Apache Module mod_auth

AuthAuthoritative Directive

Description:	Sets whether authorization and authentication are passed to lower level modules
Syntax:	AuthAuthoritative On|Off
Default:	AuthAuthoritative On
Context:	directory, .htaccess
Override:	AuthConfig
Status:	Base
Module:	mod_auth

Setting the AuthAuthoritative directive explicitly to Off allows for both authentication and authorization to be passed on to lower level modules (as defined in the modules.c files) if there is no userID or rule matching the supplied userID. If there is a userID and/or rule specified; the usual password and access checks will be applied and a failure will give an "Authentication Required" reply.

So if a userID appears in the database of more than one module; or if a valid Require directive applies to more than one module; then the first module will verify the credentials; and no access is passed on; regardless of the AuthAuthoritative setting.

A common use for this is in conjunction with one of the database modules; such as mod_auth_dbm, mod_auth_msql, and mod_auth_anon. These modules supply the bulk of the user credential checking; but a few (administrator) related accesses fall through to a lower level with a well protected AuthUserFile.

By default control is not passed on and an unknown userID or rule will result in an "Authentication Required" reply. Not setting it thus keeps the system secure and forces an NCSA compliant behaviour.

AuthGroupFile Directive

Description:	Sets the name of a text file containing the list of user groups for authentication
Syntax:	AuthGroupFile file-path
Context:	directory, .htaccess
Override:	AuthConfig
Status:	Base
Module:	mod_auth

The AuthGroupFile directive sets the name of a textual file containing the list of user groups for user authentication. File-path is the path to the group file. If it is not absolute, it is treated as relative to the ServerRoot.

Each line of the group file contains a groupname followed by a colon, followed by the member usernames separated by spaces.

Note that searching large text files is very inefficient; AuthDBMGroupFile provides a much better performance.

AuthUserFile Directive

Description:	Sets the name of a text file containing the list of users and passwords for authentication
Syntax:	AuthUserFile file-path
Context:	directory, .htaccess
Override:	AuthConfig
Status:	Base
Module:	mod_auth

The AuthUserFile directive sets the name of a textual file containing the list of users and passwords for user authentication. File-path is the path to the user file. If it is not absolute (i.e., if it doesn't begin with a slash), it is treated as relative to the ServerRoot.

Each line of the user file contains a username followed by a colon, followed by the encrypted password. If the same user ID is defined multiple times, mod_auth will use the first occurrence to verify the password.

The utility htpasswd which is installed as part of the binary distribution, or which can be found in src/support, is used to maintain this password file. See the man page for more details. In short:

Create a password file Filename with username as the initial ID. It will prompt for the password:

Add or modify username2 in the password file Filename:

Note that searching large text files is very inefficient; AuthDBMUserFile should be used instead.