man.isc-hmac-fixup.html revision fdd80e9a55c70b36a3bf3e409b86897301c44ff8
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<!--
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse - Copyright (C) 2010 Internet Systems Consortium, Inc. ("ISC")
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse -
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse - Permission to use, copy, modify, and/or distribute this software for any
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse - purpose with or without fee is hereby granted, provided that the above
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse - copyright notice and this permission notice appear in all copies.
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse -
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse - AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse - INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse - LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse - OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse - PERFORMANCE OF THIS SOFTWARE.
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse-->
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<!-- $Id: man.isc-hmac-fixup.html,v 1.3 2010/01/08 01:14:07 tbox Exp $ -->
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<html>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<head>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<title>isc-hmac-fixup</title>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<meta name="generator" content="DocBook XSL Stylesheets V1.71.1">
4adca7e7219d20c7ca20933b5006222e781ff0e9Toomas Soome<link rel="start" href="Bv9ARM.html" title="BIND 9 Administrator Reference Manual">
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<link rel="up" href="Bv9ARM.ch10.html" title="Manual pages">
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<link rel="prev" href="man.genrandom.html" title="genrandom">
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<link rel="next" href="man.nsec3hash.html" title="nsec3hash">
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse</head>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<div class="navheader">
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<table width="100%" summary="Navigation header">
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<tr><th colspan="3" align="center"><span class="application">isc-hmac-fixup</span></th></tr>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<tr>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<td width="20%" align="left">
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<a accesskey="p" href="man.genrandom.html">Prev</a>�</td>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<th width="60%" align="center">Manual pages</th>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<td width="20%" align="right">�<a accesskey="n" href="man.nsec3hash.html">Next</a>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse</td>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse</tr>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse</table>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<hr>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse</div>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<div class="refentry" lang="en">
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<a name="man.isc-hmac-fixup"></a><div class="titlepage"></div>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<div class="refnamediv">
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<h2>Name</h2>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<p><span class="application">isc-hmac-fixup</span> &#8212; fixes HMAC keys generated by older versions of BIND</p>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse</div>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<div class="refsynopsisdiv">
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<h2>Synopsis</h2>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<div class="cmdsynopsis"><p><code class="command">isc-hmac-fixup</code> {<em class="replaceable"><code>algorithm</code></em>} {<em class="replaceable"><code>secret</code></em>}</p></div>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse</div>
c7c0ceafd167e558cd8cb8195b8bd63cbc817b27Toomas Soome<div class="refsect1" lang="en">
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<a name="id2641862"></a><h2>DESCRIPTION</h2>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<p>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse Versions of BIND 9 up to and including BIND 9.6 had a bug causing
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse HMAC-SHA* TSIG keys which were longer than the digest length of the
4adca7e7219d20c7ca20933b5006222e781ff0e9Toomas Soome hash algorithm (i.e., SHA1 keys longer than 160 bits, SHA256 keys
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse longer than 256 bits, etc) to be used incorrectly, generating a
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse message authentication code that was incompatible with other DNS
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse implementations.
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse </p>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse<p>
f169c0eae91b2ee787cf8d6dcf8edd9159d4c9e2Glenn Lagasse This bug has been fixed in BIND 9.7. However, the fix may
cause incompatibility between older and newer versions of
BIND, when using long keys. <span><strong class="command">isc-hmac-fixup</strong></span>
modifies those keys to restore compatibility.
</p>
<p>
To modify a key, run <span><strong class="command">isc-hmac-fixup</strong></span> and
specify the key's algorithm and secret on the command line. If the
secret is longer than the digest length of the algorithm (64 bytes
for SHA1 through SHA256, or 128 bytes for SHA384 and SHA512), then a
new secret will be generated consisting of a hash digest of the old
secret. (If the secret did not require conversion, then it will be
printed without modification.)
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2641890"></a><h2>SECURITY CONSIDERATIONS</h2>
<p>
Secrets that have been converted by <span><strong class="command">isc-hmac-fixup</strong></span>
are shortened, but as this is how the HMAC protocol works in
operation anyway, it does not affect security. RFC 2104 notes,
"Keys longer than [the digest length] are acceptable but the
extra length would not significantly increase the function
strength."
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2641906"></a><h2>SEE ALSO</h2>
<p>
<em class="citetitle">BIND 9 Administrator Reference Manual</em>,
<em class="citetitle">RFC 2104</em>.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2641923"></a><h2>AUTHOR</h2>
<p><span class="corpauthor">Internet Systems Consortium</span>
</p>
</div>
</div>
<div class="navfooter">
<hr>
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left">
<a accesskey="p" href="man.genrandom.html">Prev</a>�</td>
<td width="20%" align="center"><a accesskey="u" href="Bv9ARM.ch10.html">Up</a></td>
<td width="40%" align="right">�<a accesskey="n" href="man.nsec3hash.html">Next</a>
</td>
</tr>
<tr>
<td width="40%" align="left" valign="top">
<span class="application">genrandom</span>�</td>
<td width="20%" align="center"><a accesskey="h" href="Bv9ARM.html">Home</a></td>
<td width="40%" align="right" valign="top">�<span class="application">nsec3hash</span>
</td>
</tr>
</table>
</div>
</body>
</html>