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    2 => '生成 PKCS5 v2 PBKDF2 字符串',
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?>
<div id="function.openssl-pbkdf2" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">openssl_pbkdf2</h1>
  <p class="verinfo">(PHP 5 &gt;= 5.5.0, PHP 7, PHP 8)</p><p class="refpurpose"><span class="refname">openssl_pbkdf2</span> &mdash; <span class="dc-title">生成 PKCS5 v2 PBKDF2 字符串</span></p>

 </div>

 <div class="refsect1 description" id="refsect1-function.openssl-pbkdf2-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>openssl_pbkdf2</strong></span>(<br>&nbsp;&nbsp;&nbsp;&nbsp;<span class="methodparam"><span class="attribute"><a href="class.sensitiveparameter.php">#[\SensitiveParameter]</a> </span><span class="type"><a href="language.types.string.php" class="type string">string</a></span> <code class="parameter">$password</code></span>,<br>&nbsp;&nbsp;&nbsp;&nbsp;<span class="methodparam"><span class="type"><a href="language.types.string.php" class="type string">string</a></span> <code class="parameter">$salt</code></span>,<br>&nbsp;&nbsp;&nbsp;&nbsp;<span class="methodparam"><span class="type"><a href="language.types.integer.php" class="type int">int</a></span> <code class="parameter">$key_length</code></span>,<br>&nbsp;&nbsp;&nbsp;&nbsp;<span class="methodparam"><span class="type"><a href="language.types.integer.php" class="type int">int</a></span> <code class="parameter">$iterations</code></span>,<br>&nbsp;&nbsp;&nbsp;&nbsp;<span class="methodparam"><span class="type"><a href="language.types.string.php" class="type string">string</a></span> <code class="parameter">$digest_algo</code><span class="initializer"> = &quot;sha1&quot;</span></span><br>): <span class="type"><span class="type"><a href="language.types.string.php" class="type string">string</a></span>|<span class="type"><a href="language.types.singleton.php" class="type false">false</a></span></span></div>

  <p class="para rdfs-comment">
   <span class="function"><strong>openssl_pbkdf2()</strong></span> 计算 PBKDF2 (Password-Based Key Derivation Function 2)，在 PKCS5 v2 中定义的密钥的推导函数。
  </p>

 </div>


 <div class="refsect1 parameters" id="refsect1-function.openssl-pbkdf2-parameters">
  <h3 class="title">参数</h3>
  <dl>
   
    <dt><code class="parameter">password</code></dt>
    <dd>
     <p class="para">
      派生密钥所生成的密码。
     </p>
    </dd>
   
   
    <dt><code class="parameter">salt</code></dt>
    <dd>
     <p class="para">
      PBKDF2 推荐不少于 128 位（16 字节）的密码盐值。
     </p>
    </dd>
   
   
    <dt><code class="parameter">key_length</code></dt>
    <dd>
     <p class="para">
      希望输出密钥的长度。
     </p>
    </dd>
   
   
    <dt><code class="parameter">iterations</code></dt>
    <dd>
     <p class="para">
      需要的迭代次数。<a href="https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-132.pdf" class="link external">&raquo;&nbsp;NIST 
      建议至少 10,000 次</a>。自 2023 年起，OWASP 针对 PBKDF2-HMAC-SHA256 推荐 600,000 次迭代，针对 PBKDF2-HMAC-SHA512 推荐 210,000 次。
     </p>
    </dd>
   
   
    <dt><code class="parameter">digest_algo</code></dt>
    <dd>
     <p class="para">
      在 <span class="function"><a href="function.openssl-get-md-methods.php" class="function">openssl_get_md_methods()</a></span> 中可选的散列或摘要算法。默认是 SHA-1。推荐设置为 SHA-256 或 SHA-512。
     </p>
    </dd>
   
  </dl>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.openssl-pbkdf2-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   成功，返回原始二进制字符串 或者在失败时返回 <strong><code><a href="reserved.constants.php#constant.false">false</a></code></strong>。
  </p>
 </div>


 <div class="refsect1 examples" id="refsect1-function.openssl-pbkdf2-examples">
  <h3 class="title">示例</h3>
  <p class="para">
   <div class="example" id="example-1">
    <p><strong>示例 #1 openssl_pbkdf2() 示例</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB">&lt;?php<br />$password </span><span style="color: #007700">= </span><span style="color: #DD0000">'password'</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$salt </span><span style="color: #007700">= </span><span style="color: #0000BB">openssl_random_pseudo_bytes</span><span style="color: #007700">(</span><span style="color: #0000BB">16</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$keyLength </span><span style="color: #007700">= </span><span style="color: #0000BB">20</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$iterations </span><span style="color: #007700">= </span><span style="color: #0000BB">600000</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$generated_key </span><span style="color: #007700">= </span><span style="color: #0000BB">openssl_pbkdf2</span><span style="color: #007700">(</span><span style="color: #0000BB">$password</span><span style="color: #007700">, </span><span style="color: #0000BB">$salt</span><span style="color: #007700">, </span><span style="color: #0000BB">$keyLength</span><span style="color: #007700">, </span><span style="color: #0000BB">$iterations</span><span style="color: #007700">, </span><span style="color: #DD0000">'sha256'</span><span style="color: #007700">);<br />echo </span><span style="color: #0000BB">bin2hex</span><span style="color: #007700">(</span><span style="color: #0000BB">$generated_key</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo </span><span style="color: #0000BB">base64_encode</span><span style="color: #007700">(</span><span style="color: #0000BB">$generated_key</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?&gt;</span></span></code></div>
    </div>


   </div>
  </p>
 </div>


 <div class="refsect1 seealso" id="refsect1-function.openssl-pbkdf2-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li><span class="function"><a href="function.hash-pbkdf2.php" class="function" rel="rdfs-seeAlso">hash_pbkdf2()</a> - 生成所提供密码的 PBKDF2 密钥导出</span></li>
    <li><span class="function"><a href="function.openssl-get-md-methods.php" class="function" rel="rdfs-seeAlso">openssl_get_md_methods()</a> - 获取可用的摘要算法</span></li>
   </ul>
  </p>
 </div>


</div><?php manual_footer($setup); ?>