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 * Copyright  2003-2004 The Apache Software Foundation.
 *
 *  Licensed 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,
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 *  See the License for the specific language governing permissions and
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package com.sun.org.apache.xml.internal.security.encryption;

import java.io.IOException;

import com.sun.org.apache.xml.internal.security.c14n.CanonicalizationException;
import com.sun.org.apache.xml.internal.security.utils.resolver.ResourceResolver;
import com.sun.org.apache.xml.internal.security.utils.resolver.ResourceResolverException;
import com.sun.org.apache.xml.internal.security.exceptions.Base64DecodingException;
import com.sun.org.apache.xml.internal.security.signature.XMLSignatureInput;
import com.sun.org.apache.xml.internal.security.transforms.TransformationException;
import org.w3c.dom.Attr;
import com.sun.org.apache.xml.internal.security.utils.Base64;


XMLCipherInput is used to wrap input passed into the
XMLCipher encryption operations.
In decryption mode, it takes a CipherData object and allows
callers to dereference the CipherData into the encrypted bytes that it
actually represents.  This takes care of all base64 encoding etc.
While primarily an internal class, this can be used by applications to
quickly and easily retrieve the encrypted bytes from an EncryptedType
object
Author:
Berin Lautenbach/**
 * <code>XMLCipherInput</code> is used to wrap input passed into the
 * XMLCipher encryption operations.
 *
 * In decryption mode, it takes a <code>CipherData</code> object and allows
 * callers to dereference the CipherData into the encrypted bytes that it
 * actually represents.  This takes care of all base64 encoding etc.
 *
 * While primarily an internal class, this can be used by applications to
 * quickly and easily retrieve the encrypted bytes from an EncryptedType
 * object
 *
 * @author Berin Lautenbach
 */
public class XMLCipherInput {

    private static java.util.logging.Logger logger =
        java.util.logging.Logger.getLogger(XMLCipher.class.getName());

        
The data we are working with /** The data we are working with */
        private CipherData _cipherData;

        
MODES /** MODES */
        private int _mode;

        
Constructor for processing encrypted octets
Params:
data – The CipherData object to read the bytes from
Throws:
XMLEncryptionException – XMLEncryptionException/**
         * Constructor for processing encrypted octets
         *
         * @param data The <code>CipherData</code> object to read the bytes from
         * @throws XMLEncryptionException {@link XMLEncryptionException}
         */

        public XMLCipherInput(CipherData data) throws XMLEncryptionException {

                _cipherData = data;
                _mode = XMLCipher.DECRYPT_MODE;
                if (_cipherData == null) {
                        throw new XMLEncryptionException("CipherData is null");
                }

        }

        
Constructor for processing encrypted octets
Params:
input – The EncryptedType object to read
the bytes from.
Throws:
XMLEncryptionException – XMLEncryptionException/**
         * Constructor for processing encrypted octets
         *
         * @param input The <code>EncryptedType</code> object to read
         * the bytes from.
         * @throws XMLEncryptionException {@link XMLEncryptionException}
         */

        public XMLCipherInput(EncryptedType input) throws XMLEncryptionException {

                _cipherData = ((input == null) ? null : input.getCipherData());
                _mode = XMLCipher.DECRYPT_MODE;
                if (_cipherData == null) {
                        throw new XMLEncryptionException("CipherData is null");
                }

        }

        
Dereferences the input and returns it as a single byte array.
Throws:
XMLEncryptionException – 
Returns:
The decripted bytes./**
         * Dereferences the input and returns it as a single byte array.
         *
         * @throws XMLEncryptionException
     * @return The decripted bytes.
         */

        public byte[] getBytes() throws XMLEncryptionException {

                if (_mode == XMLCipher.DECRYPT_MODE) {
                        return getDecryptBytes();
                }
                return null;
        }

    
Internal method to get bytes in decryption mode
Throws:
XMLEncryptionException – 
Returns:
the decripted bytes/**
     * Internal method to get bytes in decryption mode
     * @return the decripted bytes
     * @throws XMLEncryptionException
     */
    private byte[] getDecryptBytes() throws XMLEncryptionException {

        String base64EncodedEncryptedOctets = null;

        if (_cipherData.getDataType() == CipherData.REFERENCE_TYPE) {
            // Fun time!
            logger.log(java.util.logging.Level.FINE, "Found a reference type CipherData");
            CipherReference cr = _cipherData.getCipherReference();

            // Need to wrap the uri in an Attribute node so that we can
            // Pass to the resource resolvers

            Attr uriAttr = cr.getURIAsAttr();
            XMLSignatureInput input = null;

            try {
                ResourceResolver resolver =
                    ResourceResolver.getInstance(uriAttr, null);
                input = resolver.resolve(uriAttr, null);
            } catch (ResourceResolverException ex) {
                throw new XMLEncryptionException("empty", ex);
            }

            if (input != null) {
                logger.log(java.util.logging.Level.FINE, "Managed to resolve URI \"" + cr.getURI() + "\"");
            } else {
                logger.log(java.util.logging.Level.FINE, "Failed to resolve URI \"" + cr.getURI() + "\"");
            }

            // Lets see if there are any transforms
            Transforms transforms = cr.getTransforms();
            if (transforms != null) {
                logger.log(java.util.logging.Level.FINE, "Have transforms in cipher reference");
                try {
                    com.sun.org.apache.xml.internal.security.transforms.Transforms dsTransforms =
                        transforms.getDSTransforms();
                    input = dsTransforms.performTransforms(input);
                } catch (TransformationException ex) {
                    throw new XMLEncryptionException("empty", ex);
                }
            }

            try {
                return input.getBytes();
            } catch (IOException ex) {
                throw new XMLEncryptionException("empty", ex);
            } catch (CanonicalizationException ex) {
                throw new XMLEncryptionException("empty", ex);
            }

        // retrieve the cipher text
        } else if (_cipherData.getDataType() == CipherData.VALUE_TYPE) {
            base64EncodedEncryptedOctets =
                _cipherData.getCipherValue().getValue();
        } else {
            throw new XMLEncryptionException("CipherData.getDataType() returned unexpected value");
        }

        logger.log(java.util.logging.Level.FINE, "Encrypted octets:\n" + base64EncodedEncryptedOctets);

        byte[] encryptedBytes = null;
        try {
            encryptedBytes = Base64.decode(base64EncodedEncryptedOctets);
        } catch (Base64DecodingException bde) {
            throw new XMLEncryptionException("empty", bde);
        }

        return (encryptedBytes);
    }
}