Sign an S/MIME message

openssl_pkcs7_encrypt
openssl_pkcs7_verify
OpenSSL Functions
PHP Manual

# openssl_pkcs7_sign

(PHP 4 >= 4.0.6, PHP 5)

openssl_pkcs7_sign — Sign an S/MIME message

### Description

bool openssl_pkcs7_sign ( string `$infilename` , string `$outfilename` , mixed `$signcert` , mixed `$privkey` , array `$headers` [, int `$flags` = PKCS7_DETACHED [, string `$extracerts` ]] )

openssl_pkcs7_sign() takes the contents of the file named `infilename` and signs them using the certificate and its matching private key specified by `signcert` and `privkey` parameters.

### Parameters

`infilename`

`outfilename`

`signcert`

`privkey`

`headers`

  `headers` is an array of headers that will be prepended to the data after it has been signed (see openssl_pkcs7_encrypt() for more information about the format of this parameter).

`flags`

  `flags` can be used to alter the output - see PKCS7 constants.

`extracerts`

  `extracerts` specifies the name of a file containing a bunch of extra certificates to include in the signature which can for example be used to help the recipient to verify the certificate that you used.

### Return Values

Returns `TRUE` on success or `FALSE` on failure.

### Examples

Example #1 openssl_pkcs7_sign() example

`<?php
// the message you want to sign so that recipient can be sure it was you that
// sent it
$data = <<<EOD
You have my authorization to spend $10,000 on dinner expenses.
The CEO
EOD;
// save message to file
$fp = fopen("msg.txt", "w");
fwrite($fp, $data);
fclose($fp);
// encrypt it
if (openssl_pkcs7_sign("msg.txt", "signed.txt", "mycert.pem",
array("file://mycert.pem", "mypassphrase"),
array("To" => "joes@example.com", // keyed syntax
"From: HQ <ceo@example.com>", // indexed syntax
"Subject" => "Eyes only")
)) {
// message signed - send it!
exec(ini_get("sendmail_path") . " < signed.txt");
}
?>`

openssl_pkcs7_encrypt
openssl_pkcs7_verify
OpenSSL Functions
PHP Manual