sub encode_base64 ($;$)
{
    #use integer;

    my $eol = $_[1];
    $eol = "\n" unless defined $eol;

    my $res = pack("u", $_[0]);
    # Remove first character of each line, remove newlines
    $res =~ s/^.//mg;
    $res =~ s/\n//g;

    $res =~ tr|` -_|AA-Za-z0-9+/|;               # `# help emacs
    # fix padding at the end
    my $padding = (3 - length($_[0]) % 3) % 3;
    $res =~ s/.{$padding}$/'=' x $padding/e if $padding;
    # break encoded string into lines of no more than 76 characters each
    if (length $eol) {
	$res =~ s/(.{1,76})/$1$eol/g;
    }
    return $res;
}