package org.bouncycastle.pqc.crypto.xmss;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import org.bouncycastle.crypto.Digest;
import org.bouncycastle.util.encoders.Hex;
/**
* Utils for XMSS implementation.
*
*/
public class XMSSUtil {
/**
* Calculates the logarithm base 2 for a given Integer.
*
* @param n
* Number.
* @return Logarithm to base 2 of {@code n}.
*/
public static int log2(int n) {
int log = 0;
while ((n >>= 1) != 0) {
log++;
}
return log;
}
/**
* Convert int/long to n-byte array.
*
* @param value
* int/long value.
* @param sizeInByte
* Size of byte array in byte.
* @return int/long as big-endian byte array of size {@code sizeInByte}.
*/
public static byte[] toBytesBigEndian(long value, int sizeInByte) {
byte[] out = new byte[sizeInByte];
for (int i = (sizeInByte - 1); i >= 0; i--) {
out[i] = (byte) value;
value >>>= 8;
}
return out;
}
/**
* Copy int to byte array in big-endian at specific offset.
*
* @param Byte
* array.
* @param Integer
* to put.
* @param Offset
* in {@code in}.
*/
public static void intToBytesBigEndianOffset(byte[] in, int value, int offset) {
if (in == null) {
throw new NullPointerException("in == null");
}
if ((in.length - offset) < 4) {
throw new IllegalArgumentException("not enough space in array");
}
in[offset] = (byte) ((value >> 24) & 0xff);
in[offset + 1] = (byte) ((value >> 16) & 0xff);
in[offset + 2] = (byte) ((value >> 8) & 0xff);
in[offset + 3] = (byte) ((value) & 0xff);
}
/**
* Copy long to byte array in big-endian at specific offset.
*
* @param Byte
* array.
* @param Long
* to put.
* @param Offset
* in {@code in}.
*/
public static void longToBytesBigEndianOffset(byte[] in, long value, int offset) {
if (in == null) {
throw new NullPointerException("in == null");
}
if ((in.length - offset) < 8) {
throw new IllegalArgumentException("not enough space in array");
}
in[offset] = (byte) ((value >> 56) & 0xff);
in[offset + 1] = (byte) ((value >> 48) & 0xff);
in[offset + 2] = (byte) ((value >> 40) & 0xff);
in[offset + 3] = (byte) ((value >> 32) & 0xff);
in[offset + 4] = (byte) ((value >> 24) & 0xff);
in[offset + 5] = (byte) ((value >> 16) & 0xff);
in[offset + 6] = (byte) ((value >> 8) & 0xff);
in[offset + 7] = (byte) ((value) & 0xff);
}
/**
* Generic convert from big endian byte array to long.
*
* @param x-byte
* array
* @param offset.
* @param size.
* @return Long.
*/
public static long bytesToXBigEndian(byte[] in, int offset, int size) {
if (in == null) {
throw new NullPointerException("in == null");
}
long res = 0;
for (int i = offset; i < (offset + size); i++) {
res = (res << 8) | (in[i] & 0xff);
}
return res;
}
/**
* Clone a byte array.
*
* @param in
* byte array.
* @return Copy of byte array.
*/
public static byte[] cloneArray(byte[] in) {
if (in == null) {
throw new NullPointerException("in == null");
}
byte[] out = new byte[in.length];
for (int i = 0; i < in.length; i++) {
out[i] = in[i];
}
return out;
}
/**
* Clone a 2d byte array.
*
* @param in
* 2d byte array.
* @return Copy of 2d byte array.
*/
public static byte[][] cloneArray(byte[][] in) {
if (hasNullPointer(in)) {
throw new NullPointerException("in has null pointers");
}
byte[][] out = new byte[in.length][];
for (int i = 0; i < in.length; i++) {
out[i] = new byte[in[i].length];
for (int j = 0; j < in[i].length; j++) {
out[i][j] = in[i][j];
}
}
return out;
}
/**
* Concatenates an arbitrary number of byte arrays.
*
* @param arrays
* Arrays that shall be concatenated.
* @return Concatenated array.
*/
public static byte[] concat(byte[]... arrays) {
int totalLength = 0;
for (int i = 0; i < arrays.length; i++) {
totalLength += arrays[i].length;
}
byte[] result = new byte[totalLength];
int currentIndex = 0;
for (int i = 0; i < arrays.length; i++) {
System.arraycopy(arrays[i], 0, result, currentIndex, arrays[i].length);
currentIndex += arrays[i].length;
}
return result;
}
/**
* Compares two byte arrays.
*
* @param a
* byte array 1.
* @param b
* byte array 2.
* @return true if all values in byte array are equal false else.
*/
public static boolean compareByteArray(byte[] a, byte[] b) {
if (a == null || b == null) {
throw new NullPointerException("a or b == null");
}
if (a.length != b.length) {
throw new IllegalArgumentException("size of a and b must be equal");
}
for (int i = 0; i < a.length; i++) {
if (a[i] != b[i]) {
return false;
}
}
return true;
}
/**
* Compares two 2d-byte arrays.
*
* @param a
* 2d-byte array 1.
* @param b
* 2d-byte array 2.
* @return true if all values in 2d-byte array are equal false else.
*/
public static boolean compareByteArray(byte[][] a, byte[][] b) {
if (hasNullPointer(a) || hasNullPointer(b)) {
throw new NullPointerException("a or b == null");
}
for (int i = 0; i < a.length; i++) {
if (!compareByteArray(a[i], b[i])) {
return false;
}
}
return true;
}
/**
* Dump content of 2d byte array.
*
* @param x
* byte array.
*/
public static void dumpByteArray(byte[][] x) {
if (hasNullPointer(x)) {
throw new NullPointerException("x has null pointers");
}
for (int i = 0; i < x.length; i++) {
System.out.println(Hex.toHexString(x[i]));
}
}
/**
* Checks whether 2d byte array has null pointers.
*
* @param in
* 2d byte array.
* @return true if at least one null pointer is found false else.
*/
public static boolean hasNullPointer(byte[][] in) {
if (in == null) {
return true;
}
for (int i = 0; i < in.length; i++) {
if (in[i] == null) {
return true;
}
}
return false;
}
/**
* Copy src byte array to dst byte array at offset.
*
* @param dst
* Destination.
* @param src
* Source.
* @param offset
* Destination offset.
*/
public static void copyBytesAtOffset(byte[] dst, byte[] src, int offset) {
if (dst == null) {
throw new NullPointerException("dst == null");
}
if (src == null) {
throw new NullPointerException("src == null");
}
if (offset < 0) {
throw new IllegalArgumentException("offset hast to be >= 0");
}
if ((src.length + offset) > dst.length) {
throw new IllegalArgumentException("src length + offset must not be greater than size of destination");
}
for (int i = 0; i < src.length; i++) {
dst[offset + i] = src[i];
}
}
/**
* Copy length bytes at position offset from src.
*
* @param src
* Source byte array.
* @param offset
* Offset in source byte array.
* @param length
* Length of bytes to copy.
* @return New byte array.
*/
public static byte[] extractBytesAtOffset(byte[] src, int offset, int length) {
if (src == null) {
throw new NullPointerException("src == null");
}
if (offset < 0) {
throw new IllegalArgumentException("offset hast to be >= 0");
}
if (length < 0) {
throw new IllegalArgumentException("length hast to be >= 0");
}
if ((offset + length) > src.length) {
throw new IllegalArgumentException("offset + length must not be greater then size of source array");
}
byte[] out = new byte[length];
for (int i = 0; i < out.length; i++) {
out[i] = src[offset + i];
}
return out;
}
/**
* Check whether an index is valid or not.
*
* @param height
* Height of binary tree.
* @param index
* Index to validate.
* @return true if index is valid false else.
*/
public static boolean isIndexValid(int height, long index) {
if (index < 0) {
throw new IllegalStateException("index must not be negative");
}
return index < (1L << height);
}
/**
* Determine digest size of digest.
*
* @param digest
* Digest.
* @return Digest size.
*/
public static int getDigestSize(Digest digest) {
if (digest == null) {
throw new NullPointerException("digest == null");
}
String algorithmName = digest.getAlgorithmName();
if (algorithmName.equals("SHAKE128")) {
return 32;
}
if (algorithmName.equals("SHAKE256")) {
return 64;
}
return digest.getDigestSize();
}
public static long getTreeIndex(long index, int xmssTreeHeight) {
return index >> xmssTreeHeight;
}
public static int getLeafIndex(long index, int xmssTreeHeight) {
return (int) (index & ((1L << xmssTreeHeight) - 1L));
}
public static byte[] serialize(Object obj) throws IOException {
ByteArrayOutputStream out = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(out);
oos.writeObject(obj);
oos.flush();
return out.toByteArray();
}
public static Object deserialize(byte[] data) throws IOException, ClassNotFoundException {
ByteArrayInputStream in = new ByteArrayInputStream(data);
ObjectInputStream is = new ObjectInputStream(in);
return is.readObject();
}
public static int calculateTau(int index, int height) {
int tau = 0;
for (int i = 0; i < height; i++) {
if (((index >> i) & 1) == 0) {
tau = i;
break;
}
}
return tau;
}
public static boolean isNewBDSInitNeeded(long globalIndex, int xmssHeight, int layer) {
if (globalIndex == 0) {
return false;
}
return (globalIndex % (long) Math.pow((1 << xmssHeight), layer + 1) == 0) ? true : false;
}
public static boolean isNewAuthenticationPathNeeded(long globalIndex, int xmssHeight, int layer) {
if (globalIndex == 0) {
return false;
}
return ((globalIndex + 1) % (long) Math.pow((1 << xmssHeight), layer) == 0) ? true : false;
}
}