/*
 * 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) 2015-2017, The Linux Foundation.
 */

/*
 * Copyright (C) 2011 Deutsche Telekom, A.G.
 *
 * 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.
 */

/*
 * Contributed by: Giesecke & Devrient GmbH.
 */

package com.android.se.security.arf.pkcs15;

import android.util.Log;

import com.android.se.internal.Util;
import com.android.se.security.arf.ASN1;
import com.android.se.security.arf.DERParser;
import com.android.se.security.arf.SecureElement;
import com.android.se.security.arf.SecureElementException;

import java.io.IOException;
import java.util.Arrays;

/** EF_ACMain related features */
public class EFACMain extends EF {

    public static final String TAG = "ACE ARF EF_ACMain";
    // Length of the "RefreshTag"
    public static final short REFRESHTAG_LEN = 8;

    // "EF Access Control Main" path
    private byte[] mACMainPath = null;

    /**
     * Constructor
     *
     * @param secureElement SE on which ISO7816 commands are applied
     */
    public EFACMain(SecureElement handle, byte[] path) {
        super(handle);
        mACMainPath = path;
    }

    /**
     * Decodes EF_ACMain file
     *
     * @param buffer ASN.1 data
     * @return Path to "Access Control Rules"
     */
    private byte[] decodeDER(byte[] buffer) throws PKCS15Exception {
        DERParser der = new DERParser(buffer);
        der.parseTLV(ASN1.TAG_Sequence);
        if (der.parseTLV(ASN1.TAG_OctetString) != REFRESHTAG_LEN) {
            throw new PKCS15Exception("[Parser] RefreshTag length not valid");
        }

        byte[] refreshTag = der.getTLVData();
        if (!Arrays.equals(refreshTag, this.mSEHandle.getRefreshTag())) {
            mSEHandle.setRefreshTag(refreshTag);
            return der.parsePathAttributes();
        }
        return null; // RefreshTag not updated
    }

    /**
     * Selects and Analyses EF_ACMain file
     *
     * @return Path to "EF_ACRules" if "RefreshTag" has been updated; <code>null</code> otherwise
     */
    public byte[] analyseFile() throws IOException, PKCS15Exception, SecureElementException {
        Log.i(TAG, "Analysing EF_ACMain...");
        byte[] path = mACMainPath;

    /*
    // 2012-04-12
    // extend path if ODF path was determined from EF DIR.
    if( mSEHandle.getPKCS15Path() != null ) {
        path = new byte[mSEHandle.getPKCS15Path().length + mACMainPath.length];
        System.arraycopy(mSEHandle.getPKCS15Path(), 0, path, 0, mSEHandle.getPKCS15Path().length);
        System.arraycopy(mACMainPath, 0, path, mSEHandle.getPKCS15Path().length, mACMainPath
        .length );
    }
    //---
     *
     */

        if (selectFile(path) != APDU_SUCCESS) {
            throw new PKCS15Exception("EF_ACMain not found!");
        }
        return decodeDER(readBinary(0, Util.END));
    }
}