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diff --git a/crypto/krb5/doc/html/basic/rcache_def.html b/crypto/krb5/doc/html/basic/rcache_def.html deleted file mode 100644 index 3fa0a526dfc0..000000000000 --- a/crypto/krb5/doc/html/basic/rcache_def.html +++ /dev/null @@ -1,229 +0,0 @@ -<!DOCTYPE html> - -<html lang="en" data-content_root="../"> - <head> - <meta charset="utf-8" /> - <meta name="viewport" content="width=device-width, initial-scale=1.0" /><meta name="viewport" content="width=device-width, initial-scale=1" /> - - <title>replay cache — MIT Kerberos Documentation</title> - <link rel="stylesheet" type="text/css" href="../_static/pygments.css?v=fa44fd50" /> - <link rel="stylesheet" type="text/css" href="../_static/agogo.css?v=879f3c71" /> - <link rel="stylesheet" type="text/css" href="../_static/kerb.css?v=6a0b3979" /> - <script src="../_static/documentation_options.js?v=236fef3b"></script> - <script src="../_static/doctools.js?v=888ff710"></script> - <script src="../_static/sphinx_highlight.js?v=dc90522c"></script> - <link rel="author" title="About these documents" href="../about.html" /> - <link rel="index" title="Index" href="../genindex.html" /> - <link rel="search" title="Search" href="../search.html" /> - <link rel="copyright" title="Copyright" href="../copyright.html" /> - <link rel="next" title="stash file" href="stash_file_def.html" /> - <link rel="prev" title="keytab" href="keytab_def.html" /> - </head><body> - <div class="header-wrapper"> - <div class="header"> - - - <h1><a href="../index.html">MIT Kerberos Documentation</a></h1> - - <div class="rel"> - - <a href="../index.html" title="Full Table of Contents" - accesskey="C">Contents</a> | - <a href="keytab_def.html" title="keytab" - accesskey="P">previous</a> | - <a href="stash_file_def.html" title="stash file" - accesskey="N">next</a> | - <a href="../genindex.html" title="General Index" - accesskey="I">index</a> | - <a href="../search.html" title="Enter search criteria" - accesskey="S">Search</a> | - <a href="mailto:krb5-bugs@mit.edu?subject=Documentation__replay cache">feedback</a> - </div> - </div> - </div> - - <div class="content-wrapper"> - <div class="content"> - <div class="document"> - - <div class="documentwrapper"> - <div class="bodywrapper"> - <div class="body" role="main"> - - <section id="replay-cache"> -<span id="rcache-definition"></span><h1>replay cache<a class="headerlink" href="#replay-cache" title="Link to this heading">¶</a></h1> -<p>A replay cache (or “rcache”) keeps track of all authenticators -recently presented to a service. If a duplicate authentication -request is detected in the replay cache, an error message is sent to -the application program.</p> -<p>The replay cache interface, like the credential cache and -<a class="reference internal" href="keytab_def.html#keytab-definition"><span class="std std-ref">keytab</span></a> interfaces, uses <cite>type:residual</cite> strings to -indicate the type of replay cache and any associated cache naming -data to use.</p> -<section id="background-information"> -<h2>Background information<a class="headerlink" href="#background-information" title="Link to this heading">¶</a></h2> -<p>Some Kerberos or GSSAPI services use a simple authentication mechanism -where a message is sent containing an authenticator, which establishes -the encryption key that the client will use for talking to the -service. But nothing about that prevents an eavesdropper from -recording the messages sent by the client, establishing a new -connection, and re-sending or “replaying” the same messages; the -replayed authenticator will establish the same encryption key for the -new session, and the following messages will be decrypted and -processed. The attacker may not know what the messages say, and can’t -generate new messages under the same encryption key, but in some -instances it may be harmful to the user (or helpful to the attacker) -to cause the server to see the same messages again a second time. For -example, if the legitimate client sends “delete first message in -mailbox”, a replay from an attacker may delete another, different -“first” message. (Protocol design to guard against such problems has -been discussed in <span class="target" id="index-0"></span><a class="rfc reference external" href="https://datatracker.ietf.org/doc/html/rfc4120.html#section-10"><strong>RFC 4120#section-10</strong></a>.)</p> -<p>Even if one protocol uses further protection to verify that the client -side of the connection actually knows the encryption keys (and thus is -presumably a legitimate user), if another service uses the same -service principal name, it may be possible to record an authenticator -used with the first protocol and “replay” it against the second.</p> -<p>The replay cache mitigates these attacks somewhat, by keeping track of -authenticators that have been seen until their five-minute window -expires. Different authenticators generated by multiple connections -from the same legitimate client will generally have different -timestamps, and thus will not be considered the same.</p> -<p>This mechanism isn’t perfect. If a message is sent to one application -server but a man-in-the-middle attacker can prevent it from actually -arriving at that server, the attacker could then use the authenticator -(once!) against a different service on the same host. This could be a -problem if the message from the client included something more than -authentication in the first message that could be useful to the -attacker (which is uncommon; in most protocols the server has to -indicate a successful authentication before the client sends -additional messages), or if the simple act of presenting the -authenticator triggers some interesting action in the service being -attacked.</p> -</section> -<section id="replay-cache-types"> -<h2>Replay cache types<a class="headerlink" href="#replay-cache-types" title="Link to this heading">¶</a></h2> -<p>Unlike the credential cache and keytab interfaces, replay cache types -are in lowercase. The following types are defined:</p> -<ol class="arabic simple"> -<li><p><strong>none</strong> disables the replay cache. The residual value is ignored.</p></li> -<li><p><strong>file2</strong> (new in release 1.18) uses a hash-based format to store -replay records. The file may grow to accommodate hash collisions. -The residual value is the filename.</p></li> -<li><p><strong>dfl</strong> is the default type if no environment variable or -configuration specifies a different type. It stores replay data in -a file2 replay cache with a filename based on the effective uid. -The residual value is ignored.</p></li> -</ol> -<p>For the dfl type, the location of the replay cache file is determined -as follows:</p> -<ol class="arabic simple"> -<li><p>The directory is taken from the <strong>KRB5RCACHEDIR</strong> environment -variable, or the <strong>TMPDIR</strong> environment variable, or a temporary -directory determined at configuration time such as <code class="docutils literal notranslate"><span class="pre">/var/tmp</span></code>, in -descending order of preference.</p></li> -<li><p>The filename is <code class="docutils literal notranslate"><span class="pre">krb5_EUID.rcache2</span></code> where EUID is the effective -uid of the process.</p></li> -<li><p>The file is opened without following symbolic links, and ownership -of the file is verified to match the effective uid.</p></li> -</ol> -<p>On Windows, the directory for the dfl type is the local appdata -directory, unless overridden by the <strong>KRB5RCACHEDIR</strong> environment -variable. The filename on Windows is <code class="docutils literal notranslate"><span class="pre">krb5.rcache2</span></code>, and the file -is opened normally.</p> -</section> -<section id="default-replay-cache-name"> -<h2>Default replay cache name<a class="headerlink" href="#default-replay-cache-name" title="Link to this heading">¶</a></h2> -<p>The default replay cache name is determined by the following, in -descending order of priority:</p> -<ol class="arabic simple"> -<li><p>The <strong>KRB5RCACHENAME</strong> environment variable (new in release 1.18).</p></li> -<li><p>The <strong>KRB5RCACHETYPE</strong> environment variable. If this variable is -set, the residual value is empty.</p></li> -<li><p>The <strong>default_rcache_name</strong> profile variable in <a class="reference internal" href="../admin/conf_files/krb5_conf.html#libdefaults"><span class="std std-ref">[libdefaults]</span></a> -(new in release 1.18).</p></li> -<li><p>If none of the above are set, the default replay cache name is -<code class="docutils literal notranslate"><span class="pre">dfl:</span></code>.</p></li> -</ol> -</section> -</section> - - - <div class="clearer"></div> - </div> - </div> - </div> - </div> - <div class="sidebar"> - - <h2>On this page</h2> - <ul> -<li><a class="reference internal" href="#">replay cache</a><ul> -<li><a class="reference internal" href="#background-information">Background information</a></li> -<li><a class="reference internal" href="#replay-cache-types">Replay cache types</a></li> -<li><a class="reference internal" href="#default-replay-cache-name">Default replay cache name</a></li> -</ul> -</li> -</ul> - - <br/> - <h2>Table of contents</h2> - <ul class="current"> -<li class="toctree-l1"><a class="reference internal" href="../user/index.html">For users</a></li> -<li class="toctree-l1"><a class="reference internal" href="../admin/index.html">For administrators</a></li> -<li class="toctree-l1"><a class="reference internal" href="../appdev/index.html">For application developers</a></li> -<li class="toctree-l1"><a class="reference internal" href="../plugindev/index.html">For plugin module developers</a></li> -<li class="toctree-l1"><a class="reference internal" href="../build/index.html">Building Kerberos V5</a></li> -<li class="toctree-l1 current"><a class="reference internal" href="index.html">Kerberos V5 concepts</a><ul class="current"> -<li class="toctree-l2"><a class="reference internal" href="ccache_def.html">Credential cache</a></li> -<li class="toctree-l2"><a class="reference internal" href="keytab_def.html">keytab</a></li> -<li class="toctree-l2 current"><a class="current reference internal" href="#">replay cache</a></li> -<li class="toctree-l2"><a class="reference internal" href="stash_file_def.html">stash file</a></li> -<li class="toctree-l2"><a class="reference internal" href="date_format.html">Supported date and time formats</a></li> -</ul> -</li> -<li class="toctree-l1"><a class="reference internal" href="../formats/index.html">Protocols and file formats</a></li> -<li class="toctree-l1"><a class="reference internal" href="../mitK5features.html">MIT Kerberos features</a></li> -<li class="toctree-l1"><a class="reference internal" href="../build_this.html">How to build this documentation from the source</a></li> -<li class="toctree-l1"><a class="reference internal" href="../about.html">Contributing to the MIT Kerberos Documentation</a></li> -<li class="toctree-l1"><a class="reference internal" href="../resources.html">Resources</a></li> -</ul> - - <br/> - <h4><a href="../index.html">Full Table of Contents</a></h4> - <h4>Search</h4> - <form class="search" action="../search.html" method="get"> - <input type="text" name="q" size="18" /> - <input type="submit" value="Go" /> - <input type="hidden" name="check_keywords" value="yes" /> - <input type="hidden" name="area" value="default" /> - </form> - - </div> - <div class="clearer"></div> - </div> - </div> - - <div class="footer-wrapper"> - <div class="footer" > - <div class="right" ><i>Release: 1.22-final</i><br /> - © <a href="../copyright.html">Copyright</a> 1985-2025, MIT. - </div> - <div class="left"> - - <a href="../index.html" title="Full Table of Contents" - >Contents</a> | - <a href="keytab_def.html" title="keytab" - >previous</a> | - <a href="stash_file_def.html" title="stash file" - >next</a> | - <a href="../genindex.html" title="General Index" - >index</a> | - <a href="../search.html" title="Enter search criteria" - >Search</a> | - <a href="mailto:krb5-bugs@mit.edu?subject=Documentation__replay cache">feedback</a> - </div> - </div> - </div> - - </body> -</html>
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