<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://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/xhtml;charset=UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=9"/>
<meta name="generator" content="Doxygen 1.8.15"/>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<title>Crypto++: gf256.cpp Source File</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="dynsections.js"></script>
<link href="doxygen.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
<div id="titlearea">
<table cellspacing="0" cellpadding="0">
<tbody>
<tr style="height: 56px;">
<td id="projectalign" style="padding-left: 0.5em;">
<div id="projectname">Crypto++
 <span id="projectnumber">7.0</span>
</div>
<div id="projectbrief">Free C++ class library of cryptographic schemes</div>
</td>
</tr>
</tbody>
</table>
</div>
<!-- end header part -->
<!-- Generated by Doxygen 1.8.15 -->
<script type="text/javascript" src="menudata.js"></script>
<script type="text/javascript" src="menu.js"></script>
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&dn=gpl-2.0.txt GPL-v2 */
$(function() {
initMenu('',false,false,'search.php','Search');
});
/* @license-end */</script>
<div id="main-nav"></div>
</div><!-- top -->
<div class="header">
<div class="headertitle">
<div class="title">gf256.cpp</div> </div>
</div><!--header-->
<div class="contents">
<div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno"> 1</span> <span class="comment">// gf256.cpp - originally written and placed in the public domain by Wei Dai</span></div><div class="line"><a name="l00002"></a><span class="lineno"> 2</span> </div><div class="line"><a name="l00003"></a><span class="lineno"> 3</span> <span class="preprocessor">#include "<a class="code" href="pch_8h.html">pch.h</a>"</span></div><div class="line"><a name="l00004"></a><span class="lineno"> 4</span> <span class="preprocessor">#include "<a class="code" href="gf256_8h.html">gf256.h</a>"</span></div><div class="line"><a name="l00005"></a><span class="lineno"> 5</span> </div><div class="line"><a name="l00006"></a><span class="lineno"> 6</span> NAMESPACE_BEGIN(<a class="code" href="namespace_crypto_p_p.html">CryptoPP</a>)</div><div class="line"><a name="l00007"></a><span class="lineno"> 7</span> </div><div class="line"><a name="l00008"></a><span class="lineno"> 8</span> GF256::Element GF256::Multiply(Element a, Element b)<span class="keyword"> const</span></div><div class="line"><a name="l00009"></a><span class="lineno"> 9</span> <span class="keyword"></span>{</div><div class="line"><a name="l00010"></a><span class="lineno"> 10</span>  word result = 0, t = b;</div><div class="line"><a name="l00011"></a><span class="lineno"> 11</span> </div><div class="line"><a name="l00012"></a><span class="lineno"> 12</span>  <span class="keywordflow">for</span> (<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> i=0; i<8; i++)</div><div class="line"><a name="l00013"></a><span class="lineno"> 13</span>  {</div><div class="line"><a name="l00014"></a><span class="lineno"> 14</span>  result <<= 1;</div><div class="line"><a name="l00015"></a><span class="lineno"> 15</span>  <span class="keywordflow">if</span> (result & 0x100)</div><div class="line"><a name="l00016"></a><span class="lineno"> 16</span>  result ^= m_modulus;</div><div class="line"><a name="l00017"></a><span class="lineno"> 17</span> </div><div class="line"><a name="l00018"></a><span class="lineno"> 18</span>  t <<= 1;</div><div class="line"><a name="l00019"></a><span class="lineno"> 19</span>  <span class="keywordflow">if</span> (t & 0x100)</div><div class="line"><a name="l00020"></a><span class="lineno"> 20</span>  result ^= a;</div><div class="line"><a name="l00021"></a><span class="lineno"> 21</span>  }</div><div class="line"><a name="l00022"></a><span class="lineno"> 22</span> </div><div class="line"><a name="l00023"></a><span class="lineno"> 23</span>  <span class="keywordflow">return</span> (GF256::Element) result;</div><div class="line"><a name="l00024"></a><span class="lineno"> 24</span> }</div><div class="line"><a name="l00025"></a><span class="lineno"> 25</span> </div><div class="line"><a name="l00026"></a><span class="lineno"> 26</span> GF256::Element GF256::MultiplicativeInverse(Element a)<span class="keyword"> const</span></div><div class="line"><a name="l00027"></a><span class="lineno"> 27</span> <span class="keyword"></span>{</div><div class="line"><a name="l00028"></a><span class="lineno"> 28</span>  Element result = a;</div><div class="line"><a name="l00029"></a><span class="lineno"> 29</span>  <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i=1; i<7; i++)</div><div class="line"><a name="l00030"></a><span class="lineno"> 30</span>  result = Multiply(<a class="code" href="class_square.html">Square</a>(result), a);</div><div class="line"><a name="l00031"></a><span class="lineno"> 31</span>  <span class="keywordflow">return</span> <a class="code" href="class_square.html">Square</a>(result);</div><div class="line"><a name="l00032"></a><span class="lineno"> 32</span> }</div><div class="line"><a name="l00033"></a><span class="lineno"> 33</span> </div><div class="line"><a name="l00034"></a><span class="lineno"> 34</span> NAMESPACE_END</div><div class="ttc" id="class_square_html"><div class="ttname"><a href="class_square.html">Square</a></div><div class="ttdoc">Square block cipher.</div><div class="ttdef"><b>Definition:</b> <a href="square_8h_source.html#l00024">square.h:24</a></div></div>
<div class="ttc" id="pch_8h_html"><div class="ttname"><a href="pch_8h.html">pch.h</a></div><div class="ttdoc">Precompiled header file.</div></div>
<div class="ttc" id="gf256_8h_html"><div class="ttname"><a href="gf256_8h.html">gf256.h</a></div><div class="ttdoc">Classes and functions for schemes over GF(256)</div></div>
<div class="ttc" id="namespace_crypto_p_p_html"><div class="ttname"><a href="namespace_crypto_p_p.html">CryptoPP</a></div><div class="ttdoc">Crypto++ library namespace.</div></div>
</div><!-- fragment --></div><!-- contents -->
<!-- start footer part -->
<hr class="footer"/><address class="footer"><small>
Generated on Wed Nov 27 2019 15:03:32 for Crypto++ by  <a href="http://www.doxygen.org/index.html">
<img class="footer" src="doxygen.png" alt="doxygen"/>
</a> 1.8.15
</small></address>
</body>
</html>
distrib
>
Mageia
>
7
>
armv7hl
>
media
>
core-updates
>
by-pkgid
>
17f48c047155a7d4c992d6a672acd57f
>
files
>
2310
