/application/controllers/md5.php

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class Md5 extends CI_Controller {

	public function index()
	{
		$this->encode();
	}

    public function encode() {

        $this->load->library('form_validation');

        $this->form_validation->set_rules('data', 'Данные', 'required|xss_clean');

        $data = array();
        $data['page_title'] = 'MD5 encode, MD5 хеш';
        if ($this->form_validation->run() == FALSE)
        {
            $data['result'] = '';
        }
        else
        {
            $data['result'] = md5($this->input->post('data'));
        }
        $this->load->view('md5/encode', $data);
    }

    public function file() {

        $data = array();
        $data['page_title'] = 'MD5 encode file, MD5 хеш файла';
        $data['result'] = @$_FILES['data'] ? md5_file($_FILES['data']['tmp_name']) : '';

        $this->load->view('md5/file', $data);
    }
}