jodd-core/src/main/java/jodd/util/Base64.java
public static byte[] encodeToByte(final byte[] arr, final boolean lineSep) {
		int len = arr != null ? arr.length : 0;
		if (len == 0) {
			return new byte[0];
		}

		int evenlen = (len / 3) * 3;
		int cnt = ((len - 1) / 3 + 1) << 2;
		int destlen = cnt + (lineSep ? (cnt - 1) / 76 << 1 : 0);
		byte[] dest = new byte[destlen];

		for (int s = 0, d = 0, cc = 0; s < evenlen;) {
			int i = (arr[s++] & 0xff) << 16 | (arr[s++] & 0xff) << 8 | (arr[s++] & 0xff);

			dest[d++] = (byte) CHARS[(i >>> 18) & 0x3f];
			dest[d++] = (byte) CHARS[(i >>> 12) & 0x3f];
			dest[d++] = (byte) CHARS[(i >>> 6) & 0x3f];
			dest[d++] = (byte) CHARS[i & 0x3f];

			if (lineSep && ++cc == 19 && d < destlen - 2) {
				dest[d++] = '\r';
				dest[d++] = '\n';
				cc = 0;
			}
		}

		int left = len - evenlen;
		if (left > 0) {
			int i = ((arr[evenlen] & 0xff) << 10) | (left == 2 ? ((arr[len - 1] & 0xff) << 2) : 0);

			dest[destlen - 4] = (byte) CHARS[i >> 12];
			dest[destlen - 3] = (byte) CHARS[(i >>> 6) & 0x3f];
			dest[destlen - 2] = left == 2 ? (byte) CHARS[i & 0x3f] : (byte) '=';
			dest[destlen - 1] = '=';
		}
		return dest;
	}
public static byte[] encodeToByte(final byte[] arr, final boolean lineSep) {
		int len = arr != null ? arr.length : 0;
		if (len == 0) {
			return new byte[0];
		}

		int evenlen = (len / 3) * 3;
		int cnt = ((len - 1) / 3 + 1) << 2;
		int destlen = cnt + (lineSep ? (cnt - 1) / 76 << 1 : 0);
		byte[] dest = new byte[destlen];

		for (int s = 0, d = 0, cc = 0; s < evenlen;) {
			int i = (arr[s++] & 0xff) << 16 | (arr[s++] & 0xff) << 8 | (arr[s++] & 0xff);

			dest[d++] = (byte) CHARS[(i >>> 18) & 0x3f];
			dest[d++] = (byte) CHARS[(i >>> 12) & 0x3f];
			dest[d++] = (byte) CHARS[(i >>> 6) & 0x3f];
			dest[d++] = (byte) CHARS[i & 0x3f];

			if (lineSep && ++cc == 19 && d < destlen - 2) {
				dest[d++] = '\r';
				dest[d++] = '\n';
				cc = 0;
			}
		}

		int left = len - evenlen;
		if (left > 0) {
			int i = ((arr[evenlen] & 0xff) << 10) | (left == 2 ? ((arr[len - 1] & 0xff) << 2) : 0);

			dest[destlen - 4] = (byte) CHARS[i >> 12];
			dest[destlen - 3] = (byte) CHARS[(i >>> 6) & 0x3f];
			dest[destlen - 2] = left == 2 ? (byte) CHARS[i & 0x3f] : (byte) '=';
			dest[destlen - 1] = '=';
		}
		return dest;
	}
Encodes a raw byte array into a BASE64 <code>char[]</code>.
@param lineSep optional CRLF after 76 chars, unless EOF.