我不完全理解，一些文档或帮助将不胜感激:)
使用 PHP 我使用 ezcomponents Mail 对象创建了一个 MIME。但我不明白的是：
您是否通过使用openssl_pkcs7_sign对原始 MIME 进行签名来创建 S/MIME 消息？还是您从头开始创建 S/MIME 并在完成后对其进行签名？
当我试图理解正确的做事方式时，请多多包涵。
编辑：找到这段代码来更好地说明我的问题
<?
// Setup mail headers.
$headers = array("To" => "someone@nowhere.net",
"From" => "noone@somewhere.net",
"Subject" => "A signed and encrypted message.");
// Sign the message first
openssl_pkcs7_sign("msg.txt","signed.txt",
"signing_cert.pem",array("private_key.pem",
"password"),array());
// Get the public key certificate.
$pubkey = file_get_contents("cert.pem");
//encrypt the message, now put in the headers.
openssl_pkcs7_encrypt("signed.txt", "enc.txt",
$pubkey,$headers,0,1);
$data = file_get_contents("enc.txt");
// separate header and body, to use with mail function
// unfortunate but required, else we have two sets of headers
// and the email client doesn't decode the attachment
$parts = explode("\n\n", $data, 2);
// send mail (headers in the Headers parameter will override those
// generated for the To & Subject parameters)
mail($mail, $subject, $parts[1], $parts[0]);
?>