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<modulesynopsis metafile="mod_authz_dbm.xml.meta">

<name>mod_authz_dbm</name>

<description>Group authorization using DBM files</description>

<status>Extension</status>

<sourcefile>mod_authz_dbm.c</sourcefile>

<identifier>authz_dbm_module</identifier>

<compatibility>Available in Apache 2.1 and later</compatibility>

<summary>

<p>This module provides authorization capabilities so that

authenticated users can be allowed or denied access to portions

of the web site by group membership. Similar functionality is

provided by <module>mod_authz_groupfile</module>.</p>

</summary>

<seealso><directive module="core">Require</directive></seealso>

<seealso><directive module="core">Satisfy</directive></seealso>

<directivesynopsis>

<name>AuthDBMGroupFile</name>

<description>Sets the name of the database file containing the list

of user groups for authorization</description>

<syntax>AuthDBMGroupFile <var>file-path</var></syntax>

<contextlist><context>directory</context><context>.htaccess</context>

</contextlist>

<override>AuthConfig</override>

<usage>

<p>The <directive>AuthDBMGroupFile</directive> directive sets the

name of a DBM file containing the list of user groups for user

authorization. <var>File-path</var> is the absolute path to the

group file.</p>

<p>The group file is keyed on the username. The value for a

user is a comma-separated list of the groups to which the users

belongs. There must be no whitespace within the value, and it

must never contain any colons.</p>

<note type="warning"><title>Security</title>

<p>Make sure that the <directive>AuthDBMGroupFile</directive> is

stored outside the document tree of the web-server. Do

<strong>not</strong> put it in the directory that it protects.

Otherwise, clients will be able to download the

<directive>AuthDBMGroupFile</directive> unless otherwise

protected.</p>

</note>

<p>Combining Group and Password DBM files: In some cases it is

easier to manage a single database which contains both the

password and group details for each user. This simplifies any

support programs that need to be written: they now only have to

deal with writing to and locking a single DBM file. This can be

accomplished by first setting the group and password files to

point to the same DBM:</p>

<example>

AuthDBMGroupFile /www/userbase<br />

AuthDBMUserFile /www/userbase

</example>

<p>The key for the single DBM is the username. The value consists

of</p>

<example>

Encrypted Password : List of Groups [ : (ignored) ]

</example>

<p>The password section contains the encrypted

password as before. This is followed by a colon and the comma

separated list of groups. Other data may optionally be left in the

DBM file after another colon; it is ignored by the authorization

module. This is what www.telescope.org uses for its combined

password and group database.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthzDBMType</name>

<description>Sets the type of database file that is used to

store list of user groups</description>

<syntax>AuthzDBMType default|SDBM|GDBM|NDBM|DB</syntax>

<default>AuthzDBMType default</default>

<contextlist><context>directory</context><context>.htaccess</context>

</contextlist>

<override>AuthConfig</override>

<usage>

<p>Sets the type of database file that is used to store the list

of user groups.

The default database type is determined at compile time. The

availability of other types of database files also depends on

<a href="/install.html#dbm">compile-time settings</a>.</p>

<p>It is crucial that whatever program you use to create your group

files is configured to use the same type of database.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthzDBMAuthoritative</name>

<description>Sets whether authorization will be passed on to lower level

modules</description>

<syntax>AuthzDBMAuthoritative On|Off</syntax>

<default>AuthzDBMAuthoritative On</default>

<contextlist><context>directory</context><context>.htaccess</context>

</contextlist>

<override>AuthConfig</override>

<usage>

<p>Setting the <directive>AuthzDBMAuthoritative</directive>

directive explicitly to <code>Off</code> allows group authorization

to be passed on to lower level modules (as defined in the

<code>modules.c</code> file) if there is no group found

for the the supplied userID. If there are any groups

specified, the usual checks will be applied and a failure will

give an Authentication Required reply.</p>

<p>So if a userID appears in the database of more than one module;

or if a valid <directive module="core">Require</directive>

directive applies to more than one module; then the first module

will verify the credentials; and no access is passed on;

regardless of the <directive>AuthAuthoritative</directive> setting.</p>

<p>A common use for this is in conjunction with one of the

auth providers; such as <module>mod_authn_dbm</module> or

<module>mod_authn_file</module>. 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

<code>.htpasswd</code> file.</p>

<p>By default, control is not passed on and an unknown group

will result in an Authentication Required reply. Not

setting it thus keeps the system secure and forces an NCSA

compliant behaviour.</p>

<note type="warning"><title>Security</title>

<p>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 <code>.htpasswd</code> file, than it is to secure a

database which might have more access interfaces.</p>

</note>

</usage>

</directivesynopsis>

</modulesynopsis>