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to you under the Apache License, Version 2.0 (the
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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.crypto.jna;

import java.nio.ByteBuffer;
import java.security.GeneralSecurityException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.security.spec.AlgorithmParameterSpec;
import java.util.Properties;
import java.util.StringTokenizer;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.ShortBufferException;
import javax.crypto.spec.IvParameterSpec;

import org.apache.commons.crypto.cipher.CryptoCipher;
import org.apache.commons.crypto.cipher.CryptoCipherFactory;
import org.apache.commons.crypto.utils.Utils;

import com.sun.jna.NativeLong;
import com.sun.jna.ptr.PointerByReference;

Implements the CryptoCipher using JNA into OpenSSL.
/**
 * Implements the CryptoCipher using JNA into OpenSSL.
 */
class OpenSslJnaCipher implements CryptoCipher {

    private PointerByReference algo;
    private final PointerByReference context;
    private final AlgorithmMode algMode;
    private final int padding;
    private final String transformation;

    
Constructs a CryptoCipher using JNA into OpenSSL 
Params:
props – properties for OpenSSL cipher
transformation – transformation for OpenSSL cipher
Throws:
GeneralSecurityException – if OpenSSL cipher initialize failed/**
     * Constructs a {@link CryptoCipher} using JNA into OpenSSL
     *
     * @param props properties for OpenSSL cipher
     * @param transformation transformation for OpenSSL cipher
     * @throws GeneralSecurityException if OpenSSL cipher initialize failed
     */
    public OpenSslJnaCipher(Properties props, String transformation) // NOPMD
            throws GeneralSecurityException {
        if (!OpenSslJna.isEnabled()) {
            throw new GeneralSecurityException("Could not enable JNA access", OpenSslJna.initialisationError());
        }
        this.transformation = transformation;
        Transform transform = tokenizeTransformation(transformation);
        algMode = AlgorithmMode.get(transform.algorithm, transform.mode);
        
        if(algMode != AlgorithmMode.AES_CBC && algMode != AlgorithmMode.AES_CTR) {
            throw new GeneralSecurityException("unknown algorithm "+transform.algorithm + "_" + transform.mode);
        }

        padding = Padding.get(transform.padding);
        context = OpenSslNativeJna.EVP_CIPHER_CTX_new();

    }

    
Initializes the cipher with mode, key and iv.
Params:
mode – Cipher.ENCRYPT_MODE or Cipher.DECRYPT_MODE
key – crypto key for the cipher
params – the algorithm parameters
Throws:
InvalidKeyException – If key length is invalid
InvalidAlgorithmParameterException – if IV length is wrong/**
     * Initializes the cipher with mode, key and iv.
     *
     * @param mode {@link Cipher#ENCRYPT_MODE} or {@link Cipher#DECRYPT_MODE}
     * @param key crypto key for the cipher
     * @param params the algorithm parameters
     * @throws InvalidKeyException If key length is invalid
     * @throws InvalidAlgorithmParameterException if IV length is wrong
     */
    @Override
    public void init(int mode, Key key, AlgorithmParameterSpec params)
            throws InvalidKeyException, InvalidAlgorithmParameterException {
        Utils.checkNotNull(key);
        Utils.checkNotNull(params);
        int cipherMode = OpenSslNativeJna.OOSL_JNA_DECRYPT_MODE;
        if (mode == Cipher.ENCRYPT_MODE) {
            cipherMode = OpenSslNativeJna.OOSL_JNA_ENCRYPT_MODE;
        }
        byte[] iv;
        if (params instanceof IvParameterSpec) {
            iv = ((IvParameterSpec) params).getIV();
        } else {
            // other AlgorithmParameterSpec such as GCMParameterSpec is not
            // supported now.
            throw new InvalidAlgorithmParameterException("Illegal parameters");
        }
        
       if(algMode == AlgorithmMode.AES_CBC) {
            switch (key.getEncoded().length) {
                case 16: algo = OpenSslNativeJna.EVP_aes_128_cbc(); break;
                case 24: algo = OpenSslNativeJna.EVP_aes_192_cbc(); break;
                case 32: algo = OpenSslNativeJna.EVP_aes_256_cbc(); break;
            default:
                throw new InvalidKeyException("keysize unsupported (" + key.getEncoded().length + ")");
            }

        } else {
            switch (key.getEncoded().length) {
                case 16: algo = OpenSslNativeJna.EVP_aes_128_ctr(); break;
                case 24: algo = OpenSslNativeJna.EVP_aes_192_ctr(); break;
                case 32: algo = OpenSslNativeJna.EVP_aes_256_ctr(); break;
            default:
                throw new InvalidKeyException("keysize unsupported (" + key.getEncoded().length + ")");
            }
        }
        
        int retVal = OpenSslNativeJna.EVP_CipherInit_ex(context, algo, null, key.getEncoded(), iv, cipherMode);
        throwOnError(retVal);
        OpenSslNativeJna.EVP_CIPHER_CTX_set_padding(context, padding);
    }

    
Continues a multiple-part encryption/decryption operation. The data is
encrypted or decrypted, depending on how this cipher was initialized.
Params:
inBuffer – the input ByteBuffer
outBuffer – the output ByteBuffer
Throws:
ShortBufferException – if there is insufficient space in the output
        buffer
Returns:
int number of bytes stored in output/**
     * Continues a multiple-part encryption/decryption operation. The data is
     * encrypted or decrypted, depending on how this cipher was initialized.
     *
     * @param inBuffer the input ByteBuffer
     * @param outBuffer the output ByteBuffer
     * @return int number of bytes stored in <code>output</code>
     * @throws ShortBufferException if there is insufficient space in the output
     *         buffer
     */
    @Override
    public int update(ByteBuffer inBuffer, ByteBuffer outBuffer)
            throws ShortBufferException {
        int[] outlen = new int[1];
        int retVal = OpenSslNativeJna.EVP_CipherUpdate(context, outBuffer, outlen, inBuffer, inBuffer.remaining());
        throwOnError(retVal);
        int len = outlen[0];
        inBuffer.position(inBuffer.limit());
        outBuffer.position(outBuffer.position() + len);
        return len;
    }

    
Continues a multiple-part encryption/decryption operation. The data is
encrypted or decrypted, depending on how this cipher was initialized.
Params:
input – the input byte array
inputOffset – the offset in input where the input starts
inputLen – the input length
output – the byte array for the result
outputOffset – the offset in output where the result is stored
Throws:
ShortBufferException – if there is insufficient space in the output
        byte array
Returns:
the number of bytes stored in output/**
     * Continues a multiple-part encryption/decryption operation. The data is
     * encrypted or decrypted, depending on how this cipher was initialized.
     *
     * @param input the input byte array
     * @param inputOffset the offset in input where the input starts
     * @param inputLen the input length
     * @param output the byte array for the result
     * @param outputOffset the offset in output where the result is stored
     * @return the number of bytes stored in output
     * @throws ShortBufferException if there is insufficient space in the output
     *         byte array
     */
    @Override
    public int update(byte[] input, int inputOffset, int inputLen,
            byte[] output, int outputOffset) throws ShortBufferException {
        ByteBuffer outputBuf = ByteBuffer.wrap(output, outputOffset, output.length - outputOffset);
        ByteBuffer inputBuf = ByteBuffer.wrap(input, inputOffset, inputLen);
        return update(inputBuf, outputBuf);
    }
    
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.
Params:
inBuffer – the input ByteBuffer
outBuffer – the output ByteBuffer
Throws:
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
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.
ShortBufferException – if the given output buffer is too small to
        hold the result
Returns:
int number of bytes stored in output/**
     * 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.
     *
     * @param inBuffer the input ByteBuffer
     * @param outBuffer the output ByteBuffer
     * @return int number of bytes stored in <code>output</code>
     * @throws 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
     * @throws 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.
     * @throws ShortBufferException if the given output buffer is too small to
     *         hold the result
     */
    @Override
    public int doFinal(ByteBuffer inBuffer, ByteBuffer outBuffer)
            throws ShortBufferException, IllegalBlockSizeException,
            BadPaddingException {
        int uptLen = update(inBuffer, outBuffer);
        int[] outlen = new int[1];
        int retVal = OpenSslNativeJna.EVP_CipherFinal_ex(context, outBuffer, outlen);
        throwOnError(retVal);
        int len = uptLen + outlen[0];
        outBuffer.position(outBuffer.position() + outlen[0]);
        return len;
    }

    
Encrypts or decrypts data in a single-part operation, or finishes a
multiple-part operation.
Params:
input – the input byte array
inputOffset – the offset in input where the input starts
inputLen – the input length
output – the byte array for the result
outputOffset – the offset in output where the result is stored
Throws:
ShortBufferException – if the given output byte array is too small
        to hold the result
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
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.
Returns:
the number of bytes stored in output/**
     * Encrypts or decrypts data in a single-part operation, or finishes a
     * multiple-part operation.
     *
     * @param input the input byte array
     * @param inputOffset the offset in input where the input starts
     * @param inputLen the input length
     * @param output the byte array for the result
     * @param outputOffset the offset in output where the result is stored
     * @return the number of bytes stored in output
     * @throws ShortBufferException if the given output byte array is too small
     *         to hold the result
     * @throws 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
     * @throws 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.
     */
    @Override
    public int doFinal(byte[] input, int inputOffset, int inputLen,
            byte[] output, int outputOffset) throws ShortBufferException,
            IllegalBlockSizeException, BadPaddingException {
        ByteBuffer outputBuf = ByteBuffer.wrap(output, outputOffset, output.length-outputOffset);
        ByteBuffer inputBuf = ByteBuffer.wrap(input, inputOffset, inputLen);
        return doFinal(inputBuf, outputBuf);
    }

    
Closes the OpenSSL cipher. Clean the OpenSsl native context.
/**
     * Closes the OpenSSL cipher. Clean the OpenSsl native context.
     */
    @Override
    public void close() {
        if (context != null) {
            OpenSslNativeJna.EVP_CIPHER_CTX_cleanup(context);
            // Freeing the context multiple times causes a JVM crash
            // A work-round is to only free it at finalize time
            // TODO is that sufficient?
//            OpenSslNativeJna.EVP_CIPHER_CTX_free(context);
        }
    }

    
Params:
retVal – the result value of error./**
     * @param retVal the result value of error.
     */
    private void throwOnError(int retVal) {
        if (retVal != 1) {
            NativeLong err = OpenSslNativeJna.ERR_peek_error();
            String errdesc = OpenSslNativeJna.ERR_error_string(err, null);
            
            if (context != null) {
                OpenSslNativeJna.EVP_CIPHER_CTX_cleanup(context);
            }
            throw new RuntimeException("return code "+retVal+" from OpenSSL. Err code is "+err+": "+errdesc);
        }
    }

    //TODO DUPLICATED CODE, needs cleanup
    
Nested class for algorithm, mode and padding. /** Nested class for algorithm, mode and padding. */
    private static class Transform {
        final String algorithm;
        final String mode;
        final String padding;

        
Constructor of Transform.
Params:
algorithm – the algorithm name
mode – the mode name
padding – the padding name/**
         * Constructor of Transform.
         * @param algorithm the algorithm name
         * @param mode the mode name
         * @param padding the padding name
         */
        public Transform(String algorithm, String mode, String padding) {
            this.algorithm = algorithm;
            this.mode = mode;
            this.padding = padding;
        }
    }

    
Tokenize the transformation.
Params:
transformation – current transformation
Throws:
NoSuchAlgorithmException – if the algorithm is not supported
Returns:
the Transform/**
     * Tokenize the transformation.
     * @param transformation current transformation
     * @return the Transform
     * @throws NoSuchAlgorithmException if the algorithm is not supported
     */
    private static Transform 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 (e.g., AES) index 1: mode (e.g., CTR) index 2: padding
         * (e.g., NoPadding)
         */
        String[] parts = new String[3];
        int count = 0;
        StringTokenizer parser = new StringTokenizer(transformation, "/");
        while (parser.hasMoreTokens() && count < 3) {
            parts[count++] = parser.nextToken().trim();
        }
        if (count != 3 || parser.hasMoreTokens()) {
            throw new NoSuchAlgorithmException(
                    "Invalid transformation format: " + transformation);
        }
        return new Transform(parts[0], parts[1], parts[2]);
    }
    
    
AlgorithmMode of JNA.  Currently only support AES/CTR/NoPadding.
/**
     * AlgorithmMode of JNA.  Currently only support AES/CTR/NoPadding.
     */
    private static enum AlgorithmMode {
        AES_CTR, AES_CBC;

        
Gets the AlgorithmMode instance.
Params:
algorithm – the algorithm name
mode – the mode name
Throws:
NoSuchAlgorithmException – if the algorithm is not support
Returns:
the AlgorithmMode instance/**
         * Gets the AlgorithmMode instance.
         * @param algorithm the algorithm name
         * @param mode the mode name
         * @return the AlgorithmMode instance
         * @throws NoSuchAlgorithmException if the algorithm is not support
         */
        static AlgorithmMode get(String algorithm, String mode) throws NoSuchAlgorithmException {
            try {
                return AlgorithmMode.valueOf(algorithm + "_" + mode);
            } catch (Exception e) {
                throw new NoSuchAlgorithmException("Doesn't support algorithm: " + algorithm + " and mode: " + mode);
            }
        }
    }

    
Padding of JNA.
/**
     * Padding of JNA.
     */
    private static enum Padding {
        NoPadding, PKCS5Padding;

        
Gets the Padding instance.
Params:
padding – the padding name
Throws:
NoSuchPaddingException – if the algorithm is not support
Returns:
the AlgorithmMode instance/**
         * Gets the Padding instance.
         *
         * @param padding the padding name
         * @return the AlgorithmMode instance
         * @throws NoSuchPaddingException if the algorithm is not support
         */
        static int get(String padding) throws NoSuchPaddingException {
            try {
                return Padding.valueOf(padding).ordinal();
            } catch (Exception e) {
                throw new NoSuchPaddingException("Doesn't support padding: " + padding);
            }
        }
    }

    @Override
    public int getBlockSize() {
        return CryptoCipherFactory.AES_BLOCK_SIZE;
    }

    @Override
    public String getAlgorithm() {
        return transformation;
    }

    @Override
    protected void finalize() throws Throwable {
        OpenSslNativeJna.EVP_CIPHER_CTX_free(context);
        super.finalize();
    }
}