EVOLUTION-MANAGER
Edit File: keytab_file_format.html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Keytab file format — MIT Kerberos Documentation</title> <link rel="stylesheet" href="../_static/agogo.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <link rel="stylesheet" href="../_static/kerb.css" type="text/css" /> <script type="text/javascript"> var DOCUMENTATION_OPTIONS = { URL_ROOT: '../', VERSION: '1.15.1', COLLAPSE_INDEX: false, FILE_SUFFIX: '.html', HAS_SOURCE: true }; </script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <link rel="author" title="About these documents" href="../about.html" /> <link rel="copyright" title="Copyright" href="../copyright.html" /> <link rel="top" title="MIT Kerberos Documentation" href="../index.html" /> <link rel="up" title="Protocols and file formats" href="index.html" /> <link rel="next" title="KDC cookie format" href="cookie.html" /> <link rel="prev" title="Credential cache file format" href="ccache_file_format.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="ccache_file_format.html" title="Credential cache file format" accesskey="P">previous</a> | <a href="cookie.html" title="KDC cookie format" 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__Keytab file format">feedback</a> </div> </div> </div> <div class="content-wrapper"> <div class="content"> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body"> <div class="section" id="keytab-file-format"> <span id="id1"></span><h1>Keytab file format<a class="headerlink" href="#keytab-file-format" title="Permalink to this headline">¶</a></h1> <p>There are two versions of the file format used by the FILE keytab type. The first byte of the file always has the value 5, and the value of the second byte contains the version number (1 or 2). Version 1 of the file format uses native byte order for integer representations. Version 2 always uses big-endian byte order.</p> <p>After the two-byte version indicator, the file contains a sequence of signed 32-bit record lengths followed by key records or holes. A positive record length indicates a valid key entry whose size is equal to or less than the record length. A negative length indicates a zero-filled hole whose size is the inverse of the length. A length of 0 indicates the end of the file.</p> <div class="section" id="key-entry-format"> <h2>Key entry format<a class="headerlink" href="#key-entry-format" title="Permalink to this headline">¶</a></h2> <p>A key entry may be smaller in size than the record length which precedes it, because it may have replaced a hole which is larger than the key entry. Key entries use the following informal grammar:</p> <div class="highlight-python"><pre>entry ::= principal timestamp (32 bits) key version (8 bits) enctype (16 bits) key length (16 bits) key contents key version (32 bits) [in release 1.14 and later] principal ::= count of components (16 bits) [includes realm in version 1] realm (data) component1 (data) component2 (data) ... name type (32 bits) [omitted in version 1] data ::= length (16 bits) value (length bytes)</pre> </div> <p>The 32-bit key version overrides the 8-bit key version. To determine if it is present, the implementation must check that at least 4 bytes remain in the record after the other fields are read, and that the value of the 32-bit integer contained in those bytes is non-zero.</p> </div> </div> </div> </div> </div> </div> <div class="sidebar"> <h2>On this page</h2> <ul> <li><a class="reference internal" href="#">Keytab file format</a><ul> <li><a class="reference internal" href="#key-entry-format">Key entry format</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"><a class="reference internal" href="../basic/index.html">Kerberos V5 concepts</a></li> <li class="toctree-l1 current"><a class="reference internal" href="index.html">Protocols and file formats</a><ul class="current"> <li class="toctree-l2"><a class="reference internal" href="ccache_file_format.html">Credential cache file format</a></li> <li class="toctree-l2 current"><a class="current reference internal" href="">Keytab file format</a><ul class="simple"> </ul> </li> <li class="toctree-l2"><a class="reference internal" href="cookie.html">KDC cookie format</a></li> </ul> </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: 1.15.1</i><br /> © <a href="../copyright.html">Copyright</a> 1985-2017, MIT. </div> <div class="left"> <a href="../index.html" title="Full Table of Contents" >Contents</a> | <a href="ccache_file_format.html" title="Credential cache file format" >previous</a> | <a href="cookie.html" title="KDC cookie format" >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__Keytab file format">feedback</a> </div> </div> </div> </body> </html>