Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
import java.io.*;

public class Main {
    /**
     * Converts an Oid in dot-separated string representation to a
     * DER-encoded byte array.
     *
     * @param oid Oid in dot-separated String representation
     * @return DER-encoded Oid byte array
     *
     */
    public static byte[] OidString2DER(String oid) {

        int octet = 0;
        int base = 0;
        int times = 0;
        int tbMaj = 0;

        ByteArrayOutputStream bytearray = new ByteArrayOutputStream();
        ByteArrayOutputStream tmpArray = new ByteArrayOutputStream();

        /* Convert String to int[] */
        String[] tmp = oid.split("\\.");
        int[] input = new int[tmp.length];
        for (int i = 0; i < tmp.length; i++) {
            input[i] = Integer.parseInt(tmp[i]);
        }

        /* Add tag for OID (0x06) */
        bytearray.write(6);

        /* Calculate first byte */
        tmpArray.write((input[0] * 40) + input[1]);

        /* Encode the rest of the OID nodes in DER format */
        for (int j = 2; j < input.length; j++) {

            if (input[j] <= 127) {

                /* Encode directly */
                tmpArray.write(input[j]);

            } else if (input[j] > 127) {

                /* Reset variables */
                octet = input[j];
                base = 128;
                times = 0;
                tbMaj = 8;

                /* If bigger than 16383 */
                if (octet > 16383) {

                    base = 262144;
                    times = (int) Math.floor(octet / base);
                    tbMaj = 8 + times;
                    octet = octet - (times * base);

                    base = 16384;
                    times = (int) Math.floor(octet / base);
                    tmpArray.write((16 * tbMaj) + times);

                    /* Reset tbMaj in case we're skipping next if */
                    tbMaj = 8;
                }

                /* 2047 < octet <= 16383 */
                if (octet > 2047 && octet <= 16383) {

                    base = 2048;
                    times = (int) Math.floor(octet / base);
                    tbMaj = 8 + times;
                    octet = octet - (times * base);
                }

                /* 127 < octet < 2047 */
                base = 128;
                times = (int) Math.floor(octet / base);
                tmpArray.write((16 * tbMaj) + times);
                tmpArray.write(octet - (times * 128));
            }
        }

        byte[] convArray = tmpArray.toByteArray();
        bytearray.write(convArray.length);
        for (int k = 0; k < convArray.length; k++) {
            bytearray.write(convArray[k]);
        }

        return bytearray.toByteArray();

    }
}