apache/docs/manual/mod/mod_authz_owner.xml

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

<name>mod_authz_owner</name> 
<description>Authorization based on file ownership</description>
<status>Extension</status>
<sourcefile>mod_authz_owner.c</sourcefile>
<identifier>authz_owner_module</identifier>
<compatibility>Available in Apache 2.1 and later</compatibility>

<summary>
    <p>This module authorizes access to files by comparing the userid used
    for HTTP authentication (the web userid) with the file-system owner or
    group of the requested file. The supplied username and password
    must be already properly verified by an authentication module,
    such as <module>mod_auth_basic</module> or
    <module>mod_auth_digest</module>. <module>mod_authz_owner</module>
    recognizes two arguments for the <directive module="core"
    >Require</directive> directive, <code>file-owner</code> and
    <code>file-group</code>, as follows:</p>

    <dl>
      <dt><code>file-owner</code></dt>
      <dd>The supplied web-username must match the system's name for the
      owner of the file being requested. That is, if the operating system
      says the requested file is owned by <code>jones</code>, then the
      username used to access it through the web must be <code>jones</code>
      as well.</dd>

      <dt><code>file-group</code></dt>
      <dd>The name of the system group that owns the file must be present
      in a group database, which is provided, for example, by <module
      >mod_authz_groupfile</module> or <module>mod_authz_dbm</module>,
      and the web-username must be a member of that group. For example, if
      the operating system says the requested file is owned by (system)
      group <code>accounts</code>, the group <code>accounts</code> must
      appear in the group database and the web-username used in the request
      must be a member of that group.</dd>
    </dl>

    <note><title>Note</title>
      <p>If <module>mod_authz_owner</module> is used in order to authorize
      a resource that is not actually present in the filesystem
      (<em>i.e.</em> a virtual resource), it will deny the access.</p>

      <p>Particularly it will never authorize <a
      href="../content-negotiation.html#multiviews">content negotiated
      "MultiViews"</a> resources.</p>
    </note>
</summary>
<seealso><directive module="core">Require</directive></seealso>
<seealso><directive module="core">Satisfy</directive></seealso>

<section id="examples"><title>Configuration Examples</title>

    <section id="examples.file-owner"><title>Require file-owner</title>
      <p>Consider a multi-user system running the Apache Web server, with
      each user having his or her own files in <code
      >~/public_html/private</code>. Assuming that there is a single
      <directive module="mod_authn_dbm">AuthDBMUserFile</directive> database
      that lists all of their web-usernames, and that these usernames match
      the system's usernames that actually own the files on the server, then
      the following stanza would allow only the user himself access to his
      own files. User <code>jones</code> would not be allowed to access
      files in <code>/home/smith/public_html/private</code> unless they
      were owned by <code>jones</code> instead of <code>smith</code>.</p>

      <example>
        &lt;Directory /home/*/public_html/private&gt;<br />
        <indent>
          AuthType Basic<br />
          AuthName MyPrivateFiles<br />
          AuthBasicProvider dbm<br />
          AuthDBMUserFile /usr/local/apache2/etc/.htdbm-all<br />
          Satisfy All<br />
          Require file-owner<br />
        </indent>
        &lt;/Directory&gt;
      </example>
    </section>

    <section id="examples.file-group"><title>Require file-group</title>
      <p>Consider a system similar to the one described above, but with
      some users that share their project files in
      <code>~/public_html/project-foo</code>. The files are owned by the
      system group <code>foo</code> and there is a single <directive
      module="mod_authz_dbm">AuthDBMGroupFile</directive> database that
      contains all of the web-usernames and their group membership,
      <em>i.e.</em> they must be at least member of a group named
      <code>foo</code>. So if <code>jones</code> and <code>smith</code>
      are both member of the group <code>foo</code>, then both will be
      authorized to access the <code>project-foo</code> directories of
      each other.</p>

      <example>
        &lt;Directory /home/*/public_html/project-foo&gt;<br />
        <indent>
          AuthType Basic<br />
          AuthName "Project Foo Files"<br />
          AuthBasicProvider dbm<br />
          <br />
          # combined user/group database<br />
          AuthDBMUserFile  /usr/local/apache2/etc/.htdbm-all<br />
          AuthDBMGroupFile /usr/local/apache2/etc/.htdbm-all<br />
          <br />
          Satisfy All<br />
          Require file-group<br />
        </indent>
        &lt;/Directory&gt;
      </example>
    </section>
</section>

<directivesynopsis>
<name>AuthzOwnerAuthoritative</name>
<description>Sets whether authorization will be passed on to lower level
modules</description>
<syntax>AuthzOwnerAuthoritative On|Off</syntax>
<default>AuthzOwnerAuthoritative On</default>
<contextlist><context>directory</context><context>.htaccess</context>
</contextlist>
<override>AuthConfig</override>

<usage>
    <p>Setting the <directive>AuthzOwnerAuthoritative</directive>
    directive explicitly to <code>Off</code> allows for
    user authorization to be passed on to lower level modules (as defined
    in the <code>modules.c</code> files) if:</p>

    <ul>
    <li>in the case of <code>file-owner</code> the file-system owner does not
    match the supplied web-username or could not be determined, or</li>

    <li>in the case of <code>file-group</code> the file-system group does not
    contain the supplied web-username or could not be determined.</li>
    </ul>

    <p>Note that setting the value to <code>Off</code> also allows the
    combination of <code>file-owner</code> and <code>file-group</code>, so
    access will be allowed if either one or the other (or both) match.</p>

    <p>By default, control is not passed on and an authorization failure
    will result in an "Authentication Required" reply. Not
    setting it to <code>Off</code> thus keeps the system secure and forces
    an NCSA compliant behaviour.</p>
</usage>
</directivesynopsis>

</modulesynopsis>