openssl_pkcs7_encrypt
  (PHP 4 >= 4.0.6, PHP 5)
openssl_pkcs7_encrypt — Encrypt an S/MIME message
  
 
 
  Description
  
   bool openssl_pkcs7_encrypt
    ( 
string $infile
   , 
string $outfile
   , 
mixed $recipcerts
   , 
array $headers
   [, 
int $flags
   [, 
int $cipherid
  ]] )
 
  
  
 
  Parameters
  
   
    - 
     infile
     
 - 
      
      
      
    
    - 
     outfile
     
 - 
      
      
      
    
    - 
     recipcerts
     
 - 
      
       Either a lone X.509 certificate, or an array of X.509 certificates.
      
      
    
    - 
     headers
     
 - 
      
       headers
 is an array of headers that
       will be prepended to the data after it has been encrypted.
      
      
       headers
 can be either an associative array
       keyed by header name, or an indexed array, where each element contains
       a single header line.
      
      
    
    - 
     flags
     
 - 
      
       flags
 can be used to specify options that affect
       the encoding process - see PKCS7
       constants.
      
      
    
    - 
     cipherid
     
 - 
      
       Cipher can be selected with cipherid
.
      
      
    
   
  
  
 
  Return Values
  
   Returns TRUE on success or FALSE on failure.
  
  
 
 
  Examples
  
   
    Example #1 openssl_pkcs7_encrypt() example
    
<?php
// the message you want to encrypt and send to your secret agent
// in the field, known as nighthawk.  You have his certificate
// in the file nighthawk.pem
$data = <<<EOD
Nighthawk,
Top secret, for your eyes only!
The enemy is closing in! Meet me at the cafe at 8.30am
to collect your forged passport!
HQ
EOD;
// load key
$key = file_get_contents("nighthawk.pem");
// save message to file
$fp = fopen("msg.txt", "w");
fwrite($fp, $data);
fclose($fp);
// encrypt it
if (openssl_pkcs7_encrypt("msg.txt", "enc.txt", $key,
    array("To" => "[email protected]", // keyed syntax
          "From: HQ <[email protected]>", // indexed syntax
          "Subject" => "Eyes only"))) {
    // message encrypted - send it!
    exec(ini_get("sendmail_path") . " < enc.txt");
}
?>