CI =& get_instance(); // 获取config文件中的配置数据 foreach (array('sess_encrypt_cookie','sess_use_database','sess_table_name','sess_expiration','sess_expire_on_close','sess_match_ip','sess_match_useragent','sess_cookie_name','cookie_path','cookie_domain','cookie_secure','sess_time_to_update','time_reference','cookie_prefix','encryption_key') as $key) { $this->$key = (isset($params[$key])) ? $params[$key] : $this->CI->config->item($key); } //必须设置encryption_key if ($this->encryption_key == '') { show_error('In order to use the Session class you are required to set an encryption key in your config file.'); } // 加载string helper函数 $this->CI->load->helper('string'); // D如果对cookie进行加密，则引入加密类 if ($this->sess_encrypt_cookie == TRUE) { $this->CI->load->library('encrypt'); } // 如果session计入数据库，则引入db if ($this->sess_use_database === TRUE AND $this->sess_table_name != '') { $this->CI->load->database(); } // 获取当前时间 $this->now = $this->_get_time(); // 如果没有设置session的有效时间，默认两年 if ($this->sess_expiration == 0) { $this->sess_expiration = (60*60*24*365*2); } // 获取cookie名称 $this->sess_cookie_name = $this->cookie_prefix.$this->sess_cookie_name; // 如果session不存在，创建新会话 if ( ! $this->sess_read()) { $this->sess_create(); } else { $this->sess_update(); } // 闪出标记old的闪出数据 $this->_flashdata_sweep(); //将新的闪出数据标记成old 标记成old的数据的数据将会在下次请求时闪出 $this->_flashdata_mark(); //回收/删除 过期的session $this->_sess_gc(); log_message('debug',"Session routines successfully run"); } // -------------------------------------------------------------------- /** * 读取session数据 */ function sess_read() { // 获取session $session = $this->CI->input->cookie($this->sess_cookie_name); // 没有session 拜拜 if ($session === FALSE) { log_message('debug','A session cookie was not found.'); return FALSE; } // 如果加密了cookie if ($this->sess_encrypt_cookie == TRUE) { $session = $this->CI->encrypt->decode($session); } else { // encryption was not used,so we need to check the md5 hash $hash = substr($session,strlen($session)-32); // get last 32 chars $session = substr($session,strlen($session)-32); // Does the md5 hash match? This is to prevent manipulation of session data in userspace if ($hash !== md5($session.$this->encryption_key)) { log_message('error','The session cookie data did not match what was expected. This could be a possible hacking attempt.'); $this->sess_destroy(); return FALSE; } } // 反序列化存入cookie的session数组 $session = $this->_unserialize($session); // 检测session的数据 if ( ! is_array($session) OR ! isset($session['session_id']) OR ! isset($session['ip_address']) OR ! isset($session['user_agent']) OR ! isset($session['last_activity'])) { $this->sess_destroy(); return FALSE; } // session数据过期了吗 if (($session['last_activity'] + $this->sess_expiration) < $this->now) { $this->sess_destroy(); return FALSE; } // 是否是根据用户ip来读取session数据 if ($this->sess_match_ip == TRUE AND $session['ip_address'] != $this->CI->input->ip_address()) { $this->sess_destroy(); return FALSE; } // 是否根据ua来匹配session数据 if ($this->sess_match_useragent == TRUE AND trim($session['user_agent']) != trim(substr($this->CI->input->user_agent(),120))) { $this->sess_destroy(); return FALSE; } // 如果session入库了，这种方式应该更安全点，当然负载大时，就不建议了，数据库读写压力大 if ($this->sess_use_database === TRUE) { $this->CI->db->where('session_id',$session['session_id']); if ($this->sess_match_ip == TRUE) { $this->CI->db->where('ip_address',$session['ip_address']); } if ($this->sess_match_useragent == TRUE) { $this->CI->db->where('user_agent',$session['user_agent']); } $query = $this->CI->db->get($this->sess_table_name); // No result? Kill it! if ($query->num_rows() == 0) { $this->sess_destroy(); return FALSE; } // Is there custom data? If so,add it to the main session array $row = $query->row(); if (isset($row->user_data) AND $row->user_data != '') { $custom_data = $this->_unserialize($row->user_data); if (is_array($custom_data)) { foreach ($custom_data as $key => $val) { $session[$key] = $val; } } } } // Session is valid! $this->userdata = $session; unset($session); return TRUE; } // -------------------------------------------------------------------- /** * 将读取的session数据写入 */ function sess_write() { // 是否写入db if ($this->sess_use_database === FALSE) { $this->_set_cookie(); return; } // set the custom userdata,the session data we will set in a second $custom_userdata = $this->userdata; $cookie_userdata = array(); // Before continuing,we need to determine if there is any custom data to deal with. // Let's determine this by removing the default indexes to see if there's anything left in the array // and set the session data while we're at it foreach (array('session_id','ip_address','user_agent','last_activity') as $val) { unset($custom_userdata[$val]); $cookie_userdata[$val] = $this->userdata[$val]; } // Did we find any custom data? If not,we turn the empty array into a string // since there's no reason to serialize and store an empty array in the DB if (count($custom_userdata) === 0) { $custom_userdata = ''; } else { // Serialize the custom data array so we can store it $custom_userdata = $this->_serialize($custom_userdata); } // 更新session记录 $this->CI->db->where('session_id',$this->userdata['session_id']); $this->CI->db->update($this->sess_table_name,array('last_activity' => $this->userdata['last_activity'],'user_data' => $custom_userdata)); // Write the cookie. Notice that we manually pass the cookie data array to the // _set_cookie() function. Normally that function will store $this->userdata,but // in this case that array contains custom data,which we do not want in the cookie. $this->_set_cookie($cookie_userdata); } // -------------------------------------------------------------------- /** * 创建一个新的session */ function sess_create() { //保证sessid 安全唯一 $sessid = ''; while (strlen($sessid) < 32) { $sessid .= mt_rand(0,mt_getrandmax()); } $sessid .= $this->CI->input->ip_address(); $this->userdata = array( 'session_id'=> md5(uniqid($sessid,TRUE)), 'ip_address'=> $this->CI->input->ip_address(), 'user_agent'=> substr($this->CI->input->user_agent(),120), 'last_activity'=> $this->now, 'user_data'=> '' ); // Save the data to the DB if needed if ($this->sess_use_database === TRUE) { $this->CI->db->query($this->CI->db->insert_string($this->sess_table_name,$this->userdata)); } // Write the cookie $this->_set_cookie(); } // -------------------------------------------------------------------- /** * 更新session */ function sess_update() { // 默认五分钟更新 if (($this->userdata['last_activity'] + $this->sess_time_to_update) >= $this->now) { return; } // Save the old session id so we know which record to // update in the database if we need it $old_sessid = $this->userdata['session_id']; $new_sessid = ''; while (strlen($new_sessid) < 32) { $new_sessid .= mt_rand(0,mt_getrandmax()); } // To make the session ID even more secure we'll combine it with the user's IP $new_sessid .= $this->CI->input->ip_address(); // Turn it into a hash $new_sessid = md5(uniqid($new_sessid,TRUE)); // Update the session data in the session data array $this->userdata['session_id'] = $new_sessid; $this->userdata['last_activity'] = $this->now; // _set_cookie() will handle this for us if we aren't using database sessions // by pushing all userdata to the cookie. $cookie_data = NULL; // 更新数据库中几率 if ($this->sess_use_database === TRUE) { // set cookie explicitly to only have our session data $cookie_data = array(); foreach (array('session_id','last_activity') as $val) { $cookie_data[$val] = $this->userdata[$val]; } $this->CI->db->query($this->CI->db->update_string($this->sess_table_name,array('last_activity' => $this->now,'session_id' => $new_sessid),array('session_id' => $old_sessid))); } // 重新写入session $this->_set_cookie($cookie_data); } // -------------------------------------------------------------------- /** *销毁当前所有session数据 */ function sess_destroy() { // Kill the session DB row if ($this->sess_use_database === TRUE && isset($this->userdata['session_id'])) { $this->CI->db->where('session_id',$this->userdata['session_id']); $this->CI->db->delete($this->sess_table_name); } // Kill the cookie setcookie( $this->sess_cookie_name, addslashes(serialize(array())), ($this->now - 31500000), $this->cookie_path, $this->cookie_domain, 0 ); // Kill session data $this->userdata = array(); } // -------------------------------------------------------------------- /** * 获取session数组指定元素的值 */ function userdata($item) { return ( ! isset($this->userdata[$item])) ? FALSE : $this->userdata[$item]; } // -------------------------------------------------------------------- /** * 获取所有session数据 */ function all_userdata() { return $this->userdata; } // -------------------------------------------------------------------- /** * 添加和修改自定义的session数据 */ function set_userdata($newdata = array(),$newval = '') { if (is_string($newdata)) { $newdata = array($newdata => $newval); } //支持数组组合方式 if (count($newdata) > 0) { foreach ($newdata as $key => $val) { $this->userdata[$key] = $val; } } $this->sess_write(); } // -------------------------------------------------------------------- /** * 删除session数组中的元素， */ function unset_userdata($newdata = array()) { if (is_string($newdata)) { $newdata = array($newdata => ''); } if (count($newdata) > 0) { foreach ($newdata as $key => $val) { unset($this->userdata[$key]); } } $this->sess_write(); } // ------------------------------------------------------------------------ /** * Add or change flashdata,only available * until the next request * * @accesspublic * @parammixed * @paramstring * @returnvoid */ function set_flashdata($newdata = array(),$newval = '') { if (is_string($newdata)) { $newdata = array($newdata => $newval); } if (count($newdata) > 0) { foreach ($newdata as $key => $val) { $flashdata_key = $this->flashdata_key.':new:'.$key; $this->set_userdata($flashdata_key,$val); } } } // ------------------------------------------------------------------------ /** * CI支持闪出数据也就是说 Session数据只对下次服务器请求可用,有时候如果你还想在下个请求后的请求还有效。。。 * keep_flashdata功能就是讲持续保持闪出数据，使其在下个请求也有效 */ function keep_flashdata($key) { //将闪出数据标记成new $old_flashdata_key = $this->flashdata_key.':old:'.$key; $value = $this->userdata($old_flashdata_key); $new_flashdata_key = $this->flashdata_key.':new:'.$key; $this->set_userdata($new_flashdata_key,$value); } // ------------------------------------------------------------------------ /** * 获取闪出数据 */ function flashdata($key) { $flashdata_key = $this->flashdata_key.':old:'.$key; return $this->userdata($flashdata_key); } // ------------------------------------------------------------------------ /** * 将闪出数据标记成old，以便_flashdata_sweep清除数据 */ function _flashdata_mark() { $userdata = $this->all_userdata(); foreach ($userdata as $name => $value) { $parts = explode(':new:',$name); if (is_array($parts) && count($parts) === 2) { $new_name = $this->flashdata_key.':old:'.$parts[1]; $this->set_userdata($new_name,$value); $this->unset_userdata($name); } } } // ------------------------------------------------------------------------ /** * 将标记成old的闪出数据闪出 */ function _flashdata_sweep() { $userdata = $this->all_userdata(); foreach ($userdata as $key => $value) { if (strpos($key,':old:')) { $this->unset_userdata($key); } } } //获取当前时间 function _get_time() { if (strtolower($this->time_reference) == 'gmt') { $now = time(); $time = mktime(gmdate("H",$now),gmdate("i",gmdate("s",gmdate("m",gmdate("d",gmdate("Y",$now)); } else { $time = time(); } return $time; } // -------------------------------------------------------------------- /** * 写入session cookie * */ function _set_cookie($cookie_data = NULL) { if (is_null($cookie_data)) { $cookie_data = $this->userdata; } // 序列化数组 $cookie_data = $this->_serialize($cookie_data); //加密数据 if ($this->sess_encrypt_cookie == TRUE) { $cookie_data = $this->CI->encrypt->encode($cookie_data); } else { // if encryption is not used,we provide an md5 hash to prevent userside tampering $cookie_data = $cookie_data.md5($cookie_data.$this->encryption_key); } //sess_expire_on_close为TRUE则，浏览器关闭，session失效 $expire = ($this->sess_expire_on_close === TRUE) ? 0 : $this->sess_expiration + time(); // Set the cookie setcookie( $this->sess_cookie_name, $cookie_data, $expire, $this->cookie_secure ); } // -------------------------------------------------------------------- /** * 序列化数组 */ function _serialize($data) { if (is_array($data)) { foreach ($data as $key => $val) { if (is_string($val)) { $data[$key] = str_replace('\\','{{slash}}',$val); } } } else { if (is_string($data)) { $data = str_replace('\\',$data); } } return serialize($data); } // -------------------------------------------------------------------- /** * 反序列化数组 */ function _unserialize($data) { $data = @unserialize(strip_slashes($data)); if (is_array($data)) { foreach ($data as $key => $val) { if (is_string($val)) { $data[$key] = str_replace('{{slash}}','\\',$val); } } return $data; } return (is_string($data)) ? str_replace('{{slash}}',$data) : $data; } // -------------------------------------------------------------------- /** * 回收/删除数据库中失效的session信息 */ function _sess_gc() { if ($this->sess_use_database != TRUE) { return; } srand(time()); if ((rand() % 100) < $this->gc_probability) { $expire = $this->now - $this->sess_expiration; $this->CI->db->where("last_activity < {$expire}"); $this->CI->db->delete($this->sess_table_name); log_message('debug','Session garbage collection performed.'); } } }