src/org/simalliance/openmobileapi/service/security/gpac/dataobjects/Response_AR_DO.java

/*
 * Copyright 2012 Giesecke & Devrient GmbH.
 *
 * 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 org.simalliance.openmobileapi.service.security.gpac.dataobjects;



/**
 * Response-AR-DO
 * If access rules can be found in the Secure Element which corresponds to the specified AR-DO 
 * in the GET DATA (Specific) command these must be returned by the ARA-M 
 * in the response data field within a Response-AR-DO. 
 * The GET DATA command can also be applied iteratively with subsequent GET DATA (next) commands 
 * if the Response-AR-DO is too large for the GET DATA (Specific) command. 
 * The length field of the Response-AR-DO shall always contain the full length of the DOs value 
 * to determine on device side if a subsequent GET DATA (Next) command is needed.
 *
 * 
 *
 */
public class Response_AR_DO extends BerTlv {
	
	public final static int _TAG = 0xFF50;
	
	private AR_DO mArDo = null;

	public Response_AR_DO(byte[] rawData, int valueIndex,
			int valueLength) {
		super(rawData, _TAG, valueIndex, valueLength);
	}
	
	public AR_DO getArDo(){
		return mArDo;
	}

	@Override
	/**
	 * Tag: FF 50
	 * 
	 * Length: n or 0
	 * If n is equal to zero, then there are no rules to fetch.
	 * 
	 * Value: 
	 * An AR-DO if the referenced access rules exist. 
	 * The value is empty if access rules do not exist to the defined reference
	 */
	public void interpret() 
		throws ParserException {
	
		byte[] data = getRawData();
		int index = getValueIndex();
		
		if( getValueLength() == 0 ){
			// No Access rule available for the requested reference.
			return;
		}
		
		if( index + getValueLength() > data.length){
			throw new ParserException( "Not enough data for Response_AR_DO!");
		}
		
		int currentPos = index;
		int endPos = index + getValueLength();
		do {
			BerTlv temp = BerTlv.decode(data, currentPos);
			
			if( temp.getTag() == AR_DO._TAG) { // AR-DO tag
				mArDo = new AR_DO( data, temp.getValueIndex(), temp.getValueLength());
				mArDo.interpret();
			} else {
				// un-comment following line if a more restrictive 
				// behavior is necessary.
				//throw new ParserException("Invalid DO in Response-AR-DO!");
			}
			// get REF-AR-DOs as long as data is available.
			currentPos = temp.getValueIndex() + temp.getValueLength();
		} while( currentPos < endPos );  
	}
}