Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;

import java.math.BigInteger;

import java.security.InvalidKeyException;

public class Main {
    /**
     *  @param bi non-negative
     *  @return array of exactly len bytes
     */
    public static byte[] rectify(BigInteger bi, int len) throws InvalidKeyException {
        byte[] b = bi.toByteArray();
        if (b.length == len) {
            // just right
            return b;
        }
        if (b.length > len + 1)
            throw new InvalidKeyException("key too big (" + b.length + ") max is " + (len + 1));
        byte[] rv = new byte[len];
        if (b.length == 0)
            return rv;
        if ((b[0] & 0x80) != 0)
            throw new InvalidKeyException("negative");
        if (b.length > len) {
            // leading 0 byte
            if (b[0] != 0)
                throw new InvalidKeyException("key too big (" + b.length + ") max is " + len);
            System.arraycopy(b, 1, rv, 0, len);
        } else {
            // smaller
            System.arraycopy(b, 0, rv, len - b.length, b.length);
        }
        return rv;
    }
}