htaccess compare cookie value and redirect if evaluation returns true/false

Question

I would like somebody to help me with an if-else statement in htaccess. What I want is htaccess to read a cookie and check if its value equals a defined value. If it evaluat

Answer 1

The %{HTTP_COOKIE} string looks like a series of escaped name-value pairs separated by semicolons, and each semicolon is followed by a space. From MDN:

Syntax

Cookie: <cookie-list>
Cookie: name=value
Cookie: name=value; name2=value2; name3=value3

<cookie-list>

• A list of name-value pairs in the form of =. Pairs in the list are separated by a semicolon and a space ('; ').

Examples

Cookie: PHPSESSID=298zf09hf012fh2; csrftoken=u32t4o3tb3gg43; _gat=1

So in your regular expression, you need to optionally match the semicolon followed by a space at the beginning and the semicolon at the end like so:

RewriteCond %{HTTP_COOKIE} "!(?:^|; )cookie_name=specific_value(?:;|$)"

Note: Different set-cookie functions escape different characters. So while one function might escape the @ symbol, another one might not causing inconsistencies in how your cookie string looks. For example a search for useremail@gmail.com might fail if it is stored as useremail%40gmail.com. They are both valid.

Answer 2

You can use this code that checks for specific value in the cookie:

RewriteEngine On

RewriteCond %{HTTP_COOKIE} !cookie_name=specific_value [NC]
RewriteRule ^ http://www.google.com [NC,L,R=302]

Answer 3

Replace required_value with the value that needs to be matched.

RewriteEngine On
RewriteCond %{HTTP_COOKIE} !cookie_name=required_value;? [NC]
RewriteRule ^ http://www.google.com [R=301,L]

;? makes sure that the match happens both when there are multiple cookie value pairs or when cookie_name is the only cookie set. This also prevents from matching on a cookie value like off when a match on only of (a substring) is required.

Answer 4

You're close. The cookie string needs a =:

RewriteEngine On
RewriteCond %{HTTP_COOKIE} !cookie_name=specific_value; [NC]
RewriteRule ^ http://www.google.com [NC,L]