/*
* Copyright (c) 2005, 2006, 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
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package javax.smartcardio;
import java.util.Arrays;
import java.nio.ByteBuffer;
/**
* A command APDU following the structure defined in ISO/IEC 7816-4.
* It consists of a four byte header and a conditional body of variable length.
* This class does not attempt to verify that the APDU encodes a semantically
* valid command.
*
* <p>Note that when the expected length of the response APDU is specified
* in the {@linkplain #CommandAPDU(int,int,int,int,int) constructors},
* the actual length (Ne) must be specified, not its
* encoded form (Le). Similarly, {@linkplain #getNe} returns the actual
* value Ne. In other words, a value of 0 means "no data in the response APDU"
* rather than "maximum length."
*
* <p>This class supports both the short and extended forms of length
* encoding for Ne and Nc. However, note that not all terminals and Smart Cards
* are capable of accepting APDUs that use the extended form.
*
* <p>For the header bytes CLA, INS, P1, and P2 the Java type <code>int</code>
* is used to represent the 8 bit unsigned values. In the constructors, only
* the 8 lowest bits of the <code>int</code> value specified by the application
* are significant. The accessor methods always return the byte as an unsigned
* value between 0 and 255.
*
* <p>Instances of this class are immutable. Where data is passed in or out
* via byte arrays, defensive cloning is performed.
*
* @see ResponseAPDU
* @see CardChannel#transmit CardChannel.transmit
*
* @since 1.6
* @author Andreas Sterbenz
* @author JSR 268 Expert Group
*/
public final class CommandAPDU implements java.io.Serializable {
private static final long serialVersionUID = 398698301286670877L;
private static final int MAX_APDU_SIZE = 65544;
/** @serial */
private byte[] apdu;
// value of nc
private transient int nc;
// value of ne
private transient int ne;
// index of start of data within the apdu array
private transient int dataOffset;
/**
* Constructs a CommandAPDU from a byte array containing the complete
* APDU contents (header and body).
*
* <p>Note that the apdu bytes are copied to protect against
* subsequent modification.
*
* @param apdu the complete command APDU
*
* @throws NullPointerException if apdu is null
* @throws IllegalArgumentException if apdu does not contain a valid
* command APDU
*/
public CommandAPDU(byte[] apdu) {
this.apdu = apdu.clone();
parse();
}
/**
* Constructs a CommandAPDU from a byte array containing the complete
* APDU contents (header and body). The APDU starts at the index
* <code>apduOffset</code> in the byte array and is <code>apduLength</code>
* bytes long.
*
* <p>Note that the apdu bytes are copied to protect against
* subsequent modification.
*
* @param apdu the complete command APDU
* @param apduOffset the offset in the byte array at which the apdu
* data begins
* @param apduLength the length of the APDU
*
* @throws NullPointerException if apdu is null
* @throws IllegalArgumentException if apduOffset or apduLength are
* negative or if apduOffset + apduLength are greater than apdu.length,
* or if the specified bytes are not a valid APDU
*/
public CommandAPDU(byte[] apdu, int apduOffset, int apduLength) {
checkArrayBounds(apdu, apduOffset, apduLength);
this.apdu = new byte[apduLength];
System.arraycopy(apdu, apduOffset, this.apdu, 0, apduLength);
parse();
}
private void checkArrayBounds(byte[] b, int ofs, int len) {
if ((ofs < 0) || (len < 0)) {
throw new IllegalArgumentException
("Offset and length must not be negative");
}
if (b == null) {
if ((ofs != 0) && (len != 0)) {
throw new IllegalArgumentException
("offset and length must be 0 if array is null");
}
} else {
if (ofs > b.length - len) {
throw new IllegalArgumentException
("Offset plus length exceed array size");
}
}
}
/**
* Creates a CommandAPDU from the ByteBuffer containing the complete APDU
* contents (header and body).
* The buffer's <code>position</code> must be set to the start of the APDU,
* its <code>limit</code> to the end of the APDU. Upon return, the buffer's
* <code>position</code> is equal to its limit; its limit remains unchanged.
*
* <p>Note that the data in the ByteBuffer is copied to protect against
* subsequent modification.
*
* @param apdu the ByteBuffer containing the complete APDU
*
* @throws NullPointerException if apdu is null
* @throws IllegalArgumentException if apdu does not contain a valid
* command APDU
*/
public CommandAPDU(ByteBuffer apdu) {
this.apdu = new byte[apdu.remaining()];
apdu.get(this.apdu);
parse();
}
/**
* Constructs a CommandAPDU from the four header bytes. This is case 1
* in ISO 7816, no command body.
*
* @param cla the class byte CLA
* @param ins the instruction byte INS
* @param p1 the parameter byte P1
* @param p2 the parameter byte P2
*/
public CommandAPDU(int cla, int ins, int p1, int p2) {
this(cla, ins, p1, p2, null, 0, 0, 0);
}
/**
* Constructs a CommandAPDU from the four header bytes and the expected
* response data length. This is case 2 in ISO 7816, empty command data
* field with Ne specified. If Ne is 0, the APDU is encoded as ISO 7816
* case 1.
*
* @param cla the class byte CLA
* @param ins the instruction byte INS
* @param p1 the parameter byte P1
* @param p2 the parameter byte P2
* @param ne the maximum number of expected data bytes in a response APDU
*
* @throws IllegalArgumentException if ne is negative or greater than
* 65536
*/
public CommandAPDU(int cla, int ins, int p1, int p2, int ne) {
this(cla, ins, p1, p2, null, 0, 0, ne);
}
/**
* Constructs a CommandAPDU from the four header bytes and command data.
* This is case 3 in ISO 7816, command data present and Ne absent. The
* value Nc is taken as data.length. If <code>data</code> is null or
* its length is 0, the APDU is encoded as ISO 7816 case 1.
*
* <p>Note that the data bytes are copied to protect against
* subsequent modification.
*
* @param cla the class byte CLA
* @param ins the instruction byte INS
* @param p1 the parameter byte P1
* @param p2 the parameter byte P2
* @param data the byte array containing the data bytes of the command body
*
* @throws IllegalArgumentException if data.length is greater than 65535
*/
public CommandAPDU(int cla, int ins, int p1, int p2, byte[] data) {
this(cla, ins, p1, p2, data, 0, arrayLength(data), 0);
}
/**
* Constructs a CommandAPDU from the four header bytes and command data.
* This is case 3 in ISO 7816, command data present and Ne absent. The
* value Nc is taken as dataLength. If <code>dataLength</code>
* is 0, the APDU is encoded as ISO 7816 case 1.
*
* <p>Note that the data bytes are copied to protect against
* subsequent modification.
*
* @param cla the class byte CLA
* @param ins the instruction byte INS
* @param p1 the parameter byte P1
* @param p2 the parameter byte P2
* @param data the byte array containing the data bytes of the command body
* @param dataOffset the offset in the byte array at which the data
* bytes of the command body begin
* @param dataLength the number of the data bytes in the command body
*
* @throws NullPointerException if data is null and dataLength is not 0
* @throws IllegalArgumentException if dataOffset or dataLength are
* negative or if dataOffset + dataLength are greater than data.length
* or if dataLength is greater than 65535
*/
public CommandAPDU(int cla, int ins, int p1, int p2, byte[] data,
int dataOffset, int dataLength) {
this(cla, ins, p1, p2, data, dataOffset, dataLength, 0);
}
/**
* Constructs a CommandAPDU from the four header bytes, command data,
* and expected response data length. This is case 4 in ISO 7816,
* command data and Ne present. The value Nc is taken as data.length
* if <code>data</code> is non-null and as 0 otherwise. If Ne or Nc
* are zero, the APDU is encoded as case 1, 2, or 3 per ISO 7816.
*
* <p>Note that the data bytes are copied to protect against
* subsequent modification.
*
* @param cla the class byte CLA
* @param ins the instruction byte INS
* @param p1 the parameter byte P1
* @param p2 the parameter byte P2
* @param data the byte array containing the data bytes of the command body
* @param ne the maximum number of expected data bytes in a response APDU
*
* @throws IllegalArgumentException if data.length is greater than 65535
* or if ne is negative or greater than 65536
*/
public CommandAPDU(int cla, int ins, int p1, int p2, byte[] data, int ne) {
this(cla, ins, p1, p2, data, 0, arrayLength(data), ne);
}
private static int arrayLength(byte[] b) {
return (b != null) ? b.length : 0;
}
/**
* Command APDU encoding options:
*
* case 1: |CLA|INS|P1 |P2 | len = 4
* case 2s: |CLA|INS|P1 |P2 |LE | len = 5
* case 3s: |CLA|INS|P1 |P2 |LC |...BODY...| len = 6..260
* case 4s: |CLA|INS|P1 |P2 |LC |...BODY...|LE | len = 7..261
* case 2e: |CLA|INS|P1 |P2 |00 |LE1|LE2| len = 7
* case 3e: |CLA|INS|P1 |P2 |00 |LC1|LC2|...BODY...| len = 8..65542
* case 4e: |CLA|INS|P1 |P2 |00 |LC1|LC2|...BODY...|LE1|LE2| len =10..65544
*
* LE, LE1, LE2 may be 0x00.
* LC must not be 0x00 and LC1|LC2 must not be 0x00|0x00
*/
private void parse() {
if (apdu.length < 4) {
throw new IllegalArgumentException("apdu must be at least 4 bytes long");
}
if (apdu.length == 4) {
// case 1
return;
}
int l1 = apdu[4] & 0xff;
if (apdu.length == 5) {
// case 2s
this.ne = (l1 == 0) ? 256 : l1;
return;
}
if (l1 != 0) {
if (apdu.length == 4 + 1 + l1) {
// case 3s
this.nc = l1;
this.dataOffset = 5;
return;
} else if (apdu.length == 4 + 2 + l1) {
// case 4s
this.nc = l1;
this.dataOffset = 5;
int l2 = apdu[apdu.length - 1] & 0xff;
this.ne = (l2 == 0) ? 256 : l2;
return;
} else {
throw new IllegalArgumentException
("Invalid APDU: length=" + apdu.length + ", b1=" + l1);
}
}
if (apdu.length < 7) {
throw new IllegalArgumentException
("Invalid APDU: length=" + apdu.length + ", b1=" + l1);
}
int l2 = ((apdu[5] & 0xff) << 8) | (apdu[6] & 0xff);
if (apdu.length == 7) {
// case 2e
this.ne = (l2 == 0) ? 65536 : l2;
return;
}
if (l2 == 0) {
throw new IllegalArgumentException("Invalid APDU: length="
+ apdu.length + ", b1=" + l1 + ", b2||b3=" + l2);
}
if (apdu.length == 4 + 3 + l2) {
// case 3e
this.nc = l2;
this.dataOffset = 7;
return;
} else if (apdu.length == 4 + 5 + l2) {
// case 4e
this.nc = l2;
this.dataOffset = 7;
int leOfs = apdu.length - 2;
int l3 = ((apdu[leOfs] & 0xff) << 8) | (apdu[leOfs + 1] & 0xff);
this.ne = (l3 == 0) ? 65536 : l3;
} else {
throw new IllegalArgumentException("Invalid APDU: length="
+ apdu.length + ", b1=" + l1 + ", b2||b3=" + l2);
}
}
/**
* Constructs a CommandAPDU from the four header bytes, command data,
* and expected response data length. This is case 4 in ISO 7816,
* command data and Le present. The value Nc is taken as
* <code>dataLength</code>.
* If Ne or Nc
* are zero, the APDU is encoded as case 1, 2, or 3 per ISO 7816.
*
* <p>Note that the data bytes are copied to protect against
* subsequent modification.
*
* @param cla the class byte CLA
* @param ins the instruction byte INS
* @param p1 the parameter byte P1
* @param p2 the parameter byte P2
* @param data the byte array containing the data bytes of the command body
* @param dataOffset the offset in the byte array at which the data
* bytes of the command body begin
* @param dataLength the number of the data bytes in the command body
* @param ne the maximum number of expected data bytes in a response APDU
*
* @throws NullPointerException if data is null and dataLength is not 0
* @throws IllegalArgumentException if dataOffset or dataLength are
* negative or if dataOffset + dataLength are greater than data.length,
* or if ne is negative or greater than 65536,
* or if dataLength is greater than 65535
*/
public CommandAPDU(int cla, int ins, int p1, int p2, byte[] data,
int dataOffset, int dataLength, int ne) {
checkArrayBounds(data, dataOffset, dataLength);
if (dataLength > 65535) {
throw new IllegalArgumentException("dataLength is too large");
}
if (ne < 0) {
throw new IllegalArgumentException("ne must not be negative");
}
if (ne > 65536) {
throw new IllegalArgumentException("ne is too large");
}
this.ne = ne;
this.nc = dataLength;
if (dataLength == 0) {
if (ne == 0) {
// case 1
this.apdu = new byte[4];
setHeader(cla, ins, p1, p2);
} else {
// case 2s or 2e
if (ne <= 256) {
// case 2s
// 256 is encoded as 0x00
byte len = (ne != 256) ? (byte)ne : 0;
this.apdu = new byte[5];
setHeader(cla, ins, p1, p2);
this.apdu[4] = len;
} else {
// case 2e
byte l1, l2;
// 65536 is encoded as 0x00 0x00
if (ne == 65536) {
l1 = 0;
l2 = 0;
} else {
l1 = (byte)(ne >> 8);
l2 = (byte)ne;
}
this.apdu = new byte[7];
setHeader(cla, ins, p1, p2);
this.apdu[5] = l1;
this.apdu[6] = l2;
}
}
} else {
if (ne == 0) {
// case 3s or 3e
if (dataLength <= 255) {
// case 3s
apdu = new byte[4 + 1 + dataLength];
setHeader(cla, ins, p1, p2);
apdu[4] = (byte)dataLength;
this.dataOffset = 5;
System.arraycopy(data, dataOffset, apdu, 5, dataLength);
} else {
// case 3e
apdu = new byte[4 + 3 + dataLength];
setHeader(cla, ins, p1, p2);
apdu[4] = 0;
apdu[5] = (byte)(dataLength >> 8);
apdu[6] = (byte)dataLength;
this.dataOffset = 7;
System.arraycopy(data, dataOffset, apdu, 7, dataLength);
}
} else {
// case 4s or 4e
if ((dataLength <= 255) && (ne <= 256)) {
// case 4s
apdu = new byte[4 + 2 + dataLength];
setHeader(cla, ins, p1, p2);
apdu[4] = (byte)dataLength;
this.dataOffset = 5;
System.arraycopy(data, dataOffset, apdu, 5, dataLength);
apdu[apdu.length - 1] = (ne != 256) ? (byte)ne : 0;
} else {
// case 4e
apdu = new byte[4 + 5 + dataLength];
setHeader(cla, ins, p1, p2);
apdu[4] = 0;
apdu[5] = (byte)(dataLength >> 8);
apdu[6] = (byte)dataLength;
this.dataOffset = 7;
System.arraycopy(data, dataOffset, apdu, 7, dataLength);
if (ne != 65536) {
int leOfs = apdu.length - 2;
apdu[leOfs] = (byte)(ne >> 8);
apdu[leOfs + 1] = (byte)ne;
} // else le == 65536: no need to fill in, encoded as 0
}
}
}
}
private void setHeader(int cla, int ins, int p1, int p2) {
apdu[0] = (byte)cla;
apdu[1] = (byte)ins;
apdu[2] = (byte)p1;
apdu[3] = (byte)p2;
}
/**
* Returns the value of the class byte CLA.
*
* @return the value of the class byte CLA.
*/
public int getCLA() {
return apdu[0] & 0xff;
}
/**
* Returns the value of the instruction byte INS.
*
* @return the value of the instruction byte INS.
*/
public int getINS() {
return apdu[1] & 0xff;
}
/**
* Returns the value of the parameter byte P1.
*
* @return the value of the parameter byte P1.
*/
public int getP1() {
return apdu[2] & 0xff;
}
/**
* Returns the value of the parameter byte P2.
*
* @return the value of the parameter byte P2.
*/
public int getP2() {
return apdu[3] & 0xff;
}
/**
* Returns the number of data bytes in the command body (Nc) or 0 if this
* APDU has no body. This call is equivalent to
* <code>getData().length</code>.
*
* @return the number of data bytes in the command body or 0 if this APDU
* has no body.
*/
public int getNc() {
return nc;
}
/**
* Returns a copy of the data bytes in the command body. If this APDU as
* no body, this method returns a byte array with length zero.
*
* @return a copy of the data bytes in the command body or the empty
* byte array if this APDU has no body.
*/
public byte[] getData() {
byte[] data = new byte[nc];
System.arraycopy(apdu, dataOffset, data, 0, nc);
return data;
}
/**
* Returns the maximum number of expected data bytes in a response
* APDU (Ne).
*
* @return the maximum number of expected data bytes in a response APDU.
*/
public int getNe() {
return ne;
}
/**
* Returns a copy of the bytes in this APDU.
*
* @return a copy of the bytes in this APDU.
*/
public byte[] getBytes() {
return apdu.clone();
}
/**
* Returns a string representation of this command APDU.
*
* @return a String representation of this command APDU.
*/
public String toString() {
return "CommmandAPDU: " + apdu.length + " bytes, nc=" + nc + ", ne=" + ne;
}
/**
* Compares the specified object with this command APDU for equality.
* Returns true if the given object is also a CommandAPDU and its bytes are
* identical to the bytes in this CommandAPDU.
*
* @param obj the object to be compared for equality with this command APDU
* @return true if the specified object is equal to this command APDU
*/
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj instanceof CommandAPDU == false) {
return false;
}
CommandAPDU other = (CommandAPDU)obj;
return Arrays.equals(this.apdu, other.apdu);
}
/**
* Returns the hash code value for this command APDU.
*
* @return the hash code value for this command APDU.
*/
public int hashCode() {
return Arrays.hashCode(apdu);
}
private void readObject(java.io.ObjectInputStream in)
throws java.io.IOException, ClassNotFoundException {
apdu = (byte[])in.readUnshared();
// initialize transient fields
parse();
}
}