Apache HTTP Server Version 2.0
Apache HTTP Server Version 2.0
| Description: | User authentication using DBM files |
|---|---|
| Status: | Extension |
| Module Identifier: | authn_dbm_module |
| Source File: | mod_authn_dbm.c |
| Compatibility: | Available in Apache 2.0.42 and later |
This module provides authentication front-ends such as
mod_auth_digest and mod_auth_basic
to authenticate users by looking up users in plain text password files.
Similar functionality is provided by mod_authn_file.
When using mod_auth_basic or
mod_auth_digest, this module is invoked via the
AuthBasicProvider or
AuthDigestProvider
with the 'dbm' value.
| Description: | Sets whether authentication and authorization will be passwed on to lower level modules |
|---|---|
| Syntax: | AuthDBMAuthoritative on|off |
| Default: | AuthDBMAuthoritative on |
| Context: | directory, .htaccess |
| Override: | AuthConfig |
| Status: | Extension |
| Module: | mod_authn_dbm |
Setting the AuthDBMAuthoritative
directive explicitly to 'off' allows for both
authentication and authorization to be passed on to lower level
modules (as defined in the Configuration and
modules.c file 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 Authorization
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
auth providers; such as mod_authn_file. Whereas this
DBM module supplies the bulk of the user credential checking; a
few (administrator) related accesses fall through to a lower
level with a well protected .htpasswd file.
By default, control is not passed on and an unknown userID or rule will result in an Authorization Required reply. Not setting it thus keeps the system secure and forces an NCSA compliant behaviour.
Security: Do consider the implications of allowing a user to allow fall-through in his .htaccess file; and verify that this is really what you want; Generally it is easier to just secure a single .htpasswd file, than it is to secure a database which might have more access interfaces.
| Description: | Sets the type of database file that is used to store passwords |
|---|---|
| Syntax: | AuthDBMType default|SDBM|GDBM|NDBM|DB |
| Default: | AuthDBMType default |
| Context: | directory, .htaccess |
| Override: | AuthConfig |
| Status: | Extension |
| Module: | mod_authn_dbm |
| Compatibility: | Available in version 2.0.30 and later. |
Sets the type of database file that is used to store the passwords. The default database type is determined at compile time. The availability of other types of database files also depends on compile-time settings.
It is crucial that whatever program you use to create your password files is configured to use the same type of database.
| Description: | Sets the name of a database file containing the list of users and passwords for authentication |
|---|---|
| Syntax: | AuthDBMUserFile file-path |
| Context: | directory, .htaccess |
| Override: | AuthConfig |
| Status: | Extension |
| Module: | mod_authn_dbm |
The AuthDBMUserFile directive sets the
name of a DBM file containing the list of users and passwords for
user authentication. File-path is the absolute path to
the user file.
The user file is keyed on the username. The value for a user is
the crypt() encrypted password, optionally followed
by a colon and arbitrary data. The colon and the data following it
will be ignored by the server.
Security: make sure that the
AuthDBMUserFile is stored outside the
document tree of the web-server; do not put it in the
directory that it protects. Otherwise, clients will be able to
download the AuthDBMUserFile.
Important compatibility note: The implementation of "dbmopen" in the apache modules reads the string length of the hashed values from the DBM data structures, rather than relying upon the string being NULL-appended. Some applications, such as the Netscape web server, rely upon the string being NULL-appended, so if you are having trouble using DBM files interchangeably between applications this may be a part of the problem.
A perl script called dbmmanage is included with Apache. This program can be used to create and update DBM format password files for use with this module.
