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> Redes de Computadoras y Seguridad en Internet
Redes de computadoras y seguridad en Internet
El término "redes de computadoras" puede referirse
tanto a dos computadoras conectadas entre si, como a
Redes de Area Local (LANs), y hasta a la propia Internet
- la "red de redes".
Las redes pueden ayudar para que las organizaciones
trabajen en colaboración mediante el intercambio de
información, y también pueden permitir que compartan
recursos como las impresoras.
Un buen punto de partida para aprender sobre lo básico
de las redes de computadoras (en inglés) es la sección
TechSoup "Computer
Networks"
La seguridad y la privacidad en línea debería ser
una preocupación de todo usuario de Internet. Si su
organización opera una red o un servidor Internet, mecanismos
confiables de seguridad como "firewalls" (cortafuegos)
son esenciales.
Redes de Computadoras
-86400
// generalized version of cmd[]-c
// - fields and operators specifed
// - unlimited number of conditions
// - all default conditions from view definition are
// completely redefined by the specified ones
//optionaly set[] // setings to modify view behavior (can be combined with cmd)
// set[23]=listlen-20
// set[23]=mlx-EN-FR-DE
// - sets maximal number of viewed items in view 23 to 20
// - there can be more settings (future) - comma separated
//optionaly als[] // user alias - see slice.php3 for more details
// for more info see AA FAQ: http://apc-aa.sourceforge.net/faq/index.shtml#219
//ini_set('display_errors', 1);
// ----- input variables normalization - start --------------------------------
// This code handles with "magic quotes" and "register globals" PHP (<5.4) setting
// It make us sure, taht
// 1) in $_POST,$_GET,$_COOKIE,$_REQUEST variables the values are not quoted
// 2) the variables are imported in global scope and is quoted
// We are trying to remove any dependecy on the point 2) and use only $_* superglobals
function AddslashesDeep($value) { return is_array($value) ? array_map('AddslashesDeep', $value) : addslashes($value); }
function StripslashesDeep($value) { return is_array($value) ? array_map('StripslashesDeep', $value) : stripslashes($value); }
if ( get_magic_quotes_gpc() ) {
$_POST = StripslashesDeep($_POST);
$_GET = StripslashesDeep($_GET);
$_COOKIE = StripslashesDeep($_COOKIE);
$_REQUEST = StripslashesDeep($_REQUEST);
}
if (!ini_get('register_globals') OR !get_magic_quotes_gpc()) {
foreach ($_REQUEST as $k => $v) {
$$k = AddslashesDeep($v);
}
}
// ----- input variables normalization - end ----------------------------------
require_once "./include/config.php3";
require_once AA_INC_PATH."easy_scroller.php3";
require_once AA_INC_PATH."util.php3";
require_once AA_INC_PATH."item.php3";
require_once AA_INC_PATH."view.php3";
require_once AA_INC_PATH."discussion.php3";
require_once AA_INC_PATH."pagecache.php3";
require_once AA_INC_PATH."searchlib.php3";
$encap = true; // just for calling extsessi.php
require_once AA_INC_PATH."locsess.php3"; // DB_AA object definition
add_vars();
// we tried to remove all global $db, so let's try to comment out following global object
// honza 2015-12-30
// is_object( $db ) || ($db = getDB());
if (ctype_digit((string)$time_limit)) {
@set_time_limit((int)$time_limit);
}
AA::$debug && AA::$dbg->group("/view.php3", "Start");
// Need to be able to set content-type for RSS, cannot do it in the view
// because the cache wont reflect this
if ($contenttype) {
$contenttype = trim(strtolower($contenttype));
if ($len = strspn($contenttype,'abcdefghijklmnopqrstuvwxyz/')) {
AA::$headers['type'] = substr($contenttype,0,$len);
}
}
if ($filename) {
header('Content-Description: File Transfer');
if (!$contenttype) {
header('Content-Type: application/octet-stream');
}
header('Content-Disposition: attachment; filename='.basename($filename));
header('Content-Transfer-Encoding: binary');
}
$view_param = ParseViewParameters();
if ($convertfrom) {
$view_param['convertfrom'] = $convertfrom;
}
if ($convertto) {
$view_param['convertto'] = $convertto;
} elseif (!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && (strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest')) {
$view_param['convertto'] = 'utf-8';
}
//create keystring from values, which exactly identifies resulting content
$cache_key = get_hash($view_param, PageCache::globalKeyArray());
if ($cacheentry = $pagecache->getPage($cache_key, $nocache)) {
$cacheentry->processPage();
} else {
list($page_content, $cache_sid) = GetViewFromDB($view_param, true);
$cacheentry = new AA_Cacheentry($page_content, AA::getHeaders());
$cacheentry->processPage();
if (!$nocache) {
$str2find = new CacheStr2find($cache_sid, 'slice_id');
$pagecache->storePage($cache_key, $cacheentry, $str2find);
}
}
AA::$debug && AA::$dbg->groupend("/view.php3", "Completed view");
if (AA::$debug) {
AA::$dbg->duration_stat();
}
exit;
?>
Seguridad en Internet
-86400
// generalized version of cmd[]-c
// - fields and operators specifed
// - unlimited number of conditions
// - all default conditions from view definition are
// completely redefined by the specified ones
//optionaly set[] // setings to modify view behavior (can be combined with cmd)
// set[23]=listlen-20
// set[23]=mlx-EN-FR-DE
// - sets maximal number of viewed items in view 23 to 20
// - there can be more settings (future) - comma separated
//optionaly als[] // user alias - see slice.php3 for more details
// for more info see AA FAQ: http://apc-aa.sourceforge.net/faq/index.shtml#219
//ini_set('display_errors', 1);
// ----- input variables normalization - start --------------------------------
// This code handles with "magic quotes" and "register globals" PHP (<5.4) setting
// It make us sure, taht
// 1) in $_POST,$_GET,$_COOKIE,$_REQUEST variables the values are not quoted
// 2) the variables are imported in global scope and is quoted
// We are trying to remove any dependecy on the point 2) and use only $_* superglobals
function AddslashesDeep($value) { return is_array($value) ? array_map('AddslashesDeep', $value) : addslashes($value); }
function StripslashesDeep($value) { return is_array($value) ? array_map('StripslashesDeep', $value) : stripslashes($value); }
if ( get_magic_quotes_gpc() ) {
$_POST = StripslashesDeep($_POST);
$_GET = StripslashesDeep($_GET);
$_COOKIE = StripslashesDeep($_COOKIE);
$_REQUEST = StripslashesDeep($_REQUEST);
}
if (!ini_get('register_globals') OR !get_magic_quotes_gpc()) {
foreach ($_REQUEST as $k => $v) {
$$k = AddslashesDeep($v);
}
}
// ----- input variables normalization - end ----------------------------------
require_once "./include/config.php3";
require_once AA_INC_PATH."easy_scroller.php3";
require_once AA_INC_PATH."util.php3";
require_once AA_INC_PATH."item.php3";
require_once AA_INC_PATH."view.php3";
require_once AA_INC_PATH."discussion.php3";
require_once AA_INC_PATH."pagecache.php3";
require_once AA_INC_PATH."searchlib.php3";
$encap = true; // just for calling extsessi.php
require_once AA_INC_PATH."locsess.php3"; // DB_AA object definition
add_vars();
// we tried to remove all global $db, so let's try to comment out following global object
// honza 2015-12-30
// is_object( $db ) || ($db = getDB());
if (ctype_digit((string)$time_limit)) {
@set_time_limit((int)$time_limit);
}
AA::$debug && AA::$dbg->group("/view.php3", "Start");
// Need to be able to set content-type for RSS, cannot do it in the view
// because the cache wont reflect this
if ($contenttype) {
$contenttype = trim(strtolower($contenttype));
if ($len = strspn($contenttype,'abcdefghijklmnopqrstuvwxyz/')) {
AA::$headers['type'] = substr($contenttype,0,$len);
}
}
if ($filename) {
header('Content-Description: File Transfer');
if (!$contenttype) {
header('Content-Type: application/octet-stream');
}
header('Content-Disposition: attachment; filename='.basename($filename));
header('Content-Transfer-Encoding: binary');
}
$view_param = ParseViewParameters();
if ($convertfrom) {
$view_param['convertfrom'] = $convertfrom;
}
if ($convertto) {
$view_param['convertto'] = $convertto;
} elseif (!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && (strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest')) {
$view_param['convertto'] = 'utf-8';
}
//create keystring from values, which exactly identifies resulting content
$cache_key = get_hash($view_param, PageCache::globalKeyArray());
if ($cacheentry = $pagecache->getPage($cache_key, $nocache)) {
$cacheentry->processPage();
} else {
list($page_content, $cache_sid) = GetViewFromDB($view_param, true);
$cacheentry = new AA_Cacheentry($page_content, AA::getHeaders());
$cacheentry->processPage();
if (!$nocache) {
$str2find = new CacheStr2find($cache_sid, 'slice_id');
$pagecache->storePage($cache_key, $cacheentry, $str2find);
}
}
AA::$debug && AA::$dbg->groupend("/view.php3", "Completed view");
if (AA::$debug) {
AA::$dbg->duration_stat();
}
exit;
?>
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