private Util() {

throw new UnsupportedOperationException("Not allowed to instantiate");

}

public static String getSpaces(int length) {

StringBuilder buf = new StringBuilder(length);

for (int i = 0; i < length; i++) {

buf.append(" ");

}

return buf.toString();

}

public static String prettyPrintHex(String in, int indent, boolean wrapLines) {

StringBuilder buf = new StringBuilder();

for (int i = 0; i < in.length(); i++) {

char c = in.charAt(i);

buf.append(c);

int nextPos = i+1;

if (wrapLines && nextPos % 32 == 0 && nextPos != in.length()) {

buf.append("\n").append(getSpaces(indent));

} else if (nextPos % 2 == 0 && nextPos != in.length()) {

buf.append(" ");

}

}

return buf.toString();

}

public static String prettyPrintHex(String in, int indent){

return prettyPrintHex(in, indent, true);

}

public static String prettyPrintHex(byte[] data, int indent) {

return Util.prettyPrintHex(Util.byteArrayToHexString(data), indent, true);

}

public static String prettyPrintHex(byte[] data) {

return Util.prettyPrintHex(Util.byteArrayToHexString(data), 0, true);

}

public static String prettyPrintHex(byte[] data, int startPos, int length) {

return Util.prettyPrintHex(Util.byteArrayToHexString(data, startPos, length), 0, true);

}

public static String prettyPrintHexNoWrap(byte[] data) {

return Util.prettyPrintHex(Util.byteArrayToHexString(data), 0, false);

}

public static String prettyPrintHexNoWrap(byte[] data, int startPos, int length) {

return Util.prettyPrintHex(Util.byteArrayToHexString(data, startPos, length), 0, false);

}

public static String prettyPrintHexNoWrap(String in) {

return Util.prettyPrintHex(in, 0, false);

}

public static String prettyPrintHex(String in) {

return prettyPrintHex(in, 0, true);

}

public static String prettyPrintHex(BigInteger bi) {

byte[] data = bi.toByteArray();

if (data[0] == (byte) 0x00) {

byte[] tmp = new byte[data.length - 1];

System.arraycopy(data, 1, tmp, 0, data.length - 1);

data = tmp;

}

return prettyPrintHex(data);

}

public static byte[] performRSA(byte[] dataBytes, byte[] expBytes, byte[] modBytes) {

int inBytesLength = dataBytes.length;

if (expBytes[0] >= (byte) 0x80) {

//Prepend 0x00 to modulus

byte[] tmp = new byte[expBytes.length + 1];

tmp[0] = (byte) 0x00;

System.arraycopy(expBytes, 0, tmp, 1, expBytes.length);

expBytes = tmp;

}

if (modBytes[0] >= (byte) 0x80) {

//Prepend 0x00 to modulus

byte[] tmp = new byte[modBytes.length + 1];

tmp[0] = (byte) 0x00;

System.arraycopy(modBytes, 0, tmp, 1, modBytes.length);

modBytes = tmp;

}

if (dataBytes[0] >= (byte) 0x80) {

//Prepend 0x00 to signed data to avoid that the most significant bit is interpreted as the "signed" bit

byte[] tmp = new byte[dataBytes.length + 1];

tmp[0] = (byte) 0x00;

System.arraycopy(dataBytes, 0, tmp, 1, dataBytes.length);

dataBytes = tmp;

}

BigInteger exp = new BigInteger(expBytes);

BigInteger mod = new BigInteger(modBytes);

BigInteger data = new BigInteger(dataBytes);

byte[] result = data.modPow(exp, mod).toByteArray();

if (result.length == (inBytesLength+1) && result[0] == (byte)0x00) {

//Remove 0x00 from beginning of array

byte[] tmp = new byte[inBytesLength];

System.arraycopy(result, 1, tmp, 0, inBytesLength);

result = tmp;

}

return result;

}

public static byte[] calculateSHA1(byte[] data) throws NoSuchAlgorithmException {

MessageDigest sha1 = MessageDigest.getInstance("SHA-1");

return sha1.digest(data);

}

public static String byte2Hex(byte b) {

String[] HEX_DIGITS = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};

int nb = b & 0xFF;

int i_1 = (nb >>> 4) & 0xF;

int i_2 = nb & 0xF;

return HEX_DIGITS[i_1] + HEX_DIGITS[i_2];

}

public static String short2Hex(short s) {

byte b1 = (byte) (s >>> 8);

byte b2 = (byte) (s & 0xFF);

return byte2Hex(b1) + byte2Hex(b2);

}

public static int byteToInt(byte b) {

return (int) b & 0xFF;

}

public static int byteToInt(byte first, byte second) {

int value = (first & 0xFF) << 8;

value += second & 0xFF;

return value;

}

public static short byte2Short(byte b1, byte b2) {

return (short) ((b1 << 8) | (b2 & 0xFF));

}

public static String getFormattedNanoTime(long nano) {

StringBuilder buf = new StringBuilder();

buf.append((int) (nano / 1000000));

buf.append("ms ");

buf.append(nano % 1000000);

buf.append("ns");

return buf.toString();

}

public static byte[] getCurrentDateAsNumericEncodedByteArray(){

SimpleDateFormat format = new SimpleDateFormat("yyMMdd");

return fromHexString(format.format(new Date()));

}

//This prints all non-control characters common to all parts of ISO/IEC 8859

//See EMV book 4 Annex B: Table 36: Common Character Set

public static String getSafePrintChars(byte[] byteArray) {

if (byteArray == null) {

return "";

}

return getSafePrintChars(byteArray, 0, byteArray.length);

}

public static String getSafePrintChars(byte[] byteArray, int startPos, int length) {

if (byteArray == null) {

return "";

}

if(byteArray.length < startPos+length){

throw new IllegalArgumentException("startPos("+startPos+")+length("+length+") > byteArray.length("+byteArray.length+")");

}

StringBuilder buf = new StringBuilder();

for (int i = startPos; i < startPos+length; i++) {

if (byteArray[i] >= (byte) 0x20 && byteArray[i] < (byte) 0x7F) {

buf.append((char) byteArray[i]);

} else {

buf.append(".");

}

}

return buf.toString();

}

/**

public static String byteArrayToHexString(final byte[] byteArray) {

if (byteArray == null) {

return "";

}

return byteArrayToHexString(byteArray, 0, byteArray.length);

}

public static String byteArrayToHexString(final byte[] byteArray, int startPos, int length) {

if (byteArray == null) {

return "";

}

if(byteArray.length < startPos+length){

throw new IllegalArgumentException("startPos("+startPos+")+length("+length+") > byteArray.length("+byteArray.length+")");

}

StringBuilder hexData = new StringBuilder();

int onebyte;

for (int i = 0; i < length; i++) {

onebyte = ((0x000000ff & byteArray[startPos+i]) | 0xffffff00);

hexData.append(Integer.toHexString(onebyte).substring(6));

}

return hexData.toString();

}

public static String int2Hex(int i) {

String hex = Integer.toHexString(i);

if (hex.length() % 2 != 0) {

hex = "0" + hex;

}

return hex;

}

public static String int2HexZeroPad(int i) {

String hex = int2Hex(i);

if (hex.length() % 2 != 0) {

hex = "0" + hex;

}

return hex;

}

/**

public static byte[] intToByteArray(int value) {

ByteArrayOutputStream baos = new ByteArrayOutputStream();

byte one = (byte) (value >>> 24);

byte two = (byte) (value >>> 16);

byte three = (byte) (value >>> 8);

byte four = (byte) (value);

boolean found = false;

if (one > 0x00) {

baos.write(one);

found = true;

}

if (found || two > 0x00) {

baos.write(two);

found = true;

}

if (found || three > 0x00) {

baos.write(three);

}

baos.write(four);

return baos.toByteArray();

}

/**

public static byte[] intToByteArray4(int value) {

return new byte[]{

(byte) (value >>> 24),

(byte) (value >>> 16),

(byte) (value >>> 8),

(byte) value};

}

public static int byteArrayToInt(byte[] byteArray) {

return byteArrayToInt(byteArray, 0, byteArray.length);

}

public static int byteArrayToInt(byte[] byteArray, int startPos, int length) {

if (byteArray == null) {

throw new IllegalArgumentException("Parameter 'byteArray' cannot be null");

}

if (length <= 0 || length > 4) {

throw new IllegalArgumentException("Length must be between 1 and 4. Length = " + length);

}

if (length == 4 && Util.isBitSet(byteArray[startPos], 8)){

throw new IllegalArgumentException("Signed bit is set (leftmost bit): " + Util.byte2Hex(byteArray[startPos]));

}

int value = 0;

for (int i = 0; i < length; i++) {

value += ((byteArray[startPos+i] & 0xFF) << 8 * (length - i - 1));

}

return value;

}

public static long byteArrayToLong(byte[] byteArray, int startPos, int length) {

if (byteArray == null) {

throw new IllegalArgumentException("Parameter 'byteArray' cannot be null");

}

if (length <= 0 || length > 8) {

throw new IllegalArgumentException("Length must be between 1 and 4. Length = " + length);

}

if (length == 8 && Util.isBitSet(byteArray[startPos], 8)){

throw new IllegalArgumentException("Signed bit is set (leftmost bit): " + Util.byte2Hex(byteArray[startPos]));

}

long value = 0;

for (int i = 0; i < length; i++) {

value += ((byteArray[startPos+i] & (long)0xFF) << 8 * (length - i - 1));

}

return value;

}

public static byte[] fromHexString(String encoded) {

encoded = removeSpaces(encoded);

if (encoded.length() == 0){

return new byte[0];

}

if ((encoded.length() % 2) != 0) {

throw new IllegalArgumentException("Input string must contain an even number of characters: "+encoded);

}

final byte result[] = new byte[encoded.length() / 2];

final char enc[] = encoded.toCharArray();

for (int i = 0; i < enc.length; i += 2) {

StringBuilder curr = new StringBuilder(2);

curr.append(enc[i]).append(enc[i + 1]);

result[i / 2] = (byte) Integer.parseInt(curr.toString(), 16);

}

return result;

}

public static String removeCRLFTab(String s) {

StringTokenizer st = new StringTokenizer(s, "\r\n\t", false);

StringBuilder buf = new StringBuilder();

while (st.hasMoreElements()) {

buf.append(st.nextElement());

}

return buf.toString();

}

public static String removeSpaces(String s) {

return s.replaceAll(" ", "");

}

/**

public static byte[] intToBinaryEncodedDecimalByteArray(int val){

String str = String.valueOf(val);

if(str.length() % 2 != 0){

str = "0"+str;

}

return Util.fromHexString(str);

}

/**

public static int binaryCodedDecimalToInt(byte b) {

String hex = Util.byte2Hex(b);

try {

return Integer.parseInt(hex);

} catch (NumberFormatException ex) {

throw new IllegalArgumentException("The hex representation of argument b must be digits only, and integer", ex);

}

}

/**

public static int binaryHexCodedDecimalToInt(String hex) {

if (hex == null) {

throw new IllegalArgumentException("Param hex cannot be null");

}

hex = Util.removeSpaces(hex);

if (hex.length() > 10) {

throw new IllegalArgumentException("There must be a maximum of 5 hex octets. hex=" + hex);

}

try {

return Integer.parseInt(hex);

} catch (NumberFormatException ex) {

throw new IllegalArgumentException("Argument hex must be all digits. hex="+hex, ex);

}

}

/**

public static int binaryHexCodedDecimalToInt(byte[] bcdArray) {

if (bcdArray == null) {

throw new IllegalArgumentException("Param bcdArray cannot be null");

}

return binaryHexCodedDecimalToInt(Util.byteArrayToHexString(bcdArray));

}

/**

public static String byte2BinaryLiteral(byte val) {

String s = Integer.toBinaryString(Util.byteToInt(val));

if (s.length() < 8) {

StringBuilder sb = new StringBuilder();

for (int i = 0; i < 8 - s.length(); i++) {

sb.append('0');

}

sb.append(s);

s = sb.toString();

}

return s;

}

/**

public static BitSet byteArray2BitSet(byte[] bytes) {

BitSet bits = new BitSet();

for (int i = 0; i < bytes.length * 8; i++) {

if ((bytes[bytes.length - i / 8 - 1] & (1 << (i % 8))) > 0) {

bits.set(i);

}

}

return bits;

}

/* Returns a byte array of at least length 1.

public static byte[] bitSet2ByteArray(BitSet bits) {

byte[] bytes = new byte[bits.length() / 8 + 1];

for (int i = 0; i < bits.length(); i++) {

if (bits.get(i)) {

bytes[bytes.length - i / 8 - 1] |= 1 << (i % 8);

}

}

return bytes;

}

/**

public static boolean isBitSet(byte val, int bitPos) {

if (bitPos < 1 || bitPos > 8) {

throw new IllegalArgumentException("parameter 'bitPos' must be between 1 and 8. bitPos=" + bitPos);

}

if ((val >>> (bitPos - 1) & 0x1) == 1) {

return true;

}

return false;

}

/**

public static byte setBit(byte data, int bitPos, boolean on) {

if (bitPos < 1 || bitPos > 8) {

throw new IllegalArgumentException("parameter 'bitPos' must be between 1 and 8. bitPos=" + bitPos);

}

if (on) { //Set bit

return data |= 1 << (bitPos - 1);

} else { //Unset bit

return data &= ~(1 << (bitPos - 1));

}

}

public static byte[] generateRandomBytes(int numBytes){

//TODO get bytes from a hardware RNG, or set seed

byte[] rndBytes = new byte[numBytes];

SecureRandom random = new SecureRandom();

random.nextBytes(rndBytes);

return rndBytes;

}

public static InputStream loadResource(Class cls, String path){

return cls.getResourceAsStream(path);

}

/**

public static byte[] resizeArray(byte[] original, int newLength) {

if(original == null){

throw new IllegalArgumentException("byte array cannot be null");

}

if(newLength < 0){

throw new IllegalArgumentException("Illegal new length: "+newLength+". Must be >= 0");

}

if(newLength == 0){

return new byte[0];

}

byte[] tmp = new byte[newLength];

int srcPos = tmp.length > original.length ? 0 : original.length - tmp.length;

int destPos = tmp.length > original.length ? tmp.length - original.length : 0;

int length = tmp.length > original.length ? original.length : tmp.length;

System.arraycopy(original, srcPos, tmp, destPos, length);

return tmp;

}

public static byte[] copyByteArray(byte[] array2Copy){

if (array2Copy == null) {

//return new byte[0] instead?

throw new IllegalArgumentException("Argument 'array2Copy' cannot be null");

}

return copyByteArray(array2Copy, 0, array2Copy.length);

}

public static byte[] copyByteArray(byte[] array2Copy, int startPos, int length){

if (array2Copy == null) {

//return new byte[0] instead?

throw new IllegalArgumentException("Argument 'array2Copy' cannot be null");

}

if(array2Copy.length < startPos+length){

throw new IllegalArgumentException("startPos("+startPos+")+length("+length+") > byteArray.length("+array2Copy.length+")");

}

byte[] copy = new byte[array2Copy.length];

System.arraycopy(array2Copy, startPos, copy, 0, length);

return copy;

}

public static String getStackTrace(Throwable t){

StringWriter sw = new StringWriter();

t.printStackTrace(new PrintWriter(sw));

return sw.toString();

}

public static String readInputStreamToString(InputStream is, String encoding) throws IOException {

InputStreamReader input = new InputStreamReader(is, encoding);

final int CHARS_PER_PAGE = 5000; //counting spaces

final char[] buffer = new char[CHARS_PER_PAGE];

StringBuilder output = new StringBuilder(CHARS_PER_PAGE);

for (int read = input.read(buffer, 0, buffer.length);

read != -1;

read = input.read(buffer, 0, buffer.length)) {

output.append(buffer, 0, read);

}

String text = output.toString();

return text;

}

public static void writeStringToFile(String string, String fileName, boolean append) throws IOException {

BufferedWriter out = new BufferedWriter(new FileWriter(fileName, append));

out.write(string);

out.close();

}

public static Class getCallerClass(int i) {

Class[] classContext = new SecurityManager() {

@Override public Class[] getClassContext() {

return super.getClassContext();

}

}.getClassContext();

if (classContext != null) {

for (int j = 0; j < classContext.length; j++) {

if (classContext[j] == Util.class) {

return classContext[i+j];

}

}

} else {

// SecurityManager.getClassContext() returns null on Android 4.0

try {

StackTraceElement[] classNames = Thread.currentThread().getStackTrace();

for (int j = 0; j < classNames.length; j++) {

if (Class.forName(classNames[j].getClassName()) == Util.class) {

return Class.forName(classNames[i+j].getClassName());

}

}

} catch (ClassNotFoundException e) { }

}

return null;

}

public static void main(String[] args) {

System.out.println(Util.prettyPrintHexNoWrap(Util.resizeArray(new byte[]{0x01}, 0)));

System.out.println(Util.prettyPrintHexNoWrap(Util.resizeArray(new byte[]{0x01}, 1)));

System.out.println(Util.prettyPrintHexNoWrap(Util.resizeArray(new byte[]{0x01}, 2)));

System.out.println(Util.prettyPrintHexNoWrap(Util.resizeArray(new byte[]{0x01, 0x02}, 1)));

System.out.println(Util.prettyPrintHexNoWrap(Util.resizeArray(new byte[]{0x01, 0x02}, 4)));

}