(PHP 5 >= 5.2.2)
openssl_pkcs12_export — Exports a PKCS#12 Compatible Certificate Store File to variable.
$x509
   , string &$out
   , mixed $priv_key
   , string $pass
   [, array $args
  ] )
   openssl_pkcs12_export() stores
   x509 into a string named by
   out in a PKCS#12 file format.
  
x509See Key/Certificate parameters for a list of valid values.
outOn success, this will hold the PKCS#12.
priv_keyPrivate key component of PKCS#12 file.
passEncryption password for unlocking the PKCS#12 file.
args
   Returns TRUE on success or FALSE on failure.