/*
* 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,
* 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 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;
/**
* <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 */
private CipherData _cipherData;
/** MODES */
private int _mode;
/**
* 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
*
* @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
* @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
* @return the decripted bytes
* @throws XMLEncryptionException
*/
private byte[] getDecryptBytes() throws XMLEncryptionException {
String base64EncodedEncryptedOctets = null;
if (_cipherData.getDataType() == CipherData.REFERENCE_TYPE) {
// Fun time!
if (logger.isLoggable(java.util.logging.Level.FINE)) 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) {
if (logger.isLoggable(java.util.logging.Level.FINE)) logger.log(java.util.logging.Level.FINE, "Managed to resolve URI \"" + cr.getURI() + "\"");
}
else {
if (logger.isLoggable(java.util.logging.Level.FINE)) 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) {
if (logger.isLoggable(java.util.logging.Level.FINE)) 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) {
CipherValue cv = _cipherData.getCipherValue();
base64EncodedEncryptedOctets = new String(cv.getValue());
} else {
throw new XMLEncryptionException("CipherData.getDataType() returned unexpected value");
}
if (logger.isLoggable(java.util.logging.Level.FINE)) 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);
}
}