/*

 * Copyright (c) 2005, 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package sun.security.smartcardio;

import java.nio.ByteBuffer;

import java.security.AccessController;

import java.security.PrivilegedAction;

import javax.smartcardio.*;

import static sun.security.smartcardio.PCSC.*;

/**

 * Card implementation.

 *

 * @since   1.6

 * @author  Andreas Sterbenz

 */

final class CardImpl extends Card {

    private static enum State { OK, REMOVED, DISCONNECTED };

    // the terminal that created this card

    private final TerminalImpl terminal;

    // the native SCARDHANDLE

    final long cardId;

    // atr of this card

    private final ATR atr;

    // protocol in use, one of SCARD_PROTOCOL_T0 and SCARD_PROTOCOL_T1

    final int protocol;

    // the basic logical channel (channel 0)

    private final ChannelImpl basicChannel;

    // state of this card connection

    private volatile State state;

    // thread holding exclusive access to the card, or null

    private volatile Thread exclusiveThread;

    // used for platform specific logic

    private static final boolean isWindows;

    static {

        final String osName = AccessController.doPrivileged(

            (PrivilegedAction<String>) () -> System.getProperty("os.name"));

        isWindows = osName.startsWith("Windows");

    }

    CardImpl(TerminalImpl terminal, String protocol) throws PCSCException {

        this.terminal = terminal;

        int sharingMode = SCARD_SHARE_SHARED;

        int connectProtocol;

        if (protocol.equals("*")) {

            connectProtocol = SCARD_PROTOCOL_T0 | SCARD_PROTOCOL_T1;

        } else if (protocol.equalsIgnoreCase("T=0")) {

            connectProtocol = SCARD_PROTOCOL_T0;

        } else if (protocol.equalsIgnoreCase("T=1")) {

            connectProtocol = SCARD_PROTOCOL_T1;

        } else if (protocol.equalsIgnoreCase("direct")) {

            // testing

            // MSDN states that the preferred protocol can be zero, but doesn't

            //     specify whether other values are allowed.

            // pcsc-lite implementation expects the preferred protocol to be non zero.

            connectProtocol = isWindows ? 0 : SCARD_PROTOCOL_RAW;

            sharingMode = SCARD_SHARE_DIRECT;

        } else {

            throw new IllegalArgumentException("Unsupported protocol " + protocol);

        }

        cardId = SCardConnect(terminal.contextId, terminal.name,

                    sharingMode, connectProtocol);

        byte[] status = new byte[2];

        byte[] atrBytes = SCardStatus(cardId, status);

        atr = new ATR(atrBytes);

        this.protocol = status[1] & 0xff;

        basicChannel = new ChannelImpl(this, 0);

        state = State.OK;

    }

    void checkState()  {

        State s = state;

        if (s == State.DISCONNECTED) {

            throw new IllegalStateException("Card has been disconnected");

        } else if (s == State.REMOVED) {

            throw new IllegalStateException("Card has been removed");

        }

    }

    boolean isValid() {

        if (state != State.OK) {

            return false;

        }

        // ping card via SCardStatus

        try {

            SCardStatus(cardId, new byte[2]);

            return true;

        } catch (PCSCException e) {

            state = State.REMOVED;

            return false;

        }

    }

    private void checkSecurity(String action) {

        SecurityManager sm = System.getSecurityManager();

        if (sm != null) {

            sm.checkPermission(new CardPermission(terminal.name, action));

        }

    }

    void handleError(PCSCException e) {

        if (e.code == SCARD_W_REMOVED_CARD) {

            state = State.REMOVED;

        }

    }

    public ATR getATR() {

        return atr;

    }

    public String getProtocol() {

        switch (protocol) {

        case SCARD_PROTOCOL_T0:

            return "T=0";

        case SCARD_PROTOCOL_T1:

            return "T=1";

        default:

            // should never occur

            return "Unknown protocol " + protocol;

        }

    }

    public CardChannel getBasicChannel() {

        checkSecurity("getBasicChannel");

        checkState();

        return basicChannel;

    }

    private static int getSW(byte[] b) {

        if (b.length < 2) {

            return -1;

        }

        int sw1 = b[b.length - 2] & 0xff;

        int sw2 = b[b.length - 1] & 0xff;

        return (sw1 << 8) | sw2;

    }

    private static byte[] commandOpenChannel = new byte[] {0, 0x70, 0, 0, 1};

    public CardChannel openLogicalChannel() throws CardException {

        checkSecurity("openLogicalChannel");

        checkState();

        checkExclusive();

        try {

            byte[] response = SCardTransmit

                (cardId, protocol, commandOpenChannel, 0, commandOpenChannel.length);

            if ((response.length != 3) || (getSW(response) != 0x9000)) {

                throw new CardException

                        ("openLogicalChannel() failed, card response: "

                        + PCSC.toString(response));

            }

            return new ChannelImpl(this, response[0]);

        } catch (PCSCException e) {

            handleError(e);

            throw new CardException("openLogicalChannel() failed", e);

        }

    }

    void checkExclusive() throws CardException {

        Thread t = exclusiveThread;

        if (t == null) {

            return;

        }

        if (t != Thread.currentThread()) {

            throw new CardException("Exclusive access established by another Thread");

        }

    }

    public synchronized void beginExclusive() throws CardException {

        checkSecurity("exclusive");

        checkState();

        if (exclusiveThread != null) {

            throw new CardException

                    ("Exclusive access has already been assigned to Thread "

                    + exclusiveThread.getName());

        }

        try {

            SCardBeginTransaction(cardId);

        } catch (PCSCException e) {

            handleError(e);

            throw new CardException("beginExclusive() failed", e);

        }

        exclusiveThread = Thread.currentThread();

    }

    public synchronized void endExclusive() throws CardException {

        checkState();

        if (exclusiveThread != Thread.currentThread()) {

            throw new IllegalStateException

                    ("Exclusive access not assigned to current Thread");

        }

        try {

            SCardEndTransaction(cardId, SCARD_LEAVE_CARD);

        } catch (PCSCException e) {

            handleError(e);

            throw new CardException("endExclusive() failed", e);

        } finally {

            exclusiveThread = null;

        }

    }

    public byte[] transmitControlCommand(int controlCode, byte[] command)

            throws CardException {

        checkSecurity("transmitControl");

        checkState();

        checkExclusive();

        if (command == null) {

            throw new NullPointerException();

        }

        try {

            byte[] r = SCardControl(cardId, controlCode, command);

            return r;

        } catch (PCSCException e) {

            handleError(e);

            throw new CardException("transmitControlCommand() failed", e);

        }

    }

    public void disconnect(boolean reset) throws CardException {

        if (reset) {

            checkSecurity("reset");

        }

        if (state != State.OK) {

            return;

        }

        checkExclusive();

        try {

            SCardDisconnect(cardId, (reset ? SCARD_RESET_CARD : SCARD_LEAVE_CARD));

        } catch (PCSCException e) {

            throw new CardException("disconnect() failed", e);

        } finally {

            state = State.DISCONNECTED;

            exclusiveThread = null;

        }

    }

    public String toString() {

        return "PC/SC card in " + terminal.getName()

            + ", protocol " + getProtocol() + ", state " + state;

    }

    protected void finalize() throws Throwable {

        try {

            if (state == State.OK) {

                SCardDisconnect(cardId, SCARD_LEAVE_CARD);

            }

        } finally {

            super.finalize();

        }

    }

}