/*
* Copyright (C) 2010 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.
*/
package android.nfc.tech;
import android.nfc.ErrorCodes;
import android.nfc.Tag;
import android.nfc.TagLostException;
import android.os.RemoteException;
import android.util.Log;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
/**
* Provides access to MIFARE Classic properties and I/O operations on a {@link Tag}.
*
* <p>Acquire a {@link MifareClassic} object using {@link #get}.
*
* <p>MIFARE Classic is also known as MIFARE Standard.
* <p>MIFARE Classic tags are divided into sectors, and each sector is sub-divided into
* blocks. Block size is always 16 bytes ({@link #BLOCK_SIZE}. Sector size varies.
* <ul>
* <li>MIFARE Classic Mini are 320 bytes ({@link #SIZE_MINI}), with 5 sectors each of 4 blocks.
* <li>MIFARE Classic 1k are 1024 bytes ({@link #SIZE_1K}), with 16 sectors each of 4 blocks.
* <li>MIFARE Classic 2k are 2048 bytes ({@link #SIZE_2K}), with 32 sectors each of 4 blocks.
* <li>MIFARE Classic 4k} are 4096 bytes ({@link #SIZE_4K}). The first 32 sectors contain 4 blocks
* and the last 8 sectors contain 16 blocks.
* </ul>
*
* <p>MIFARE Classic tags require authentication on a per-sector basis before any
* other I/O operations on that sector can be performed. There are two keys per sector,
* and ACL bits determine what I/O operations are allowed on that sector after
* authenticating with a key. {@see #authenticateSectorWithKeyA} and
* {@see #authenticateSectorWithKeyB}.
*
* <p>Three well-known authentication keys are defined in this class:
* {@link #KEY_DEFAULT}, {@link #KEY_MIFARE_APPLICATION_DIRECTORY},
* {@link #KEY_NFC_FORUM}.
* <ul>
* <li>{@link #KEY_DEFAULT} is the default factory key for MIFARE Classic.
* <li>{@link #KEY_MIFARE_APPLICATION_DIRECTORY} is the well-known key for
* MIFARE Classic cards that have been formatted according to the
* MIFARE Application Directory (MAD) specification.
* <li>{@link #KEY_NFC_FORUM} is the well-known key for MIFARE Classic cards that
* have been formatted according to the NXP specification for NDEF on MIFARE Classic.
*
* <p>Implementation of this class on a Android NFC device is optional.
* If it is not implemented, then
* {@link MifareClassic} will never be enumerated in {@link Tag#getTechList}.
* If it is enumerated, then all {@link MifareClassic} I/O operations will be supported,
* and {@link Ndef#MIFARE_CLASSIC} NDEF tags will also be supported. In either case,
* {@link NfcA} will also be enumerated on the tag, because all MIFARE Classic tags are also
* {@link NfcA}.
*
* <p class="note"><strong>Note:</strong> Methods that perform I/O operations
* require the {@link android.Manifest.permission#NFC} permission.
*/
public final class MifareClassic extends BasicTagTechnology {
private static final String TAG = "NFC";
/**
* The default factory key.
*/
public static final byte[] KEY_DEFAULT =
{(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF};
/**
* The well-known key for tags formatted according to the
* MIFARE Application Directory (MAD) specification.
*/
public static final byte[] KEY_MIFARE_APPLICATION_DIRECTORY =
{(byte)0xA0,(byte)0xA1,(byte)0xA2,(byte)0xA3,(byte)0xA4,(byte)0xA5};
/**
* The well-known key for tags formatted according to the
* NDEF on MIFARE Classic specification.
*/
public static final byte[] KEY_NFC_FORUM =
{(byte)0xD3,(byte)0xF7,(byte)0xD3,(byte)0xF7,(byte)0xD3,(byte)0xF7};
/** A MIFARE Classic compatible card of unknown type */
public static final int TYPE_UNKNOWN = -1;
/** A MIFARE Classic tag */
public static final int TYPE_CLASSIC = 0;
/** A MIFARE Plus tag */
public static final int TYPE_PLUS = 1;
/** A MIFARE Pro tag */
public static final int TYPE_PRO = 2;
/** Tag contains 16 sectors, each with 4 blocks. */
public static final int SIZE_1K = 1024;
/** Tag contains 32 sectors, each with 4 blocks. */
public static final int SIZE_2K = 2048;
/**
* Tag contains 40 sectors. The first 32 sectors contain 4 blocks and the last 8 sectors
* contain 16 blocks.
*/
public static final int SIZE_4K = 4096;
/** Tag contains 5 sectors, each with 4 blocks. */
public static final int SIZE_MINI = 320;
/** Size of a MIFARE Classic block (in bytes) */
public static final int BLOCK_SIZE = 16;
private static final int MAX_BLOCK_COUNT = 256;
private static final int MAX_SECTOR_COUNT = 40;
private boolean mIsEmulated;
private int mType;
private int mSize;
/**
* Get an instance of {@link MifareClassic} for the given tag.
* <p>Does not cause any RF activity and does not block.
* <p>Returns null if {@link MifareClassic} was not enumerated in {@link Tag#getTechList}.
* This indicates the tag is not MIFARE Classic compatible, or this Android
* device does not support MIFARE Classic.
*
* @param tag an MIFARE Classic compatible tag
* @return MIFARE Classic object
*/
public static MifareClassic get(Tag tag) {
if (!tag.hasTech(TagTechnology.MIFARE_CLASSIC)) return null;
try {
return new MifareClassic(tag);
} catch (RemoteException e) {
return null;
}
}
/** @hide */
public MifareClassic(Tag tag) throws RemoteException {
super(tag, TagTechnology.MIFARE_CLASSIC);
NfcA a = NfcA.get(tag); // MIFARE Classic is always based on NFC a
mIsEmulated = false;
switch (a.getSak()) {
case 0x01:
case 0x08:
mType = TYPE_CLASSIC;
mSize = SIZE_1K;
break;
case 0x09:
mType = TYPE_CLASSIC;
mSize = SIZE_MINI;
break;
case 0x10:
mType = TYPE_PLUS;
mSize = SIZE_2K;
// SecLevel = SL2
break;
case 0x11:
mType = TYPE_PLUS;
mSize = SIZE_4K;
// Seclevel = SL2
break;
case 0x18:
mType = TYPE_CLASSIC;
mSize = SIZE_4K;
break;
case 0x28:
mType = TYPE_CLASSIC;
mSize = SIZE_1K;
mIsEmulated = true;
break;
case 0x38:
mType = TYPE_CLASSIC;
mSize = SIZE_4K;
mIsEmulated = true;
break;
case 0x88:
mType = TYPE_CLASSIC;
mSize = SIZE_1K;
// NXP-tag: false
break;
case 0x98:
case 0xB8:
mType = TYPE_PRO;
mSize = SIZE_4K;
break;
default:
// Stack incorrectly reported a MifareClassic. We cannot handle this
// gracefully - we have no idea of the memory layout. Bail.
throw new RuntimeException(
"Tag incorrectly enumerated as MIFARE Classic, SAK = " + a.getSak());
}
}
/**
* Return the type of this MIFARE Classic compatible tag.
* <p>One of {@link #TYPE_UNKNOWN}, {@link #TYPE_CLASSIC}, {@link #TYPE_PLUS} or
* {@link #TYPE_PRO}.
* <p>Does not cause any RF activity and does not block.
*
* @return type
*/
public int getType() {
return mType;
}
/**
* Return the size of the tag in bytes
* <p>One of {@link #SIZE_MINI}, {@link #SIZE_1K}, {@link #SIZE_2K}, {@link #SIZE_4K}.
* These constants are equal to their respective size in bytes.
* <p>Does not cause any RF activity and does not block.
* @return size in bytes
*/
public int getSize() {
return mSize;
}
/**
* Return true if the tag is emulated, determined at discovery time.
* These are actually smart-cards that emulate a MIFARE Classic interface.
* They can be treated identically to a MIFARE Classic tag.
* @hide
*/
public boolean isEmulated() {
return mIsEmulated;
}
/**
* Return the number of MIFARE Classic sectors.
* <p>Does not cause any RF activity and does not block.
* @return number of sectors
*/
public int getSectorCount() {
switch (mSize) {
case SIZE_1K:
return 16;
case SIZE_2K:
return 32;
case SIZE_4K:
return 40;
case SIZE_MINI:
return 5;
default:
return 0;
}
}
/**
* Return the total number of MIFARE Classic blocks.
* <p>Does not cause any RF activity and does not block.
* @return total number of blocks
*/
public int getBlockCount() {
return mSize / BLOCK_SIZE;
}
/**
* Return the number of blocks in the given sector.
* <p>Does not cause any RF activity and does not block.
*
* @param sectorIndex index of sector, starting from 0
* @return number of blocks in the sector
*/
public int getBlockCountInSector(int sectorIndex) {
validateSector(sectorIndex);
if (sectorIndex < 32) {
return 4;
} else {
return 16;
}
}
/**
* Return the sector that contains a given block.
* <p>Does not cause any RF activity and does not block.
*
* @param blockIndex index of block to lookup, starting from 0
* @return sector index that contains the block
*/
public int blockToSector(int blockIndex) {
validateBlock(blockIndex);
if (blockIndex < 32 * 4) {
return blockIndex / 4;
} else {
return 32 + (blockIndex - 32 * 4) / 16;
}
}
/**
* Return the first block of a given sector.
* <p>Does not cause any RF activity and does not block.
*
* @param sectorIndex index of sector to lookup, starting from 0
* @return block index of first block in sector
*/
public int sectorToBlock(int sectorIndex) {
if (sectorIndex < 32) {
return sectorIndex * 4;
} else {
return 32 * 4 + (sectorIndex - 32) * 16;
}
}
/**
* Authenticate a sector with key A.
*
* <p>Successful authentication of a sector with key A enables other
* I/O operations on that sector. The set of operations granted by key A
* key depends on the ACL bits set in that sector. For more information
* see the MIFARE Classic specification on {@see http://www.nxp.com}.
*
* <p>A failed authentication attempt causes an implicit reconnection to the
* tag, so authentication to other sectors will be lost.
*
* <p>This is an I/O operation and will block until complete. It must
* not be called from the main application thread. A blocked call will be canceled with
* {@link IOException} if {@link #close} is called from another thread.
*
* <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
*
* @param sectorIndex index of sector to authenticate, starting from 0
* @param key 6-byte authentication key
* @return true on success, false on authentication failure
* @throws TagLostException if the tag leaves the field
* @throws IOException if there is an I/O failure, or the operation is canceled
*/
public boolean authenticateSectorWithKeyA(int sectorIndex, byte[] key) throws IOException {
return authenticate(sectorIndex, key, true);
}
/**
* Authenticate a sector with key B.
*
* <p>Successful authentication of a sector with key B enables other
* I/O operations on that sector. The set of operations granted by key B
* depends on the ACL bits set in that sector. For more information
* see the MIFARE Classic specification on {@see http://www.nxp.com}.
*
* <p>A failed authentication attempt causes an implicit reconnection to the
* tag, so authentication to other sectors will be lost.
*
* <p>This is an I/O operation and will block until complete. It must
* not be called from the main application thread. A blocked call will be canceled with
* {@link IOException} if {@link #close} is called from another thread.
*
* <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
*
* @param sectorIndex index of sector to authenticate, starting from 0
* @param key 6-byte authentication key
* @return true on success, false on authentication failure
* @throws TagLostException if the tag leaves the field
* @throws IOException if there is an I/O failure, or the operation is canceled
*/
public boolean authenticateSectorWithKeyB(int sectorIndex, byte[] key) throws IOException {
return authenticate(sectorIndex, key, false);
}
private boolean authenticate(int sector, byte[] key, boolean keyA) throws IOException {
validateSector(sector);
checkConnected();
byte[] cmd = new byte[12];
// First byte is the command
if (keyA) {
cmd[0] = 0x60; // phHal_eMifareAuthentA
} else {
cmd[0] = 0x61; // phHal_eMifareAuthentB
}
// Second byte is block address
// Authenticate command takes a block address. Authenticating a block
// of a sector will authenticate the entire sector.
cmd[1] = (byte) sectorToBlock(sector);
// Next 4 bytes are last 4 bytes of UID
byte[] uid = getTag().getId();
System.arraycopy(uid, uid.length - 4, cmd, 2, 4);
// Next 6 bytes are key
System.arraycopy(key, 0, cmd, 6, 6);
try {
if (transceive(cmd, false) != null) {
return true;
}
} catch (TagLostException e) {
throw e;
} catch (IOException e) {
// No need to deal with, will return false anyway
}
return false;
}
/**
* Read 16-byte block.
*
* <p>This is an I/O operation and will block until complete. It must
* not be called from the main application thread. A blocked call will be canceled with
* {@link IOException} if {@link #close} is called from another thread.
*
* <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
*
* @param blockIndex index of block to read, starting from 0
* @return 16 byte block
* @throws TagLostException if the tag leaves the field
* @throws IOException if there is an I/O failure, or the operation is canceled
*/
public byte[] readBlock(int blockIndex) throws IOException {
validateBlock(blockIndex);
checkConnected();
byte[] cmd = { 0x30, (byte) blockIndex };
return transceive(cmd, false);
}
/**
* Write 16-byte block.
*
* <p>This is an I/O operation and will block until complete. It must
* not be called from the main application thread. A blocked call will be canceled with
* {@link IOException} if {@link #close} is called from another thread.
*
* <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
*
* @param blockIndex index of block to write, starting from 0
* @param data 16 bytes of data to write
* @throws TagLostException if the tag leaves the field
* @throws IOException if there is an I/O failure, or the operation is canceled
*/
public void writeBlock(int blockIndex, byte[] data) throws IOException {
validateBlock(blockIndex);
checkConnected();
if (data.length != 16) {
throw new IllegalArgumentException("must write 16-bytes");
}
byte[] cmd = new byte[data.length + 2];
cmd[0] = (byte) 0xA0; // MF write command
cmd[1] = (byte) blockIndex;
System.arraycopy(data, 0, cmd, 2, data.length);
transceive(cmd, false);
}
/**
* Increment a value block, storing the result in the temporary block on the tag.
*
* <p>This is an I/O operation and will block until complete. It must
* not be called from the main application thread. A blocked call will be canceled with
* {@link IOException} if {@link #close} is called from another thread.
*
* <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
*
* @param blockIndex index of block to increment, starting from 0
* @param value non-negative to increment by
* @throws TagLostException if the tag leaves the field
* @throws IOException if there is an I/O failure, or the operation is canceled
*/
public void increment(int blockIndex, int value) throws IOException {
validateBlock(blockIndex);
validateValueOperand(value);
checkConnected();
ByteBuffer cmd = ByteBuffer.allocate(6);
cmd.order(ByteOrder.LITTLE_ENDIAN);
cmd.put( (byte) 0xC1 );
cmd.put( (byte) blockIndex );
cmd.putInt(value);
transceive(cmd.array(), false);
}
/**
* Decrement a value block, storing the result in the temporary block on the tag.
*
* <p>This is an I/O operation and will block until complete. It must
* not be called from the main application thread. A blocked call will be canceled with
* {@link IOException} if {@link #close} is called from another thread.
*
* <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
*
* @param blockIndex index of block to decrement, starting from 0
* @param value non-negative to decrement by
* @throws TagLostException if the tag leaves the field
* @throws IOException if there is an I/O failure, or the operation is canceled
*/
public void decrement(int blockIndex, int value) throws IOException {
validateBlock(blockIndex);
validateValueOperand(value);
checkConnected();
ByteBuffer cmd = ByteBuffer.allocate(6);
cmd.order(ByteOrder.LITTLE_ENDIAN);
cmd.put( (byte) 0xC0 );
cmd.put( (byte) blockIndex );
cmd.putInt(value);
transceive(cmd.array(), false);
}
/**
* Copy from the temporary block to a value block.
*
* <p>This is an I/O operation and will block until complete. It must
* not be called from the main application thread. A blocked call will be canceled with
* {@link IOException} if {@link #close} is called from another thread.
*
* <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
*
* @param blockIndex index of block to copy to
* @throws TagLostException if the tag leaves the field
* @throws IOException if there is an I/O failure, or the operation is canceled
*/
public void transfer(int blockIndex) throws IOException {
validateBlock(blockIndex);
checkConnected();
byte[] cmd = { (byte) 0xB0, (byte) blockIndex };
transceive(cmd, false);
}
/**
* Copy from a value block to the temporary block.
*
* <p>This is an I/O operation and will block until complete. It must
* not be called from the main application thread. A blocked call will be canceled with
* {@link IOException} if {@link #close} is called from another thread.
*
* <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
*
* @param blockIndex index of block to copy from
* @throws TagLostException if the tag leaves the field
* @throws IOException if there is an I/O failure, or the operation is canceled
*/
public void restore(int blockIndex) throws IOException {
validateBlock(blockIndex);
checkConnected();
byte[] cmd = { (byte) 0xC2, (byte) blockIndex };
transceive(cmd, false);
}
/**
* Send raw NfcA data to a tag and receive the response.
*
* <p>This is equivalent to connecting to this tag via {@link NfcA}
* and calling {@link NfcA#transceive}. Note that all MIFARE Classic
* tags are based on {@link NfcA} technology.
*
* <p>Use {@link #getMaxTransceiveLength} to retrieve the maximum number of bytes
* that can be sent with {@link #transceive}.
*
* <p>This is an I/O operation and will block until complete. It must
* not be called from the main application thread. A blocked call will be canceled with
* {@link IOException} if {@link #close} is called from another thread.
*
* <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
*
* @see NfcA#transceive
*/
public byte[] transceive(byte[] data) throws IOException {
return transceive(data, true);
}
/**
* Return the maximum number of bytes that can be sent with {@link #transceive}.
* @return the maximum number of bytes that can be sent with {@link #transceive}.
*/
public int getMaxTransceiveLength() {
return getMaxTransceiveLengthInternal();
}
/**
* Set the {@link #transceive} timeout in milliseconds.
*
* <p>The timeout only applies to {@link #transceive} on this object,
* and is reset to a default value when {@link #close} is called.
*
* <p>Setting a longer timeout may be useful when performing
* transactions that require a long processing time on the tag
* such as key generation.
*
* <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
*
* @param timeout timeout value in milliseconds
*/
public void setTimeout(int timeout) {
try {
int err = mTag.getTagService().setTimeout(TagTechnology.MIFARE_CLASSIC, timeout);
if (err != ErrorCodes.SUCCESS) {
throw new IllegalArgumentException("The supplied timeout is not valid");
}
} catch (RemoteException e) {
Log.e(TAG, "NFC service dead", e);
}
}
/**
* Get the current {@link #transceive} timeout in milliseconds.
*
* <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
*
* @return timeout value in milliseconds
*/
public int getTimeout() {
try {
return mTag.getTagService().getTimeout(TagTechnology.MIFARE_CLASSIC);
} catch (RemoteException e) {
Log.e(TAG, "NFC service dead", e);
return 0;
}
}
private static void validateSector(int sector) {
// Do not be too strict on upper bounds checking, since some cards
// have more addressable memory than they report. For example,
// MIFARE Plus 2k cards will appear as MIFARE Classic 1k cards when in
// MIFARE Classic compatibility mode.
// Note that issuing a command to an out-of-bounds block is safe - the
// tag should report error causing IOException. This validation is a
// helper to guard against obvious programming mistakes.
if (sector < 0 || sector >= MAX_SECTOR_COUNT) {
throw new IndexOutOfBoundsException("sector out of bounds: " + sector);
}
}
private static void validateBlock(int block) {
// Just looking for obvious out of bounds...
if (block < 0 || block >= MAX_BLOCK_COUNT) {
throw new IndexOutOfBoundsException("block out of bounds: " + block);
}
}
private static void validateValueOperand(int value) {
if (value < 0) {
throw new IllegalArgumentException("value operand negative");
}
}
}