package org.spongycastle.jce.provider;

import java.security.AlgorithmParameters;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.SecureRandom;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEParameterSpec;
import javax.crypto.spec.RC2ParameterSpec;
import javax.crypto.spec.RC5ParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import org.spongycastle.crypto.BlockCipher;
import org.spongycastle.crypto.BufferedBlockCipher;
import org.spongycastle.crypto.CipherParameters;
import org.spongycastle.crypto.DataLengthException;
import org.spongycastle.crypto.InvalidCipherTextException;
import org.spongycastle.crypto.engines.DESEngine;
import org.spongycastle.crypto.engines.DESedeEngine;
import org.spongycastle.crypto.engines.TwofishEngine;
import org.spongycastle.crypto.modes.CBCBlockCipher;
import org.spongycastle.crypto.modes.CFBBlockCipher;
import org.spongycastle.crypto.modes.CTSBlockCipher;
import org.spongycastle.crypto.modes.OFBBlockCipher;
import org.spongycastle.crypto.paddings.PaddedBufferedBlockCipher;
import org.spongycastle.crypto.params.KeyParameter;
import org.spongycastle.crypto.params.ParametersWithIV;
import org.spongycastle.crypto.params.RC2Parameters;
import org.spongycastle.crypto.params.RC5Parameters;
import org.spongycastle.jcajce.provider.symmetric.util.BCPBEKey;
import org.spongycastle.util.Strings;

public class BrokenJCEBlockCipher
    implements BrokenPBE
{
    //
    // specs we can handle.
    //
    private Class[]                 availableSpecs =
                                    {
                                        IvParameterSpec.class,
                                        PBEParameterSpec.class,
                                        RC2ParameterSpec.class,
                                        RC5ParameterSpec.class
                                    };
 
    private BufferedBlockCipher     cipher;
    private ParametersWithIV        ivParam;

    private int                     pbeType = PKCS12;
    private int                     pbeHash = SHA1;
    private int                     pbeKeySize;
    private int                     pbeIvSize;

    private int                     ivLength = 0;

    private AlgorithmParameters     engineParams = null;

    protected BrokenJCEBlockCipher(
        BlockCipher engine)
    {
        cipher = new PaddedBufferedBlockCipher(engine);
    }
        
    protected BrokenJCEBlockCipher(
        BlockCipher engine,
        int         pbeType,
        int         pbeHash,
        int         pbeKeySize,
        int         pbeIvSize)
    {
        cipher = new PaddedBufferedBlockCipher(engine);

        this.pbeType = pbeType;
        this.pbeHash = pbeHash;
        this.pbeKeySize = pbeKeySize;
        this.pbeIvSize = pbeIvSize;
    }

    protected int engineGetBlockSize() 
    {
        return cipher.getBlockSize();
    }

    protected byte[] engineGetIV() 
    {
        return (ivParam != null) ? ivParam.getIV() : null;
    }

    protected int engineGetKeySize(
        Key     key) 
    {
        return key.getEncoded().length;
    }

    protected int engineGetOutputSize(
        int     inputLen) 
    {
        return cipher.getOutputSize(inputLen);
    }

    protected AlgorithmParameters engineGetParameters() 
    {
        if (engineParams == null)
        {
            if (ivParam != null)
            {
                String  name = cipher.getUnderlyingCipher().getAlgorithmName();

                if (name.indexOf('/') >= 0)
                {
                    name = name.substring(0, name.indexOf('/'));
                }

                try
                {
                    engineParams = AlgorithmParameters.getInstance(name, BouncyCastleProvider.PROVIDER_NAME);
                    engineParams.init(ivParam.getIV());
                }
                catch (Exception e)
                {
                    throw new RuntimeException(e.toString());
                }
            }
        }

        return engineParams;
    }

    protected void engineSetMode(
        String  mode) 
    {
        String  modeName = Strings.toUpperCase(mode);

        if (modeName.equals("ECB"))
        {
            ivLength = 0;
            cipher = new PaddedBufferedBlockCipher(cipher.getUnderlyingCipher());
        }
        else if (modeName.equals("CBC"))
        {
            ivLength = cipher.getUnderlyingCipher().getBlockSize();
            cipher = new PaddedBufferedBlockCipher(
                            new CBCBlockCipher(cipher.getUnderlyingCipher()));
        }
        else if (modeName.startsWith("OFB"))
        {
            ivLength = cipher.getUnderlyingCipher().getBlockSize();
            if (modeName.length() != 3)
            {
                int wordSize = Integer.parseInt(modeName.substring(3));

                cipher = new PaddedBufferedBlockCipher(
                                new OFBBlockCipher(cipher.getUnderlyingCipher(), wordSize));
            }
            else
            {
                cipher = new PaddedBufferedBlockCipher(
                        new OFBBlockCipher(cipher.getUnderlyingCipher(), 8 * cipher.getBlockSize()));
            }
        }
        else if (modeName.startsWith("CFB"))
        {
            ivLength = cipher.getUnderlyingCipher().getBlockSize();
            if (modeName.length() != 3)
            {
                int wordSize = Integer.parseInt(modeName.substring(3));

                cipher = new PaddedBufferedBlockCipher(
                                new CFBBlockCipher(cipher.getUnderlyingCipher(), wordSize));
            }
            else
            {
                cipher = new PaddedBufferedBlockCipher(
                        new CFBBlockCipher(cipher.getUnderlyingCipher(), 8 * cipher.getBlockSize()));
            }
        }
        else
        {
            throw new IllegalArgumentException("can't support mode " + mode);
        }
    }

    protected void engineSetPadding(
        String  padding) 
    throws NoSuchPaddingException
    {
        String  paddingName = Strings.toUpperCase(padding);

        if (paddingName.equals("NOPADDING"))
        {
            cipher = new BufferedBlockCipher(cipher.getUnderlyingCipher());
        }
        else if (paddingName.equals("PKCS5PADDING") || paddingName.equals("PKCS7PADDING") || paddingName.equals("ISO10126PADDING"))
        {
            cipher = new PaddedBufferedBlockCipher(cipher.getUnderlyingCipher());
        }
        else if (paddingName.equals("WITHCTS"))
        {
            cipher = new CTSBlockCipher(cipher.getUnderlyingCipher());
        }
        else
        {
            throw new NoSuchPaddingException("Padding " + padding + " unknown.");
        }
    }

    protected void engineInit(
        int                     opmode,
        Key                     key,
        AlgorithmParameterSpec  params,
        SecureRandom            random) 
    throws InvalidKeyException, InvalidAlgorithmParameterException
    {
        CipherParameters        param;

        //
        // a note on iv's - if ivLength is zero the IV gets ignored (we don't use it).
        //
        if (key instanceof BCPBEKey)
        {
            param = BrokenPBE.Util.makePBEParameters((BCPBEKey)key, params, pbeType, pbeHash,
                        cipher.getUnderlyingCipher().getAlgorithmName(), pbeKeySize, pbeIvSize);

            if (pbeIvSize != 0)
            {
                ivParam = (ParametersWithIV)param;
            }
        }
        else if (params == null)
        {
            param = new KeyParameter(key.getEncoded());
        }
        else if (params instanceof IvParameterSpec)
        {
            if (ivLength != 0)
            {
                param = new ParametersWithIV(new KeyParameter(key.getEncoded()), ((IvParameterSpec)params).getIV());
                ivParam = (ParametersWithIV)param;
            }
            else
            {
                param = new KeyParameter(key.getEncoded());
            }
        }
        else if (params instanceof RC2ParameterSpec)
        {
            RC2ParameterSpec    rc2Param = (RC2ParameterSpec)params;

            param = new RC2Parameters(key.getEncoded(), ((RC2ParameterSpec)params).getEffectiveKeyBits());

            if (rc2Param.getIV() != null && ivLength != 0)
            {
                param = new ParametersWithIV(param, rc2Param.getIV());
                ivParam = (ParametersWithIV)param;
            }
        }
        else if (params instanceof RC5ParameterSpec)
        {
            RC5ParameterSpec    rc5Param = (RC5ParameterSpec)params;

            param = new RC5Parameters(key.getEncoded(), ((RC5ParameterSpec)params).getRounds());
            if (rc5Param.getWordSize() != 32)
            {
                throw new IllegalArgumentException("can only accept RC5 word size 32 (at the moment...)");
            }
            if ((rc5Param.getIV() != null) && (ivLength != 0))
            {
                param = new ParametersWithIV(param, rc5Param.getIV());
                ivParam = (ParametersWithIV)param;
            }
        }
        else
        {
            throw new InvalidAlgorithmParameterException("unknown parameter type.");
        }

        if ((ivLength != 0) && !(param instanceof ParametersWithIV))
        {
            if (random == null)
            {
                random = new SecureRandom();
            }

            if ((opmode == Cipher.ENCRYPT_MODE) || (opmode == Cipher.WRAP_MODE))
            {
                byte[]  iv = new byte[ivLength];

                random.nextBytes(iv);
                param = new ParametersWithIV(param, iv);
                ivParam = (ParametersWithIV)param;
            }
            else
            {
                throw new InvalidAlgorithmParameterException("no IV set when one expected");
            }
        }

        switch (opmode)
        {
        case Cipher.ENCRYPT_MODE:
        case Cipher.WRAP_MODE:
            cipher.init(true, param);
            break;
        case Cipher.DECRYPT_MODE:
        case Cipher.UNWRAP_MODE:
            cipher.init(false, param);
            break;
        default:
            System.out.println("eeek!");
        }
    }

    protected void engineInit(
        int                 opmode,
        Key                 key,
        AlgorithmParameters params,
        SecureRandom        random) 
    throws InvalidKeyException, InvalidAlgorithmParameterException
    {
        AlgorithmParameterSpec  paramSpec = null;

        if (params != null)
        {
            for (int i = 0; i != availableSpecs.length; i++)
            {
                try
                {
                    paramSpec = params.getParameterSpec(availableSpecs[i]);
                    break;
                }
                catch (Exception e)
                {
                    continue;
                }
            }

            if (paramSpec == null)
            {
                throw new InvalidAlgorithmParameterException("can't handle parameter " + params.toString());
            }
        }

        engineParams = params;
        engineInit(opmode, key, paramSpec, random);
    }

    protected void engineInit(
        int                 opmode,
        Key                 key,
        SecureRandom        random) 
        throws InvalidKeyException
    {
        try
        {
            engineInit(opmode, key, (AlgorithmParameterSpec)null, random);
        }
        catch (InvalidAlgorithmParameterException e)
        {
            throw new IllegalArgumentException(e.getMessage());
        }
    }

    protected byte[] engineUpdate(
        byte[]  input,
        int     inputOffset,
        int     inputLen) 
    {
        int     length = cipher.getUpdateOutputSize(inputLen);

        if (length > 0)
        {
                byte[]  out = new byte[length];

                cipher.processBytes(input, inputOffset, inputLen, out, 0);
                return out;
        }

        cipher.processBytes(input, inputOffset, inputLen, null, 0);

        return null;
    }

    protected int engineUpdate(
        byte[]  input,
        int     inputOffset,
        int     inputLen,
        byte[]  output,
        int     outputOffset) 
    {
        return cipher.processBytes(input, inputOffset, inputLen, output, outputOffset);
    }

    protected byte[] engineDoFinal(
        byte[]  input,
        int     inputOffset,
        int     inputLen) 
        throws IllegalBlockSizeException, BadPaddingException
    {
        int     len = 0;
        byte[]  tmp = new byte[engineGetOutputSize(inputLen)];

        if (inputLen != 0)
        {
            len = cipher.processBytes(input, inputOffset, inputLen, tmp, 0);
        }

        try
        {
            len += cipher.doFinal(tmp, len);
        }
        catch (DataLengthException e)
        {
            throw new IllegalBlockSizeException(e.getMessage());
        }
        catch (InvalidCipherTextException e)
        {
            throw new BadPaddingException(e.getMessage());
        }

        byte[]  out = new byte[len];

        System.arraycopy(tmp, 0, out, 0, len);

        return out;
    }

    protected int engineDoFinal(
        byte[]  input,
        int     inputOffset,
        int     inputLen,
        byte[]  output,
        int     outputOffset) 
        throws IllegalBlockSizeException, BadPaddingException
    {
        int     len = 0;

        if (inputLen != 0)
        {
                len = cipher.processBytes(input, inputOffset, inputLen, output, outputOffset);
        }

        try
        {
            return len + cipher.doFinal(output, outputOffset + len);
        }
        catch (DataLengthException e)
        {
            throw new IllegalBlockSizeException(e.getMessage());
        }
        catch (InvalidCipherTextException e)
        {
            throw new BadPaddingException(e.getMessage());
        }
    }

    protected byte[] engineWrap(
        Key     key) 
    throws IllegalBlockSizeException, java.security.InvalidKeyException
    {
        byte[] encoded = key.getEncoded();
        if (encoded == null)
        {
            throw new InvalidKeyException("Cannot wrap key, null encoding.");
        }

        try
        {
            return engineDoFinal(encoded, 0, encoded.length);
        }
        catch (BadPaddingException e)
        {
            throw new IllegalBlockSizeException(e.getMessage());
        }
    }

    protected Key engineUnwrap(
        byte[]  wrappedKey,
        String  wrappedKeyAlgorithm,
        int     wrappedKeyType) 
    throws InvalidKeyException
    {
        byte[] encoded = null;
        try
        {
            encoded = engineDoFinal(wrappedKey, 0, wrappedKey.length);
        }
        catch (BadPaddingException e)
        {
            throw new InvalidKeyException(e.getMessage());
        }
        catch (IllegalBlockSizeException e2)
        {
            throw new InvalidKeyException(e2.getMessage());
        }

        if (wrappedKeyType == Cipher.SECRET_KEY)
        {
            return new SecretKeySpec(encoded, wrappedKeyAlgorithm);
        }
        else
        {
            try
            {
                KeyFactory kf = KeyFactory.getInstance(wrappedKeyAlgorithm, BouncyCastleProvider.PROVIDER_NAME);

                if (wrappedKeyType == Cipher.PUBLIC_KEY)
                {
                    return kf.generatePublic(new X509EncodedKeySpec(encoded));
                }
                else if (wrappedKeyType == Cipher.PRIVATE_KEY)
                {
                    return kf.generatePrivate(new PKCS8EncodedKeySpec(encoded));
                }
            }
            catch (NoSuchProviderException e)
            {
                throw new InvalidKeyException("Unknown key type " + e.getMessage());
            }
            catch (NoSuchAlgorithmException e)
            {
                throw new InvalidKeyException("Unknown key type " + e.getMessage());
            }
            catch (InvalidKeySpecException e2)
            {
                throw new InvalidKeyException("Unknown key type " + e2.getMessage());
            }

            throw new InvalidKeyException("Unknown key type " + wrappedKeyType);
        }
    }

    /*
     * The ciphers that inherit from us.
     */

    /**
     * PBEWithMD5AndDES
     */
    static public class BrokePBEWithMD5AndDES
        extends BrokenJCEBlockCipher
    {
        public BrokePBEWithMD5AndDES()
        {
            super(new CBCBlockCipher(new DESEngine()), PKCS5S1, MD5, 64, 64);
        }
    }

    /**
     * PBEWithSHA1AndDES
     */
    static public class BrokePBEWithSHA1AndDES
        extends BrokenJCEBlockCipher
    {
        public BrokePBEWithSHA1AndDES()
        {
            super(new CBCBlockCipher(new DESEngine()), PKCS5S1, SHA1, 64, 64);
        }
    }

    /**
     * PBEWithSHAAnd3-KeyTripleDES-CBC
     */
    static public class BrokePBEWithSHAAndDES3Key
        extends BrokenJCEBlockCipher
    {
        public BrokePBEWithSHAAndDES3Key()
        {
            super(new CBCBlockCipher(new DESedeEngine()), PKCS12, SHA1, 192, 64);
        }
    }

    /**
     * OldPBEWithSHAAnd3-KeyTripleDES-CBC
     */
    static public class OldPBEWithSHAAndDES3Key
        extends BrokenJCEBlockCipher
    {
        public OldPBEWithSHAAndDES3Key()
        {
            super(new CBCBlockCipher(new DESedeEngine()), OLD_PKCS12, SHA1, 192, 64);
        }
    }

    /**
     * PBEWithSHAAnd2-KeyTripleDES-CBC
     */
    static public class BrokePBEWithSHAAndDES2Key
        extends BrokenJCEBlockCipher
    {
        public BrokePBEWithSHAAndDES2Key()
        {
            super(new CBCBlockCipher(new DESedeEngine()), PKCS12, SHA1, 128, 64);
        }
    }

    /**
     * OldPBEWithSHAAndTwofish-CBC
     */
    static public class OldPBEWithSHAAndTwofish
        extends BrokenJCEBlockCipher
    {
        public OldPBEWithSHAAndTwofish()
        {
            super(new CBCBlockCipher(new TwofishEngine()), OLD_PKCS12, SHA1, 256, 128);
        }
    }
}
