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	/*
	* Copyright (c) 2002, 2021, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package com.sun.crypto.provider;

	import java.security.*;
	import java.security.spec.*;
	import java.util.Arrays;
	import javax.crypto.*;
	import javax.crypto.spec.*;

	/**
	* This class represents password-based encryption as defined by the PKCS #5
	* standard.
	*
	* @author Jan Luehe
	*
	*
	* @see javax.crypto.Cipher
	*/
	final class PBES1Core {

	// the encapsulated DES cipher
	private CipherCore cipher;
	private MessageDigest md;
	private int blkSize;
	private String algo = null;
	private byte[] salt = null;
	private int iCount = 10;

	/**
	* Creates an instance of PBE Cipher using the specified CipherSpi
	* instance.
	*
	*/
	PBES1Core(String cipherAlg) throws NoSuchAlgorithmException,
	NoSuchPaddingException {
	algo = cipherAlg;
	if (algo.equals("DES")) {
	cipher = new CipherCore(new DESCrypt(),
	DESConstants.DES_BLOCK_SIZE);
	} else if (algo.equals("DESede")) {

	cipher = new CipherCore(new DESedeCrypt(),
	DESConstants.DES_BLOCK_SIZE);
	} else {
	throw new NoSuchAlgorithmException("No Cipher implementation " +
	"for PBEWithMD5And" + algo);
	}
	cipher.setMode("CBC");
	cipher.setPadding("PKCS5Padding");
	// get instance of MD5
	md = MessageDigest.getInstance("MD5");
	}

	/**
	* Sets the mode of this cipher. This algorithm can only be run in CBC
	* mode.
	*
	* @param mode the cipher mode
	*
	* @exception NoSuchAlgorithmException if the requested cipher mode is
	* invalid
	*/
	void setMode(String mode) throws NoSuchAlgorithmException {
	cipher.setMode(mode);
	}

	/**
	* Sets the padding mechanism of this cipher. This algorithm only uses
	* PKCS #5 padding.
	*
	* @param paddingScheme the padding mechanism
	*
	* @exception NoSuchPaddingException if the requested padding mechanism
	* is invalid
	*/
	void setPadding(String paddingScheme) throws NoSuchPaddingException {
	cipher.setPadding(paddingScheme);
	}

	/**
	* Returns the block size (in bytes).
	*
	* @return the block size (in bytes)
	*/
	int getBlockSize() {
	return DESConstants.DES_BLOCK_SIZE;
	}

	/**
	* 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)
	*
	*/
	int getOutputSize(int inputLen) {
	return cipher.getOutputSize(inputLen);
	}

	/**
	* Returns the initialization vector (IV) in a new buffer.
	*
	* <p> This is useful in the case where a random IV has been created
	* (see <a href = "#init">init</a>),
	* 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.
	*/
	byte[] getIV() {
	return cipher.getIV();
	}

	/**
	* 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 the default set of parameters or a set of
	* randomly generated parameters used by the underlying cipher
	* implementation (provided that the underlying cipher implementation
	* uses a default set of parameters or creates new parameters if it needs
	* parameters but was not initialized with any).
	*
	* @return the parameters used with this cipher, or null if this cipher
	* does not use any parameters.
	*/
	AlgorithmParameters getParameters() {
	AlgorithmParameters params = null;
	if (salt == null) {
	salt = new byte[8];
	SunJCE.getRandom().nextBytes(salt);
	}
	PBEParameterSpec pbeSpec = new PBEParameterSpec(salt, iCount);
	try {
	params = AlgorithmParameters.getInstance("PBEWithMD5And" +
	(algo.equalsIgnoreCase("DES")? "DES":"TripleDES"),
	SunJCE.getInstance());
	params.init(pbeSpec);
	} catch (NoSuchAlgorithmException nsae) {
	// should never happen
	throw new RuntimeException("SunJCE called, but not configured");
	} catch (InvalidParameterSpecException ipse) {
	// should never happen
	throw new RuntimeException("PBEParameterSpec not supported");
	}
	return params;
	}

	/**
	* Initializes this cipher with a key, a set of
	* algorithm parameters, and a source of randomness.
	* 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 (including its underlying feedback or padding scheme)
	* requires any random bytes, it will get them from <code>random</code>.
	*
	* @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
	* @exception InvalidAlgorithmParameterException if the given algorithm
	* parameters are inappropriate for this cipher
	*/
	void init(int opmode, Key key, AlgorithmParameterSpec params,
	SecureRandom random)
	throws InvalidKeyException, InvalidAlgorithmParameterException {
	if (((opmode == Cipher.DECRYPT_MODE) \|\|
	(opmode == Cipher.UNWRAP_MODE)) && (params == null)) {
	throw new InvalidAlgorithmParameterException("Parameters "
	+ "missing");
	}
	if (key == null) {
	throw new InvalidKeyException("Null key");
	}

	byte[] derivedKey;
	byte[] passwdBytes = key.getEncoded();
	try {
	if ((passwdBytes == null) \|\|
	!(key.getAlgorithm().regionMatches(true, 0, "PBE", 0, 3))) {
	throw new InvalidKeyException("Missing password");
	}

	if (params == null) {
	// create random salt and use default iteration count
	salt = new byte[8];
	random.nextBytes(salt);
	} else {
	if (!(params instanceof PBEParameterSpec)) {
	throw new InvalidAlgorithmParameterException
	("Wrong parameter type: PBE expected");
	}
	salt = ((PBEParameterSpec) params).getSalt();
	// salt must be 8 bytes long (by definition)
	if (salt.length != 8) {
	throw new InvalidAlgorithmParameterException
	("Salt must be 8 bytes long");
	}
	iCount = ((PBEParameterSpec) params).getIterationCount();
	if (iCount <= 0) {
	throw new InvalidAlgorithmParameterException
	("IterationCount must be a positive number");
	}
	}
	derivedKey = deriveCipherKey(passwdBytes);
	} finally {
	if (passwdBytes != null) Arrays.fill(passwdBytes, (byte) 0x00);
	}
	// use all but the last 8 bytes as the key value
	SecretKeySpec cipherKey = new SecretKeySpec(derivedKey, 0,
	derivedKey.length-8, algo);
	// use the last 8 bytes as the IV
	IvParameterSpec ivSpec = new IvParameterSpec(derivedKey,
	derivedKey.length-8,
	8);
	// initialize the underlying cipher
	cipher.init(opmode, cipherKey, ivSpec, random);
	}

	private byte[] deriveCipherKey(byte[] passwdBytes) {

	byte[] result = null;

	if (algo.equals("DES")) {
	// P \|\| S (password concatenated with salt)
	md.update(passwdBytes);
	md.update(salt);
	// digest P \|\| S with iCount iterations
	// first iteration
	byte[] toBeHashed = md.digest(); // this resets the digest
	// remaining (iCount - 1) iterations
	for (int i = 1; i < iCount; ++i) {
	md.update(toBeHashed);
	try {
	md.digest(toBeHashed, 0, toBeHashed.length);
	} catch (DigestException e) {
	throw new ProviderException("Internal error", e);
	}
	}
	result = toBeHashed;
	} else if (algo.equals("DESede")) {
	// if the 2 salt halves are the same, invert one of them
	int i;
	for (i=0; i<4; i++) {
	if (salt[i] != salt[i+4])
	break;
	}
	if (i==4) { // same, invert 1st half
	for (i=0; i<2; i++) {
	byte tmp = salt[i];
	salt[i] = salt[3-i];
	salt[3-i] = tmp;
	}
	}

	// Now digest each half (concatenated with password). For each
	// half, go through the loop as many times as specified by the
	// iteration count parameter (inner for loop).
	// Concatenate the output from each digest round with the
	// password, and use the result as the input to the next digest
	// operation.
	byte[] toBeHashed = null;
	result = new byte[DESedeKeySpec.DES_EDE_KEY_LEN +
	DESConstants.DES_BLOCK_SIZE];
	for (i = 0; i < 2; i++) {
	// first iteration
	md.update(salt, i * (salt.length / 2), salt.length / 2);
	md.update(passwdBytes);
	toBeHashed = md.digest();
	// remaining (iCount - 1) iterations
	for (int j = 1; j < iCount; ++j) {
	md.update(toBeHashed);
	md.update(passwdBytes);
	try {
	md.digest(toBeHashed, 0, toBeHashed.length);
	} catch (DigestException e) {
	throw new ProviderException("Internal error", e);
	}
	}
	System.arraycopy(toBeHashed, 0, result, i*16,
	toBeHashed.length);
	}
	}
	// clear data used in message
	md.reset();
	return result;
	}

	void init(int opmode, Key key, AlgorithmParameters params,
	SecureRandom random)
	throws InvalidKeyException, InvalidAlgorithmParameterException {
	PBEParameterSpec pbeSpec = null;
	if (params != null) {
	try {
	pbeSpec = params.getParameterSpec(PBEParameterSpec.class);
	} catch (InvalidParameterSpecException ipse) {
	throw new InvalidAlgorithmParameterException("Wrong parameter "
	+ "type: PBE "
	+ "expected");
	}
	}
	init(opmode, key, pbeSpec, random);
	}

	/**
	* 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>, are processed, and the
	* result is stored in a new buffer.
	*
	* @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
	*
	*/
	byte[] update(byte[] input, int inputOffset, int inputLen) {
	return cipher.update(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>, are processed, and the
	* result is stored in the <code>output</code> buffer, starting at
	* <code>outputOffset</code>.
	*
	* @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 ShortBufferException if the given output buffer is too small
	* to hold the result
	*/
	int update(byte[] input, int inputOffset, int inputLen,
	byte[] output, int outputOffset)
	throws ShortBufferException {
	return cipher.update(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>The first <code>inputLen</code> bytes in the <code>input</code>
	* buffer, starting at <code>inputOffset</code>, 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>The cipher is reset to its initial state (uninitialized) after this
	* call.
	*
	* @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 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
	* @exception BadPaddingException if decrypting and padding is chosen,
	* but the last input data does not have proper padding bytes.
	*/
	byte[] doFinal(byte[] input, int inputOffset, int inputLen)
	throws IllegalBlockSizeException, BadPaddingException {
	return cipher.doFinal(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>, 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>.
	*
	* <p>The cipher is reset to its initial state (uninitialized) after this
	* call.
	*
	* @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 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
	* @exception ShortBufferException if the given output buffer is too small
	* to hold the result
	* @exception BadPaddingException if decrypting and padding is chosen,
	* but the last input data does not have proper padding bytes.
	*/
	int doFinal(byte[] input, int inputOffset, int inputLen,
	byte[] output, int outputOffset)
	throws ShortBufferException, IllegalBlockSizeException,
	BadPaddingException {
	return cipher.doFinal(input, inputOffset, inputLen,
	output, outputOffset);
	}

	/**
	* 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).
	*/
	byte[] wrap(Key key)
	throws IllegalBlockSizeException, InvalidKeyException {
	byte[] result = null;
	byte[] encodedKey = null;
	try {
	encodedKey = key.getEncoded();
	if ((encodedKey == null) \|\| (encodedKey.length == 0)) {
	throw new InvalidKeyException("Cannot get an encoding of " +
	"the key to be wrapped");
	}

	result = doFinal(encodedKey, 0, encodedKey.length);
	} catch (BadPaddingException e) {
	// Should never happen
	} finally {
	if (encodedKey != null) Arrays.fill(encodedKey, (byte)0x00);
	}

	return result;
	}

	/**
	* 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>.
	*/
	Key unwrap(byte[] wrappedKey,
	String wrappedKeyAlgorithm,
	int wrappedKeyType)
	throws InvalidKeyException, NoSuchAlgorithmException {
	try {
	byte[] encodedKey = doFinal(wrappedKey, 0, wrappedKey.length);
	try {
	return ConstructKeys.constructKey(encodedKey, wrappedKeyAlgorithm,
	wrappedKeyType);
	} finally {
	Arrays.fill(encodedKey, (byte)0);
	}
	} catch (BadPaddingException ePadding) {
	throw new InvalidKeyException("The wrapped key is not padded " +
	"correctly");
	} catch (IllegalBlockSizeException eBlockSize) {
	throw new InvalidKeyException("The wrapped key does not have " +
	"the correct length");
	}
	}
	}

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