package com.taobao.api.internal.util;

import java.util.Arrays;

/**
 * A very fast and memory efficient class to encode and decode to and from
 * BASE64 in full accordance with RFC 2045.<br>
 * <br>
 * On Windows XP sp1 with 1.4.2_04 and later ;), this encoder and decoder
 * is about 10 times faster on small arrays (10 - 1000 bytes) and 2-3 times
 * as fast on larger arrays (10000 - 1000000 bytes) compared to
 * <code>sun.misc.Encoder()/Decoder()</code>.<br>
 * <br>
 *
 * On byte arrays the encoder is about 20% faster than Jakarta Commons
 * Base64 Codec for encode and about 50% faster for decoding large arrays.
 * This implementation is about twice as fast on very small arrays (&lt 30
 * bytes). If source/destination is a <code>String</code> this version is
 * about three times as fast due to the fact that the Commons Codec result
 * has to be recoded to a <code>String</code> from <code>byte[]</code>,
 * which is very expensive.<br>
 * <br>
 *
 * This encode/decode algorithm doesn't create any temporary arrays as many
 * other codecs do, it only allocates the resulting array. This produces
 * less garbage and it is possible to handle arrays twice as large as
 * algorithms that create a temporary array. (E.g. Jakarta Commons Codec).
 * It is unknown whether Sun's <code>sun.misc.Encoder()/Decoder()</code>
 * produce temporary arrays but since performance is quite low it probably
 * does.<br>
 * <br>
 *
 * The encoder produces the same output as the Sun one except that the
 * Sun's encoder appends a trailing line separator if the last character
 * isn't a pad. Unclear why but it only adds to the length and is probably
 * a side effect. Both are in conformance with RFC 2045 though.<br>
 * Commons codec seem to always att a trailing line separator.<br>
 * <br>
 *
 * <b>Note!</b> The encode/decode method pairs (types) come in three
 * versions with the <b>exact</b> same algorithm and thus a lot of code
 * redundancy. This is to not create any temporary arrays for transcoding
 * to/from different format types. The methods not used can simply be
 * commented out.<br>
 * <br>
 *
 * There is also a "fast" version of all decode methods that works the same
 * way as the normal ones, but har a few demands on the decoded input.
 * Normally though, these fast verions should be used if the source if the
 * input is known and it hasn't bee tampered with.<br>
 * <br>
 *
 * If you find the code useful or you find a bug, please send me a note at
 * base64 @ miginfocom . com.
 *
 * Licence (BSD): ==============
 *
 * Copyright (c) 2004, Mikael Grev, MiG InfoCom AB. (base64 @ miginfocom .
 * com) All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * Neither the name of the MiG InfoCom AB nor the names of its contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @version 2.2
 * @author Mikael Grev Date: 2004-aug-02 Time: 11:31:11
 */

public class Base64 {

    private static final char[] CA = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
            .toCharArray();

    private static final int[] IA = new int[256];

    static {
        Arrays.fill(IA, -1);
        for (int i = 0, iS = CA.length; i < iS; i++) {
            IA[CA[i]] = i;
        }
        IA['='] = 0;
    }

    // ****************************************************************************************
    // *  char[] version
    // ****************************************************************************************

    /**
     * Decodes a BASE64 encoded byte array. All illegal characters will be
     * ignored and can handle both arrays with and without line separators.
     * 
     * @param sArr The source array. Length 0 will return an empty array.
     *        <code>null</code> will throw an exception.
     * @return The decoded array of bytes. May be of length 0. Will be
     *         <code>null</code> if the legal characters (including '=')
     *         isn't divideable by 4. (I.e. definitely corrupted).
     */
    public final static byte[] decode(byte[] sArr) {
        // Check special case
        int sLen = sArr.length;

        // Count illegal characters (including '\r', '\n') to know what size the returned array will be,
        // so we don't have to reallocate & copy it later.
        int sepCnt = 0; // Number of separator characters. (Actually illegal characters, but that's a bonus...)
        for (int i = 0; i < sLen; i++) {
            // If input is "pure" (I.e. no line separators or illegal chars) base64 this loop can be commented out.
            if (IA[sArr[i] & 0xff] < 0) {
                sepCnt++;
            }
        }

        // Check so that legal chars (including '=') are evenly divideable by 4 as specified in RFC 2045.
        if (((sLen - sepCnt) % 4) != 0) {
            return null;
        }

        int pad = 0;
        for (int i = sLen; (i > 1) && (IA[sArr[--i] & 0xff] <= 0);) {
            if (sArr[i] == '=') {
                pad++;
            }
        }

        int len = (((sLen - sepCnt) * 6) >> 3) - pad;

        byte[] dArr = new byte[len]; // Preallocate byte[] of exact length

        for (int s = 0, d = 0; d < len;) {
            // Assemble three bytes into an int from four "valid" characters.
            int i = 0;
            for (int j = 0; j < 4; j++) { // j only increased if a valid char was found.
                int c = IA[sArr[s++] & 0xff];
                if (c >= 0) {
                    i |= c << (18 - (j * 6));
                } else {
                    j--;
                }
            }

            // Add the bytes
            dArr[d++] = (byte) (i >> 16);
            if (d < len) {
                dArr[d++] = (byte) (i >> 8);
                if (d < len) {
                    dArr[d++] = (byte) i;
                }
            }
        }

        return dArr;
    }

    /**
     * Decodes a BASE64 encoded char array. All illegal characters will be
     * ignored and can handle both arrays with and without line separators.
     * 
     * @param sArr The source array. <code>null</code> or length 0 will
     *        return an empty array.
     * @return The decoded array of bytes. May be of length 0. Will be
     *         <code>null</code> if the legal characters (including '=')
     *         isn't divideable by 4. (I.e. definitely corrupted).
     */
    public final static byte[] decode(char[] sArr) {
        // Check special case
        int sLen = sArr != null ? sArr.length : 0;
        if (sLen == 0) {
            return new byte[0];
        }

        // Count illegal characters (including '\r', '\n') to know what size the returned array will be,
        // so we don't have to reallocate & copy it later.
        int sepCnt = 0; // Number of separator characters. (Actually illegal characters, but that's a bonus...)
        for (int i = 0; i < sLen; i++) {
            // If input is "pure" (I.e. no line separators or illegal chars) base64 this loop can be commented out.
            if (IA[sArr[i]] < 0) {
                sepCnt++;
            }
        }

        // Check so that legal chars (including '=') are evenly divideable by 4 as specified in RFC 2045.
        if (((sLen - sepCnt) % 4) != 0) {
            return null;
        }

        int pad = 0;
        for (int i = sLen; (i > 1) && (IA[sArr[--i]] <= 0);) {
            if (sArr[i] == '=') {
                pad++;
            }
        }

        int len = (((sLen - sepCnt) * 6) >> 3) - pad;

        byte[] dArr = new byte[len]; // Preallocate byte[] of exact length

        for (int s = 0, d = 0; d < len;) {
            // Assemble three bytes into an int from four "valid" characters.
            int i = 0;
            for (int j = 0; j < 4; j++) { // j only increased if a valid char was found.
                int c = IA[sArr[s++]];
                if (c >= 0) {
                    i |= c << (18 - (j * 6));
                } else {
                    j--;
                }
            }
            // Add the bytes
            dArr[d++] = (byte) (i >> 16);
            if (d < len) {
                dArr[d++] = (byte) (i >> 8);
                if (d < len) {
                    dArr[d++] = (byte) i;
                }
            }
        }
        return dArr;
    }

    /**
     * Decodes a BASE64 encoded <code>String</code>. All illegal characters
     * will be ignored and can handle both strings with and without line
     * separators.<br>
     * <b>Note!</b> It can be up to about 2x the speed to call
     * <code>decode(str.toCharArray())</code> instead. That will create a
     * temporary array though. This version will use
     * <code>str.charAt(i)</code> to iterate the string.
     * 
     * @param str The source string. <code>null</code> or length 0 will
     *        return an empty array.
     * @return The decoded array of bytes. May be of length 0. Will be
     *         <code>null</code> if the legal characters (including '=')
     *         isn't divideable by 4. (I.e. definitely corrupted).
     */
    public final static byte[] decode(String str) {
        // Check special case
        int sLen = str != null ? str.length() : 0;
        if (sLen == 0) {
            return new byte[0];
        }

        // Count illegal characters (including '\r', '\n') to know what size the returned array will be,
        // so we don't have to reallocate & copy it later.
        int sepCnt = 0; // Number of separator characters. (Actually illegal characters, but that's a bonus...)
        for (int i = 0; i < sLen; i++) {
            // If input is "pure" (I.e. no line separators or illegal chars) base64 this loop can be commented out.
            if (IA[str.charAt(i)] < 0) {
                sepCnt++;
            }
        }

        // Check so that legal chars (including '=') are evenly divideable by 4 as specified in RFC 2045.
        if (((sLen - sepCnt) % 4) != 0) {
            return null;
        }

        // Count '=' at end
        int pad = 0;
        for (int i = sLen; (i > 1) && (IA[str.charAt(--i)] <= 0);) {
            if (str.charAt(i) == '=') {
                pad++;
            }
        }

        int len = (((sLen - sepCnt) * 6) >> 3) - pad;

        byte[] dArr = new byte[len]; // Preallocate byte[] of exact length

        for (int s = 0, d = 0; d < len;) {
            // Assemble three bytes into an int from four "valid" characters.
            int i = 0;
            for (int j = 0; j < 4; j++) { // j only increased if a valid char was found.
                int c = IA[str.charAt(s++)];
                if (c >= 0) {
                    i |= c << (18 - (j * 6));
                } else {
                    j--;
                }
            }
            // Add the bytes
            dArr[d++] = (byte) (i >> 16);
            if (d < len) {
                dArr[d++] = (byte) (i >> 8);
                if (d < len) {
                    dArr[d++] = (byte) i;
                }
            }
        }
        return dArr;
    }

    // ****************************************************************************************
    // *  byte[] version
    // ****************************************************************************************

    /**
     * Decodes a BASE64 encoded byte array that is known to be resonably
     * well formatted. The method is about twice as fast as
     * {@link #decode(byte[])}. The preconditions are:<br>
     * + The array must have a line length of 76 chars OR no line
     * separators at all (one line).<br>
     * + Line separator must be "\r\n", as specified in RFC 2045 + The
     * array must not contain illegal characters within the encoded string
     * <br>
     * + The array CAN have illegal characters at the beginning and end,
     * those will be dealt with appropriately.<br>
     * 
     * @param sArr The source array. Length 0 will return an empty array.
     *        <code>null</code> will throw an exception.
     * @return The decoded array of bytes. May be of length 0.
     */
    public final static byte[] decodeFast(byte[] sArr) {
        // Check special case
        int sLen = sArr.length;
        if (sLen == 0) {
            return new byte[0];
        }

        int sIx = 0, eIx = sLen - 1; // Start and end index after trimming.

        // Trim illegal chars from start
        while ((sIx < eIx) && (IA[sArr[sIx] & 0xff] < 0)) {
            sIx++;
        }

        // Trim illegal chars from end
        while ((eIx > 0) && (IA[sArr[eIx] & 0xff] < 0)) {
            eIx--;
        }

        // get the padding count (=) (0, 1 or 2)
        int pad = sArr[eIx] == '=' ? (sArr[eIx - 1] == '=' ? 2 : 1) : 0; // Count '=' at end.
        int cCnt = (eIx - sIx) + 1; // Content count including possible separators
        int sepCnt = sLen > 76 ? (sArr[76] == '\r' ? cCnt / 78 : 0) << 1 : 0;

        int len = (((cCnt - sepCnt) * 6) >> 3) - pad; // The number of decoded bytes
        byte[] dArr = new byte[len]; // Preallocate byte[] of exact length

        // Decode all but the last 0 - 2 bytes.
        int d = 0;
        for (int cc = 0, eLen = (len / 3) * 3; d < eLen;) {
            // Assemble three bytes into an int from four "valid" characters.
            int i = (IA[sArr[sIx++]] << 18) | (IA[sArr[sIx++]] << 12) | (IA[sArr[sIx++]] << 6)
                    | IA[sArr[sIx++]];

            // Add the bytes
            dArr[d++] = (byte) (i >> 16);
            dArr[d++] = (byte) (i >> 8);
            dArr[d++] = (byte) i;

            // If line separator, jump over it.
            if ((sepCnt > 0) && (++cc == 19)) {
                sIx += 2;
                cc = 0;
            }
        }

        if (d < len) {
            // Decode last 1-3 bytes (incl '=') into 1-3 bytes
            int i = 0;
            for (int j = 0; sIx <= (eIx - pad); j++) {
                i |= IA[sArr[sIx++]] << (18 - (j * 6));
            }

            for (int r = 16; d < len; r -= 8) {
                dArr[d++] = (byte) (i >> r);
            }
        }

        return dArr;
    }

    /**
     * Decodes a BASE64 encoded char array that is known to be resonably
     * well formatted. The method is about twice as fast as
     * {@link #decode(char[])}. The preconditions are:<br>
     * + The array must have a line length of 76 chars OR no line
     * separators at all (one line).<br>
     * + Line separator must be "\r\n", as specified in RFC 2045 + The
     * array must not contain illegal characters within the encoded string
     * <br>
     * + The array CAN have illegal characters at the beginning and end,
     * those will be dealt with appropriately.<br>
     * 
     * @param sArr The source array. Length 0 will return an empty array.
     *        <code>null</code> will throw an exception.
     * @return The decoded array of bytes. May be of length 0.
     */
    public final static byte[] decodeFast(char[] sArr) {
        // Check special case
        int sLen = sArr.length;
        if (sLen == 0) {
            return new byte[0];
        }

        int sIx = 0, eIx = sLen - 1; // Start and end index after trimming.

        // Trim illegal chars from start
        while ((sIx < eIx) && (IA[sArr[sIx]] < 0)) {
            sIx++;
        }

        // Trim illegal chars from end
        while ((eIx > 0) && (IA[sArr[eIx]] < 0)) {
            eIx--;
        }

        // get the padding count (=) (0, 1 or 2)
        int pad = sArr[eIx] == '=' ? (sArr[eIx - 1] == '=' ? 2 : 1) : 0; // Count '=' at end.
        int cCnt = (eIx - sIx) + 1; // Content count including possible separators
        int sepCnt = sLen > 76 ? (sArr[76] == '\r' ? cCnt / 78 : 0) << 1 : 0;

        int len = (((cCnt - sepCnt) * 6) >> 3) - pad; // The number of decoded bytes
        byte[] dArr = new byte[len]; // Preallocate byte[] of exact length

        // Decode all but the last 0 - 2 bytes.
        int d = 0;
        for (int cc = 0, eLen = (len / 3) * 3; d < eLen;) {
            // Assemble three bytes into an int from four "valid" characters.
            int i = (IA[sArr[sIx++]] << 18) | (IA[sArr[sIx++]] << 12) | (IA[sArr[sIx++]] << 6)
                    | IA[sArr[sIx++]];

            // Add the bytes
            dArr[d++] = (byte) (i >> 16);
            dArr[d++] = (byte) (i >> 8);
            dArr[d++] = (byte) i;

            // If line separator, jump over it.
            if ((sepCnt > 0) && (++cc == 19)) {
                sIx += 2;
                cc = 0;
            }
        }

        if (d < len) {
            // Decode last 1-3 bytes (incl '=') into 1-3 bytes
            int i = 0;
            for (int j = 0; sIx <= (eIx - pad); j++) {
                i |= IA[sArr[sIx++]] << (18 - (j * 6));
            }

            for (int r = 16; d < len; r -= 8) {
                dArr[d++] = (byte) (i >> r);
            }
        }

        return dArr;
    }

    /**
     * Decodes a BASE64 encoded string that is known to be resonably well
     * formatted. The method is about twice as fast as
     * {@link #decode(String)}. The preconditions are:<br>
     * + The array must have a line length of 76 chars OR no line
     * separators at all (one line).<br>
     * + Line separator must be "\r\n", as specified in RFC 2045 + The
     * array must not contain illegal characters within the encoded string
     * <br>
     * + The array CAN have illegal characters at the beginning and end,
     * those will be dealt with appropriately.<br>
     * 
     * @param s The source string. Length 0 will return an empty array.
     *        <code>null</code> will throw an exception.
     * @return The decoded array of bytes. May be of length 0.
     */
    public final static byte[] decodeFast(String s) {
        // Check special case
        int sLen = s.length();
        if (sLen == 0) {
            return new byte[0];
        }

        int sIx = 0, eIx = sLen - 1; // Start and end index after trimming.

        // Trim illegal chars from start
        while ((sIx < eIx) && (IA[s.charAt(sIx) & 0xff] < 0)) {
            sIx++;
        }

        // Trim illegal chars from end
        while ((eIx > 0) && (IA[s.charAt(eIx) & 0xff] < 0)) {
            eIx--;
        }

        // get the padding count (=) (0, 1 or 2)
        int pad = s.charAt(eIx) == '=' ? (s.charAt(eIx - 1) == '=' ? 2 : 1) : 0; // Count '=' at end.
        int cCnt = (eIx - sIx) + 1; // Content count including possible separators
        int sepCnt = sLen > 76 ? (s.charAt(76) == '\r' ? cCnt / 78 : 0) << 1 : 0;

        int len = (((cCnt - sepCnt) * 6) >> 3) - pad; // The number of decoded bytes
        byte[] dArr = new byte[len]; // Preallocate byte[] of exact length

        // Decode all but the last 0 - 2 bytes.
        int d = 0;
        for (int cc = 0, eLen = (len / 3) * 3; d < eLen;) {
            // Assemble three bytes into an int from four "valid" characters.
            int i = (IA[s.charAt(sIx++)] << 18) | (IA[s.charAt(sIx++)] << 12)
                    | (IA[s.charAt(sIx++)] << 6) | IA[s.charAt(sIx++)];

            // Add the bytes
            dArr[d++] = (byte) (i >> 16);
            dArr[d++] = (byte) (i >> 8);
            dArr[d++] = (byte) i;

            // If line separator, jump over it.
            if ((sepCnt > 0) && (++cc == 19)) {
                sIx += 2;
                cc = 0;
            }
        }

        if (d < len) {
            // Decode last 1-3 bytes (incl '=') into 1-3 bytes
            int i = 0;
            for (int j = 0; sIx <= (eIx - pad); j++) {
                i |= IA[s.charAt(sIx++)] << (18 - (j * 6));
            }

            for (int r = 16; d < len; r -= 8) {
                dArr[d++] = (byte) (i >> r);
            }
        }

        return dArr;
    }

    // ****************************************************************************************
    // * String version
    // ****************************************************************************************

    /**
     * Encodes a raw byte array into a BASE64 <code>byte[]</code>
     * representation i accordance with RFC 2045.
     * 
     * @param sArr The bytes to convert. If <code>null</code> or length 0
     *        an empty array will be returned.
     * @param lineSep Optional "\r\n" after 76 characters, unless end of
     *        file.<br>
     *        No line separator will be in breach of RFC 2045 which
     *        specifies max 76 per line but will be a little faster.
     * @return A BASE64 encoded array. Never <code>null</code>.
     */
    public final static byte[] encodeToByte(byte[] sArr, boolean lineSep) {
        // Check special case
        int sLen = sArr != null ? sArr.length : 0;
        if (sLen == 0) {
            return new byte[0];
        }

        int eLen = (sLen / 3) * 3; // Length of even 24-bits.
        int cCnt = (((sLen - 1) / 3) + 1) << 2; // Returned character count
        int dLen = cCnt + (lineSep ? ((cCnt - 1) / 76) << 1 : 0); // Length of returned array
        byte[] dArr = new byte[dLen];

        // Encode even 24-bits
        for (int s = 0, d = 0, cc = 0; s < eLen;) {
            // Copy next three bytes into lower 24 bits of int, paying attension to sign.
            int i = ((sArr[s++] & 0xff) << 16) | ((sArr[s++] & 0xff) << 8) | (sArr[s++] & 0xff);

            // Encode the int into four chars
            dArr[d++] = (byte) CA[(i >>> 18) & 0x3f];
            dArr[d++] = (byte) CA[(i >>> 12) & 0x3f];
            dArr[d++] = (byte) CA[(i >>> 6) & 0x3f];
            dArr[d++] = (byte) CA[i & 0x3f];

            // Add optional line separator
            if (lineSep && (++cc == 19) && (d < (dLen - 2))) {
                dArr[d++] = '\r';
                dArr[d++] = '\n';
                cc = 0;
            }
        }

        // Pad and encode last bits if source isn't an even 24 bits.
        int left = sLen - eLen; // 0 - 2.
        if (left > 0) {
            // Prepare the int
            int i = ((sArr[eLen] & 0xff) << 10) | (left == 2 ? ((sArr[sLen - 1] & 0xff) << 2) : 0);

            // Set last four chars
            dArr[dLen - 4] = (byte) CA[i >> 12];
            dArr[dLen - 3] = (byte) CA[(i >>> 6) & 0x3f];
            dArr[dLen - 2] = left == 2 ? (byte) CA[i & 0x3f] : (byte) '=';
            dArr[dLen - 1] = '=';
        }
        return dArr;
    }

    /**
     * Encodes a raw byte array into a BASE64 <code>char[]</code>
     * representation i accordance with RFC 2045.
     * 
     * @param sArr The bytes to convert. If <code>null</code> or length 0
     *        an empty array will be returned.
     * @param lineSep Optional "\r\n" after 76 characters, unless end of
     *        file.<br>
     *        No line separator will be in breach of RFC 2045 which
     *        specifies max 76 per line but will be a little faster.
     * @return A BASE64 encoded array. Never <code>null</code>.
     */
    public final static char[] encodeToChar(byte[] sArr, boolean lineSep) {
        // Check special case
        int sLen = sArr != null ? sArr.length : 0;
        if (sLen == 0) {
            return new char[0];
        }

        int eLen = (sLen / 3) * 3; // Length of even 24-bits.
        int cCnt = (((sLen - 1) / 3) + 1) << 2; // Returned character count
        int dLen = cCnt + (lineSep ? ((cCnt - 1) / 76) << 1 : 0); // Length of returned array
        char[] dArr = new char[dLen];

        // Encode even 24-bits
        for (int s = 0, d = 0, cc = 0; s < eLen;) {
            // Copy next three bytes into lower 24 bits of int, paying attension to sign.
            int i = ((sArr[s++] & 0xff) << 16) | ((sArr[s++] & 0xff) << 8) | (sArr[s++] & 0xff);

            // Encode the int into four chars
            dArr[d++] = CA[(i >>> 18) & 0x3f];
            dArr[d++] = CA[(i >>> 12) & 0x3f];
            dArr[d++] = CA[(i >>> 6) & 0x3f];
            dArr[d++] = CA[i & 0x3f];

            // Add optional line separator
            if (lineSep && (++cc == 19) && (d < (dLen - 2))) {
                dArr[d++] = '\r';
                dArr[d++] = '\n';
                cc = 0;
            }
        }

        // Pad and encode last bits if source isn't even 24 bits.
        int left = sLen - eLen; // 0 - 2.
        if (left > 0) {
            // Prepare the int
            int i = ((sArr[eLen] & 0xff) << 10) | (left == 2 ? ((sArr[sLen - 1] & 0xff) << 2) : 0);

            // Set last four chars
            dArr[dLen - 4] = CA[i >> 12];
            dArr[dLen - 3] = CA[(i >>> 6) & 0x3f];
            dArr[dLen - 2] = left == 2 ? CA[i & 0x3f] : '=';
            dArr[dLen - 1] = '=';
        }
        return dArr;
    }

    /**
     * Encodes a raw byte array into a BASE64 <code>String</code>
     * representation i accordance with RFC 2045.
     * 
     * @param sArr The bytes to convert. If <code>null</code> or length 0
     *        an empty array will be returned.
     * @param lineSep Optional "\r\n" after 76 characters, unless end of
     *        file.<br>
     *        No line separator will be in breach of RFC 2045 which
     *        specifies max 76 per line but will be a little faster.
     * @return A BASE64 encoded array. Never <code>null</code>.
     */
    public final static String encodeToString(byte[] sArr, boolean lineSep) {
        // Reuse char[] since we can't create a String incrementally anyway and StringBuffer/Builder would be slower.
        return new String(encodeToChar(sArr, lineSep));
    }
}
