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<div id="projectname">Crypto++
 <span id="projectnumber">7.0</span>
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<div id="projectbrief">Free C++ class library of cryptographic schemes</div>
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<a href="#pub-methods">Public Member Functions</a> |
<a href="#pub-static-methods">Static Public Member Functions</a> |
<a href="class_scrypt-members.html">List of all members</a> </div>
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<div class="title">Scrypt Class Reference</div> </div>
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<p><a class="el" href="class_scrypt.html" title="Scrypt key derivation function. ">Scrypt</a> key derivation function.
<a href="class_scrypt.html#details">More...</a></p>
<div id="dynsection-0" onclick="return toggleVisibility(this)" class="dynheader closed" style="cursor:pointer;">
<img id="dynsection-0-trigger" src="closed.png" alt="+"/> Inheritance diagram for Scrypt:</div>
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<img src="class_scrypt.png" usemap="#Scrypt_map" alt=""/>
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<area href="class_key_derivation_function.html" title="Interface for key derivation functions. " alt="KeyDerivationFunction" shape="rect" coords="0,112,141,136"/>
<area href="class_algorithm.html" title="Interface for all crypto algorithms. " alt="Algorithm" shape="rect" coords="0,56,141,80"/>
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<table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="pub-methods"></a>
Public Member Functions</h2></td></tr>
<tr class="memitem:a102cc305016c030ad04a9ca3fa80bee2"><td class="memItemLeft" align="right" valign="top">std::string </td><td class="memItemRight" valign="bottom"><a class="el" href="class_scrypt.html#a102cc305016c030ad04a9ca3fa80bee2">AlgorithmName</a> () const</td></tr>
<tr class="memdesc:a102cc305016c030ad04a9ca3fa80bee2"><td class="mdescLeft"> </td><td class="mdescRight">Provides the name of this algorithm. <a href="#a102cc305016c030ad04a9ca3fa80bee2">More...</a><br /></td></tr>
<tr class="separator:a102cc305016c030ad04a9ca3fa80bee2"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:ab3b23597d8bcb9af8d55bc8aa57bf709"><td class="memItemLeft" align="right" valign="top">size_t </td><td class="memItemRight" valign="bottom"><a class="el" href="class_scrypt.html#ab3b23597d8bcb9af8d55bc8aa57bf709">MaxDerivedLength</a> () const</td></tr>
<tr class="memdesc:ab3b23597d8bcb9af8d55bc8aa57bf709"><td class="mdescLeft"> </td><td class="mdescRight">Determine maximum number of bytes. <a href="#ab3b23597d8bcb9af8d55bc8aa57bf709">More...</a><br /></td></tr>
<tr class="separator:ab3b23597d8bcb9af8d55bc8aa57bf709"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:a6faaa4a7749a950e1e7d74bbb734ce12"><td class="memItemLeft" align="right" valign="top">size_t </td><td class="memItemRight" valign="bottom"><a class="el" href="class_scrypt.html#a6faaa4a7749a950e1e7d74bbb734ce12">GetValidDerivedLength</a> (size_t keylength) const</td></tr>
<tr class="memdesc:a6faaa4a7749a950e1e7d74bbb734ce12"><td class="mdescLeft"> </td><td class="mdescRight">Returns a valid key length for the derivation function. <a href="#a6faaa4a7749a950e1e7d74bbb734ce12">More...</a><br /></td></tr>
<tr class="separator:a6faaa4a7749a950e1e7d74bbb734ce12"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:acb52a9def0feda98787bd82fe8bfeded"><td class="memItemLeft" align="right" valign="top">size_t </td><td class="memItemRight" valign="bottom"><a class="el" href="class_scrypt.html#acb52a9def0feda98787bd82fe8bfeded">DeriveKey</a> (byte *derived, size_t derivedLen, const byte *secret, size_t secretLen, const <a class="el" href="class_name_value_pairs.html">NameValuePairs</a> &params) const</td></tr>
<tr class="memdesc:acb52a9def0feda98787bd82fe8bfeded"><td class="mdescLeft"> </td><td class="mdescRight">Derive a key from a seed. <a href="#acb52a9def0feda98787bd82fe8bfeded">More...</a><br /></td></tr>
<tr class="separator:acb52a9def0feda98787bd82fe8bfeded"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:a620e5573d4199cf2a84968afc4e98576"><td class="memItemLeft" align="right" valign="top">size_t </td><td class="memItemRight" valign="bottom"><a class="el" href="class_scrypt.html#a620e5573d4199cf2a84968afc4e98576">DeriveKey</a> (byte *derived, size_t derivedLen, const byte *secret, size_t secretLen, const byte *salt, size_t saltLen, word64 cost=2, word64 blockSize=8, word64 parallelization=1) const</td></tr>
<tr class="memdesc:a620e5573d4199cf2a84968afc4e98576"><td class="mdescLeft"> </td><td class="mdescRight">Derive a key from a seed. <a href="#a620e5573d4199cf2a84968afc4e98576">More...</a><br /></td></tr>
<tr class="separator:a620e5573d4199cf2a84968afc4e98576"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="inherit_header pub_methods_class_key_derivation_function"><td colspan="2" onclick="javascript:toggleInherit('pub_methods_class_key_derivation_function')"><img src="closed.png" alt="-"/> Public Member Functions inherited from <a class="el" href="class_key_derivation_function.html">KeyDerivationFunction</a></td></tr>
<tr class="memitem:a7a78c05721ca33d0aaa6a33a5d7e78e4 inherit pub_methods_class_key_derivation_function"><td class="memItemLeft" align="right" valign="top">virtual size_t </td><td class="memItemRight" valign="bottom"><a class="el" href="class_key_derivation_function.html#a7a78c05721ca33d0aaa6a33a5d7e78e4">MinDerivedLength</a> () const</td></tr>
<tr class="memdesc:a7a78c05721ca33d0aaa6a33a5d7e78e4 inherit pub_methods_class_key_derivation_function"><td class="mdescLeft"> </td><td class="mdescRight">Determine minimum number of bytes. <a href="class_key_derivation_function.html#a7a78c05721ca33d0aaa6a33a5d7e78e4">More...</a><br /></td></tr>
<tr class="separator:a7a78c05721ca33d0aaa6a33a5d7e78e4 inherit pub_methods_class_key_derivation_function"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:abe22587a8e66ee7e8de494edb1b3f6f9 inherit pub_methods_class_key_derivation_function"><td class="memItemLeft" align="right" valign="top">virtual bool </td><td class="memItemRight" valign="bottom"><a class="el" href="class_key_derivation_function.html#abe22587a8e66ee7e8de494edb1b3f6f9">IsValidDerivedLength</a> (size_t keylength) const</td></tr>
<tr class="memdesc:abe22587a8e66ee7e8de494edb1b3f6f9 inherit pub_methods_class_key_derivation_function"><td class="mdescLeft"> </td><td class="mdescRight">Returns whether keylength is a valid key length. <a href="class_key_derivation_function.html#abe22587a8e66ee7e8de494edb1b3f6f9">More...</a><br /></td></tr>
<tr class="separator:abe22587a8e66ee7e8de494edb1b3f6f9 inherit pub_methods_class_key_derivation_function"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:a4e86125e9ca40e3aac741ef240016087 inherit pub_methods_class_key_derivation_function"><td class="memItemLeft" align="right" valign="top">virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="class_key_derivation_function.html#a4e86125e9ca40e3aac741ef240016087">SetParameters</a> (const <a class="el" href="class_name_value_pairs.html">NameValuePairs</a> &params)</td></tr>
<tr class="memdesc:a4e86125e9ca40e3aac741ef240016087 inherit pub_methods_class_key_derivation_function"><td class="mdescLeft"> </td><td class="mdescRight">Set or change parameters. <a href="class_key_derivation_function.html#a4e86125e9ca40e3aac741ef240016087">More...</a><br /></td></tr>
<tr class="separator:a4e86125e9ca40e3aac741ef240016087 inherit pub_methods_class_key_derivation_function"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="inherit_header pub_methods_class_algorithm"><td colspan="2" onclick="javascript:toggleInherit('pub_methods_class_algorithm')"><img src="closed.png" alt="-"/> Public Member Functions inherited from <a class="el" href="class_algorithm.html">Algorithm</a></td></tr>
<tr class="memitem:a1c77f5117ca2cd881baf26a364cfc606 inherit pub_methods_class_algorithm"><td class="memItemLeft" align="right" valign="top"> </td><td class="memItemRight" valign="bottom"><a class="el" href="class_algorithm.html#a1c77f5117ca2cd881baf26a364cfc606">Algorithm</a> (bool checkSelfTestStatus=true)</td></tr>
<tr class="memdesc:a1c77f5117ca2cd881baf26a364cfc606 inherit pub_methods_class_algorithm"><td class="mdescLeft"> </td><td class="mdescRight">Interface for all crypto algorithms. <a href="class_algorithm.html#a1c77f5117ca2cd881baf26a364cfc606">More...</a><br /></td></tr>
<tr class="separator:a1c77f5117ca2cd881baf26a364cfc606 inherit pub_methods_class_algorithm"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="inherit_header pub_methods_class_clonable"><td colspan="2" onclick="javascript:toggleInherit('pub_methods_class_clonable')"><img src="closed.png" alt="-"/> Public Member Functions inherited from <a class="el" href="class_clonable.html">Clonable</a></td></tr>
<tr class="memitem:ad0016ba2d505c23aa85aad49e6c19bb7 inherit pub_methods_class_clonable"><td class="memItemLeft" align="right" valign="top">virtual <a class="el" href="class_clonable.html">Clonable</a> * </td><td class="memItemRight" valign="bottom"><a class="el" href="class_clonable.html#ad0016ba2d505c23aa85aad49e6c19bb7">Clone</a> () const</td></tr>
<tr class="memdesc:ad0016ba2d505c23aa85aad49e6c19bb7 inherit pub_methods_class_clonable"><td class="mdescLeft"> </td><td class="mdescRight">Copies this object. <a href="class_clonable.html#ad0016ba2d505c23aa85aad49e6c19bb7">More...</a><br /></td></tr>
<tr class="separator:ad0016ba2d505c23aa85aad49e6c19bb7 inherit pub_methods_class_clonable"><td class="memSeparator" colspan="2"> </td></tr>
</table><table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="pub-static-methods"></a>
Static Public Member Functions</h2></td></tr>
<tr class="memitem:aa8905d6276b0d4c60e79aafc0d1a8c4e"><td class="memItemLeft" align="right" valign="top"><a id="aa8905d6276b0d4c60e79aafc0d1a8c4e"></a>
static std::string </td><td class="memItemRight" valign="bottom"><b>StaticAlgorithmName</b> ()</td></tr>
<tr class="separator:aa8905d6276b0d4c60e79aafc0d1a8c4e"><td class="memSeparator" colspan="2"> </td></tr>
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<a name="details" id="details"></a><h2 class="groupheader">Detailed Description</h2>
<div class="textblock"><p><a class="el" href="class_scrypt.html" title="Scrypt key derivation function. ">Scrypt</a> key derivation function. </p>
<p>The Crypto++ implementation uses OpenMP to accelerate the derivation when available.</p>
<p>The Crypto++ implementation of <a class="el" href="class_scrypt.html" title="Scrypt key derivation function. ">Scrypt</a> is limited by C++ datatypes. For example, the library is limited to a derived key length of <code>SIZE_MAX</code>, and not <code>(2^32 - 1) * 32</code>. </p><dl class="section see"><dt>See also</dt><dd><a href="https://www.tarsnap.com/scrypt/scrypt.pdf">Stronger Key Derivation via Sequential Memory-Hard Functions</a>, <a href="https://www.tarsnap.com/scrypt.html">The scrypt key derivation function</a> and <a href="https://tools.ietf.org/html/rfc7914">RFC 7914, The scrypt Password-Based Key Derivation Function</a> </dd></dl>
<dl class="section since"><dt>Since</dt><dd>Crypto++ 6.2 </dd></dl>
<p class="definition">Definition at line <a class="el" href="scrypt_8h_source.html#l00033">33</a> of file <a class="el" href="scrypt_8h_source.html">scrypt.h</a>.</p>
</div><h2 class="groupheader">Member Function Documentation</h2>
<a id="a102cc305016c030ad04a9ca3fa80bee2"></a>
<h2 class="memtitle"><span class="permalink"><a href="#a102cc305016c030ad04a9ca3fa80bee2">◆ </a></span>AlgorithmName()</h2>
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<td class="memname">std::string Scrypt::AlgorithmName </td>
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<p>Provides the name of this algorithm. </p>
<dl class="section return"><dt>Returns</dt><dd>the standard algorithm name </dd></dl>
<p>Implements <a class="el" href="class_key_derivation_function.html#ad82f2d983ca8d389346357b378fa969e">KeyDerivationFunction</a>.</p>
<p class="definition">Definition at line <a class="el" href="scrypt_8h_source.html#l00043">43</a> of file <a class="el" href="scrypt_8h_source.html">scrypt.h</a>.</p>
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<h2 class="memtitle"><span class="permalink"><a href="#ab3b23597d8bcb9af8d55bc8aa57bf709">◆ </a></span>MaxDerivedLength()</h2>
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<p>Determine maximum number of bytes. </p>
<dl class="section return"><dt>Returns</dt><dd>Maximum number of bytes which can be derived </dd></dl>
<p>Reimplemented from <a class="el" href="class_key_derivation_function.html#a009b339865543eb62af91240ac099a8f">KeyDerivationFunction</a>.</p>
<p class="definition">Definition at line <a class="el" href="scrypt_8h_source.html#l00048">48</a> of file <a class="el" href="scrypt_8h_source.html">scrypt.h</a>.</p>
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<h2 class="memtitle"><span class="permalink"><a href="#a6faaa4a7749a950e1e7d74bbb734ce12">◆ </a></span>GetValidDerivedLength()</h2>
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<td class="paramtype">size_t </td>
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<p>Returns a valid key length for the derivation function. </p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">keylength</td><td>the size of the derived key, in bytes </td></tr>
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<dl class="section return"><dt>Returns</dt><dd>the valid key length, in bytes </dd></dl>
<p>Implements <a class="el" href="class_key_derivation_function.html#ac0f7e2658135a0df411aa619c7fcac90">KeyDerivationFunction</a>.</p>
<p class="definition">Definition at line <a class="el" href="scrypt_8cpp_source.html#l00154">154</a> of file <a class="el" href="scrypt_8cpp_source.html">scrypt.cpp</a>.</p>
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<h2 class="memtitle"><span class="permalink"><a href="#acb52a9def0feda98787bd82fe8bfeded">◆ </a></span>DeriveKey() <span class="overload">[1/2]</span></h2>
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<td>(</td>
<td class="paramtype">byte * </td>
<td class="paramname"><em>derived</em>, </td>
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<td class="paramkey"></td>
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<td class="paramtype">size_t </td>
<td class="paramname"><em>derivedLen</em>, </td>
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<td class="paramtype">const byte * </td>
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<td class="paramtype">size_t </td>
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<p>Derive a key from a seed. </p>
<dl class="params"><dt>Parameters</dt><dd>
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<tr><td class="paramname">derived</td><td>the derived output buffer </td></tr>
<tr><td class="paramname">derivedLen</td><td>the size of the derived buffer, in bytes </td></tr>
<tr><td class="paramname">secret</td><td>the seed input buffer </td></tr>
<tr><td class="paramname">secretLen</td><td>the size of the secret buffer, in bytes </td></tr>
<tr><td class="paramname">params</td><td>additional initialization parameters to configure this object </td></tr>
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<dl class="section return"><dt>Returns</dt><dd>the number of iterations performed </dd></dl>
<dl class="exception"><dt>Exceptions</dt><dd>
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<tr><td class="paramname"><a class="el" href="class_invalid_derived_length.html" title="Exception thrown when an invalid derived key length is encountered. ">InvalidDerivedLength</a></td><td>if <code>derivedLen</code> is invalid for the scheme</td></tr>
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<p><a class="el" href="class_scrypt.html#acb52a9def0feda98787bd82fe8bfeded" title="Derive a key from a seed. ">DeriveKey()</a> provides a standard interface to derive a key from a secret seed and other parameters. Each class that derives from <a class="el" href="class_key_derivation_function.html" title="Interface for key derivation functions. ">KeyDerivationFunction</a> provides an overload that accepts most parameters used by the derivation function.</p>
<p>the number of iterations performed by <a class="el" href="class_scrypt.html#acb52a9def0feda98787bd82fe8bfeded" title="Derive a key from a seed. ">DeriveKey()</a> may be 1. For example, a scheme like <a class="el" href="class_h_k_d_f.html" title="Extract-and-Expand Key Derivation Function (HKDF) ">HKDF</a> does not use the iteration count so it returns 1. </p>
<p>Implements <a class="el" href="class_key_derivation_function.html#a97cb4cd409b17220063c891e80acdf8d">KeyDerivationFunction</a>.</p>
<p class="definition">Definition at line <a class="el" href="scrypt_8cpp_source.html#l00210">210</a> of file <a class="el" href="scrypt_8cpp_source.html">scrypt.cpp</a>.</p>
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<td class="memname">size_t Scrypt::DeriveKey </td>
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<td class="paramtype">const byte * </td>
<td class="paramname"><em>salt</em>, </td>
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<td class="paramkey"></td>
<td></td>
<td class="paramtype">size_t </td>
<td class="paramname"><em>saltLen</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">word64 </td>
<td class="paramname"><em>cost</em> = <code>2</code>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">word64 </td>
<td class="paramname"><em>blockSize</em> = <code>8</code>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">word64 </td>
<td class="paramname"><em>parallelization</em> = <code>1</code> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td> const</td>
</tr>
</table>
</div><div class="memdoc">
<p>Derive a key from a seed. </p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">derived</td><td>the derived output buffer </td></tr>
<tr><td class="paramname">derivedLen</td><td>the size of the derived buffer, in bytes </td></tr>
<tr><td class="paramname">secret</td><td>the seed input buffer </td></tr>
<tr><td class="paramname">secretLen</td><td>the size of the secret buffer, in bytes </td></tr>
<tr><td class="paramname">salt</td><td>the salt input buffer </td></tr>
<tr><td class="paramname">saltLen</td><td>the size of the salt buffer, in bytes </td></tr>
<tr><td class="paramname">cost</td><td>the CPU/memory cost factor </td></tr>
<tr><td class="paramname">blockSize</td><td>the block size </td></tr>
<tr><td class="paramname">parallelization</td><td>the parallelization factor </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>the number of iterations performed </dd></dl>
<dl class="exception"><dt>Exceptions</dt><dd>
<table class="exception">
<tr><td class="paramname"><a class="el" href="class_invalid_derived_length.html" title="Exception thrown when an invalid derived key length is encountered. ">InvalidDerivedLength</a></td><td>if <code>derivedLen</code> is invalid for the scheme</td></tr>
</table>
</dd>
</dl>
<p><a class="el" href="class_scrypt.html#acb52a9def0feda98787bd82fe8bfeded" title="Derive a key from a seed. ">DeriveKey()</a> provides a standard interface to derive a key from a seed and other parameters. Each class that derives from <a class="el" href="class_key_derivation_function.html" title="Interface for key derivation functions. ">KeyDerivationFunction</a> provides an overload that accepts most parameters used by the derivation function.</p>
<p>The CPU/Memory <code>cost</code> parameter ("N" in the documents) must be larger than 1, a power of 2, and less than <code>2^(128 * r / 8)</code>.</p>
<p>The parameter <code>blockSize</code> ("r" in the documents) specifies the block size.</p>
<p>The <code>parallelization</code> parameter ("p" in the documents) is a positive integer less than or equal to <code>((2^32-1) * 32) / (128 * r)</code>.</p>
<p><a class="el" href="class_scrypt.html" title="Scrypt key derivation function. ">Scrypt</a> always returns 1 because it only performs 1 iteration. Other derivation functions, like PBKDF's, will return more interesting values.</p>
<p>The Crypto++ implementation of <a class="el" href="class_scrypt.html" title="Scrypt key derivation function. ">Scrypt</a> is limited by C++ datatypes. For example, the library is limited to a derived key length of <code>SIZE_MAX</code>, and not <code>(2^32 - 1) * 32</code>. </p>
<p class="definition">Definition at line <a class="el" href="scrypt_8cpp_source.html#l00233">233</a> of file <a class="el" href="scrypt_8cpp_source.html">scrypt.cpp</a>.</p>
</div>
</div>
<hr/>The documentation for this class was generated from the following files:<ul>
<li><a class="el" href="scrypt_8h_source.html">scrypt.h</a></li>
<li><a class="el" href="scrypt_8cpp_source.html">scrypt.cpp</a></li>
</ul>
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