/**
* Searches for an index to the file specified by the id in the file structure starting from
* position start.
*
* @param fileStructureArray the array with the file structure
* @param shift the shift in the input array (e.g. when the array is the APDU with the header
* bytes)
* @param start starting position to search
* @param lastOffset the last valid offset in the input array
* @param id the id of the file that is searched
* @return the index of the file, if found
* @throws ArrayIndexOutOfBoundsException when start and lastOffset point outside of the input
* array
* @throws FileNotFoundException when file not found
*/
short searchId(byte[] fileStructureArray, short shift, short start, short lastOffset, short id)
throws ArrayIndexOutOfBoundsException, FileNotFoundException {
if (start < 0 || start > (short) (lastOffset - 5)) {
// This sould produce ArrayIndexOutOfBoundsException
fileStructureArray[fileStructureArray.length] = (byte) 0xFF;
}
short fid = Util.getShort(fileStructureArray, (short) (start + 1));
if (fid == id) {
return start;
}
if (fileStructureArray[start] != DIR) {
throw fnfe;
} else {
short childNum = fileStructureArray[(short) (start + 4)];
if (start > (short) ((short) (lastOffset - 5) - childNum)) {
fileStructureArray[fileStructureArray.length] = (byte) 0xFF;
}
for (short i = 0; i < childNum; i++) {
try {
return searchId(
fileStructureArray,
shift,
(short) (fileStructureArray[(short) (start + (short) (5 + i))] + shift),
lastOffset,
id);
} catch (FileNotFoundException e) {
}
}
}
throw fnfe;
}
/* input data is supposed to have been validaded before */
public static short GetBERTLVDataLen(byte[] buf, short offset, short len) {
short size = 0;
short sizeforsize = 0;
short i = 1;
if ((buf[offset] & 0x1F) != 0x1F) {
// simplified tag
} else {
// tag start with all 5 last bits to 1
// skip the tag
while (((buf[(short) (offset + i)] & 0x80) != 0) && ((short) (i + offset)) < len) {
i++;
}
// pass the last byte of the tag
i += 1;
}
// check the size
if ((buf[(short) (offset + i)] & 0x80) != 0) {
// size encoded in many bytes
sizeforsize = (short) (buf[(short) (offset + i)] & 0x7F);
if (sizeforsize > 2) {
// more than two bytes for encoding => not something than we can handle
return 0;
} else if (sizeforsize == 1) {
size = Util.makeShort((byte) 0, buf[(short) (offset + i + 1)]);
} else if (sizeforsize == 2) {
size = Util.getShort(buf, (short) (offset + i + 1));
}
} else {
// size encode in one byte
size = Util.makeShort((byte) 0, buf[(short) (offset + i)]);
}
return size;
}
private void processCreateFile(APDU apdu) {
if (state != STATE_INITIAL) {
ISOException.throwIt(SW_INS_NOT_SUPPORTED);
}
byte[] buf = apdu.getBuffer();
short lc = unsigned(buf[OFFSET_LC]);
apdu.setIncomingAndReceive();
if (lc != 5) {
ISOException.throwIt(SW_WRONG_LENGTH);
}
short offset = OFFSET_CDATA;
short id = Util.getShort(buf, offset);
offset += 2;
short len = Util.getShort(buf, offset);
offset += 2;
byte perm = buf[offset];
if (!fileSystem.createFile(id, len, perm)) {
ISOException.throwIt(SW_WRONG_DATA);
}
}
/* returns 0 or the size of the BERTLV structure */
public static short CheckBERTLV(byte[] buf, short offset, short len) {
short size = 0;
short sizeforsize = 0;
short i = 1;
short totalsize = 0;
if ((buf[offset] & 0x1F) != 0x1F) {
// simplified tag
} else {
// tag start with all 5 last bits to 1
// skip the tag
while (((buf[(short) (offset + i)] & 0x80) != 0) && i < len) {
i++;
}
// pass the last byte of the tag
i += 1;
}
if ((short) (i + 1) > len) {
return 0;
}
// check the size
if ((buf[(short) (offset + i)] & 0x80) != 0) {
// size encoded in many bytes
sizeforsize = (short) (buf[(short) (offset + i)] & 0x7F);
if ((short) (i + 1 + sizeforsize) > len) {
return 0;
}
if (sizeforsize > (short) 2) {
// more than two bytes for encoding => not something than we can handle
return 0;
} else if (sizeforsize == (short) 1) {
if ((short) (offset + i + 1 + sizeforsize) > len) {
return 0;
}
size = Util.makeShort((byte) 0, buf[(short) (offset + i + 1)]);
} else if (sizeforsize == 2) {
totalsize = (short) (i + 1 + sizeforsize + size);
if ((short) (offset + i + 1 + sizeforsize) > len) {
return (short) 0;
}
size = Util.getShort(buf, (short) (offset + i + 1));
}
} else {
// size encode in one byte
size = Util.makeShort((byte) 0, buf[(short) (offset + i)]);
}
totalsize = (short) (i + 1 + sizeforsize + size);
if (totalsize < (short) 240 && (short) (offset + totalsize) > len) {
return (short) 0;
}
return totalsize;
}
/**
* \brief Decode the length field of a TLV-entry.
*
* <p>The length field itself can be 1, 2 or 3 bytes long: - If the length is between 0 and 127,
* it is 1 byte long. - If the length is between 128 and 255, it is 2 bytes long. The first byte
* is 0x81 to indicate this. - If the length is between 256 and 65535, it is 3 bytes long. The
* first byte is 0x82, the following 2 contain the actual length. Note: Only lengths up to 0x7FFF
* (32767) are supported here, because a short in Java is signed.
*
* <p>\param buf The buffer containing the length field.
*
* <p>\param offset The offset at where the length field starts.
*
* <p>\param length The length of the buffer (buf). This is to prevent that the index gets out of
* bounds.
*
* <p>\return The (positive) length encoded by the length field, or in case of an error, -1.
*
* <p>\throw InvalidArgumentsException If offset is too big for a signed Java short If the first
* byte of the length field is invalid
*/
public static short decodeLengthField(byte[] buf, short offset) throws InvalidArgumentsException {
if (buf[offset] == (byte) 0x82) { // 256..65535
// Check for short overflow
// (In Java, a short is signed: positive values are 0000..7FFF)
if (buf[(short) (offset + 1)] < 0) { // 80..FF
throw InvalidArgumentsException.getInstance();
}
return Util.getShort(buf, (short) (offset + 1));
} else if (buf[offset] == (byte) 0x81) {
return (short) (0x00FF & buf[(short) (offset + 1)]);
} else if (buf[offset] > 0) { // 00..7F
return (short) (0x007F & buf[offset]);
} else {
throw InvalidArgumentsException.getInstance();
}
}
private short findEntryRelative(short start, short id) throws FileNotFoundException {
try {
if (fileStructure[start] != DIR) {
throw fnfe;
}
short childNum = fileStructure[(short) (start + 4)];
for (short i = 0; i < childNum; i++) {
short index = fileStructure[(short) (start + (short) (5 + i))];
short fid = Util.getShort(fileStructure, (short) (index + 1));
if (fid == id) {
return index;
}
}
} catch (ArrayIndexOutOfBoundsException aioobe) {
}
throw fnfe;
}
private short getFileIndex(short fid) throws ISOException {
short result = -1;
switch (fid) {
case EF_DG1_FID:
result = EF_DG1_INDEX;
break;
case EF_DG2_FID:
result = EF_DG2_INDEX;
break;
case EF_DG3_FID:
result = EF_DG3_INDEX;
break;
case EF_DG4_FID:
result = EF_DG4_INDEX;
break;
case EF_DG5_FID:
result = EF_DG5_INDEX;
break;
case EF_DG6_FID:
result = EF_DG6_INDEX;
break;
case EF_DG7_FID:
result = EF_DG7_INDEX;
break;
case EF_DG8_FID:
result = EF_DG8_INDEX;
break;
case EF_DG9_FID:
result = EF_DG9_INDEX;
break;
case EF_DG10_FID:
result = EF_DG10_INDEX;
break;
case EF_DG11_FID:
result = EF_DG11_INDEX;
break;
case EF_DG12_FID:
result = EF_DG12_INDEX;
break;
case EF_DG13_FID:
result = EF_DG13_INDEX;
break;
case EF_DG14_FID:
result = EF_DG14_INDEX;
break;
case EF_DG15_FID:
result = EF_DG15_INDEX;
break;
case EF_DG16_FID:
result = EF_DG16_INDEX;
break;
case EF_SOD_FID:
result = EF_SOD_INDEX;
break;
case EF_COM_FID:
result = EF_COM_INDEX;
break;
default:
result = -1;
break;
}
if (result != -1 && SmartIDApplet.isLocked() && SmartIDApplet.hasMutualAuthenticationKeys()) {
// We are in the personalized state and BAC is active,
// we need to control the access
// a. check that the current authorization level is sufficient to
// access
// the given file
// b. if we are passed the EAC protocol we also need to check
// whether the current certificate authorization allows us to read the file.
byte perm = filePerms[result];
if ((byte) (perm & SmartIDApplet.volatileState[0]) != perm) {
ISOException.throwIt(ISO7816.SW_SECURITY_STATUS_NOT_SATISFIED);
}
if (result <= EF_DG16_INDEX
&& SmartIDApplet.hasTerminalAuthenticated()
&& perm == SmartIDApplet.TERMINAL_AUTHENTICATED) {
short m = (short) (0x1 << result);
if ((Util.getShort(currentAuthorization, (short) 1) & m) != m) {
ISOException.throwIt(ISO7816.SW_SECURITY_STATUS_NOT_SATISFIED);
}
}
}
return result;
}
