Joomla - No puedo acceder al backend de joomla 3

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# @package    Joomla

# @copyright  Copyright (C) 2005 - 2015 Open Source Matters. All rights reserved.

# @license    GNU General Public License version 2 or later; see LICENSE.txt

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# READ THIS COMPLETELY IF YOU CHOOSE TO USE THIS FILE!

#

# The line just below this section: 'Options +FollowSymLinks' may cause problems

# with some server configurations.  It is required for use of mod_rewrite, but may already

# be set by your server administrator in a way that disallows changing it in

# your .htaccess file.  If using it causes your server to error out, comment it out (add # to

# beginning of line), reload your site in your browser and test your sef url's.  If they work,

# it has been set by your server administrator and you do not need it set here.

##

## No directory listings

IndexIgnore *

## Can be commented out if causes errors, see notes above.

Options +FollowSymlinks

Options -Indexes

## Mod_rewrite in use.

RewriteEngine On

## Begin - Rewrite rules to block out some common exploits.

# If you experience problems on your site block out the operations listed below

# This attempts to block the most common type of exploit `attempts` to Joomla!

#

# Block out any script trying to base64_encode data within the URL.

RewriteCond %{QUERY_STRING} base64_encode[^(]*\([^)]*\) [OR]

# Block out any script that includes a <script> tag in URL.

RewriteCond %{QUERY_STRING} (<|%3C)([^s]*s)+cript.*(>|%3E) [NC,OR]

# Block out any script trying to set a PHP GLOBALS variable via URL.

RewriteCond %{QUERY_STRING} GLOBALS(=|\[|\%[0-9A-Z]{0,2}) [OR]

# Block out any script trying to modify a _REQUEST variable via URL.

RewriteCond %{QUERY_STRING} _REQUEST(=|\[|\%[0-9A-Z]{0,2})

# Return 403 Forbidden header and show the content of the root homepage

RewriteRule .* index.php [F]

#

## End - Rewrite rules to block out some common exploits.

## Begin - Custom redirects

#

# If you need to redirect some pages, or set a canonical non-www to

# www redirect (or vice versa), place that code here. Ensure those

# redirects use the correct RewriteRule syntax and the [R=301,L] flags.

#

## End - Custom redirects

##

# Uncomment following line if your webserver's URL

# is not directly related to physical file paths.

# Update Your Joomla! Directory (just / for root).

##

# RewriteBase /

## Begin - Joomla! core SEF Section.

#

RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]

#

# If the requested path and file is not /index.php and the request

# has not already been internally rewritten to the index.php script

RewriteCond %{REQUEST_URI} !^/index\.php

# and the requested path and file doesn't directly match a physical file

RewriteCond %{REQUEST_FILENAME} !-f

# and the requested path and file doesn't directly match a physical folder

RewriteCond %{REQUEST_FILENAME} !-d

# internally rewrite the request to the index.php script

RewriteRule .* index.php [L]

#

## End - Joomla! core SEF Section.