http_userid module#

module sets cookies suitable for client identification. Received and set cookies can be logged using the Built-in variables $uid_got and $uid_set. This module is compatible with the mod_uid module for Apache.

Example Configuration#

userid         on;
userid_name    uid;
userid_domain  example.com;
userid_path    /;
userid_expires 365d;
userid_p3p     'policyref="/w3c/p3p.xml", CP="CUR ADM OUR NOR STA NID"';

Directives#

userid#

:Syntax userid on | v1 | log | off; :Default: userid off; :Context: http, server, location

Enables or disables setting cookies and logging the received cookies:

on

enables the setting of version 2 cookies and logging of the received cookies;

v1

enables the setting of version 1 cookies and logging of the received cookies;

log

disables the setting of cookies, but enables logging of the received cookies;

off

disables the setting of cookies and logging of the received cookies.

userid_domain#

:Syntax userid_domain name | none; :Default: userid_domain none; :Context: http, server, location

Defines a domain for which the cookie is set. The none parameter disables setting of a domain for the cookie.

userid_expires#

:Syntax userid_expires time | max | off; :Default: userid_expires off; :Context: http, server, location

Sets a time during which a browser should keep the cookie. The parameter max will cause the cookie to expire on “31 Dec 2037 23:55:55 GMT”. The parameter off will cause the cookie to expire at the end of a browser session.

userid_flags#

:Syntax userid_flags off | flag …; :Default: userid_flags off; :Context: http, server, location

If the parameter is not off, defines one or more additional flags for the cookie: secure, httponly, samesite=strict, samesite=lax, samesite=none.

userid_mark#

:Syntax userid_mark letter | digit | = | off; :Default: userid_mark off; :Context: http, server, location

If the parameter is not off, enables the cookie marking mechanism and sets the character used as a mark. This mechanism is used to add or change userid_p3p and/or a cookie expiration time while preserving the client identifier. A mark can be any letter of the English alphabet (case-sensitive), digit, or the “=” character.

If the mark is set, it is compared with the first padding symbol in the base64 representation of the client identifier passed in a cookie. If they do not match, the cookie is resent with the specified mark, expiration time, and “P3P” header.

userid_name#

:Syntax userid_name name; :Default: userid_name uid; :Context: http, server, location

Sets the cookie name.

userid_p3p#

:Syntax userid_p3p string | none; :Default: userid_p3p none; :Context: http, server, location

Sets a value for the “P3P” header field that will be sent along with the cookie. If the directive is set to the special value none, the “P3P” header will not be sent in a response.

userid_path#

:Syntax userid_path path; :Default: userid_path /; :Context: http, server, location

Defines a path for which the cookie is set.

userid_service#

:Syntax userid_service number; :Default: userid_service IP address of the server; :Context: http, server, location

If identifiers are issued by multiple servers (services), each service should be assigned its own number to ensure that client identifiers are unique. For version 1 cookies, the default value is zero. For version 2 cookies, the default value is the number composed from the last four octets of the server’s IP address.

Built-in Variables#

$uid_got#

The cookie name and received client identifier.

$uid_reset#

If the variable is set to a non-empty string that is not 0, the client identifiers are reset. The special value log additionally leads to the output of messages about the reset identifiers to the error_log.

$uid_set#

The cookie name and sent client identifier.