SecureRandom random) throws InvalidKeyException,
InvalidAlgorithmParameterException {
switch (type) {
case I_KEY:
checkCryptoPerm(thisSpi, key);
thisSpi.engineInit(opmode, key, random);
break;
case I_PARAMSPEC:
checkCryptoPerm(thisSpi, key, paramSpec);
thisSpi.engineInit(opmode, key, paramSpec, random);
break;
case I_PARAMS:
checkCryptoPerm(thisSpi, key, params);
thisSpi.engineInit(opmode, key, params, random);
break;
case I_CERT:
checkCryptoPerm(thisSpi, key);
thisSpi.engineInit(opmode, key, random);
break;
default:
throw new AssertionError("Internal Cipher error: " + type);
}
}
private void chooseProvider(int initType, int opmode, Key key,
AlgorithmParameterSpec paramSpec,
AlgorithmParameters params, SecureRandom random)
throws InvalidKeyException, InvalidAlgorithmParameterException {
synchronized (lock) {
if (spi != null) {
implInit(spi, initType, opmode, key, paramSpec, params, random);
return;
}
Exception lastException = null;
while ((firstService != null) || serviceIterator.hasNext()) {
Service s;
CipherSpi thisSpi;
if (firstService != null) {
s = firstService;
thisSpi = firstSpi;
firstService = null;
firstSpi = null;
} else {
s = (Service)serviceIterator.next();
thisSpi = null;
}
// if provider says it does not support this key, ignore it
if (s.supportsParameter(key) == false) {
continue;
}
if (JceSecurity.canUseProvider(s.getProvider()) == false) {
continue;
}
Transform tr = getTransform(s, transforms);
if (tr == null) {
// should never happen
continue;
}
if (tr.supportsModePadding(s) == S_NO) {
continue;
}
try {
if (thisSpi == null) {
thisSpi = (CipherSpi)s.newInstance(null);
}
tr.setModePadding(thisSpi);
initCryptoPermission();
implInit(thisSpi, initType, opmode, key, paramSpec,
params, random);
provider = s.getProvider();
this.spi = thisSpi;
firstService = null;
serviceIterator = null;
transforms = null;
return;
} catch (Exception e) {
// NoSuchAlgorithmException from newInstance()
// InvalidKeyException from init()
// RuntimeException (ProviderException) from init()
// SecurityException from crypto permission check
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>Cipher</code> object.
*
* @return the provider of this <code>Cipher</code> object
*/
public final Provider getProvider() {
chooseFirstProvider();
return this.provider;
}
/**
* Returns the algorithm name of this <code>Cipher</code> object.
*
* <p>This is the same name that was specified in one of the
* <code>getInstance</code> calls that created this <code>Cipher</code>
* object..
*
* @return the algorithm name of this <code>Cipher</code> object.
*/
public final String getAlgorithm() {
return this.transformation;
}
/**
* Returns the block size (in bytes).
*
* @return the block size (in bytes), or 0 if the underlying algorithm is
* not a block cipher
*/
public final int getBlockSize() {
chooseFirstProvider();
return spi.engineGetBlockSize();
}
/**
* Returns the length in bytes that an output buffer would need to be in
* order to hold the result of the next <code>update</code> or
* <code>doFinal</code> operation, given the input length
* <code>inputLen</code> (in bytes).
*
* <p>This call takes into account any unprocessed (buffered) data from a
* previous <code>update</code> call, and padding.
*
* <p>The actual output length of the next <code>update</code> or
* <code>doFinal</code> call may be smaller than the length returned by
* this method.
*
* @param inputLen the input length (in bytes)
*
* @return the required output buffer size (in bytes)
*
* @exception IllegalStateException if this cipher is in a wrong state
* (e.g., has not yet been initialized)
*/
public final int getOutputSize(int inputLen) {
if (!initialized && !(this instanceof NullCipher)) {
throw new IllegalStateException("Cipher not initialized");
}
if (inputLen < 0) {
throw new IllegalArgumentException("Input size must be equal " +
"to or greater than zero");
}
chooseFirstProvider();
return spi.engineGetOutputSize(inputLen);
}
/**
* Returns the initialization vector (IV) in a new buffer.
*
* <p>This is useful in the case where a random IV was created,
* or in the context of password-based encryption or
* decryption, where the IV is derived from a user-supplied password.
*
* @return the initialization vector in a new buffer, or null if the
* underlying algorithm does not use an IV, or if the IV has not yet
* been set.
*/
public final byte[] getIV() {
chooseFirstProvider();
return spi.engineGetIV();
}
/**
* Returns the parameters used with this cipher.
*
* <p>The returned parameters may be the same that were used to initialize
* this cipher, or may contain a combination of default and random
* parameter values used by the underlying cipher implementation if this
* cipher requires algorithm parameters but was not initialized with any.
*
* @return the parameters used with this cipher, or null if this cipher
* does not use any parameters.
*/
public final AlgorithmParameters getParameters() {
chooseFirstProvider();
return spi.engineGetParameters();
}
/**
* Returns the exemption mechanism object used with this cipher.
*
* @return the exemption mechanism object used with this cipher, or
* null if this cipher does not use any exemption mechanism.
*/
public final ExemptionMechanism getExemptionMechanism() {
chooseFirstProvider();
return exmech;
}
//
// Crypto permission check code below
//
private void checkCryptoPerm(CipherSpi checkSpi, Key key)
throws InvalidKeyException {
if (cryptoPerm == CryptoAllPermission.INSTANCE) {
return;
}
// Check if key size and default parameters are within legal limits
AlgorithmParameterSpec params;
try {
params = getAlgorithmParameterSpec(checkSpi.engineGetParameters());
} catch (InvalidParameterSpecException ipse) {
throw new InvalidKeyException
("Unsupported default algorithm parameters");
}
if (!passCryptoPermCheck(checkSpi, key, params)) {
throw new InvalidKeyException(
"Illegal key size or default parameters");
}
}
private void checkCryptoPerm(CipherSpi checkSpi, Key key,
AlgorithmParameterSpec params) throws InvalidKeyException,
InvalidAlgorithmParameterException {
if (cryptoPerm == CryptoAllPermission.INSTANCE) {
return;
}
// Determine keysize and check if it is within legal limits
if (!passCryptoPermCheck(checkSpi, key, null)) {
throw new InvalidKeyException("Illegal key size");
}
if ((params != null) && (!passCryptoPermCheck(checkSpi, key, params))) {
throw new InvalidAlgorithmParameterException("Illegal parameters");
}
}
private void checkCryptoPerm(CipherSpi checkSpi, Key key,
AlgorithmParameters params)
throws InvalidKeyException, InvalidAlgorithmParameterException {
if (cryptoPerm == CryptoAllPermission.INSTANCE) {
return;
}
// Convert the specified parameters into specs and then delegate.
AlgorithmParameterSpec pSpec;
try {
pSpec = getAlgorithmParameterSpec(params);
} catch (InvalidParameterSpecException ipse) {
throw new InvalidAlgorithmParameterException
("Failed to retrieve algorithm parameter specification");
}
checkCryptoPerm(checkSpi, key, pSpec);
}
private boolean passCryptoPermCheck(CipherSpi checkSpi, Key key,
AlgorithmParameterSpec params)
throws InvalidKeyException {
String em = cryptoPerm.getExemptionMechanism();
int keySize = checkSpi.engineGetKeySize(key);
// Use the "algorithm" component of the cipher
// transformation so that the perm check would
// work when the key has the "aliased" algo.
String algComponent;
int index = transformation.indexOf('/');
if (index != -1) {
algComponent = transformation.substring(0, index);
} else {
algComponent = transformation;
}
CryptoPermission checkPerm =
new CryptoPermission(algComponent, keySize, params, em);
if (!cryptoPerm.implies(checkPerm)) {
if (debug != null) {
debug.println("Crypto Permission check failed");
debug.println("granted: " + cryptoPerm);
debug.println("requesting: " + checkPerm);
}
return false;
}
if (exmech == null) {
return true;
}
try {
if (!exmech.isCryptoAllowed(key)) {
if (debug != null) {
debug.println(exmech.getName() + " isn't enforced");
}
return false;
}
} catch (ExemptionMechanismException eme) {
if (debug != null) {
debug.println("Cannot determine whether "+
exmech.getName() + " has been enforced");
eme.printStackTrace();
}
return false;
}
return true;
}
// check if opmode is one of the defined constants
// throw InvalidParameterExeption if not
private static void checkOpmode(int opmode) {
if ((opmode < ENCRYPT_MODE) || (opmode > UNWRAP_MODE)) {
throw new InvalidParameterException("Invalid operation mode");
}
}
/**
* Initializes this cipher with a key.
*
* <p>The cipher is initialized for one of the following four operations:
* encryption, decryption, key wrapping or key unwrapping, depending
* on the value of <code>opmode</code>.
*
* <p>If this cipher requires any algorithm parameters that cannot be
* derived from the given <code>key</code>, the underlying cipher
* implementation is supposed to generate the required parameters itself
* (using provider-specific default or random values) if it is being
* initialized for encryption or key wrapping, and raise an
* <code>InvalidKeyException</code> if it is being
* initialized for decryption or key unwrapping.
* The generated parameters can be retrieved using
* {@link #getParameters() getParameters} or
* {@link #getIV() getIV} (if the parameter is an IV).
*
* <p>If this cipher (including its underlying feedback or padding scheme)
* requires any random bytes (e.g., for parameter generation), it will get
* them using the {@link SecureRandom <code>SecureRandom</code>}
* implementation of the highest-priority
* installed provider as the source of randomness.
* (If none of the installed providers supply an implementation of
* SecureRandom, a system-provided source of randomness will be used.)
*
* <p>Note that when a Cipher object is initialized, it loses all
* previously-acquired state. In other words, initializing a Cipher is
* equivalent to creating a new instance of that Cipher and initializing
* it.
*
* @param opmode the operation mode of this cipher (this is one of
* the following:
* <code>ENCRYPT_MODE</code>, <code>DECRYPT_MODE</code>,
* <code>WRAP_MODE</code> or <code>UNWRAP_MODE</code>)
* @param key the key
*
* @exception InvalidKeyException if the given key is inappropriate for
* initializing this cipher, or if this cipher is being initialized for
* decryption and requires algorithm parameters that cannot be
* determined from the given key, or if the given key has a keysize that
* exceeds the maximum allowable keysize (as determined from the
* configured jurisdiction policy files).
*/
public final void init(int opmode, Key key) throws InvalidKeyException {
init(opmode, key, JceSecurity.RANDOM);
}
/**
* Initializes this cipher with a key and a source of randomness.
*
* <p>The cipher is initialized for one of the following four operations:
* encryption, decryption, key wrapping or key unwrapping, depending
* on the value of <code>opmode</code>.
*
* <p>If this cipher requires any algorithm parameters that cannot be
* derived from the given <code>key</code>, the underlying cipher
* implementation is supposed to generate the required parameters itself
* (using provider-specific default or random values) if it is being
* initialized for encryption or key wrapping, and raise an
* <code>InvalidKeyException</code> if it is being
* initialized for decryption or key unwrapping.
* The generated parameters can be retrieved using
* {@link #getParameters() getParameters} or
* {@link #getIV() getIV} (if the parameter is an IV).
*
* <p>If this cipher (including its underlying feedback or padding scheme)
* requires any random bytes (e.g., for parameter generation), it will get
* them from <code>random</code>.
*
* <p>Note that when a Cipher object is initialized, it loses all
* previously-acquired state. In other words, initializing a Cipher is
* equivalent to creating a new instance of that Cipher and initializing
* it.
*
* @param opmode the operation mode of this cipher (this is one of the
* following:
* <code>ENCRYPT_MODE</code>, <code>DECRYPT_MODE</code>,
* <code>WRAP_MODE</code> or <code>UNWRAP_MODE</code>)
* @param key the encryption key
* @param random the source of randomness
*
* @exception InvalidKeyException if the given key is inappropriate for
* initializing this cipher, or if this cipher is being initialized for
* decryption and requires algorithm parameters that cannot be
* determined from the given key, or if the given key has a keysize that
* exceeds the maximum allowable keysize (as determined from the
* configured jurisdiction policy files).
*/
public final void init(int opmode, Key key, SecureRandom random)
throws InvalidKeyException
{
initialized = false;
checkOpmode(opmode);
if (spi != null) {
checkCryptoPerm(spi, key);
spi.engineInit(opmode, key, random);
} else {
try {
chooseProvider(I_KEY, opmode, key, null, null, random);
} catch (InvalidAlgorithmParameterException e) {
// should never occur
throw new InvalidKeyException(e);
}
}
initialized = true;
this.opmode = opmode;
}
/**
* Initializes this cipher with a key and a set of algorithm
* parameters.
*
* <p>The cipher is initialized for one of the following four operations:
* encryption, decryption, key wrapping or key unwrapping, depending
* on the value of <code>opmode</code>.
*
* <p>If this cipher requires any algorithm parameters and
* <code>params</code> is null, the underlying cipher implementation is
* supposed to generate the required parameters itself (using
* provider-specific default or random values) if it is being
* initialized for encryption or key wrapping, and raise an
* <code>InvalidAlgorithmParameterException</code> if it is being
* initialized for decryption or key unwrapping.
* The generated parameters can be retrieved using
* {@link #getParameters() getParameters} or
* {@link #getIV() getIV} (if the parameter is an IV).
*
* <p>If this cipher (including its underlying feedback or padding scheme)
* requires any random bytes (e.g., for parameter generation), it will get
* them using the {@link SecureRandom <code>SecureRandom</code>}
* implementation of the highest-priority
* installed provider as the source of randomness.
* (If none of the installed providers supply an implementation of
* SecureRandom, a system-provided source of randomness will be used.)
*
* <p>Note that when a Cipher object is initialized, it loses all
* previously-acquired state. In other words, initializing a Cipher is
* equivalent to creating a new instance of that Cipher and initializing
* it.
*
* @param opmode the operation mode of this cipher (this is one of the
* following:
* <code>ENCRYPT_MODE</code>, <code>DECRYPT_MODE</code>,
* <code>WRAP_MODE</code> or <code>UNWRAP_MODE</code>)
* @param key the encryption key
* @param params the algorithm parameters
*
* @exception InvalidKeyException if the given key is inappropriate for
* initializing this cipher, or its keysize exceeds the maximum allowable
* keysize (as determined from the configured jurisdiction policy files).
* @exception InvalidAlgorithmParameterException if the given algorithm
* parameters are inappropriate for this cipher,
* or this cipher is being initialized for decryption and requires
* algorithm parameters and <code>params</code> is null, or the given
* algorithm parameters imply a cryptographic strength that would exceed
* the legal limits (as determined from the configured jurisdiction
* policy files).
*/
public final void init(int opmode, Key key, AlgorithmParameterSpec params)
throws InvalidKeyException, InvalidAlgorithmParameterException
{
init(opmode, key, params, JceSecurity.RANDOM);
}
/**
* Initializes this cipher with a key, a set of algorithm
* parameters, and a source of randomness.
*
* <p>The cipher is initialized for one of the following four operations:
* encryption, decryption, key wrapping or key unwrapping, depending
* on the value of <code>opmode</code>.
*
* <p>If this cipher requires any algorithm parameters and
* <code>params</code> is null, the underlying cipher implementation is
* supposed to generate the required parameters itself (using
* provider-specific default or random values) if it is being
* initialized for encryption or key wrapping, and raise an
* <code>InvalidAlgorithmParameterException</code> if it is being
* initialized for decryption or key unwrapping.
* The generated parameters can be retrieved using
* {@link #getParameters() getParameters} or
* {@link #getIV() getIV} (if the parameter is an IV).
*
* <p>If this cipher (including its underlying feedback or padding scheme)
* requires any random bytes (e.g., for parameter generation), it will get
* them from <code>random</code>.
*
* <p>Note that when a Cipher object is initialized, it loses all
* previously-acquired state. In other words, initializing a Cipher is
* equivalent to creating a new instance of that Cipher and initializing
* it.
*
* @param opmode the operation mode of this cipher (this is one of the
* following:
* <code>ENCRYPT_MODE</code>, <code>DECRYPT_MODE</code>,
* <code>WRAP_MODE</code> or <code>UNWRAP_MODE</code>)
* @param key the encryption key
* @param params the algorithm parameters
* @param random the source of randomness
*
* @exception InvalidKeyException if the given key is inappropriate for
* initializing this cipher, or its keysize exceeds the maximum allowable
* keysize (as determined from the configured jurisdiction policy files).
* @exception InvalidAlgorithmParameterException if the given algorithm
* parameters are inappropriate for this cipher,
* or this cipher is being initialized for decryption and requires
* algorithm parameters and <code>params</code> is null, or the given
* algorithm parameters imply a cryptographic strength that would exceed
* the legal limits (as determined from the configured jurisdiction
* policy files).
*/
public final void init(int opmode, Key key, AlgorithmParameterSpec params,
SecureRandom random)
throws InvalidKeyException, InvalidAlgorithmParameterException
{
initialized = false;
checkOpmode(opmode);
if (spi != null) {
checkCryptoPerm(spi, key, params);
spi.engineInit(opmode, key, params, random);
} else {
chooseProvider(I_PARAMSPEC, opmode, key, params, null, random);
}
initialized = true;
this.opmode = opmode;
}
/**
* Initializes this cipher with a key and a set of algorithm
* parameters.
*
* <p>The cipher is initialized for one of the following four operations:
* encryption, decryption, key wrapping or key unwrapping, depending
* on the value of <code>opmode</code>.
*
* <p>If this cipher requires any algorithm parameters and
* <code>params</code> is null, the underlying cipher implementation is
* supposed to generate the required parameters itself (using
* provider-specific default or random values) if it is being
* initialized for encryption or key wrapping, and raise an
* <code>InvalidAlgorithmParameterException</code> if it is being
* initialized for decryption or key unwrapping.
* The generated parameters can be retrieved using
* {@link #getParameters() getParameters} or
* {@link #getIV() getIV} (if the parameter is an IV).
*
* <p>If this cipher (including its underlying feedback or padding scheme)
* requires any random bytes (e.g., for parameter generation), it will get
* them using the {@link SecureRandom <code>SecureRandom</code>}
* implementation of the highest-priority
* installed provider as the source of randomness.
* (If none of the installed providers supply an implementation of
* SecureRandom, a system-provided source of randomness will be used.)
*
* <p>Note that when a Cipher object is initialized, it loses all
* previously-acquired state. In other words, initializing a Cipher is
* equivalent to creating a new instance of that Cipher and initializing
* it.
*
* @param opmode the operation mode of this cipher (this is one of the
* following: <code>ENCRYPT_MODE</code>,
* <code>DECRYPT_MODE</code>, <code>WRAP_MODE</code>
* or <code>UNWRAP_MODE</code>)
* @param key the encryption key
* @param params the algorithm parameters
*
* @exception InvalidKeyException if the given key is inappropriate for
* initializing this cipher, or its keysize exceeds the maximum allowable
* keysize (as determined from the configured jurisdiction policy files).
* @exception InvalidAlgorithmParameterException if the given algorithm
* parameters are inappropriate for this cipher,
* or this cipher is being initialized for decryption and requires
* algorithm parameters and <code>params</code> is null, or the given
* algorithm parameters imply a cryptographic strength that would exceed
* the legal limits (as determined from the configured jurisdiction
* policy files).
*/
public final void init(int opmode, Key key, AlgorithmParameters params)
throws InvalidKeyException, InvalidAlgorithmParameterException
{
init(opmode, key, params, JceSecurity.RANDOM);
}
/**
* Initializes this cipher with a key, a set of algorithm
* parameters, and a source of randomness.
*
* <p>The cipher is initialized for one of the following four operations:
* encryption, decryption, key wrapping or key unwrapping, depending
* on the value of <code>opmode</code>.
*
* <p>If this cipher requires any algorithm parameters and
* <code>params</code> is null, the underlying cipher implementation is
* supposed to generate the required parameters itself (using
* provider-specific default or random values) if it is being
* initialized for encryption or key wrapping, and raise an
* <code>InvalidAlgorithmParameterException</code> if it is being
* initialized for decryption or key unwrapping.
* The generated parameters can be retrieved using
* {@link #getParameters() getParameters} or
* {@link #getIV() getIV} (if the parameter is an IV).
*
* <p>If this cipher (including its underlying feedback or padding scheme)
* requires any random bytes (e.g., for parameter generation), it will get
* them from <code>random</code>.
*
* <p>Note that when a Cipher object is initialized, it loses all
* previously-acquired state. In other words, initializing a Cipher is
* equivalent to creating a new instance of that Cipher and initializing
* it.
*
* @param opmode the operation mode of this cipher (this is one of the
* following: <code>ENCRYPT_MODE</code>,
* <code>DECRYPT_MODE</code>, <code>WRAP_MODE</code>
* or <code>UNWRAP_MODE</code>)
* @param key the encryption key
* @param params the algorithm parameters
* @param random the source of randomness
*
* @exception InvalidKeyException if the given key is inappropriate for
* initializing this cipher, or its keysize exceeds the maximum allowable
* keysize (as determined from the configured jurisdiction policy files).
* @exception InvalidAlgorithmParameterException if the given algorithm
* parameters are inappropriate for this cipher,
* or this cipher is being initialized for decryption and requires
* algorithm parameters and <code>params</code> is null, or the given
* algorithm parameters imply a cryptographic strength that would exceed
* the legal limits (as determined from the configured jurisdiction
* policy files).
*/
public final void init(int opmode, Key key, AlgorithmParameters params,
SecureRandom random)
throws InvalidKeyException, InvalidAlgorithmParameterException
{
initialized = false;
checkOpmode(opmode);
if (spi != null) {
checkCryptoPerm(spi, key, params);
spi.engineInit(opmode, key, params, random);
} else {
chooseProvider(I_PARAMS, opmode, key, null, params, random);
}
initialized = true;
this.opmode = opmode;
}
/**
* Initializes this cipher with the public key from the given certificate.
* <p> The cipher is initialized for one of the following four operations:
* encryption, decryption, key wrapping or key unwrapping, depending
* on the value of <code>opmode</code>.
*
* <p>If the certificate is of type X.509 and has a <i>key usage</i>
* extension field marked as critical, and the value of the <i>key usage</i>
* extension field implies that the public key in
* the certificate and its corresponding private key are not
* supposed to be used for the operation represented by the value
* of <code>opmode</code>,
* an <code>InvalidKeyException</code>
* is thrown.
*
* <p> If this cipher requires any algorithm parameters that cannot be
* derived from the public key in the given certificate, the underlying
* cipher
* implementation is supposed to generate the required parameters itself
* (using provider-specific default or ramdom values) if it is being
* initialized for encryption or key wrapping, and raise an <code>
* InvalidKeyException</code> if it is being initialized for decryption or
* key unwrapping.
* The generated parameters can be retrieved using
* {@link #getParameters() getParameters} or
* {@link #getIV() getIV} (if the parameter is an IV).
*
* <p>If this cipher (including its underlying feedback or padding scheme)
* requires any random bytes (e.g., for parameter generation), it will get
* them using the
* <code>SecureRandom</code>
* implementation of the highest-priority
* installed provider as the source of randomness.
* (If none of the installed providers supply an implementation of
* SecureRandom, a system-provided source of randomness will be used.)
*
* <p>Note that when a Cipher object is initialized, it loses all
* previously-acquired state. In other words, initializing a Cipher is
* equivalent to creating a new instance of that Cipher and initializing
* it.
*
* @param opmode the operation mode of this cipher (this is one of the
* following:
* <code>ENCRYPT_MODE</code>, <code>DECRYPT_MODE</code>,
* <code>WRAP_MODE</code> or <code>UNWRAP_MODE</code>)
* @param certificate the certificate
*
* @exception InvalidKeyException if the public key in the given
* certificate is inappropriate for initializing this cipher, or this
* cipher is being initialized for decryption or unwrapping keys and
* requires algorithm parameters that cannot be determined from the
* public key in the given certificate, or the keysize of the public key
* in the given certificate has a keysize that exceeds the maximum
* allowable keysize (as determined by the configured jurisdiction policy
* files).
*/
public final void init(int opmode, Certificate certificate)
throws InvalidKeyException
{
init(opmode, certificate, JceSecurity.RANDOM);
}
/**
* Initializes this cipher with the public key from the given certificate
* and
* a source of randomness.
*
* <p>The cipher is initialized for one of the following four operations:
* encryption, decryption, key wrapping
* or key unwrapping, depending on
* the value of <code>opmode</code>.
*
* <p>If the certificate is of type X.509 and has a <i>key usage</i>
* extension field marked as critical, and the value of the <i>key usage</i>
* extension field implies that the public key in
* the certificate and its corresponding private key are not
* supposed to be used for the operation represented by the value of
* <code>opmode</code>,
* an <code>InvalidKeyException</code>
* is thrown.
*
* <p>If this cipher requires any algorithm parameters that cannot be
* derived from the public key in the given <code>certificate</code>,
* the underlying cipher
* implementation is supposed to generate the required parameters itself
* (using provider-specific default or random values) if it is being
* initialized for encryption or key wrapping, and raise an
* <code>InvalidKeyException</code> if it is being
* initialized for decryption or key unwrapping.
* The generated parameters can be retrieved using
* {@link #getParameters() getParameters} or
* {@link #getIV() getIV} (if the parameter is an IV).
*
* <p>If this cipher (including its underlying feedback or padding scheme)
* requires any random bytes (e.g., for parameter generation), it will get
* them from <code>random</code>.
*
* <p>Note that when a Cipher object is initialized, it loses all
* previously-acquired state. In other words, initializing a Cipher is
* equivalent to creating a new instance of that Cipher and initializing
* it.
*
* @param opmode the operation mode of this cipher (this is one of the
* following:
* <code>ENCRYPT_MODE</code>, <code>DECRYPT_MODE</code>,
* <code>WRAP_MODE</code> or <code>UNWRAP_MODE</code>)
* @param certificate the certificate
* @param random the source of randomness
*
* @exception InvalidKeyException if the public key in the given
* certificate is inappropriate for initializing this cipher, or this
* cipher is being initialized for decryption or unwrapping keys and
* requires algorithm parameters that cannot be determined from the
* public key in the given certificate, or the keysize of the public key
* in the given certificate has a keysize that exceeds the maximum
* allowable keysize (as determined by the configured jurisdiction policy
* files).
*/
public final void init(int opmode, Certificate certificate,
SecureRandom random)
throws InvalidKeyException
{
initialized = false;
checkOpmode(opmode);
// Check key usage if the certificate is of
// type X.509.
if (certificate instanceof java.security.cert.X509Certificate) {
// Check whether the cert has a key usage extension
// marked as a critical extension.
X509Certificate cert = (X509Certificate)certificate;
Set critSet = cert.getCriticalExtensionOIDs();
if (critSet != null && !critSet.isEmpty()
&& critSet.contains(KEY_USAGE_EXTENSION_OID)) {
boolean[] keyUsageInfo = cert.getKeyUsage();
// keyUsageInfo[2] is for keyEncipherment;
// keyUsageInfo[3] is for dataEncipherment.
if ((keyUsageInfo != null) &&
(((opmode == Cipher.ENCRYPT_MODE) &&
(keyUsageInfo.length > 3) &&
(keyUsageInfo[3] == false)) ||
((opmode == Cipher.WRAP_MODE) &&
(keyUsageInfo.length > 2) &&
(keyUsageInfo[2] == false)))) {
throw new InvalidKeyException("Wrong key usage");
}
}
}
PublicKey publicKey =
(certificate==null? null:certificate.getPublicKey());
if (spi != null) {
checkCryptoPerm(spi, publicKey);
spi.engineInit(opmode, publicKey, random);
} else {
try {
chooseProvider(I_CERT, opmode, publicKey, null, null, random);
} catch (InvalidAlgorithmParameterException e) {
// should never occur
throw new InvalidKeyException(e);
}
}
initialized = true;
this.opmode = opmode;
}
/**
* Ensures that Cipher is in a valid state for update() and doFinal()
* calls - should be initialized and in ENCRYPT_MODE or DECRYPT_MODE.
* @throws IllegalStateException if Cipher object is not in valid state.
*/
private void checkCipherState() {
if (!(this instanceof NullCipher)) {
if (!initialized) {
throw new IllegalStateException("Cipher not initialized");
}
if ((opmode != Cipher.ENCRYPT_MODE) &&
(opmode != Cipher.DECRYPT_MODE)) {
throw new IllegalStateException("Cipher not initialized " +
"for encryption/decryption");
}
}
}
/**
* Continues a multiple-part encryption or decryption operation
* (depending on how this cipher was initialized), processing another data
* part.
*
* <p>The bytes in the <code>input</code> buffer are processed, and the
* result is stored in a new buffer.
*
* <p>If <code>input</code> has a length of zero, this method returns
* <code>null</code>.
*
* @param input the input buffer
*
* @return the new buffer with the result, or null if the underlying
* cipher is a block cipher and the input data is too short to result in a
* new block.
*
* @exception IllegalStateException if this cipher is in a wrong state
* (e.g., has not been initialized)
*/
public final byte[] update(byte[] input) {
checkCipherState();
// Input sanity check
if (input == null) {
throw new IllegalArgumentException("Null input buffer");
}
chooseFirstProvider();
if (input.length == 0) {
return null;
}
return spi.engineUpdate(input, 0, input.length);
}
/**
* Continues a multiple-part encryption or decryption operation
* (depending on how this cipher was initialized), processing another data
* part.
*
* <p>The first <code>inputLen</code> bytes in the <code>input</code>
* buffer, starting at <code>inputOffset</code> inclusive, are processed,
* and the result is stored in a new buffer.
*
* <p>If <code>inputLen</code> is zero, this method returns
* <code>null</code>.
*
* @param input the input buffer
* @param inputOffset the offset in <code>input</code> where the input
* starts
* @param inputLen the input length
*
* @return the new buffer with the result, or null if the underlying
* cipher is a block cipher and the input data is too short to result in a
* new block.
*
* @exception IllegalStateException if this cipher is in a wrong state
* (e.g., has not been initialized)
*/
public final byte[] update(byte[] input, int inputOffset, int inputLen) {
checkCipherState();
// Input sanity check
if (input == null || inputOffset < 0
|| inputLen > (input.length - inputOffset) || inputLen < 0) {
throw new IllegalArgumentException("Bad arguments");
}
chooseFirstProvider();
if (inputLen == 0) {
return null;
}
return spi.engineUpdate(input, inputOffset, inputLen);
}
/**
* Continues a multiple-part encryption or decryption operation
* (depending on how this cipher was initialized), processing another data
* part.
*
* <p>The first <code>inputLen</code> bytes in the <code>input</code>
* buffer, starting at <code>inputOffset</code> inclusive, are processed,
* and the result is stored in the <code>output</code> buffer.
*
* <p>If the <code>output</code> buffer is too small to hold the result,
* a <code>ShortBufferException</code> is thrown. In this case, repeat this
* call with a larger output buffer. Use
* {@link #getOutputSize(int) getOutputSize} to determine how big
* the output buffer should be.
*
* <p>If <code>inputLen</code> is zero, this method returns
* a length of zero.
*
* <p>Note: this method should be copy-safe, which means the
* <code>input</code> and <code>output</code> buffers can reference
* the same byte array and no unprocessed input data is overwritten
* when the result is copied into the output buffer.
*
* @param input the input buffer
* @param inputOffset the offset in <code>input</code> where the input
* starts
* @param inputLen the input length
* @param output the buffer for the result
*
* @return the number of bytes stored in <code>output</code>
*
* @exception IllegalStateException if this cipher is in a wrong state
* (e.g., has not been initialized)
* @exception ShortBufferException if the given output buffer is too small
* to hold the result
*/
public final int update(byte[] input, int inputOffset, int inputLen,
byte[] output)
throws ShortBufferException {
checkCipherState();
// Input sanity check
if (input == null || inputOffset < 0
|| inputLen > (input.length - inputOffset) || inputLen < 0) {
throw new IllegalArgumentException("Bad arguments");
}
chooseFirstProvider();
if (inputLen == 0) {
return 0;
}
return spi.engineUpdate(input, inputOffset, inputLen,
output, 0);
}
/**
* Continues a multiple-part encryption or decryption operation
* (depending on how this cipher was initialized), processing another data
* part.
*
* <p>The first <code>inputLen</code> bytes in the <code>input</code>
* buffer, starting at <code>inputOffset</code> inclusive, are processed,
* and the result is stored in the <code>output</code> buffer, starting at
* <code>outputOffset</code> inclusive.
*
* <p>If the <code>output</code> buffer is too small to hold the result,
* a <code>ShortBufferException</code> is thrown. In this case, repeat this
* call with a larger output buffer. Use
* {@link #getOutputSize(int) getOutputSize} to determine how big
* the output buffer should be.
*
* <p>If <code>inputLen</code> is zero, this method returns
* a length of zero.
*
* <p>Note: this method should be copy-safe, which means the
* <code>input</code> and <code>output</code> buffers can reference
* the same byte array and no unprocessed input data is overwritten
* when the result is copied into the output buffer.
*
* @param input the input buffer
* @param inputOffset the offset in <code>input</code> where the input
* starts
* @param inputLen the input length
* @param output the buffer for the result
* @param outputOffset the offset in <code>output</code> where the result
* is stored
*
* @return the number of bytes stored in <code>output</code>
*
* @exception IllegalStateException if this cipher is in a wrong state
* (e.g., has not been initialized)
* @exception ShortBufferException if the given output buffer is too small
* to hold the result
*/
public final int update(byte[] input, int inputOffset, int inputLen,
byte[] output, int outputOffset)
throws ShortBufferException {
checkCipherState();
// Input sanity check
if (input == null || inputOffset < 0
|| inputLen > (input.length - inputOffset) || inputLen < 0
|| outputOffset < 0) {
throw new IllegalArgumentException("Bad arguments");
}
chooseFirstProvider();
if (inputLen == 0) {
return 0;
}
return spi.engineUpdate(input, inputOffset, inputLen,
output, outputOffset);
}
/**
* Continues a multiple-part encryption or decryption operation
* (depending on how this cipher was initialized), processing another data
* part.
*
* <p>All <code>input.remaining()</code> bytes starting at
* <code>input.position()</code> are processed. The result is stored
* in the output buffer.
* Upon return, the input buffer's position will be equal
* to its limit; its limit will not have changed. The output buffer's
* position will have advanced by n, where n is the value returned
* by this method; the output buffer's limit will not have changed.
*
* <p>If <code>output.remaining()</code> bytes are insufficient to
* hold the result, a <code>ShortBufferException</code> is thrown.
* In this case, repeat this call with a larger output buffer. Use
* {@link #getOutputSize(int) getOutputSize} to determine how big
* the output buffer should be.
*
* <p>Note: this method should be copy-safe, which means the
* <code>input</code> and <code>output</code> buffers can reference
* the same block of memory and no unprocessed input data is overwritten
* when the result is copied into the output buffer.
*
* @param input the input ByteBuffer
* @param output the output ByteByffer
*
* @return the number of bytes stored in <code>output</code>
*
* @exception IllegalStateException if this cipher is in a wrong state
* (e.g., has not been initialized)
* @exception IllegalArgumentException if input and output are the
* same object
* @exception ReadOnlyBufferException if the output buffer is read-only
* @exception ShortBufferException if there is insufficient space in the
* output buffer
* @since 1.5
*/
public final int update(ByteBuffer input, ByteBuffer output)
throws ShortBufferException {
checkCipherState();
if ((input == null) || (output == null)) {
throw new IllegalArgumentException("Buffers must not be null");
}
if (input == output) {
throw new IllegalArgumentException("Input and output buffers must "
+ "not be the same object, consider using buffer.duplicate()");
}
if (output.isReadOnly()) {
throw new ReadOnlyBufferException();
}
chooseFirstProvider();
return spi.engineUpdate(input, output);
}
/**
* Finishes a multiple-part encryption or decryption operation, depending
* on how this cipher was initialized.
*
* <p>Input data that may have been buffered during a previous
* <code>update</code> operation is processed, with padding (if requested)
* being applied.
* The result is stored in a new buffer.
*
* <p>Upon finishing, this method resets this cipher object to the state
* it was in when previously initialized via a call to <code>init</code>.
* That is, the object is reset and available to encrypt or decrypt
* (depending on the operation mode that was specified in the call to
* <code>init</code>) more data.
*
* <p>Note: if any exception is thrown, this cipher object may need to
* be reset before it can be used again.
*
* @return the new buffer with the result
*
* @exception IllegalStateException if this cipher is in a wrong state
* (e.g., has not been initialized)
* @exception IllegalBlockSizeException if this cipher is a block cipher,
* no padding has been requested (only in encryption mode), and the total
* input length of the data processed by this cipher is not a multiple of
* block size; or if this encryption algorithm is unable to
* process the input data provided.
* @exception BadPaddingException if this cipher is in decryption mode,
* and (un)padding has been requested, but the decrypted data is not
* bounded by the appropriate padding bytes
*/
public final byte[] doFinal()
throws IllegalBlockSizeException, BadPaddingException {
checkCipherState();
chooseFirstProvider();
return spi.engineDoFinal(null, 0, 0);
}
/**
* Finishes a multiple-part encryption or decryption operation, depending
* on how this cipher was initialized.
*
* <p>Input data that may have been buffered during a previous
* <code>update</code> operation is processed, with padding (if requested)
* being applied.
* The result is stored in the <code>output</code> buffer, starting at
* <code>outputOffset</code> inclusive.
*
* <p>If the <code>output</code> buffer is too small to hold the result,
* a <code>ShortBufferException</code> is thrown. In this case, repeat this
* call with a larger output buffer. Use
* {@link #getOutputSize(int) getOutputSize} to determine how big
* the output buffer should be.
*
* <p>Upon finishing, this method resets this cipher object to the state
* it was in when previously initialized via a call to <code>init</code>.
* That is, the object is reset and available to encrypt or decrypt
* (depending on the operation mode that was specified in the call to
* <code>init</code>) more data.
*
* <p>Note: if any exception is thrown, this cipher object may need to
* be reset before it can be used again.
*
* @param output the buffer for the result
* @param outputOffset the offset in <code>output</code> where the result
* is stored
*
* @return the number of bytes stored in <code>output</code>
*
* @exception IllegalStateException if this cipher is in a wrong state
* (e.g., has not been initialized)
* @exception IllegalBlockSizeException if this cipher is a block cipher,
* no padding has been requested (only in encryption mode), and the total
* input length of the data processed by this cipher is not a multiple of
* block size; or if this encryption algorithm is unable to
* process the input data provided.
* @exception ShortBufferException if the given output buffer is too small
* to hold the result
* @exception BadPaddingException if this cipher is in decryption mode,
* and (un)padding has been requested, but the decrypted data is not
* bounded by the appropriate padding bytes
*/
public final int doFinal(byte[] output, int outputOffset)
throws IllegalBlockSizeException, ShortBufferException,
BadPaddingException {
checkCipherState();
// Input sanity check
if ((output == null) || (outputOffset < 0)) {
throw new IllegalArgumentException("Bad arguments");
}
chooseFirstProvider();
return spi.engineDoFinal(null, 0, 0, output, outputOffset);
}
/**
* Encrypts or decrypts data in a single-part operation, or finishes a
* multiple-part operation. The data is encrypted or decrypted,
* depending on how this cipher was initialized.
*
* <p>The bytes in the <code>input</code> buffer, and any input bytes that
* may have been buffered during a previous <code>update</code> operation,
* are processed, with padding (if requested) being applied.
* The result is stored in a new buffer.
*
* <p>Upon finishing, this method resets this cipher object to the state
* it was in when previously initialized via a call to <code>init</code>.
* That is, the object is reset and available to encrypt or decrypt
* (depending on the operation mode that was specified in the call to
* <code>init</code>) more data.
*
* <p>Note: if any exception is thrown, this cipher object may need to
* be reset before it can be used again.
*
* @param input the input buffer
*
* @return the new buffer with the result
*
* @exception IllegalStateException if this cipher is in a wrong state
* (e.g., has not been initialized)
* @exception IllegalBlockSizeException if this cipher is a block cipher,
* no padding has been requested (only in encryption mode), and the total
* input length of the data processed by this cipher is not a multiple of
* block size; or if this encryption algorithm is unable to
* process the input data provided.
* @exception BadPaddingException if this cipher is in decryption mode,
* and (un)padding has been requested, but the decrypted data is not
* bounded by the appropriate padding bytes
*/
public final byte[] doFinal(byte[] input)
throws IllegalBlockSizeException, BadPaddingException {
checkCipherState();
// Input sanity check
if (input == null) {
throw new IllegalArgumentException("Null input buffer");
}
chooseFirstProvider();
return spi.engineDoFinal(input, 0, input.length);
}
/**
* Encrypts or decrypts data in a single-part operation, or finishes a
* multiple-part operation. The data is encrypted or decrypted,
* depending on how this cipher was initialized.
*
* <p>The first <code>inputLen</code> bytes in the <code>input</code>
* buffer, starting at <code>inputOffset</code> inclusive, and any input
* bytes that may have been buffered during a previous <code>update</code>
* operation, are processed, with padding (if requested) being applied.
* The result is stored in a new buffer.
*
* <p>Upon finishing, this method resets this cipher object to the state
* it was in when previously initialized via a call to <code>init</code>.
* That is, the object is reset and available to encrypt or decrypt
* (depending on the operation mode that was specified in the call to
* <code>init</code>) more data.
*
* <p>Note: if any exception is thrown, this cipher object may need to
* be reset before it can be used again.
*
* @param input the input buffer
* @param inputOffset the offset in <code>input</code> where the input
* starts
* @param inputLen the input length
*
* @return the new buffer with the result
*
* @exception IllegalStateException if this cipher is in a wrong state
* (e.g., has not been initialized)
* @exception IllegalBlockSizeException if this cipher is a block cipher,
* no padding has been requested (only in encryption mode), and the total
* input length of the data processed by this cipher is not a multiple of
* block size; or if this encryption algorithm is unable to
* process the input data provided.
* @exception BadPaddingException if this cipher is in decryption mode,
* and (un)padding has been requested, but the decrypted data is not
* bounded by the appropriate padding bytes
*/
public final byte[] doFinal(byte[] input, int inputOffset, int inputLen)
throws IllegalBlockSizeException, BadPaddingException {
checkCipherState();
// Input sanity check
if (input == null || inputOffset < 0
|| inputLen > (input.length - inputOffset) || inputLen < 0) {
throw new IllegalArgumentException("Bad arguments");
}
chooseFirstProvider();
return spi.engineDoFinal(input, inputOffset, inputLen);
}
/**
* Encrypts or decrypts data in a single-part operation, or finishes a
* multiple-part operation. The data is encrypted or decrypted,
* depending on how this cipher was initialized.
*
* <p>The first <code>inputLen</code> bytes in the <code>input</code>
* buffer, starting at <code>inputOffset</code> inclusive, and any input
* bytes that may have been buffered during a previous <code>update</code>
* operation, are processed, with padding (if requested) being applied.
* The result is stored in the <code>output</code> buffer.
*
* <p>If the <code>output</code> buffer is too small to hold the result,
* a <code>ShortBufferException</code> is thrown. In this case, repeat this
* call with a larger output buffer. Use
* {@link #getOutputSize(int) getOutputSize} to determine how big
* the output buffer should be.
*
* <p>Upon finishing, this method resets this cipher object to the state
* it was in when previously initialized via a call to <code>init</code>.
* That is, the object is reset and available to encrypt or decrypt
* (depending on the operation mode that was specified in the call to
* <code>init</code>) more data.
*
* <p>Note: if any exception is thrown, this cipher object may need to
* be reset before it can be used again.
*
* <p>Note: this method should be copy-safe, which means the
* <code>input</code> and <code>output</code> buffers can reference
* the same byte array and no unprocessed input data is overwritten
* when the result is copied into the output buffer.
*
* @param input the input buffer
* @param inputOffset the offset in <code>input</code> where the input
* starts
* @param inputLen the input length
* @param output the buffer for the result
*
* @return the number of bytes stored in <code>output</code>
*
* @exception IllegalStateException if this cipher is in a wrong state
* (e.g., has not been initialized)
* @exception IllegalBlockSizeException if this cipher is a block cipher,
* no padding has been requested (only in encryption mode), and the total
* input length of the data processed by this cipher is not a multiple of
* block size; or if this encryption algorithm is unable to
* process the input data provided.
* @exception ShortBufferException if the given output buffer is too small
* to hold the result
* @exception BadPaddingException if this cipher is in decryption mode,
* and (un)padding has been requested, but the decrypted data is not
* bounded by the appropriate padding bytes
*/
public final int doFinal(byte[] input, int inputOffset, int inputLen,
byte[] output)
throws ShortBufferException, IllegalBlockSizeException,
BadPaddingException {
checkCipherState();
// Input sanity check
if (input == null || inputOffset < 0
|| inputLen > (input.length - inputOffset) || inputLen < 0) {
throw new IllegalArgumentException("Bad arguments");
}
chooseFirstProvider();
return spi.engineDoFinal(input, inputOffset, inputLen,
output, 0);
}
/**
* Encrypts or decrypts data in a single-part operation, or finishes a
* multiple-part operation. The data is encrypted or decrypted,
* depending on how this cipher was initialized.
*
* <p>The first <code>inputLen</code> bytes in the <code>input</code>
* buffer, starting at <code>inputOffset</code> inclusive, and any input
* bytes that may have been buffered during a previous
* <code>update</code> operation, are processed, with padding
* (if requested) being applied.
* The result is stored in the <code>output</code> buffer, starting at
* <code>outputOffset</code> inclusive.
*
* <p>If the <code>output</code> buffer is too small to hold the result,
* a <code>ShortBufferException</code> is thrown. In this case, repeat this
* call with a larger output buffer. Use
* {@link #getOutputSize(int) getOutputSize} to determine how big
* the output buffer should be.
*
* <p>Upon finishing, this method resets this cipher object to the state
* it was in when previously initialized via a call to <code>init</code>.
* That is, the object is reset and available to encrypt or decrypt
* (depending on the operation mode that was specified in the call to
* <code>init</code>) more data.
*
* <p>Note: if any exception is thrown, this cipher object may need to
* be reset before it can be used again.
*
* <p>Note: this method should be copy-safe, which means the
* <code>input</code> and <code>output</code> buffers can reference
* the same byte array and no unprocessed input data is overwritten
* when the result is copied into the output buffer.
*
* @param input the input buffer
* @param inputOffset the offset in <code>input</code> where the input
* starts
* @param inputLen the input length
* @param output the buffer for the result
* @param outputOffset the offset in <code>output</code> where the result
* is stored
*
* @return the number of bytes stored in <code>output</code>
*
* @exception IllegalStateException if this cipher is in a wrong state
* (e.g., has not been initialized)
* @exception IllegalBlockSizeException if this cipher is a block cipher,
* no padding has been requested (only in encryption mode), and the total
* input length of the data processed by this cipher is not a multiple of
* block size; or if this encryption algorithm is unable to
* process the input data provided.
* @exception ShortBufferException if the given output buffer is too small
* to hold the result
* @exception BadPaddingException if this cipher is in decryption mode,
* and (un)padding has been requested, but the decrypted data is not
* bounded by the appropriate padding bytes
*/
public final int doFinal(byte[] input, int inputOffset, int inputLen,
byte[] output, int outputOffset)
throws ShortBufferException, IllegalBlockSizeException,
BadPaddingException {
checkCipherState();
// Input sanity check
if (input == null || inputOffset < 0
|| inputLen > (input.length - inputOffset) || inputLen < 0
|| outputOffset < 0) {
throw new IllegalArgumentException("Bad arguments");
}
chooseFirstProvider();
return spi.engineDoFinal(input, inputOffset, inputLen,
output, outputOffset);
}
/**
* Encrypts or decrypts data in a single-part operation, or finishes a
* multiple-part operation. The data is encrypted or decrypted,
* depending on how this cipher was initialized.
*
* <p>All <code>input.remaining()</code> bytes starting at
* <code>input.position()</code> are processed. The result is stored
* in the output buffer.
* Upon return, the input buffer's position will be equal
* to its limit; its limit will not have changed. The output buffer's
* position will have advanced by n, where n is the value returned
* by this method; the output buffer's limit will not have changed.
*
* <p>If <code>output.remaining()</code> bytes are insufficient to
* hold the result, a <code>ShortBufferException</code> is thrown.
* In this case, repeat this call with a larger output buffer. Use
* {@link #getOutputSize(int) getOutputSize} to determine how big
* the output buffer should be.
*
* <p>Upon finishing, this method resets this cipher object to the state
* it was in when previously initialized via a call to <code>init</code>.
* That is, the object is reset and available to encrypt or decrypt
* (depending on the operation mode that was specified in the call to
* <code>init</code>) more data.
*
* <p>Note: if any exception is thrown, this cipher object may need to
* be reset before it can be used again.
*
* <p>Note: this method should be copy-safe, which means the
* <code>input</code> and <code>output</code> buffers can reference
* the same byte array and no unprocessed input data is overwritten
* when the result is copied into the output buffer.
*
* @param input the input ByteBuffer
* @param output the output ByteBuffer
*
* @return the number of bytes stored in <code>output</code>
*
* @exception IllegalStateException if this cipher is in a wrong state
* (e.g., has not been initialized)
* @exception IllegalArgumentException if input and output are the
* same object
* @exception ReadOnlyBufferException if the output buffer is read-only
* @exception IllegalBlockSizeException if this cipher is a block cipher,
* no padding has been requested (only in encryption mode), and the total
* input length of the data processed by this cipher is not a multiple of
* block size; or if this encryption algorithm is unable to
* process the input data provided.
* @exception ShortBufferException if there is insufficient space in the
* output buffer
* @exception BadPaddingException if this cipher is in decryption mode,
* and (un)padding has been requested, but the decrypted data is not
* bounded by the appropriate padding bytes
* @since 1.5
*/
public final int doFinal(ByteBuffer input, ByteBuffer output)
throws ShortBufferException, IllegalBlockSizeException,
BadPaddingException {
checkCipherState();
if ((input == null) || (output == null)) {
throw new IllegalArgumentException("Buffers must not be null");
}
if (input == output) {
throw new IllegalArgumentException("Input and output buffers must "
+ "not be the same object, consider using buffer.duplicate()");
}
if (output.isReadOnly()) {
throw new ReadOnlyBufferException();
}
chooseFirstProvider();
return spi.engineDoFinal(input, output);
}
/**
* Wrap a key.
*
* @param key the key to be wrapped.
*
* @return the wrapped key.
*
* @exception IllegalStateException if this cipher is in a wrong
* state (e.g., has not been initialized).
*
* @exception IllegalBlockSizeException if this cipher is a block
* cipher, no padding has been requested, and the length of the
* encoding of the key to be wrapped is not a
* multiple of the block size.
*
* @exception InvalidKeyException if it is impossible or unsafe to
* wrap the key with this cipher (e.g., a hardware protected key is
* being passed to a software-only cipher).
*/
public final byte[] wrap(Key key)
throws IllegalBlockSizeException, InvalidKeyException {
if (!(this instanceof NullCipher)) {
if (!initialized) {
throw new IllegalStateException("Cipher not initialized");
}
if (opmode != Cipher.WRAP_MODE) {
throw new IllegalStateException("Cipher not initialized " +
"for wrapping keys");
}
}
chooseFirstProvider();
return spi.engineWrap(key);
}
/**
* Unwrap a previously wrapped key.
*
* @param wrappedKey the key to be unwrapped.
*
* @param wrappedKeyAlgorithm the algorithm associated with the wrapped
* key.
*
* @param wrappedKeyType the type of the wrapped key. This must be one of
* <code>SECRET_KEY</code>, <code>PRIVATE_KEY</code>, or
* <code>PUBLIC_KEY</code>.
*
* @return the unwrapped key.
*
* @exception IllegalStateException if this cipher is in a wrong state
* (e.g., has not been initialized).
*
* @exception NoSuchAlgorithmException if no installed providers
* can create keys of type <code>wrappedKeyType</code> for the
* <code>wrappedKeyAlgorithm</code>.
*
* @exception InvalidKeyException if <code>wrappedKey</code> does not
* represent a wrapped key of type <code>wrappedKeyType</code> for
* the <code>wrappedKeyAlgorithm</code>.
*/
public final Key unwrap(byte[] wrappedKey,
String wrappedKeyAlgorithm,
int wrappedKeyType)
throws InvalidKeyException, NoSuchAlgorithmException {
if (!(this instanceof NullCipher)) {
if (!initialized) {
throw new IllegalStateException("Cipher not initialized");
}
if (opmode != Cipher.UNWRAP_MODE) {
throw new IllegalStateException("Cipher not initialized " +
"for unwrapping keys");
}
}
if ((wrappedKeyType != SECRET_KEY) &&
(wrappedKeyType != PRIVATE_KEY) &&
(wrappedKeyType != PUBLIC_KEY)) {
throw new InvalidParameterException("Invalid key type");
}
chooseFirstProvider();
return spi.engineUnwrap(wrappedKey,
wrappedKeyAlgorithm,
wrappedKeyType);
}
private AlgorithmParameterSpec getAlgorithmParameterSpec(
AlgorithmParameters params)
throws InvalidParameterSpecException {
if (params == null) {
return null;
}
String alg = params.getAlgorithm().toUpperCase(Locale.ENGLISH);
if (alg.equalsIgnoreCase("RC2")) {
return params.getParameterSpec(RC2ParameterSpec.class);
}
if (alg.equalsIgnoreCase("RC5")) {
return params.getParameterSpec(RC5ParameterSpec.class);
}
if (alg.startsWith("PBE")) {
return params.getParameterSpec(PBEParameterSpec.class);
}
if (alg.startsWith("DES")) {
return params.getParameterSpec(IvParameterSpec.class);
}
return null;
}
private static CryptoPermission getConfiguredPermission(
String transformation) throws NullPointerException,
NoSuchAlgorithmException {
if (transformation == null) throw new NullPointerException();
String[] parts = tokenizeTransformation(transformation);
return JceSecurityManager.INSTANCE.getCryptoPermission(parts[0]);
}
/**
* Returns the maximum key length for the specified transformation
* according to the installed JCE jurisdiction policy files. If
* JCE unlimited strength jurisdiction policy files are installed,
* Integer.MAX_VALUE will be returned.
* For more information on default key size in JCE jurisdiction
* policy files, please see Appendix E in the
* <a href=
* "{@docRoot}/../technotes/guides/security/crypto/CryptoSpec.html#AppE">
* Java Cryptography Architecture Reference Guide</a>.
*
* @param transformation the cipher transformation.
* @return the maximum key length in bits or Integer.MAX_VALUE.
* @exception NullPointerException if <code>transformation</code> is null.
* @exception NoSuchAlgorithmException if <code>transformation</code>
* is not a valid transformation, i.e. in the form of "algorithm" or
* "algorithm/mode/padding".
* @since 1.5
*/
public static final int getMaxAllowedKeyLength(String transformation)
throws NoSuchAlgorithmException {
CryptoPermission cp = getConfiguredPermission(transformation);
return cp.getMaxKeySize();
}
/**
* Returns an AlgorithmParameterSpec object which contains
* the maximum cipher parameter value according to the
* jurisdiction policy file. If JCE unlimited strength jurisdiction
* policy files are installed or there is no maximum limit on the
* parameters for the specified transformation in the policy file,
* null will be returned.
*
* @param transformation the cipher transformation.
* @return an AlgorithmParameterSpec which holds the maximum
* value or null.
* @exception NullPointerException if <code>transformation</code>
* is null.
* @exception NoSuchAlgorithmException if <code>transformation</code>
* is not a valid transformation, i.e. in the form of "algorithm" or
* "algorithm/mode/padding".
* @since 1.5
*/
public static final AlgorithmParameterSpec getMaxAllowedParameterSpec(
String transformation) throws NoSuchAlgorithmException {
CryptoPermission cp = getConfiguredPermission(transformation);
return cp.getAlgorithmParameterSpec();
}
}