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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.security.*;

import java.security.spec.*;

import javax.crypto.*;

import javax.crypto.spec.*;

/**

 * This class represents password-based encryption as defined by the PKCS #5

 * standard.

 * These algorithms implement PBE with HmacSHA1/HmacSHA2-family and AES-CBC.

 * Padding is done as described in PKCS #5.

 *

 * @author Jan Luehe

 *

 *

 * @see javax.crypto.Cipher

 */

abstract class PBES2Core extends CipherSpi {

    private static final int DEFAULT_SALT_LENGTH = 20;

    private static final int DEFAULT_COUNT = 4096;

    // the encapsulated cipher

    private final CipherCore cipher;

    private final int keyLength; // in bits

    private final int blkSize; // in bits

    private final PBKDF2Core kdf;

    private final String pbeAlgo;

    private final String cipherAlgo;

    private int iCount = DEFAULT_COUNT;

    private byte[] salt = null;

    private IvParameterSpec ivSpec = null;

    /**

     * Creates an instance of PBE Scheme 2 according to the selected

     * password-based key derivation function and encryption scheme.

     */

    PBES2Core(String kdfAlgo, String cipherAlgo, int keySize)

        throws NoSuchAlgorithmException, NoSuchPaddingException {

        this.cipherAlgo = cipherAlgo;

        keyLength = keySize * 8;

        pbeAlgo = "PBEWith" + kdfAlgo + "And" + cipherAlgo + "_" + keyLength;

        if (cipherAlgo.equals("AES")) {

            blkSize = AESConstants.AES_BLOCK_SIZE;

            cipher = new CipherCore(new AESCrypt(), blkSize);

            switch(kdfAlgo) {

            case "HmacSHA1":

                kdf = new PBKDF2Core.HmacSHA1();

                break;

            case "HmacSHA224":

                kdf = new PBKDF2Core.HmacSHA224();

                break;

            case "HmacSHA256":

                kdf = new PBKDF2Core.HmacSHA256();

                break;

            case "HmacSHA384":

                kdf = new PBKDF2Core.HmacSHA384();

                break;

            case "HmacSHA512":

                kdf = new PBKDF2Core.HmacSHA512();

                break;

            default:

                throw new NoSuchAlgorithmException(

                    "No Cipher implementation for " + kdfAlgo);

            }

        } else {

            throw new NoSuchAlgorithmException("No Cipher implementation for " +

                                               pbeAlgo);

        }

        cipher.setMode("CBC");

        cipher.setPadding("PKCS5Padding");

    }

    protected void engineSetMode(String mode) throws NoSuchAlgorithmException {

        if ((mode != null) && (!mode.equalsIgnoreCase("CBC"))) {

            throw new NoSuchAlgorithmException("Invalid cipher mode: " + mode);

        }

    }

    protected void engineSetPadding(String paddingScheme)

        throws NoSuchPaddingException {

        if ((paddingScheme != null) &&

            (!paddingScheme.equalsIgnoreCase("PKCS5Padding"))) {

            throw new NoSuchPaddingException("Invalid padding scheme: " +

                                             paddingScheme);

        }

    }

    protected int engineGetBlockSize() {

        return blkSize;

    }

    protected int engineGetOutputSize(int inputLen) {

        return cipher.getOutputSize(inputLen);

    }

    protected byte[] engineGetIV() {

        return cipher.getIV();

    }

    protected AlgorithmParameters engineGetParameters() {

        AlgorithmParameters params = null;

        if (salt == null) {

            // generate random salt and use default iteration count

            salt = new byte[DEFAULT_SALT_LENGTH];

            SunJCE.getRandom().nextBytes(salt);

            iCount = DEFAULT_COUNT;

        }

        if (ivSpec == null) {

            // generate random IV

            byte[] ivBytes = new byte[blkSize];

            SunJCE.getRandom().nextBytes(ivBytes);

            ivSpec = new IvParameterSpec(ivBytes);

        }

        PBEParameterSpec pbeSpec = new PBEParameterSpec(salt, iCount, ivSpec);

        try {

        } 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;

    }

    protected void engineInit(int opmode, Key key, SecureRandom random)

        throws InvalidKeyException {

        try {

            engineInit(opmode, key, (AlgorithmParameterSpec) null, random);

        } catch (InvalidAlgorithmParameterException ie) {

            InvalidKeyException ike =

                new InvalidKeyException("requires PBE parameters");

            ike.initCause(ie);

            throw ike;

        }

    }

    protected void engineInit(int opmode, Key key,

                              AlgorithmParameterSpec params,

                              SecureRandom random)

        throws InvalidKeyException, InvalidAlgorithmParameterException {

        if ((key == null) ||

            (key.getEncoded() == null) ||

            !(key.getAlgorithm().regionMatches(true, 0, "PBE", 0, 3))) {

            throw new InvalidKeyException("Missing password");

        }

        // TBD: consolidate the salt, ic and IV parameter checks below

        // Extract salt and iteration count from the key, if present

        if (key instanceof javax.crypto.interfaces.PBEKey) {

            salt = ((javax.crypto.interfaces.PBEKey)key).getSalt();

            if (salt != null && salt.length < 8) {

                throw new InvalidAlgorithmParameterException(

                    "Salt must be at least 8 bytes long");

            }

            iCount = ((javax.crypto.interfaces.PBEKey)key).getIterationCount();

            if (iCount == 0) {

                iCount = DEFAULT_COUNT;

            } else if (iCount < 0) {

                throw new InvalidAlgorithmParameterException(

                    "Iteration count must be a positive number");

            }

        }

        // Extract salt, iteration count and IV from the params, if present

        if (params == null) {

            if (salt == null) {

                // generate random salt and use default iteration count

                salt = new byte[DEFAULT_SALT_LENGTH];

                random.nextBytes(salt);

                iCount = DEFAULT_COUNT;

            }

            if ((opmode == Cipher.ENCRYPT_MODE) ||

                        (opmode == Cipher.WRAP_MODE)) {

                // generate random IV

                byte[] ivBytes = new byte[blkSize];

                random.nextBytes(ivBytes);

                ivSpec = new IvParameterSpec(ivBytes);

            }

        } else {

            if (!(params instanceof PBEParameterSpec)) {

                throw new InvalidAlgorithmParameterException

                    ("Wrong parameter type: PBE expected");

            }

            // salt and iteration count from the params take precedence

            byte[] specSalt = ((PBEParameterSpec) params).getSalt();

            if (specSalt != null && specSalt.length < 8) {

                throw new InvalidAlgorithmParameterException(

                    "Salt must be at least 8 bytes long");

            }

            salt = specSalt;

            int specICount = ((PBEParameterSpec) params).getIterationCount();

            if (specICount == 0) {

                specICount = DEFAULT_COUNT;

            } else if (specICount < 0) {

                throw new InvalidAlgorithmParameterException(

                    "Iteration count must be a positive number");

            }

            iCount = specICount;

            AlgorithmParameterSpec specParams =

                ((PBEParameterSpec) params).getParameterSpec();

            if (specParams != null) {

                if (specParams instanceof IvParameterSpec) {

                    ivSpec = (IvParameterSpec)specParams;

                } else {

                    throw new InvalidAlgorithmParameterException(

                        "Wrong parameter type: IV expected");

                }

            } else if ((opmode == Cipher.ENCRYPT_MODE) ||

                        (opmode == Cipher.WRAP_MODE)) {

                // generate random IV

                byte[] ivBytes = new byte[blkSize];

                random.nextBytes(ivBytes);

                ivSpec = new IvParameterSpec(ivBytes);

            } else {

                throw new InvalidAlgorithmParameterException(

                    "Missing parameter type: IV expected");

            }

        }

        SecretKeySpec cipherKey = null;

        byte[] derivedKey = null;

        byte[] passwdBytes = key.getEncoded();

        char[] passwdChars = new char[passwdBytes.length];

        for (int i=0; i<passwdChars.length; i++)

            passwdChars[i] = (char) (passwdBytes[i] & 0x7f);

        PBEKeySpec pbeSpec =

            new PBEKeySpec(passwdChars, salt, iCount, blkSize * 8);

            // password char[] was cloned in PBEKeySpec constructor,

            // so we can zero it out here

        java.util.Arrays.fill(passwdChars, ' ');

        java.util.Arrays.fill(passwdBytes, (byte)0x00);

        SecretKey s = null;

        try {

            s = kdf.engineGenerateSecret(pbeSpec);

        } catch (InvalidKeySpecException ikse) {

            InvalidKeyException ike =

                new InvalidKeyException("Cannot construct PBE key");

            ike.initCause(ikse);

            throw ike;

        }

        derivedKey = s.getEncoded();

        cipherKey = new SecretKeySpec(derivedKey, cipherAlgo);

        // initialize the underlying cipher

        cipher.init(opmode, cipherKey, ivSpec, random);

    }

    protected void engineInit(int opmode, Key key, AlgorithmParameters params,

                              SecureRandom random)

        throws InvalidKeyException, InvalidAlgorithmParameterException {

        AlgorithmParameterSpec pbeSpec = null;

        if (params != null) {

            try {

                pbeSpec = params.getParameterSpec(PBEParameterSpec.class);

            } catch (InvalidParameterSpecException ipse) {

                throw new InvalidAlgorithmParameterException(

                    "Wrong parameter type: PBE expected");

            }

        }

        engineInit(opmode, key, pbeSpec, random);

    }

    protected byte[] engineUpdate(byte[] input, int inputOffset, int inputLen) {

        return cipher.update(input, inputOffset, inputLen);

    }

    protected int engineUpdate(byte[] input, int inputOffset, int inputLen,

                               byte[] output, int outputOffset)

        throws ShortBufferException {

        return cipher.update(input, inputOffset, inputLen,

                             output, outputOffset);

    }

    protected byte[] engineDoFinal(byte[] input, int inputOffset, int inputLen)

        throws IllegalBlockSizeException, BadPaddingException {

        return cipher.doFinal(input, inputOffset, inputLen);

    }

    protected int engineDoFinal(byte[] input, int inputOffset, int inputLen,

                                byte[] output, int outputOffset)

        throws ShortBufferException, IllegalBlockSizeException,

               BadPaddingException {

        return cipher.doFinal(input, inputOffset, inputLen,

                              output, outputOffset);

    }

    protected int engineGetKeySize(Key key) throws InvalidKeyException {

        return keyLength;

    }

    protected byte[] engineWrap(Key key)

        throws IllegalBlockSizeException, InvalidKeyException {

        return cipher.wrap(key);

    }

    protected Key engineUnwrap(byte[] wrappedKey, String wrappedKeyAlgorithm,

                               int wrappedKeyType)

        throws InvalidKeyException, NoSuchAlgorithmException {

        byte[] encodedKey;

        return cipher.unwrap(wrappedKey, wrappedKeyAlgorithm,

                             wrappedKeyType);

    }

    public static final class HmacSHA1AndAES_128 extends PBES2Core {

        public HmacSHA1AndAES_128()

            throws NoSuchAlgorithmException, NoSuchPaddingException {

            super("HmacSHA1", "AES", 16);

        }

    }

    public static final class HmacSHA224AndAES_128 extends PBES2Core {

        public HmacSHA224AndAES_128()

            throws NoSuchAlgorithmException, NoSuchPaddingException {

            super("HmacSHA224", "AES", 16);

        }

    }

    public static final class HmacSHA256AndAES_128 extends PBES2Core {

        public HmacSHA256AndAES_128()

            throws NoSuchAlgorithmException, NoSuchPaddingException {

            super("HmacSHA256", "AES", 16);

        }

    }

    public static final class HmacSHA384AndAES_128 extends PBES2Core {

        public HmacSHA384AndAES_128()

            throws NoSuchAlgorithmException, NoSuchPaddingException {

            super("HmacSHA384", "AES", 16);

        }

    }

    public static final class HmacSHA512AndAES_128 extends PBES2Core {

        public HmacSHA512AndAES_128()

            throws NoSuchAlgorithmException, NoSuchPaddingException {

            super("HmacSHA512", "AES", 16);

        }

    }

    public static final class HmacSHA1AndAES_256 extends PBES2Core {

        public HmacSHA1AndAES_256()

            throws NoSuchAlgorithmException, NoSuchPaddingException {

            super("HmacSHA1", "AES", 32);

        }

    }

    public static final class HmacSHA224AndAES_256 extends PBES2Core {

        public HmacSHA224AndAES_256()

            throws NoSuchAlgorithmException, NoSuchPaddingException {

            super("HmacSHA224", "AES", 32);

        }

    }

    public static final class HmacSHA256AndAES_256 extends PBES2Core {

        public HmacSHA256AndAES_256()

            throws NoSuchAlgorithmException, NoSuchPaddingException {

            super("HmacSHA256", "AES", 32);

        }

    }

    public static final class HmacSHA384AndAES_256 extends PBES2Core {

        public HmacSHA384AndAES_256()

            throws NoSuchAlgorithmException, NoSuchPaddingException {

            super("HmacSHA384", "AES", 32);

        }

    }

    public static final class HmacSHA512AndAES_256 extends PBES2Core {

        public HmacSHA512AndAES_256()

            throws NoSuchAlgorithmException, NoSuchPaddingException {

            super("HmacSHA512", "AES", 32);

        }

    }

}