<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Verify signature</title> </head> <body><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.openssl-spki-verify.html">openssl_spki_verify</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.openssl-x509-check-private-key.html">openssl_x509_check_private_key</a></div> <div class="up"><a href="ref.openssl.html">OpenSSL Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div><hr /><div id="function.openssl-verify" class="refentry"> <div class="refnamediv"> <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> </div><hr /><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a 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