(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)
openssl_open — Open sealed data
$data,&$output,$encrypted_key,$private_key,$cipher_algo,$iv = null
   openssl_open() opens (decrypts)
   data using the private key associated with
   the key identifier private_key and the envelope key
   encrypted_key, and fills
   output with the decrypted data.
   The envelope key is generated when the
   data are sealed and can only be used by one specific private key. See
   openssl_seal() for more information.
  
data
outputIf the call is successful the opened data is returned in this parameter.
encrypted_key
private_key
cipher_algoThe cipher method.
         The default value ('RC4') is considered insecure.
         It is strongly recommended to explicitly specify a secure cipher method.
        
ivThe initialization vector.
   Returns true on success or false on failure.
  
| Version | Description | 
|---|---|
| 8.0.0 | private_keyaccepts an OpenSSLAsymmetricKey
       or OpenSSLCertificate instance now;
       previously, a resource of typeOpenSSL keyorOpenSSL X.509 CSRwas accepted. | 
| 8.0.0 | cipher_algois no longer an optional parameter. | 
Example #1 openssl_open() example
<?php
// $sealed and $env_key are assumed to contain the sealed data
// and our envelope key, both given to us by the sealer.
// fetch private key from file and ready it
$fp = fopen("/src/openssl-0.9.6/demos/sign/key.pem", "r");
$priv_key = fread($fp, 8192);
fclose($fp);
$pkeyid = openssl_get_privatekey($priv_key);
// decrypt the data and store it in $open
if (openssl_open($sealed, $open, $env_key, $pkeyid)) {
    echo "here is the opened data: ", $open;
} else {
    echo "failed to open data";
}
// free the private key from memory
openssl_free_key($pkeyid);
?>