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<h1 class="refname">openssl_verify</h1>
<p class="verinfo">(PHP 4 >= 4.0.4, PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">openssl_verify</span> — <span class="dc-title">Verify signature</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.openssl-verify-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">int</span> <span class="methodname"><strong>openssl_verify</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$data</code></span>
, <span class="methodparam"><span class="type">string</span> <code class="parameter">$signature</code></span>
, <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$pub_key_id</code></span>
[, <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$signature_alg</code><span class="initializer"> = OPENSSL_ALGO_SHA1</span></span>
] )</div>
<p class="para rdfs-comment">
<span class="function"><strong>openssl_verify()</strong></span> verifies that the
<code class="parameter">signature</code> is correct for the specified
<code class="parameter">data</code> using the public key associated with
<code class="parameter">pub_key_id</code>. This must be the public key
corresponding to the private key used for signing.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.openssl-verify-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<code class="parameter">data</code></dt>
<dd>
<p class="para">
The string of data used to generate the signature previously
</p>
</dd>
<dt>
<code class="parameter">signature</code></dt>
<dd>
<p class="para">
A raw binary string, generated by <span class="function"><a href="function.openssl-sign.html" class="function">openssl_sign()</a></span> or similar means
</p>
</dd>
<dt>
<code class="parameter">pub_key_id</code></dt>
<dd>
<p class="para">
<span class="type"><a href="language.types.resource.html" class="type resource">resource</a></span> - a key, returned by <span class="function"><a href="function.openssl-get-publickey.html" class="function">openssl_get_publickey()</a></span>
</p>
<p class="para">
<span class="type"><a href="language.types.string.html" class="type string">string</a></span> - a PEM formatted key, example, "-----BEGIN PUBLIC KEY-----
MIIBCgK..."
</p>
</dd>
<dt>
<code class="parameter">signature_alg</code></dt>
<dd>
<p class="para">
<span class="type"><a href="language.types.integer.html" class="type int">int</a></span> - one of these <a href="openssl.signature-algos.html" class="link">Signature Algorithms</a>.
</p>
<p class="para">
<span class="type"><a href="language.types.string.html" class="type string">string</a></span> - a valid string returned by <span class="function"><a href="function.openssl-get-md-methods.html" class="function">openssl_get_md_methods()</a></span> example, "sha1WithRSAEncryption" or "sha512".
</p>
</dd>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.openssl-verify-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns 1 if the signature is correct, 0 if it is incorrect, and
-1 on error.
</p>
</div>
<div class="refsect1 changelog" id="refsect1-function.openssl-verify-changelog">
<h3 class="title">Changelog</h3>
<p class="para">
<table class="doctable informaltable">
<thead>
<tr>
<th>Version</th>
<th>Description</th>
</tr>
</thead>
<tbody class="tbody">
<tr>
<td>5.2.0</td>
<td>
The <code class="parameter">signature_alg</code> parameter was added.
</td>
</tr>
</tbody>
</table>
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.openssl-verify-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-989">
<p><strong>Example #1 <span class="function"><strong>openssl_verify()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">// $data and $signature are assumed to contain the data and the signature<br /><br />// fetch public key from certificate and ready it<br /></span><span style="color: #0000BB">$pubkeyid </span><span style="color: #007700">= </span><span style="color: #0000BB">openssl_pkey_get_public</span><span style="color: #007700">(</span><span style="color: #DD0000">"file://src/openssl-0.9.6/demos/sign/cert.pem"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// state whether signature is okay or not<br /></span><span style="color: #0000BB">$ok </span><span style="color: #007700">= </span><span style="color: #0000BB">openssl_verify</span><span style="color: #007700">(</span><span style="color: #0000BB">$data</span><span style="color: #007700">, </span><span style="color: #0000BB">$signature</span><span style="color: #007700">, </span><span style="color: #0000BB">$pubkeyid</span><span style="color: #007700">);<br />if (</span><span style="color: #0000BB">$ok </span><span style="color: #007700">== </span><span style="color: #0000BB">1</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"good"</span><span style="color: #007700">;<br />} elseif (</span><span style="color: #0000BB">$ok </span><span style="color: #007700">== </span><span style="color: #0000BB">0</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"bad"</span><span style="color: #007700">;<br />} else {<br /> echo </span><span style="color: #DD0000">"ugly, error checking signature"</span><span style="color: #007700">;<br />}<br /></span><span style="color: #FF8000">// free the key from memory<br /></span><span style="color: #0000BB">openssl_free_key</span><span style="color: #007700">(</span><span style="color: #0000BB">$pubkeyid</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
<div class="example" id="example-990">
<p><strong>Example #2 <span class="function"><strong>openssl_verify()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">//data you want to sign<br /></span><span style="color: #0000BB">$data </span><span style="color: #007700">= </span><span style="color: #DD0000">'my data'</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">//create new private and public key<br /></span><span style="color: #0000BB">$private_key_res </span><span style="color: #007700">= </span><span style="color: #0000BB">openssl_pkey_new</span><span style="color: #007700">(array(<br /> </span><span style="color: #DD0000">"private_key_bits" </span><span style="color: #007700">=> </span><span style="color: #0000BB">2048</span><span style="color: #007700">,<br /> </span><span style="color: #DD0000">"private_key_type" </span><span style="color: #007700">=> </span><span style="color: #0000BB">OPENSSL_KEYTYPE_RSA</span><span style="color: #007700">,<br />));<br /></span><span style="color: #0000BB">$details </span><span style="color: #007700">= </span><span style="color: #0000BB">openssl_pkey_get_details</span><span style="color: #007700">(</span><span style="color: #0000BB">$private_key_res</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$public_key_res </span><span style="color: #007700">= </span><span style="color: #0000BB">openssl_pkey_get_public</span><span style="color: #007700">(</span><span style="color: #0000BB">$details</span><span style="color: #007700">[</span><span style="color: #DD0000">'key'</span><span style="color: #007700">]);<br /><br /></span><span style="color: #FF8000">//create signature<br /></span><span style="color: #0000BB">openssl_sign</span><span style="color: #007700">(</span><span style="color: #0000BB">$data</span><span style="color: #007700">, </span><span style="color: #0000BB">$signature</span><span style="color: #007700">, </span><span style="color: #0000BB">$private_key_res</span><span style="color: #007700">, </span><span style="color: #DD0000">"sha1WithRSAEncryption"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">//verify signature<br /></span><span style="color: #0000BB">$ok </span><span style="color: #007700">= </span><span style="color: #0000BB">openssl_verify</span><span style="color: #007700">(</span><span style="color: #0000BB">$data</span><span style="color: #007700">, </span><span style="color: #0000BB">$signature</span><span style="color: #007700">, </span><span style="color: #0000BB">$public_key_res</span><span style="color: #007700">, </span><span style="color: #0000BB">OPENSSL_ALGO_SHA1</span><span style="color: #007700">);<br />if (</span><span style="color: #0000BB">$ok </span><span style="color: #007700">== </span><span style="color: #0000BB">1</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"valid"</span><span style="color: #007700">;<br />} elseif (</span><span style="color: #0000BB">$ok </span><span style="color: #007700">== </span><span style="color: #0000BB">0</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"invalid"</span><span style="color: #007700">;<br />} else {<br /> echo </span><span style="color: #DD0000">"error: "</span><span style="color: #007700">.</span><span style="color: #0000BB">openssl_error_string</span><span style="color: #007700">();<br />}<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.openssl-verify-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"><span class="function"><a href="function.openssl-sign.html" class="function" rel="rdfs-seeAlso">openssl_sign()</a> - Generate signature</span></li>
</ul>
</p>
</div>
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