org.bouncycastle.crypto.fips.XofUtils Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of bc-fips-debug Show documentation

The FIPS 140-2 Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms certified to FIPS 140-2 level 1. This jar contains the debug version JCE provider and low-level API for the BC-FJA version 1.0.2.3, FIPS Certificate #3514. Please note the debug jar is not certified.

There is a newer version: 2.0.0

Show newest version

package org.bouncycastle.crypto.fips;

import org.bouncycastle.util.Arrays;

class XofUtils
{
    static byte[] leftEncode(long strLen)
    {
        byte n = 1;

        long v = strLen;
        while ((v >>= 8) != 0)
        {
            n++;
        }

        byte[] b = new byte[n + 1];

        b[0] = n;

        for (int i = 1; i <= n; i++)
        {
            b[i] = (byte)(strLen >> (8 * (n - i)));
        }

        return b;
    }

    static byte[] rightEncode(long strLen)
    {
        byte n = 1;

        long v = strLen;
        while ((v >>= 8) != 0)
        {
            n++;
        }

        byte[] b = new byte[n + 1];

        b[n] = n;

        for (int i = 0; i < n; i++)
        {
            b[i] = (byte)(strLen >> (8 * (n - i - 1)));
        }

        return b;
    }

    static byte[] encode(byte X)
    {
        return Arrays.concatenate(XofUtils.leftEncode(8), new byte[]{X});
    }

    static byte[] encode(byte[] in, int inOff, int len)
    {
        if (in.length == len)
        {
            return Arrays.concatenate(XofUtils.leftEncode(len * 8), in);
        }
        return Arrays.concatenate(XofUtils.leftEncode(len * 8), Arrays.copyOfRange(in, inOff, inOff + len));
    }
}