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?>
<div id="function.mcrypt-create-iv" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">mcrypt_create_iv</h1>
  <p class="verinfo">(PHP 4, PHP 5, PHP 7 &lt; 7.2.0, PECL mcrypt &gt;= 1.0.0)</p><p class="refpurpose"><span class="refname">mcrypt_create_iv</span> &mdash; <span class="dc-title">Creates an initialization vector (IV) from a random source</span></p>

 </div>
 
 <div id="function.mcrypt-create-iv-refsynopsisdiv">
  <div class="warning"><strong class="warning">Увага</strong>
   <p class="para">
 Ця функція <em>ЗАСТАРІЛА</em>, починаючи з PHP 7.1.0, та
 <em>ВИЛУЧЕНА</em> в PHP 7.2.0.
</p>
<p class="para">
 Її можна замінити на:
</p>

   <ul class="simplelist">
    <li><span class="function"><a href="function.random-bytes.php" class="function">random_bytes()</a></span></li>
   </ul>
  </div>
 </div>
 
 <div class="refsect1 description" id="refsect1-function.mcrypt-create-iv-description">
  <h3 class="title">Опис</h3>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>mcrypt_create_iv</strong></span>(<span class="methodparam"><span class="type"><a href="language.types.integer.php" class="type int">int</a></span> <code class="parameter">$size</code></span>, <span class="methodparam"><span class="type"><a href="language.types.integer.php" class="type int">int</a></span> <code class="parameter">$source</code><span class="initializer"> = MCRYPT_DEV_URANDOM</span></span>): <span class="type"><a href="language.types.string.php" class="type string">string</a></span></div>

  <p class="para rdfs-comment">
   Creates an initialization vector (IV) from a random source.
  </p>
  <p class="para">
   The IV is only meant to give an alternative seed to the encryption
   routines. This IV does not need to be secret at all, though it can be
   desirable. You even can send it along with your ciphertext without
   losing security.
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-function.mcrypt-create-iv-parameters">
  <h3 class="title">Параметри</h3>
  <p class="para">
   <dl>
    
     <dt><code class="parameter">size</code></dt>
     <dd>
      <p class="para">
       The size of the IV.
      </p>
     </dd>
    
    
     <dt><code class="parameter">source</code></dt>
     <dd>
      <p class="para">
       The source of the IV. The source can be
       <strong><code><a href="mcrypt.constants.php#constant.mcrypt-rand">MCRYPT_RAND</a></code></strong> (system random number generator),
       <strong><code><a href="mcrypt.constants.php#constant.mcrypt-dev-random">MCRYPT_DEV_RANDOM</a></code></strong> (read data from
       <var class="filename">/dev/random</var>) and
       <strong><code><a href="mcrypt.constants.php#constant.mcrypt-dev-urandom">MCRYPT_DEV_URANDOM</a></code></strong> (read data from
       <var class="filename">/dev/urandom</var>). Prior to 5.3.0,
       <strong><code><a href="mcrypt.constants.php#constant.mcrypt-rand">MCRYPT_RAND</a></code></strong> was the only one supported on Windows.
      </p>
      <p class="para">
       Note that the default value of this parameter was
       <strong><code><a href="mcrypt.constants.php#constant.mcrypt-dev-random">MCRYPT_DEV_RANDOM</a></code></strong> prior to PHP 5.6.0.
      </p>
      <blockquote class="note"><p><strong class="note">Зауваження</strong>: 
       <span class="simpara">
        Note that <strong><code><a href="mcrypt.constants.php#constant.mcrypt-dev-random">MCRYPT_DEV_RANDOM</a></code></strong> may block until more
        entropy is available.
       </span>
      </p></blockquote>
     </dd>
    
   </dl>
  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.mcrypt-create-iv-returnvalues">
  <h3 class="title">Значення, що повертаються</h3>
  <p class="para">
   Returns the initialization vector, or <strong><code><a href="reserved.constants.php#constant.false">false</a></code></strong> on error.
  </p>
 </div>


 <div class="refsect1 examples" id="refsect1-function.mcrypt-create-iv-examples">
  <h3 class="title">Приклади</h3>
  <p class="para">
   <div class="example" id="example-1">
    <p><strong>Приклад #1 <span class="function"><strong>mcrypt_create_iv()</strong></span> Example</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB">&lt;?php<br />    $size </span><span style="color: #007700">= </span><span style="color: #0000BB">mcrypt_get_iv_size</span><span style="color: #007700">(</span><span style="color: #0000BB">MCRYPT_CAST_256</span><span style="color: #007700">, </span><span style="color: #0000BB">MCRYPT_MODE_CFB</span><span style="color: #007700">);<br />    </span><span style="color: #0000BB">$iv </span><span style="color: #007700">= </span><span style="color: #0000BB">mcrypt_create_iv</span><span style="color: #007700">(</span><span style="color: #0000BB">$size</span><span style="color: #007700">, </span><span style="color: #0000BB">MCRYPT_DEV_RANDOM</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.mcrypt-create-iv-seealso">
  <h3 class="title">Прогляньте також</h3>
  <p class="para">
   <ul class="simplelist">
    <li><a href="http://www.ciphersbyritter.com/GLOSSARY.HTM#IV" class="link external">&raquo;&nbsp;http://www.ciphersbyritter.com/GLOSSARY.HTM#IV</a></li>
    <li><a href="http://www.quadibloc.com/crypto/co0409.htm" class="link external">&raquo;&nbsp;http://www.quadibloc.com/crypto/co0409.htm</a></li>
    <li>Chapter 9.3 of Applied Cryptography by Schneier (ISBN 0-471-11709-9)</li>
    <li><span class="function"><a href="function.random-bytes.php" class="function" rel="rdfs-seeAlso">random_bytes()</a> - Get cryptographically secure random bytes</span></li>
   </ul>
  </p>
 </div>

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