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<h1 align="CENTER">Module mod_auth_digest</h1>
<p>This module provides for user authentication using MD5
Digest Authentication.</p>
rel="Help"><strong>Status:</strong></a> Experimental<br />
<a href="module-dict.html#SourceFile"
rel="Help"><strong>Source File:</strong></a>
mod_auth_digest.c<br />
<a href="module-dict.html#ModuleIdentifier"
rel="Help"><strong>Module Identifier:</strong></a>
auth_digest_module</p>
<h2>Summary</h2>
<p>This is an updated version of <a
href="mod_digest.html">mod_digest</a>. However, it has not been
extensively tested and is therefore marked experimental. If you
use this module, you must make sure to <em>not</em> use
mod_digest (because they share some of the same configuration
directives).</p>
<h2>Directives</h2>
<ul>
<li><a href="#authdigestfile">AuthDigestFile</a></li>
<li><a
href="#authdigestgroupfile">AuthDigestGroupFile</a></li>
<li><a href="#authdigestqop">AuthDigestQop</a></li>
<li><a
href="#authdigestnoncelifetime">AuthDigestNonceLifetime</a></li>
<li><a
href="#authdigestnonceformat">AuthDigestNonceFormat</a></li>
<li><a href="#authdigestnccheck">AuthDigestNcCheck</a></li>
<li><a
href="#authdigestalgorithm">AuthDigestAlgorithm</a></li>
<li><a href="#authdigestdomain">AuthDigestDomain</a></li>
</ul>
<h3><a id="usingdigest" name="usingdigest">Using Digest
Authentication</a></h3>
<p>Using MD5 Digest authentication is very simple. Simply set
up authentication normally, using "AuthType Digest" and
"AuthDigestFile" instead of the normal "AuthType Basic" and
"AuthUserFile"; also, replace any "AuthGroupFile" with
"AuthDigestGroupFile". Then add a "AuthDigestDomain" directive
containing at least the root URI(s) for this protection space.
Example:</p>
<pre>
<Location /private/>
AuthType Digest
AuthName "private area"
AuthDigestDomain /private/ http://mirror.my.dom/private2/
Require valid-user
</Location>
</pre>
<p><strong>Note:</strong> MD5 authentication provides a more
secure password system than Basic authentication, but only
works with supporting browsers. As of this writing (October 2001),
the only major browsers which support digest authentication are
<a href="http://www.microsoft.com/windows/ie/">MS Internet
Therefore, we do not yet recommend using this feature on a large
Internet site. However, for personal and intra-net use, where
browser users can be controlled, it is ideal.</p>
<hr />
<h2><a id="authdigestfile"
name="authdigestfile">AuthDigestFile</a> directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> AuthDigestFile
<em>file-path</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> directory,
.htaccess<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> AuthConfig<br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Experimental<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_auth_digest<br />
<p>The AuthDigestFile directive sets the name of a textual file
containing the list of users and encoded passwords for digest
authentication. <em>File-path</em> is the absolute path to the
user file.</p>
<p>The digest file uses a special format. Files in this format
can be created using the <a
href="/programs/htdigest.html">htdigest</a> utility found in
the support/ subdirectory of the Apache distribution.</p>
<hr />
<h2><a id="authdigestgroupfile"
name="authdigestgroupfile">AuthDigestGroupFile</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> AuthDigestGroupFile
<em>file-path</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> directory,
.htaccess<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> AuthConfig<br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Experimental<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_auth_digest
<p>The AuthDigestGroupFile directive sets the name of a textual
file containing the list of groups and their members (user
names). <em>File-path</em> is the absolute path to the group
file.</p>
<p>Each line of the group file contains a groupname followed by
a colon, followed by the member usernames separated by spaces.
Example:</p>
<blockquote>
<code>mygroup: bob joe anne</code>
</blockquote>
Note that searching large text files is <em>very</em>
inefficient.
<p>Security: make sure that the AuthGroupFile is stored outside
the document tree of the web-server; do <em>not</em> put it in
the directory that it protects. Otherwise, clients will be able
to download the AuthGroupFile.</p>
<hr />
<h2><a id="authdigestqop"
name="authdigestqop">AuthDigestQop</a> directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> AuthDigestQop
none|auth|auth-int [auth|auth-int]<br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <code>AuthDigestQop
auth</code><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> directory,
.htaccess<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> AuthConfig<br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Experimental<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_auth_digest
<p>The AuthDigestQop directive determines the
quality-of-protection to use. <em>auth</em> will only do
authentication plus integrity checking (an MD5 hash of the
entity is also computed and checked); <em>none</em> will cause
the module to use the old RFC-2069 digest algorithm (which does
not include integrity checking). Both <em>auth</em> and
<em>auth-int</em> may be specified, in which the case the
browser will choose which of these to use. <em>none</em> should
only be used if the browser for some reason does not like the
challenge it receives otherwise.</p>
<p><strong><em>auth-int</em> is not implemented
yet</strong>.</p>
<hr />
<h2><a id="authdigestnoncelifetime"
name="authdigestnoncelifetime">AuthDigestNonceLifetime</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> AuthDigestNonceLifetime
<em>seconds</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a>
<code>AuthDigestNonceLifetime 300</code><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> directory,
.htaccess<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> AuthConfig<br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Experimental<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_auth_digest
<p>The AuthDigestNonceLifetime directive controls how long the
server nonce is valid. When the client contacts the server
using an expired nonce the server will send back a 401 with
<code>stale=true</code>. If <em>seconds</em> is greater than 0
then it specifies the amount of time for which the nonce is
valid; this should probably never be set to less than 10
seconds. If <em>seconds</em> is less than 0 then the nonce
never expires. <!-- Not implemented yet
If <EM>seconds</EM> is 0 then the nonce may be used exactly once
by the client. Note that while one-time-nonces provide higher security
against replay attacks, they also have significant performance
implications, as the browser cannot pipeline or multiple connections
for the requests. Because browsers cannot easily detect that
one-time-nonces are being used, this may lead to browsers trying to
pipeline requests and receiving 401 responses for all but the first
request, requiring the browser to resend the requests. Note also that
the protection against reply attacks only makes sense for dynamically
generated content and things like POST requests; for static content
the attacker may already have the complete response, so one-time-nonces
do not make sense here.
-->
</p>
<hr />
<h2><a id="authdigestnonceformat"
name="authdigestnonceformat">AuthDigestNonceFormat</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> AuthDigestNonceFormat
<em>???</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a>
<code>AuthDigestNonceFormat ???</code><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> directory,
.htaccess<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> AuthConfig<br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Experimental<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_auth_digest
<p><strong>Not implemented yet.</strong> <!--
<P>The AuthDigestNonceFormat directive determines how the nonce is
generated.
-->
</p>
<hr />
<h2><a id="authdigestnccheck"
name="authdigestnccheck">AuthDigestNcCheck</a> directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> AuthDigestNcCheck
On|Off<br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a>
<code>AuthDigestNcCheck Off</code><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Experimental<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_auth_digest
<p><strong>Not implemented yet.</strong> <!--
<P>The AuthDigestNcCheck directive enables or disables the checking of the
nonce-count sent by the server.
<P>While recommended from a security standpoint, turning this directive
On has one important performance implication. To check the nonce-count
*all* requests (which have an Authorization header, irrespective of
whether they require digest authentication) must be serialized through
a critical section. If the server is handling a large number of
requests which contain the Authorization header then this may noticeably
impact performance.
-->
</p>
<hr />
<h2><a id="authdigestalgorithm"
name="authdigestalgorithm">AuthDigestAlgorithm</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> AuthDigestAlgorithm
MD5|MD5-sess<br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a>
<code>AuthDigestAlgorithm MD5</code><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> directory,
.htaccess<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> AuthConfig<br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Experimental<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_auth_digest
<p>The AuthDigestAlgorithm directive selects the algorithm used
to calculate the challenge and response hashes.</p>
<p><strong><em>MD5-sess</em> is not correctly implemented
yet</strong>. <!--
<P>To use <EM>MD5-sess</EM> you must first code up the
<VAR>get_userpw_hash()</VAR> function in <VAR>mod_auth_digest.c</VAR> .
-->
</p>
<hr />
<h2><a id="authdigestdomain"
name="authdigestdomain">AuthDigestDomain</a> directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> AuthDigestDomain
<em>URI</em> [<em>URI</em>] ...<br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> directory,
.htaccess<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> AuthConfig<br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Experimental<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_auth_digest
<p>The AuthDigestDomain directive allows you to specify one or
more URIs which are in the same protection space (i.e. use the
prefixes, i.e. the client will assume that all URIs "below"
URIs may be either absolute URIs (i.e. inluding a scheme, host,
port, etc) or relative URIs.</p>
<p>This directive <em>should</em> always be specified and
contain at least the (set of) root URI(s) for this space.
Omitting to do so will cause the client to send the
Authorization header for <em>every request</em> sent to this
server. Apart from increasing the size of the request, it may
also have a detrimental effect on performance if
"AuthDigestNcCheck" is on.</p>
<p>The URIs specified can also point to different servers, in
which case clients (which understand this) will then share
prompting the user each time.
<!--#include virtual="footer.html" -->
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