What to shove up your .htaccess


Simon Bragg of website and design agency Sibra gave a talk on Monday about the .htaccess file. This file is found in the root directory of websites running on Apache web servers (so check what server software you are using if the htaccess is missing). It controls access to pages on the site, handles redirects and can be used for security and optimisations.

You can see Simon’s slides here:

What to shove up your htaccess presentation by Simon Bragg of Sibra
What to shove up your htaccess presentation by Simon Bragg of Sibra (click to open)

Here’s a written version of the presentation:

What to shove up your .htaccess

Simon Bragg

http://sibra.co.uk

Cambridge WordPress Meetup August 2018

The .htaccess file

.htaccess files enable:

  • Configuration changes to directory and sub-directory;
  • Without accessing httpd.conf,
  • Usually allowed;
  • Short commands:
  • key value pair.

If you screw it up syntax, you get:

Error 500 internal server error

What you can do

  • Browser caching
  • gzip compression for file transfer
  • Keep alive
  • Regex for redirects
  • Security enhancements

Browser caching

## EXPIRES CACHING ##

<IfModule mod_expires.c>

ExpiresActive On
ExpiresByType image/jpg "access plus 1 year"
ExpiresByType image/jpeg "access plus 1 year"
ExpiresByType image/gif "access plus 1 year"
ExpiresByType image/png "access plus 1 year"
ExpiresByType text/css "access plus 1 year"
ExpiresByType application/pdf "access plus 1 month"
ExpiresByType application/x-shockwave-flash "access plus 1 month"
ExpiresByType image/x-icon "access plus 1 year"
ExpiresByType text/javascript "access 1 month"
ExpiresByType text/x-javascript "access 1 month"
ExpiresByType application/javascript "access 1 month"
ExpiresByType application/x-javascript "access 1 month"
ExpiresByType application/json "access 1 month"
ExpiresByType application/vnd.ms-fontobject "access plus 1 year"
ExpiresByType application/x-font-ttf "access plus 1 year"
ExpiresByType application/x-font-opentype "access plus 1 year"
ExpiresByType application/x-font-woff "access plus 1 year"
ExpiresByType image/svg+xml "access plus 1 year"
ExpiresDefault "access plus 2 days"

</IfModule>

## EXPIRES CACHING ##

This can make a dramatic difference:

Speed check caching before
Speed check caching before
Speed check caching after
Speed check caching after htaccess changes

Compress transfer: gzip

Place this code AFTER WordPress stuff:

<IfModule mod_filter.c>

AddOutputFilterByType DEFLATE "application/atom+xml" \
"application/javascript" \
"application/json" \
"application/ld+json" \
"application/manifest+json" \
"application/rdf+xml" \
"application/rss+xml" \
"application/schema+json" \
"application/vnd.geo+json" \
"application/vnd.ms-fontobject" \
"application/x-font-ttf" \
"application/x-javascript" \
"application/x-web-app-manifest+json" \
"application/xhtml+xml" \
"application/xml" \
"font/eot" \
"font/opentype" \
"image/bmp" \
"image/svg+xml" \
"image/vnd.microsoft.icon" \
"image/x-icon" \
"text/cache-manifest" \
"text/css" \
"text/html" \
"text/javascript" \
"text/plain" \
"text/vcard" \
"text/vnd.rim.location.xloc" \
"text/vtt" \
"text/x-component" \
"text/x-cros
Speed check gzip compression after
Speed check gzip compression after

Keep alive, if allowed by host

At end of .htaccess file

## KEEP ALIVE ##

<ifModule mod_headers.c>

Header set Connection keep-alive

</ifModule>

## END ENABLE KEEP ALIVE ##

But cheapo host doesn’t allow this.

RedirectMatch for Regex redirects

Have mod_rewrite.c enabled for #Begin WordPress stuff.

So can use Regex to redirect multiple pages in one line. Some Examples:

Perhaps for tweaking URL structure:

.* means anything, (.*) means whatever, and repeat in $1

RedirectMatch 301 .*/employment/employee-shares/(.*)
http://www.website.co.uk/employee-shares/$1

^ means start of string, (/D) means 1 non digit character.

RedirectMatch 301 ^/share(\D)options$
http://www.website.co.uk/employee-shares/

Use of OR for multiple redirects to one page:

RedirectMatch 301 ((/introducing-thepod/)
|(/products/pod/)
|(/about-us/the-vision/)
|(/cambridgepod/)) https://website.co.uk/pod/

http to https

When have http site and converting to https, add in bold

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /

RewriteCond %{HTTPS} !=on
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

# BEGIN WordPress
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

Bits of code

1. Protect important files, deny access to them:

<FilesMatch "^.*(error_log|wp
config\.php|php.ini|\.[hH][tT][aApP].*)$">
Order deny,allow
Deny from all
</FilesMatch>

Check php.ini, is php.ini

2. Prevent directory browsing /wp-content/uploads/

Options All –Indexes

3. Block unauthorized execution of PHP files.

Most hackers upload backdoors to /uploads folder

<Directory "/var/www/wp-content/uploads/">
<Files "*.php">
Order Deny,Allow
Deny from All
</Files>
</Directory>

4. Protect against Script injections

Hackers change WordPress GLOBALS & REQUEST variables, so:

Options +FollowSymLinks
RewriteEngine On
RewriteCond %{QUERY_STRING} (<|%3C).*script.*(>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} GLOBALS(=|[|%[0-9A-Z]{0,2}) [OR]
RewriteCond %{QUERY_STRING} _REQUEST(=|[|%[0-9A-Z]{0,2})
RewriteRule ^(.*)$ index.php [F,L]

5. Secure wp-includes directory

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^wp-admin/includes/ - [F,L]
RewriteRule !^wp-includes/ - [S=3]
RewriteRule ^wp-includes/[^/]+\.php$ - [F,L]
RewriteRule ^wp-includes/js/tinymce/langs/.+\.php - [F,L]
RewriteRule ^wp-includes/theme-compat/ - [F,L]
</IfModule>

6. Prevent username enumeration

Visitor who enters your-site.com/?author=1 finds username. One less thing to guess. Just needs the password. So:

RewriteCond %{QUERY_STRING} author=d
RewriteRule ^ /? [L,R=301]

7. Prevent hot linking

Most hackers upload backdoors to /uploads folder

RewriteEngine On RewriteCond %{HTTP_REFERER} !^$ RewriteCond %{HTTP_REFERER}
!^http://(www\.)?your-site.com/.*$ [NC] RewriteRule \.(gif|jpg)$
http://www.your-site.com/hotlink.gif [R,L]Directory "/var/www/wpcontent/uploads/">

And replace http://www.your-site.com/hotlink.gif with image url you want to protect

xmlrpc.php blocking?

Xmlrpc : remote procedure call using XML to encode, and http for transport

Enables you to:

Post using weblog clients e.g. Windows Live Writer, IFTTT

Was a security concern, although not any more.

If want to block:

# Block WordPress xmlrpc.php requests
<Files xmlrpc.php>
order deny,allow
deny from all
allow from 123.123.123.123
</Files>

Thanks to Simon for his excellent talk!


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