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<title>Checks if the given hash matches the given options</title>
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<div class="refnamediv">
<h1 class="refname">password_needs_rehash</h1>
<p class="verinfo">(PHP 5 >= 5.5.0, PHP 7)</p><p class="refpurpose"><span class="refname">password_needs_rehash</span> — <span class="dc-title">Checks if the given hash matches the given options</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.password-needs-rehash-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">bool</span> <span class="methodname"><strong>password_needs_rehash</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$hash</code></span>
, <span class="methodparam"><span class="type">int</span> <code class="parameter">$algo</code></span>
[, <span class="methodparam"><span class="type">array</span> <code class="parameter">$options</code></span>
] )</div>
<p class="para rdfs-comment">
This function checks to see if the supplied hash implements the algorithm
and options provided. If not, it is assumed that the hash needs to be
rehashed.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.password-needs-rehash-parameters">
<h3 class="title">Parameters</h3>
<dl>
<dt>
<code class="parameter">hash</code></dt>
<dd>
<p class="para">
A hash created by <span class="function"><a href="function.password-hash.html" class="function">password_hash()</a></span>.
</p>
</dd>
<dt>
<code class="parameter">algo</code></dt>
<dd>
<p class="para">
A <a href="password.constants.html" class="link">password algorithm constant</a> denoting the algorithm to use when hashing the password.
</p>
</dd>
<dt>
<code class="parameter">options</code></dt>
<dd>
<p class="para">
An associative array containing options. See the <a href="password.constants.html" class="link">password algorithm constants</a> for documentation on the supported options for each algorithm.
</p>
</dd>
</dl>
</div>
<div class="refsect1 examples" id="refsect1-function.password-needs-rehash-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-995">
<p><strong>Example #1 Usage of <span class="function"><strong>password_needs_rehash()</strong></span></strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /><br />$password </span><span style="color: #007700">= </span><span style="color: #DD0000">'rasmuslerdorf'</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$hash </span><span style="color: #007700">= </span><span style="color: #DD0000">'$2y$10$YCFsG6elYca568hBi2pZ0.3LDL5wjgxct1N8w/oLR/jfHsiQwCqTS'</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">// The cost parameter can change over time as hardware improves<br /></span><span style="color: #0000BB">$options </span><span style="color: #007700">= array(</span><span style="color: #DD0000">'cost' </span><span style="color: #007700">=> </span><span style="color: #0000BB">11</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Verify stored hash against plain-text password<br /></span><span style="color: #007700">if (</span><span style="color: #0000BB">password_verify</span><span style="color: #007700">(</span><span style="color: #0000BB">$password</span><span style="color: #007700">, </span><span style="color: #0000BB">$hash</span><span style="color: #007700">)) {<br /> </span><span style="color: #FF8000">// Check if a newer hashing algorithm is available<br /> // or the cost has changed<br /> </span><span style="color: #007700">if (</span><span style="color: #0000BB">password_needs_rehash</span><span style="color: #007700">(</span><span style="color: #0000BB">$hash</span><span style="color: #007700">, </span><span style="color: #0000BB">PASSWORD_DEFAULT</span><span style="color: #007700">, </span><span style="color: #0000BB">$options</span><span style="color: #007700">)) {<br /> </span><span style="color: #FF8000">// If so, create a new hash, and replace the old one<br /> </span><span style="color: #0000BB">$newHash </span><span style="color: #007700">= </span><span style="color: #0000BB">password_hash</span><span style="color: #007700">(</span><span style="color: #0000BB">$password</span><span style="color: #007700">, </span><span style="color: #0000BB">PASSWORD_DEFAULT</span><span style="color: #007700">, </span><span style="color: #0000BB">$options</span><span style="color: #007700">);<br /> }<br /><br /> </span><span style="color: #FF8000">// Log user in<br /></span><span style="color: #007700">}<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.password-needs-rehash-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <strong><code>TRUE</code></strong> if the hash should be rehashed to match the given
<code class="parameter">algo</code> and <code class="parameter">options</code>, or <strong><code>FALSE</code></strong>
otherwise.
</p>
</div>
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