src/com/android/se/security/gpac/Response_ALL_AR_DO.java

/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * 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.
 */
/*
 * Copyright (c) 2017, The Linux Foundation.
 */

/*
 * 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 com.android.se.security.gpac;

import java.util.ArrayList;

/**
 * Response-ALL-AR-DO All access rules stored in the Secure Element have to be returned by the ARA-M
 * after a GET DATA (All) command in the response data field within a Response-ALL-AR-DO. The GET
 * DATA command can also be applied iteratively with subsequent GET DATA (Next) commands if the
 * Response-ALL-AR-DO is too large for the GET DATA (All) command. The length field of the
 * Response-ALL-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_ALL_AR_DO extends BerTlv {

    public static final int TAG = 0xFF40;

    private ArrayList<REF_AR_DO> mRefArDos = new ArrayList<REF_AR_DO>();

    public Response_ALL_AR_DO(byte[] rawData, int valueIndex, int valueLength) {
        super(rawData, TAG, valueIndex, valueLength);
    }

    public ArrayList<REF_AR_DO> getRefArDos() {
        return mRefArDos;
    }

    @Override
    /**
     * Tag: FF 40
     *
     * <p>Length: n or 0 If n is equal to zero, then there are no rules to fetch.
     *
     * <p>Value: REF-AR-DO 1..n or empty An REF-AR-DO if access rules exist. REF-AR-DOs can occur
     * several times in a concatenated DO chain if several REF-AR-DO exist on the SE. The value is
     * empty if access rules do not exist.
     */
    public void interpret() throws ParserException {

        mRefArDos.clear();

        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!");
        }

        BerTlv temp;
        int currentPos = index;
        int endPos = index + getValueLength();
        do {
            temp = BerTlv.decode(data, currentPos);

            REF_AR_DO tempRefArDo;

            if (temp.getTag() == REF_AR_DO.TAG) { // REF-AR-DO tag
                tempRefArDo = new REF_AR_DO(data, temp.getValueIndex(), temp.getValueLength());
                tempRefArDo.interpret();
                mRefArDos.add(tempRefArDo);
            } else {
                // uncomment following line if a more restrictive
                // behavior is necessary.
                // throw new ParserException("Invalid DO in Response-ALL-AR-DO!");
            }
            // get REF-AR-DOs as long as data is available.
            currentPos = temp.getValueIndex() + temp.getValueLength();
        } while (currentPos < endPos);
    }
}