(PHP 4 >= 4.0.6, PHP 5, PHP 7, PHP 8)
openssl_pkcs7_encrypt — Encrypt an S/MIME message
$input_filename
,$output_filename
,$certificate
,$headers
,$flags
= 0,$cipher_algo
= OPENSSL_CIPHER_AES_128_CBC
openssl_pkcs7_encrypt() takes the contents of the
file named input_filename
and encrypts them using an RC2
40-bit cipher so that they can only be read by the intended recipients
specified by certificate
.
input_filename
output_filename
certificate
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.
cipher_algo
One of cipher constants.
Returns true
on success or false
on failure.
Version | Description |
---|---|
8.1.0 |
The default cipher algorithm (cipher_algo ) is now
AES-128-CBC (OPENSSL_CIPHER_AES_128_CBC ). Previously,
PKCS7/CMS was used (OPENSSL_CIPHER_RC2_40 ).
|
8.0.0 |
certificate accepts an OpenSSLCertificate instance now;
previously, a resource of type OpenSSL X.509 CSR was accepted.
|
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" => "nighthawk@example.com", // keyed syntax
"From: HQ <hq@example.com>", // indexed syntax
"Subject" => "Eyes only"))) {
// message encrypted - send it!
exec(ini_get("sendmail_path") . " < enc.txt");
}
?>