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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package com.sun.crypto.provider;
import java.util.Arrays;
import java.security.*;
import java.security.spec.*;
import javax.crypto.*;
import javax.crypto.spec.*;
/**
* This class implements the CMS DESede KeyWrap algorithm as defined
* in <a href=http://www.w3.org/TR/xmlenc-core/#sec-Alg-SymmetricKeyWrap>
* "XML Encryption Syntax and Processing" section 5.6.2
* "CMS Triple DES Key Wrap".
* Note: only <code>CBC</code> mode and <code>NoPadding</code> padding
* scheme can be used for this algorithm.
*
* @author Valerie Peng
*
*
* @see DESedeCipher
*/
public final class DESedeWrapCipher extends CipherSpi {
private static final byte[] IV2 = {
(byte) 0x4a, (byte) 0xdd, (byte) 0xa2, (byte) 0x2c,
(byte) 0x79, (byte) 0xe8, (byte) 0x21, (byte) 0x05
};
/*
* internal cipher object which does the real work.
*/
private FeedbackCipher cipher;
/*
* iv for (re-)initializing the internal cipher object.
*/
private byte[] iv = null;
/*
* key for re-initializing the internal cipher object.
*/
private Key cipherKey = null;
/*
* are we encrypting or decrypting?
*/
private boolean decrypting = false;
/**
* Creates an instance of CMS DESede KeyWrap cipher with default
* mode, i.e. "CBC" and padding scheme, i.e. "NoPadding".
*
* @exception SecurityException if this constructor fails to verify
* its own integrity.
*/
public DESedeWrapCipher() {
SunJCE.ensureIntegrity(getClass());
cipher = new CipherBlockChaining(new DESedeCrypt());
}
/**
* Sets the mode of this cipher. Only "CBC" mode is accepted for this
* cipher.
*
* @param mode the cipher mode.
*
* @exception NoSuchAlgorithmException if the requested cipher mode
* is not "CBC".
*/
protected void engineSetMode(String mode)
throws NoSuchAlgorithmException {
if (!mode.equalsIgnoreCase("CBC")) {
throw new NoSuchAlgorithmException(mode + " cannot be used");
}
}
/**
* Sets the padding mechanism of this cipher. Only "NoPadding" schmem
* is accepted for this cipher.
*
* @param padding the padding mechanism.
*
* @exception NoSuchPaddingException if the requested padding mechanism
* is not "NoPadding".
*/
protected void engineSetPadding(String padding)
throws NoSuchPaddingException {
if (!padding.equalsIgnoreCase("NoPadding")) {
throw new NoSuchPaddingException(padding + " cannot be used");
}
}
/**
* Returns the block size (in bytes), i.e. 8 bytes.
*
* @return the block size (in bytes), i.e. 8 bytes.
*/
protected int engineGetBlockSize() {
return DESConstants.DES_BLOCK_SIZE;
}
/**
* Returns the length in bytes that an output buffer would need to be
* given the input length <code>inputLen</code> (in bytes).
*
* <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).
*/
protected int engineGetOutputSize(int inputLen) {
// can only return an upper-limit if not initialized yet.
int result = 0;
if (decrypting) {
result = inputLen - 16;
} else {
result = inputLen + 16;
}
return (result < 0? 0:result);
}
/**
* Returns the initialization vector (IV) in a new buffer.
*
* @return the initialization vector, or null if the underlying
* algorithm does not use an IV, or if the IV has not yet
* been set.
*/
protected byte[] engineGetIV() {
return (iv == null? null:(byte[]) iv.clone());
}
/**
* Initializes this cipher with a key and a source of randomness.
*
* <p>The cipher only supports the following two operation modes:<b>
* Cipher.WRAP_MODE, and <b>
* Cipher.UNWRAP_MODE.
* <p>For modes other than the above two, UnsupportedOperationException
* will be thrown.
* <p>If this cipher requires an initialization vector (IV), it will get
* it from <code>random</code>.
*
* @param opmode the operation mode of this cipher. Only
* <code>WRAP_MODE</code> or <code>UNWRAP_MODE</code>) are accepted.
* @param key the secret key.
* @param random the source of randomness.
*
* @exception InvalidKeyException if the given key is inappropriate
* or if parameters are required but not supplied.
*/
protected void engineInit(int opmode, Key key, SecureRandom random)
throws InvalidKeyException {
try {
engineInit(opmode, key, (AlgorithmParameterSpec) null, random);
} catch (InvalidAlgorithmParameterException iape) {
// should never happen
InvalidKeyException ike =
new InvalidKeyException("Parameters required");
ike.initCause(iape);
throw ike;
}
}
/**
* Initializes this cipher with a key, a set of algorithm parameters,
* and a source of randomness.
*
* <p>The cipher only supports the following two operation modes:<b>
* Cipher.WRAP_MODE, and <b>
* Cipher.UNWRAP_MODE.
* <p>For modes other than the above two, UnsupportedOperationException
* will be thrown.
* <p>If this cipher requires an initialization vector (IV), it will get
* it from <code>random</code>.
*
* @param opmode the operation mode of this cipher. Only
* <code>WRAP_MODE</code> or <code>UNWRAP_MODE</code>) are accepted.
* @param key the secret key.
* @param params the algorithm parameters.
* @param random the source of randomness.
*
* @exception InvalidKeyException if the given key is inappropriate.
* @exception InvalidAlgorithmParameterException if the given algorithm
* parameters are inappropriate for this cipher.
*/
protected void engineInit(int opmode, Key key,
AlgorithmParameterSpec params,
SecureRandom random)
throws InvalidKeyException, InvalidAlgorithmParameterException {
byte[] currIv = null;
if (opmode == Cipher.WRAP_MODE) {
decrypting = false;
if (params == null) {
iv = new byte[8];
if (random == null) {
random = SunJCE.RANDOM;
}
random.nextBytes(iv);
}
else if (params instanceof IvParameterSpec) {
iv = ((IvParameterSpec) params).getIV();
} else {
throw new InvalidAlgorithmParameterException
("Wrong parameter type: IV expected");
}
currIv = iv;
} else if (opmode == Cipher.UNWRAP_MODE) {
if (params != null) {
throw new InvalidAlgorithmParameterException
("No parameter accepted for unwrapping keys");
}
iv = null;
decrypting = true;
currIv = IV2;
} else {
throw new UnsupportedOperationException("This cipher can " +
"only be used for key wrapping and unwrapping");
}
cipher.init(decrypting, key.getAlgorithm(), key.getEncoded(),
currIv);
cipherKey = key;
}
/**
* Initializes this cipher with a key, a set of algorithm parameters,
* and a source of randomness.
*
* <p>The cipher only supports the following two operation modes:<b>
* Cipher.WRAP_MODE, and <b>
* Cipher.UNWRAP_MODE.
* <p>For modes other than the above two, UnsupportedOperationException
* will be thrown.
* <p>If this cipher requires an initialization vector (IV), it will get
* it from <code>random</code>.
*
* @param opmode the operation mode of this cipher. Only
* <code>WRAP_MODE</code> or <code>UNWRAP_MODE</code>) are accepted.
* @param key the secret key.
* @param params the algorithm parameters.
* @param random the source of randomness.
*
* @exception InvalidKeyException if the given key is inappropriate.
* @exception InvalidAlgorithmParameterException if the given algorithm
* parameters are inappropriate for this cipher.
*/
protected void engineInit(int opmode, Key key,
AlgorithmParameters params,
SecureRandom random)
throws InvalidKeyException, InvalidAlgorithmParameterException {
IvParameterSpec ivSpec = null;
if (params != null) {
try {
DESedeParameters paramsEng = new DESedeParameters();
paramsEng.engineInit(params.getEncoded());
ivSpec = (IvParameterSpec)
paramsEng.engineGetParameterSpec(IvParameterSpec.class);
} catch (Exception ex) {
InvalidAlgorithmParameterException iape =
new InvalidAlgorithmParameterException
("Wrong parameter type: IV expected");
iape.initCause(ex);
throw iape;
}
}
engineInit(opmode, key, ivSpec, random);
}
/**
* This operation is not supported by this cipher.
* Since it's impossible to initialize this cipher given the
* current Cipher.engineInit(...) implementation,
* IllegalStateException will always be thrown upon invocation.
*
* @param in the input buffer.
* @param inOffset the offset in <code>in</code> where the input
* starts.
* @param inLen the input length.
*
* @return n/a.
*
* @exception IllegalStateException upon invocation of this method.
*/
protected byte[] engineUpdate(byte[] in, int inOffset, int inLen) {
throw new IllegalStateException("Cipher has not been initialized");
}
/**
* This operation is not supported by this cipher.
* Since it's impossible to initialize this cipher given the
* current Cipher.engineInit(...) implementation,
* IllegalStateException will always be thrown upon invocation.
*
* @param in the input buffer.
* @param inOffset the offset in <code>in</code> where the input
* starts.
* @param inLen the input length.
* @param out the buffer for the result.
* @param outOffset the offset in <code>out</code> where the result
* is stored.
*
* @return n/a.
*
* @exception IllegalStateException upon invocation of this method.
*/
protected int engineUpdate(byte[] in, int inOffset, int inLen,
byte[] out, int outOffset)
throws ShortBufferException {
throw new IllegalStateException("Cipher has not been initialized");
}
/**
* This operation is not supported by this cipher.
* Since it's impossible to initialize this cipher given the
* current Cipher.engineInit(...) implementation,
* IllegalStateException will always be thrown upon invocation.
*
* @param in the input buffer.
* @param inOffset the offset in <code>in</code> where the input
* starts.
* @param inLen the input length.
*
* @return the new buffer with the result.
*
* @exception IllegalStateException upon invocation of this method.
*/
protected byte[] engineDoFinal(byte[] in, int inOffset, int inLen)
throws IllegalBlockSizeException, BadPaddingException {
throw new IllegalStateException("Cipher has not been initialized");
}
/**
* This operation is not supported by this cipher.
* Since it's impossible to initialize this cipher given the
* current Cipher.engineInit(...) implementation,
* IllegalStateException will always be thrown upon invocation.
*
* @param in the input buffer.
* @param inOffset the offset in <code>in</code> where the input
* starts.
* @param inLen the input length.
* @param out the buffer for the result.
* @param outOffset the ofset in <code>out</code> where the result
* is stored.
*
* @return the number of bytes stored in <code>out</code>.
*
* @exception IllegalStateException upon invocation of this method.
*/
protected int engineDoFinal(byte[] input, int inputOffset, int inputLen,
byte[] output, int outputOffset)
throws IllegalBlockSizeException, ShortBufferException,
BadPaddingException {
throw new IllegalStateException("Cipher has not been initialized");
}
/**
* Returns the parameters used with this cipher.
* Note that null maybe returned if this cipher does not use any
* parameters or when it has not be set, e.g. initialized with
* UNWRAP_MODE but wrapped key data has not been given.
*
* @return the parameters used with this cipher; can be null.
*/
protected AlgorithmParameters engineGetParameters() {
AlgorithmParameters params = null;
if (iv != null) {
String algo = cipherKey.getAlgorithm();
try {
params = AlgorithmParameters.getInstance(algo, "SunJCE");
} catch (NoSuchAlgorithmException nsae) {
// should never happen
throw new RuntimeException("Cannot find " + algo +
" AlgorithmParameters implementation in SunJCE provider");
} catch (NoSuchProviderException nspe) {
// should never happen
throw new RuntimeException("Cannot find SunJCE provider");
}
try {
params.init(new IvParameterSpec(iv));
} catch (InvalidParameterSpecException ipse) {
// should never happen
throw new RuntimeException("IvParameterSpec not supported");
}
}
return params;
}
/**
* Returns the key size of the given key object in number of bits.
* This cipher always return the same key size as the DESede ciphers.
*
* @param key the key object.
*
* @return the "effective" key size of the given key object.
*
* @exception InvalidKeyException if <code>key</code> is invalid.
*/
protected int engineGetKeySize(Key key) throws InvalidKeyException {
byte[] encoded = key.getEncoded();
if (encoded.length != 24) {
throw new InvalidKeyException("Invalid key length: " +
encoded.length + " bytes");
}
// Return the effective key length
return 112;
}
/**
* Wrap a key.
*
* @param key the key to be wrapped.
*
* @return the wrapped key.
*
* @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).
*/
protected byte[] engineWrap(Key key)
throws IllegalBlockSizeException, InvalidKeyException {
byte[] keyVal = key.getEncoded();
if ((keyVal == null) || (keyVal.length == 0)) {
throw new InvalidKeyException("Cannot get an encoding of " +
"the key to be wrapped");
}
byte[] cks = getChecksum(keyVal);
byte[] out = new byte[iv.length + keyVal.length + cks.length];
System.arraycopy(keyVal, 0, out, iv.length, keyVal.length);
System.arraycopy(cks, 0, out, iv.length+keyVal.length, cks.length);
cipher.encrypt(out, iv.length, keyVal.length+cks.length,
out, iv.length);
System.arraycopy(iv, 0, out, 0, iv.length);
// reverse the array content
for (int i = 0; i < out.length/2; i++) {
byte temp = out[i];
out[i] = out[out.length-1-i];
out[out.length-1-i] = temp;
}
try {
cipher.init(false, cipherKey.getAlgorithm(),
cipherKey.getEncoded(), IV2);
} catch (InvalidKeyException ike) {
// should never happen
throw new RuntimeException("Internal cipher key is corrupted");
}
cipher.encrypt(out, 0, out.length, out, 0);
// restore cipher state to prior to this call
try {
cipher.init(decrypting, cipherKey.getAlgorithm(),
cipherKey.getEncoded(), iv);
} catch (InvalidKeyException ike) {
// should never happen
throw new RuntimeException("Internal cipher key is corrupted");
}
return out;
}
/**
* Unwrap a previously wrapped key.
*
* @param wrappedKey the key to be unwrapped.
*
* @param wrappedKeyAlgorithm the algorithm the wrapped key is for.
*
* @param wrappedKeyType the type of the wrapped key.
* This is one of <code>Cipher.SECRET_KEY</code>,
* <code>Cipher.PRIVATE_KEY</code>, or <code>Cipher.PUBLIC_KEY</code>.
*
* @return the unwrapped key.
*
* @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>.
*/
protected Key engineUnwrap(byte[] wrappedKey,
String wrappedKeyAlgorithm,
int wrappedKeyType)
throws InvalidKeyException, NoSuchAlgorithmException {
if (wrappedKey.length == 0) {
throw new InvalidKeyException("The wrapped key is empty");
}
byte[] buffer = new byte[wrappedKey.length];
cipher.decrypt(wrappedKey, 0, wrappedKey.length, buffer, 0);
// reverse array content
for (int i = 0; i < buffer.length/2; i++) {
byte temp = buffer[i];
buffer[i] = buffer[buffer.length-1-i];
buffer[buffer.length-1-i] = temp;
}
iv = new byte[IV2.length];
System.arraycopy(buffer, 0, iv, 0, iv.length);
cipher.init(true, cipherKey.getAlgorithm(), cipherKey.getEncoded(),
iv);
cipher.decrypt(buffer, iv.length, buffer.length-iv.length,
buffer, iv.length);
int origLen = buffer.length - iv.length - 8;
byte[] cks = getChecksum(buffer, iv.length, origLen);
int offset = iv.length + origLen;
for (int i = 0; i < cks.length; i++) {
if (buffer[offset + i] != cks[i]) {
throw new InvalidKeyException("Checksum comparison failed");
}
}
// restore cipher state to prior to this call
cipher.init(decrypting, cipherKey.getAlgorithm(),
cipherKey.getEncoded(), IV2);
byte[] out = new byte[origLen];
System.arraycopy(buffer, iv.length, out, 0, out.length);
return ConstructKeys.constructKey(out, wrappedKeyAlgorithm,
wrappedKeyType);
}
private static final byte[] getChecksum(byte[] in) {
return getChecksum(in, 0, in.length);
}
private static final byte[] getChecksum(byte[] in, int offset, int len) {
MessageDigest md = null;
try {
md = MessageDigest.getInstance("SHA1");
} catch (NoSuchAlgorithmException nsae) {
throw new RuntimeException("SHA1 message digest not available");
}
md.update(in, offset, len);
byte[] cks = new byte[8];
System.arraycopy(md.digest(), 0, cks, 0, cks.length);
return cks;
}
}