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Apache Module mod_session_dbd z4o2c

Available Languages:  fr 

Description: DBD/SQL based session
Status: Extension
Module Identifier: session_dbd_module
Source File: mod_session_dbd.c
Compatibility: Available in Apache 2.3 and later

Summary 6m2os

Warning 6h505h

The session modules make use of HTTP cookies, and as such can fall victim to Cross Site Scripting attacks, or expose potentially private information to clients. Please ensure that the relevant risks have been taken into before enabling the session functionality on your server.

This submodule of mod_dbd module.

Sessions can either be anonymous, where the session is keyed by a unique UUID string stored on the browser in a cookie, or per , where the session is keyed against the id of the logged in .

SQL based sessions are hidden from the browser, and so offer a measure of privacy without the need for encryption.

Different webservers within a server farm may choose to share a database, and so share sessions with one another.

For more details on the session interface, see the documentation for the mod_session module.

 Apache!

Topics 2c136y

Directives 1a4l6m

Bugfix checklist 4i2533

See also 27136x

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DBD Configuration 21542b

Before the mod_dbd module must be configured to make the various database queries available to the server.

There are four queries required to keep a session maintained, to select an existing session, to update an existing session, to insert a new session, and to delete an expired or empty session. These queries are configured as per the example below.

Sample DBD configuration 491n25

DBDriver pgsql
DBDParams "dbname=apachesession =apache =xxxxx host=localhost"
DBDPrepareSQL "delete from session where key = %s" deletesession
DBDPrepareSQL "update session set value = %s, expiry = %lld, key = %s where key = %s" updatesession
DBDPrepareSQL "insert into session (value, expiry, key) values (%s, %lld, %s)" insertsession
DBDPrepareSQL "select value from session where key = %s and (expiry = 0 or expiry > %lld)" selectsession
DBDPrepareSQL "delete from session where expiry != 0 and expiry < %lld" cleansession
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Anonymous Sessions 4i2334

Anonymous sessions are keyed against a unique UUID, and stored on the browser within an HTTP cookie. This method is similar to that used by most application servers to store session information.

To create a simple anonymous session and store it in a postgres database table called apachesession, and save the session ID in a cookie called session, configure the session as follows:

SQL based anonymous session 20404n

Session On
SessionDBDCookieName session path=/

For more examples on how the session can be configured to be read from and written to by a CGI application, see the mod_session examples section.

For documentation on how the session can be used to store name and details, see the mod_auth_form module.

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Per Sessions 5k4a42

Per sessions are keyed against the name of a successfully authenticated . It offers the most privacy, as no external handle to the session exists outside of the authenticated realm.

Per sessions work within a correctly configured authenticated environment, be that using basic authentication, digest authentication or SSL client certificates. Due to the limitations of who came first, the chicken or the egg, per sessions cannot be used to store authentication credentials from a module like mod_auth_form.

To create a simple per session and store it in a postgres database table called apachesession, and with the session keyed to the id, configure the session as follows:

SQL based per session 1b3t1d

Session On
SessionDBDPer On
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Database Housekeeping 5e5446

Over the course of time, the database can be expected to start accumulating expired sessions. At this point, the mod_session_dbd module is not yet able to handle session expiry automatically.

Warning 6h505h

The will need to set up an external process via cron to clean out expired sessions.

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SessionDBDCookieName Directive 6k3p6h

Description: Name and attributes for the RFC2109 cookie storing the session ID
Syntax: SessionDBDCookieName name attributes
Default: none
Context: server config, virtual host, directory, .htaccess
Status: Extension
Module: mod_session_dbd

The SessionDBDCookieName directive specifies the name and optional attributes of an RFC2109 compliant cookie inside which the session ID will be stored. RFC2109 cookies are set using the Set-Cookie HTTP header.

An optional list of cookie attributes can be specified, as per the example below. These attributes are inserted into the cookie as is, and are not interpreted by Apache. Ensure that your attributes are defined correctly as per the cookie specification.

Cookie with attributes 6e18e

Session On
SessionDBDCookieName session path=/private;domain=example.com;httponly;secure;version=1;
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SessionDBDCookieName2 Directive 186w5k

Description: Name and attributes for the RFC2965 cookie storing the session ID
Syntax: SessionDBDCookieName2 name attributes
Default: none
Context: server config, virtual host, directory, .htaccess
Status: Extension
Module: mod_session_dbd

The SessionDBDCookieName2 directive specifies the name and optional attributes of an RFC2965 compliant cookie inside which the session ID will be stored. RFC2965 cookies are set using the Set-Cookie2 HTTP header.

An optional list of cookie attributes can be specified, as per the example below. These attributes are inserted into the cookie as is, and are not interpreted by Apache. Ensure that your attributes are defined correctly as per the cookie specification.

Cookie2 with attributes 282w20

Session On
SessionDBDCookieName2 session path=/private;domain=example.com;httponly;secure;version=1;
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SessionDBDCookieRemove Directive 3ut2i

Description: Control for whether session ID cookies should be removed from incoming HTTP headers
Syntax: SessionDBDCookieRemove On|Off
Default: SessionDBDCookieRemove On
Context: server config, virtual host, directory, .htaccess
Status: Extension
Module: mod_session_dbd

The SessionDBDCookieRemove flag controls whether the cookies containing the session ID will be removed from the headers during request processing.

In a reverse proxy situation where the Apache server acts as a server frontend for a backend origin server, revealing the contents of the session ID cookie to the backend could be a potential privacy violation. When set to on, the session ID cookie will be removed from the incoming HTTP headers.

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SessionDBDDeleteLabel Directive 634j

Description: The SQL query to use to remove sessions from the database
Syntax: SessionDBDDeleteLabel label
Default: SessionDBDDeleteLabel deletesession
Context: server config, virtual host, directory, .htaccess
Status: Extension
Module: mod_session_dbd

The SessionDBDDeleteLabel directive sets the default delete query label to be used to delete an expired or empty session. This label must have been previously defined using the DBDPrepareSQL directive.

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SessionDBDInsertLabel Directive 82b6n

Description: The SQL query to use to insert sessions into the database
Syntax: SessionDBDInsertLabel label
Default: SessionDBDInsertLabel insertsession
Context: server config, virtual host, directory, .htaccess
Status: Extension
Module: mod_session_dbd

The SessionDBDInsertLabel directive sets the default insert query label to be used to load in a session. This label must have been previously defined using the DBDPrepareSQL directive.

If an attempt to update the session affects no rows, this query will be called to insert the session into the database.

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SessionDBDPer Directive 3p6x42

Description: Enable a per session
Syntax: SessionDBDPer On|Off
Default: SessionDBDPer Off
Context: server config, virtual host, directory, .htaccess
Status: Extension
Module: mod_session_dbd

The SessionDBDPer flag enables a per session keyed against the 's name. If the is not logged in, this directive will be ignored.

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SessionDBDSelectLabel Directive 5a534q

Description: The SQL query to use to select sessions from the database
Syntax: SessionDBDSelectLabel label
Default: SessionDBDSelectLabel selectsession
Context: server config, virtual host, directory, .htaccess
Status: Extension
Module: mod_session_dbd

The SessionDBDSelectLabel directive sets the default select query label to be used to load in a session. This label must have been previously defined using the DBDPrepareSQL directive.

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SessionDBDUpdateLabel Directive 323r2d

Description: The SQL query to use to update existing sessions in the database
Syntax: SessionDBDUpdateLabel label
Default: SessionDBDUpdateLabel updatesession
Context: server config, virtual host, directory, .htaccess
Status: Extension
Module: mod_session_dbd

The SessionDBDUpdateLabel directive sets the default update query label to be used to load in a session. This label must have been previously defined using the DBDPrepareSQL directive.

If an attempt to update the session affects no rows, the insert query will be called to insert the session into the database. If the database s InsertOrUpdate, override this query to perform the update in one query instead of two.

Available Languages:  fr 

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Comments 2p1l6j

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