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diff --git a/crypto/krb5/doc/html/plugindev/gssapi.html b/crypto/krb5/doc/html/plugindev/gssapi.html new file mode 100644 index 000000000000..95db08fbcb4d --- /dev/null +++ b/crypto/krb5/doc/html/plugindev/gssapi.html @@ -0,0 +1,259 @@ + +<!DOCTYPE html> + +<html> + <head> + <meta charset="utf-8" /> + <meta name="viewport" content="width=device-width, initial-scale=1.0" /><meta name="generator" content="Docutils 0.17.1: http://docutils.sourceforge.net/" /> + + <title>GSSAPI mechanism interface — MIT Kerberos Documentation</title> + <link rel="stylesheet" type="text/css" href="../_static/pygments.css" /> + <link rel="stylesheet" type="text/css" href="../_static/agogo.css" /> + <link rel="stylesheet" type="text/css" href="../_static/kerb.css" /> + <script data-url_root="../" id="documentation_options" src="../_static/documentation_options.js"></script> + <script src="../_static/jquery.js"></script> + <script src="../_static/underscore.js"></script> + <script src="../_static/doctools.js"></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="Internal pluggable interfaces" href="internal.html" /> + <link rel="prev" title="Configuration interface (profile)" href="profile.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="profile.html" title="Configuration interface (profile)" + accesskey="P">previous</a> | + <a href="internal.html" title="Internal pluggable interfaces" + 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__GSSAPI mechanism interface">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="gssapi-mechanism-interface"> +<h1>GSSAPI mechanism interface<a class="headerlink" href="#gssapi-mechanism-interface" title="Permalink to this headline">¶</a></h1> +<p>The GSSAPI library in MIT krb5 can load mechanism modules to augment +the set of built-in mechanisms.</p> +<p>A mechanism module is a Unix shared object or Windows DLL, built +separately from the krb5 tree. Modules are loaded according to the +GSS mechanism config files described in <a class="reference internal" href="../admin/host_config.html#gssapi-plugin-config"><span class="std std-ref">GSSAPI mechanism modules</span></a>.</p> +<p>For the most part, a GSSAPI mechanism module exports the same +functions as would a GSSAPI implementation itself, with the same +function signatures. The mechanism selection layer within the GSSAPI +library (called the “mechglue”) will dispatch calls from the +application to the module if the module’s mechanism is requested. If +a module does not wish to implement a GSSAPI extension, it can simply +refrain from exporting it, and the mechglue will fail gracefully if +the application calls that function.</p> +<p>The mechglue does not invoke a module’s <strong>gss_add_cred</strong>, +<strong>gss_add_cred_from</strong>, <strong>gss_add_cred_impersonate_name</strong>, or +<strong>gss_add_cred_with_password</strong> function. A mechanism only needs to +implement the “acquire” variants of those functions.</p> +<p>A module does not need to coordinate its minor status codes with those +of other mechanisms. If the mechglue detects conflicts, it will map +the mechanism’s status codes onto unique values, and then map them +back again when <strong>gss_display_status</strong> is called.</p> +<section id="negoex-modules"> +<h2>NegoEx modules<a class="headerlink" href="#negoex-modules" title="Permalink to this headline">¶</a></h2> +<p>Some Windows GSSAPI mechanisms can only be negotiated via a Microsoft +extension to SPNEGO called NegoEx. Beginning with release 1.18, +mechanism modules can support NegoEx as follows:</p> +<ul class="simple"> +<li><p>Implement the gssspi_query_meta_data(), gssspi_exchange_meta_data(), +and gssspi_query_mechanism_info() SPIs declared in +<code class="docutils literal notranslate"><span class="pre"><gssapi/gssapi_ext.h></span></code>.</p></li> +<li><p>Implement gss_inquire_sec_context_by_oid() and answer the +<strong>GSS_C_INQ_NEGOEX_KEY</strong> and <strong>GSS_C_INQ_NEGOEX_VERIFY_KEY</strong> OIDs +to provide the checksum keys for outgoing and incoming checksums, +respectively. The answer must be in two buffers: the first buffer +contains the key contents, and the second buffer contains the key +encryption type as a four-byte little-endian integer.</p></li> +</ul> +<p>By default, NegoEx mechanisms will not be directly negotiated via +SPNEGO. If direct SPNEGO negotiation is required for +interoperability, implement gss_inquire_attrs_for_mech() and assert +the GSS_C_MA_NEGOEX_AND_SPNEGO attribute (along with any applicable +RFC 5587 attributes).</p> +</section> +<section id="interposer-modules"> +<h2>Interposer modules<a class="headerlink" href="#interposer-modules" title="Permalink to this headline">¶</a></h2> +<p>The mechglue also supports a kind of loadable module, called an +interposer module, which intercepts calls to existing mechanisms +rather than implementing a new mechanism.</p> +<p>An interposer module must export the symbol <strong>gss_mech_interposer</strong> +with the following signature:</p> +<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">gss_OID_set</span> <span class="n">gss_mech_interposer</span><span class="p">(</span><span class="n">gss_OID</span> <span class="n">mech_type</span><span class="p">);</span> +</pre></div> +</div> +<p>This function is invoked with the OID of the interposer mechanism as +specified in the mechanism config file, and returns a set of mechanism +OIDs to be interposed. The returned OID set must have been created +using the mechglue’s gss_create_empty_oid_set and +gss_add_oid_set_member functions.</p> +<p>An interposer module must use the prefix <code class="docutils literal notranslate"><span class="pre">gssi_</span></code> for the GSSAPI +functions it exports, instead of the prefix <code class="docutils literal notranslate"><span class="pre">gss_</span></code>. In most cases, +unexported <code class="docutils literal notranslate"><span class="pre">gssi_</span></code> functions will result in failure from their +corresponding <code class="docutils literal notranslate"><span class="pre">gss_</span></code> calls.</p> +<p>An interposer module can link against the GSSAPI library in order to +make calls to the original mechanism. To do so, it must specify a +special mechanism OID which is the concatention of the interposer’s +own OID byte string and the original mechanism’s OID byte string.</p> +<p>Functions that do not accept a mechanism argument directly require no +special handling, with the following exceptions:</p> +<p>Since <strong>gss_accept_sec_context</strong> does not accept a mechanism argument, +an interposer mechanism must, in order to invoke the original +mechanism’s function, acquire a credential for the concatenated OID +and pass that as the <em>verifier_cred_handle</em> parameter.</p> +<p>Since <strong>gss_import_name</strong>, <strong>gss_import_cred</strong>, and +<strong>gss_import_sec_context</strong> do not accept mechanism parameters, the SPI +has been extended to include variants which do. This allows the +interposer module to know which mechanism should be used to interpret +the token. These functions have the following signatures:</p> +<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">OM_uint32</span> <span class="n">gssi_import_sec_context_by_mech</span><span class="p">(</span><span class="n">OM_uint32</span> <span class="o">*</span><span class="n">minor_status</span><span class="p">,</span> + <span class="n">gss_OID</span> <span class="n">desired_mech</span><span class="p">,</span> <span class="n">gss_buffer_t</span> <span class="n">interprocess_token</span><span class="p">,</span> + <span class="n">gss_ctx_id_t</span> <span class="o">*</span><span class="n">context_handle</span><span class="p">);</span> + +<span class="n">OM_uint32</span> <span class="n">gssi_import_name_by_mech</span><span class="p">(</span><span class="n">OM_uint32</span> <span class="o">*</span><span class="n">minor_status</span><span class="p">,</span> + <span class="n">gss_OID</span> <span class="n">mech_type</span><span class="p">,</span> <span class="n">gss_buffer_t</span> <span class="n">input_name_buffer</span><span class="p">,</span> + <span class="n">gss_OID</span> <span class="n">input_name_type</span><span class="p">,</span> <span class="n">gss_name_t</span> <span class="n">output_name</span><span class="p">);</span> + +<span class="n">OM_uint32</span> <span class="n">gssi_import_cred_by_mech</span><span class="p">(</span><span class="n">OM_uint32</span> <span class="o">*</span><span class="n">minor_status</span><span class="p">,</span> + <span class="n">gss_OID</span> <span class="n">mech_type</span><span class="p">,</span> <span class="n">gss_buffer_t</span> <span class="n">token</span><span class="p">,</span> + <span class="n">gss_cred_id_t</span> <span class="o">*</span><span class="n">cred_handle</span><span class="p">);</span> +</pre></div> +</div> +<p>To re-enter the original mechanism when importing tokens for the above +functions, the interposer module must wrap the mechanism token in the +mechglue’s format, using the concatenated OID (except in +<strong>gss_import_name</strong>). The mechglue token formats are:</p> +<ul class="simple"> +<li><p>For <strong>gss_import_sec_context</strong>, a four-byte OID length in big-endian +order, followed by the concatenated OID, followed by the mechanism +token.</p></li> +<li><p>For <strong>gss_import_name</strong>, the bytes 04 01, followed by a two-byte OID +length in big-endian order, followed by the mechanism OID, followed +by a four-byte token length in big-endian order, followed by the +mechanism token. Unlike most uses of OIDs in the API, the mechanism +OID encoding must include the DER tag and length for an object +identifier (06 followed by the DER length of the OID byte string), +and this prefix must be included in the two-byte OID length. +input_name_type must also be set to GSS_C_NT_EXPORT_NAME.</p></li> +<li><p>For <strong>gss_import_cred</strong>, a four-byte OID length in big-endian order, +followed by the concatenated OID, followed by a four-byte token +length in big-endian order, followed by the mechanism token. This +sequence may be repeated multiple times.</p></li> +</ul> +</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="#">GSSAPI mechanism interface</a><ul> +<li><a class="reference internal" href="#negoex-modules">NegoEx modules</a></li> +<li><a class="reference internal" href="#interposer-modules">Interposer modules</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 current"><a class="reference internal" href="index.html">For plugin module developers</a><ul class="current"> +<li class="toctree-l2"><a class="reference internal" href="general.html">General plugin concepts</a></li> +<li class="toctree-l2"><a class="reference internal" href="clpreauth.html">Client preauthentication interface (clpreauth)</a></li> +<li class="toctree-l2"><a class="reference internal" href="kdcpreauth.html">KDC preauthentication interface (kdcpreauth)</a></li> +<li class="toctree-l2"><a class="reference internal" href="ccselect.html">Credential cache selection interface (ccselect)</a></li> +<li class="toctree-l2"><a class="reference internal" href="pwqual.html">Password quality interface (pwqual)</a></li> +<li class="toctree-l2"><a class="reference internal" href="kadm5_hook.html">KADM5 hook interface (kadm5_hook)</a></li> +<li class="toctree-l2"><a class="reference internal" href="kadm5_auth.html">kadmin authorization interface (kadm5_auth)</a></li> +<li class="toctree-l2"><a class="reference internal" href="hostrealm.html">Host-to-realm interface (hostrealm)</a></li> +<li class="toctree-l2"><a class="reference internal" href="localauth.html">Local authorization interface (localauth)</a></li> +<li class="toctree-l2"><a class="reference internal" href="locate.html">Server location interface (locate)</a></li> +<li class="toctree-l2"><a class="reference internal" href="profile.html">Configuration interface (profile)</a></li> +<li class="toctree-l2 current"><a class="current reference internal" href="#">GSSAPI mechanism interface</a></li> +<li class="toctree-l2"><a class="reference internal" href="internal.html">Internal pluggable interfaces</a></li> +<li class="toctree-l2"><a class="reference internal" href="certauth.html">PKINIT certificate authorization interface (certauth)</a></li> +<li class="toctree-l2"><a class="reference internal" href="kdcpolicy.html">KDC policy interface (kdcpolicy)</a></li> +</ul> +</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"><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: 1.21.3</i><br /> + © <a href="../copyright.html">Copyright</a> 1985-2024, MIT. + </div> + <div class="left"> + + <a href="../index.html" title="Full Table of Contents" + >Contents</a> | + <a href="profile.html" title="Configuration interface (profile)" + >previous</a> | + <a href="internal.html" title="Internal pluggable interfaces" + >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__GSSAPI mechanism interface">feedback</a> + </div> + </div> + </div> + + </body> +</html>
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