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diff --git a/bin/tools/isc-hmac-fixup.html b/bin/tools/isc-hmac-fixup.html new file mode 100644 index 0000000..dc1bb8a --- /dev/null +++ b/bin/tools/isc-hmac-fixup.html @@ -0,0 +1,92 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<!-- + - Copyright (C) 2010, 2013-2019 Internet Systems Consortium, Inc. ("ISC") + - + - This Source Code Form is subject to the terms of the Mozilla Public + - License, v. 2.0. If a copy of the MPL was not distributed with this + - file, You can obtain one at http://mozilla.org/MPL/2.0/. +--> +<html lang="en"> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> +<title>isc-hmac-fixup</title> +<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry"> +<a name="man.isc-hmac-fixup"></a><div class="titlepage"></div> + + + + + + <div class="refnamediv"> +<h2>Name</h2> +<p> + <span class="application">isc-hmac-fixup</span> + — fixes HMAC keys generated by older versions of BIND + </p> +</div> + + + + <div class="refsynopsisdiv"> +<h2>Synopsis</h2> + <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> + </div> + + <div class="refsection"> +<a name="id-1.7"></a><h2>DESCRIPTION</h2> + + <p> + Versions of BIND 9 up to and including BIND 9.6 had a bug causing + HMAC-SHA* TSIG keys which were longer than the digest length of the + hash algorithm (i.e., SHA1 keys longer than 160 bits, SHA256 keys + longer than 256 bits, etc) to be used incorrectly, generating a + message authentication code that was incompatible with other DNS + implementations. + </p> + <p> + This bug was fixed in BIND 9.7. However, the fix may + cause incompatibility between older and newer versions of + BIND, when using long keys. <span class="command"><strong>isc-hmac-fixup</strong></span> + modifies those keys to restore compatibility. + </p> + <p> + To modify a key, run <span class="command"><strong>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="refsection"> +<a name="id-1.8"></a><h2>SECURITY CONSIDERATIONS</h2> + + <p> + Secrets that have been converted by <span class="command"><strong>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="refsection"> +<a name="id-1.9"></a><h2>SEE ALSO</h2> + + <p> + <em class="citetitle">BIND 9 Administrator Reference Manual</em>, + <em class="citetitle">RFC 2104</em>. + </p> + </div> + +</div></body> +</html> |