<!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/xhtml;charset=UTF-8"/>
<title>Wt: Wt::Auth::HashFunction Class Reference</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<link href="doxygen.css" rel="stylesheet" type="text/css" />
<link href="search/search.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="search/search.js"></script>
<script type="text/javascript">
$(document).ready(function() { searchBox.OnSelectItem(0); });
</script>
</head>
<body>
<div id="top"><!-- do not remove this div! -->
<div id="titlearea">
<table cellspacing="0" cellpadding="0">
<tbody>
<tr style="height: 56px;">
<td style="padding-left: 0.5em;">
<div id="projectname">Wt
 <span id="projectnumber">3.2.3</span>
</div>
</td>
</tr>
</tbody>
</table>
</div>
<!-- Generated by Doxygen 1.7.5.1 -->
<script type="text/javascript">
var searchBox = new SearchBox("searchBox", "search",false,'Search');
</script>
<div id="navrow1" class="tabs">
<ul class="tablist">
<li><a href="index.html"><span>Main Page</span></a></li>
<li><a href="pages.html"><span>Related Pages</span></a></li>
<li><a href="modules.html"><span>Modules</span></a></li>
<li><a href="namespaces.html"><span>Namespaces</span></a></li>
<li class="current"><a href="annotated.html"><span>Classes</span></a></li>
<li><a href="files.html"><span>Files</span></a></li>
<li>
<div id="MSearchBox" class="MSearchBoxInactive">
<span class="left">
<img id="MSearchSelect" src="search/mag_sel.png"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
alt=""/>
<input type="text" id="MSearchField" value="Search" accesskey="S"
onfocus="searchBox.OnSearchFieldFocus(true)"
onblur="searchBox.OnSearchFieldFocus(false)"
onkeyup="searchBox.OnSearchFieldChange(event)"/>
</span><span class="right">
<a id="MSearchClose" href="javascript:searchBox.CloseResultsWindow()"><img id="MSearchCloseImg" border="0" src="search/close.png" alt=""/></a>
</span>
</div>
</li>
</ul>
</div>
<div id="navrow2" class="tabs2">
<ul class="tablist">
<li><a href="annotated.html"><span>Class List</span></a></li>
<li><a href="inherits.html"><span>Class Hierarchy</span></a></li>
<li><a href="functions.html"><span>Class Members</span></a></li>
</ul>
</div>
<div id="nav-path" class="navpath">
<ul>
<li class="navelem"><a class="el" href="namespaceWt.html">Wt</a> </li>
<li class="navelem"><a class="el" href="namespaceWt_1_1Auth.html">Auth</a> </li>
<li class="navelem"><a class="el" href="classWt_1_1Auth_1_1HashFunction.html">HashFunction</a> </li>
</ul>
</div>
</div>
<div class="header">
<div class="summary">
<a href="#pub-methods">Public Member Functions</a> </div>
<div class="headertitle">
<div class="title">Wt::Auth::HashFunction Class Reference<div class="ingroups"><a class="el" href="group__auth.html">Authentication module (Wt::Auth)</a></div></div> </div>
</div>
<div class="contents">
<!-- doxytag: class="Wt::Auth::HashFunction" -->
<p>An abstract cryptographic hash function interface.
<a href="classWt_1_1Auth_1_1HashFunction.html#details">More...</a></p>
<p><code>#include <Wt/Auth/HashFunction></code></p>
<div class="dynheader">
Inheritance diagram for Wt::Auth::HashFunction:</div>
<div class="dyncontent">
<div class="center"><img src="classWt_1_1Auth_1_1HashFunction__inherit__graph.png" border="0" usemap="#Wt_1_1Auth_1_1HashFunction_inherit__map" alt="Inheritance graph"/></div>
<map name="Wt_1_1Auth_1_1HashFunction_inherit__map" id="Wt_1_1Auth_1_1HashFunction_inherit__map">
<area shape="rect" href="classWt_1_1Auth_1_1BCryptHashFunction.html" title="An cryptographic hash function that implements bcrypt." alt="" coords="5,80,205,107"/><area shape="rect" href="classWt_1_1Auth_1_1MD5HashFunction.html" title="A cryptograhpic hash function implemented using MD5." alt="" coords="229,80,416,107"/><area shape="rect" href="classWt_1_1Auth_1_1SHA1HashFunction.html" title="A cryptographic hash function implemented using SHA1." alt="" coords="440,80,635,107"/></map>
<center><span class="legend">[<a href="graph_legend.html">legend</a>]</span></center></div>
<p><a href="classWt_1_1Auth_1_1HashFunction-members.html">List of all members.</a></p>
<table class="memberdecls">
<tr><td colspan="2"><h2><a name="pub-methods"></a>
Public Member Functions</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="af000dbbffc0dfd84c310e2bdab9c5ffe"></a><!-- doxytag: member="Wt::Auth::HashFunction::~HashFunction" ref="af000dbbffc0dfd84c310e2bdab9c5ffe" args="()" -->
virtual </td><td class="memItemRight" valign="bottom"><a class="el" href="classWt_1_1Auth_1_1HashFunction.html#af000dbbffc0dfd84c310e2bdab9c5ffe">~HashFunction</a> ()</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Destructor. <br/></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">virtual std::string </td><td class="memItemRight" valign="bottom"><a class="el" href="classWt_1_1Auth_1_1HashFunction.html#aaa3f4d60d558577c118c3d8684f72ed4">name</a> () const =0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Returns the name for this hash function. <a href="#aaa3f4d60d558577c118c3d8684f72ed4"></a><br/></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">virtual std::string </td><td class="memItemRight" valign="bottom"><a class="el" href="classWt_1_1Auth_1_1HashFunction.html#a7a79f2aae54b390ba8a3b451d590ac92">compute</a> (const std::string &msg, const std::string &salt) const =0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Computes the hash of a message + salt. <a href="#a7a79f2aae54b390ba8a3b451d590ac92"></a><br/></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">virtual bool </td><td class="memItemRight" valign="bottom"><a class="el" href="classWt_1_1Auth_1_1HashFunction.html#a4599fe0518fb61e33f5bf192531d7585">verify</a> (const std::string &msg, const std::string &salt, const std::string &hash) const </td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Verifies a message with the salted hash. <a href="#a4599fe0518fb61e33f5bf192531d7585"></a><br/></td></tr>
</table>
<hr/><a name="details" id="details"></a><h2>Detailed Description</h2>
<div class="textblock"><p>An abstract cryptographic hash function interface. </p>
<p>A cryptographic hash function computes a hash value from a message, for which it is hard to guess another message that generates the same hash.</p>
<p>These hash functions are intended for short messages, typically passwords or random tokens, and thus not suitable for computing the hash value of a large document.</p>
<p>When used for passwords, to avoid dictionary attacks, the hash functions accept also a random salt which is hashed together with the password. Not all hash functions are adequate for passwords hashes. </p>
</div><hr/><h2>Member Function Documentation</h2>
<a class="anchor" id="a7a79f2aae54b390ba8a3b451d590ac92"></a><!-- doxytag: member="Wt::Auth::HashFunction::compute" ref="a7a79f2aae54b390ba8a3b451d590ac92" args="(const std::string &msg, const std::string &salt) const =0" -->
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">virtual std::string Wt::Auth::HashFunction::compute </td>
<td>(</td>
<td class="paramtype">const std::string & </td>
<td class="paramname"><em>msg</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">const std::string & </td>
<td class="paramname"><em>salt</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td> const<code> [pure virtual]</code></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>Computes the hash of a message + salt. </p>
<p>The message is usually an ASCII or UTF-8 string.</p>
<p>The <code>salt</code> and the computed hash are encoded in printable characters. This is usually ASCII-encoded(as for the UNIX crypt() functions)or could be Base64-encoded. </p>
<p>Implemented in <a class="el" href="classWt_1_1Auth_1_1BCryptHashFunction.html#a5df3892cc0472122243d8e9a83e4cebc">Wt::Auth::BCryptHashFunction</a>, <a class="el" href="classWt_1_1Auth_1_1SHA1HashFunction.html#a62c8f4a84e5b608684a222db6f283450">Wt::Auth::SHA1HashFunction</a>, and <a class="el" href="classWt_1_1Auth_1_1MD5HashFunction.html#a41e71e2ab1bd1b0758f94ee2701b979c">Wt::Auth::MD5HashFunction</a>.</p>
</div>
</div>
<a class="anchor" id="aaa3f4d60d558577c118c3d8684f72ed4"></a><!-- doxytag: member="Wt::Auth::HashFunction::name" ref="aaa3f4d60d558577c118c3d8684f72ed4" args="() const =0" -->
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">virtual std::string Wt::Auth::HashFunction::name </td>
<td>(</td>
<td class="paramname"></td><td>)</td>
<td> const<code> [pure virtual]</code></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>Returns the name for this hash function. </p>
<p>This should return a (short) name that uniquely identifies this hash function. </p>
<p>Implemented in <a class="el" href="classWt_1_1Auth_1_1BCryptHashFunction.html#a50497e9ac2c50477a6374006a153a9cf">Wt::Auth::BCryptHashFunction</a>, <a class="el" href="classWt_1_1Auth_1_1SHA1HashFunction.html#aa6e8e77ab4840cf7e6c76dcf473a64df">Wt::Auth::SHA1HashFunction</a>, and <a class="el" href="classWt_1_1Auth_1_1MD5HashFunction.html#a6de4ed86a236fb8ce54d88631ae8aa59">Wt::Auth::MD5HashFunction</a>.</p>
</div>
</div>
<a class="anchor" id="a4599fe0518fb61e33f5bf192531d7585"></a><!-- doxytag: member="Wt::Auth::HashFunction::verify" ref="a4599fe0518fb61e33f5bf192531d7585" args="(const std::string &msg, const std::string &salt, const std::string &hash) const " -->
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">bool Wt::Auth::HashFunction::verify </td>
<td>(</td>
<td class="paramtype">const std::string & </td>
<td class="paramname"><em>msg</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">const std::string & </td>
<td class="paramname"><em>salt</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">const std::string & </td>
<td class="paramname"><em>hash</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td> const<code> [virtual]</code></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>Verifies a message with the salted hash. </p>
<p>The base implementation will recompute the hash of the message with the given salt, and compare it to the <code>hash</code>.</p>
<p>Some methods however store the salt and additional settings in the <code>hash</code>, and this information is thus needed to verify the message hash. </p>
<p>Reimplemented in <a class="el" href="classWt_1_1Auth_1_1BCryptHashFunction.html#a201bf34057eb6f4e3cd9dd72b1702cc4">Wt::Auth::BCryptHashFunction</a>.</p>
</div>
</div>
</div>
<!-- window showing the filter options -->
<div id="MSearchSelectWindow"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
onkeydown="return searchBox.OnSearchSelectKey(event)">
<a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(0)"><span class="SelectionMark"> </span>All</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(1)"><span class="SelectionMark"> </span>Classes</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(2)"><span class="SelectionMark"> </span>Namespaces</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(3)"><span class="SelectionMark"> </span>Files</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(4)"><span class="SelectionMark"> </span>Functions</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(5)"><span class="SelectionMark"> </span>Variables</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(6)"><span class="SelectionMark"> </span>Typedefs</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(7)"><span class="SelectionMark"> </span>Enumerations</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(8)"><span class="SelectionMark"> </span>Enumerator</a></div>
<!-- iframe showing the search results (closed by default) -->
<div id="MSearchResultsWindow">
<iframe src="javascript:void(0)" frameborder="0"
name="MSearchResults" id="MSearchResults">
</iframe>
</div>
<hr size="1"><address style="text-align: right; margin: 3px"><small>
Generated on Thu Nov 1 2012 for <a href="http://www.webtoolkit.eu/wt">the
C++ Web Toolkit (Wt)</a> by <a
href="http://www.doxygen.org/index.html"><img src="doxygen.png"
alt="doxygen" border="0" style="vertical-align: middle; display:
inline-block; height: 2em"></a> 1.7.5.1</small></address>
</body>
</html>
