org.gluu.oxeleven.util.Base64Util.java Source code

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Here is the source code for org.gluu.oxeleven.util.Base64Util.java

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/*
 * oxEleven is available under the MIT License (2008). See http://opensource.org/licenses/MIT for full text.
 *
 * Copyright (c) 2016, Gluu
 */

package org.gluu.oxeleven.util;

import java.math.BigInteger;

import org.apache.commons.codec.binary.Base64;

/**
 * @author Javier Rojas Blum
 * @version April 12, 2016
 */
public class Base64Util {

    public static String base64UrlEncode(byte[] arg) {
        String s = Base64.encodeBase64String(arg); // Standard base64 encoder
        s = s.split("=")[0]; // Remove any trailing '='s
        s = s.replace('+', '-'); // 62nd char of encoding
        s = s.replace('/', '_'); // 63rd char of encoding
        s = s.replace("\r", "");
        s = s.replace("\n", "");
        return s;
    }

    public static byte[] base64UrlDecode(String arg) throws IllegalArgumentException {
        String s = removePadding(arg);
        return Base64.decodeBase64(s); // Standard base64 decoder
    }

    public static String removePadding(String base64UrlEncoded) {
        String s = base64UrlEncoded;
        s = s.replace('-', '+'); // 62nd char of encoding
        s = s.replace('_', '/'); // 63rd char of encoding
        switch (s.length() % 4) // Pad with trailing '='s
        {
        case 0:
            break; // No pad chars in this case
        case 2:
            s += "==";
            break; // Two pad chars
        case 3:
            s += "=";
            break; // One pad char
        default:
            throw new IllegalArgumentException("Illegal base64url string.");
        }
        return s;
    }

    public static String base64UrlEncodeUnsignedBigInt(BigInteger bigInteger) {
        byte[] array = bigInteger.toByteArray();
        if (array[0] == 0) {
            byte[] tmp = new byte[array.length - 1];
            System.arraycopy(array, 1, tmp, 0, tmp.length);
            array = tmp;
        }

        return base64UrlEncode(array);
    }
}