mirror of
https://github.com/PHPMailer/PHPMailer.git
synced 2024-09-20 01:52:15 +02:00
82 lines
3.2 KiB
PHP
82 lines
3.2 KiB
PHP
<?php
|
|
|
|
/**
|
|
* This shows how to make a new public/private key pair suitable for use with DKIM.
|
|
* You should only need to do this once, and the public key (**not** the private key!)
|
|
* you generate should be inserted in your DNS matching the selector you want.
|
|
*
|
|
* You can also use the DKIM wizard here: https://www.sparkpost.com/resources/tools/dkim-wizard/
|
|
* but be aware that having your private key known anywhere outside your own server
|
|
* is a security risk, and it's easy enough to create your own on your own server.
|
|
*
|
|
* For security, any keys you create should not be accessible via your web site.
|
|
*
|
|
* 2048 bits is the recommended minimum key length - gmail won't accept less than 1024 bits.
|
|
* To test your DKIM config, use Sparkpost's DKIM tester:
|
|
* https://tools.sparkpost.com/dkim
|
|
*
|
|
* Note that you only need a *private* key to *send* a DKIM-signed message,
|
|
* but receivers need your *public* key in order to verify it.
|
|
*
|
|
* Your public key will need to be formatted appropriately for your DNS and
|
|
* inserted there using the selector you want to use.
|
|
*/
|
|
|
|
//Set these to match your domain and chosen DKIM selector
|
|
$domain = 'example.com';
|
|
$selector = 'phpmailer';
|
|
|
|
//Private key filename for this selector
|
|
$privatekeyfile = $selector . '_dkim_private.pem';
|
|
//Public key filename for this selector
|
|
$publickeyfile = $selector . '_dkim_public.pem';
|
|
|
|
if (file_exists($privatekeyfile)) {
|
|
echo "Using existing keys - if you want to generate new keys, delete old key files first.\n\n";
|
|
$privatekey = file_get_contents($privatekeyfile);
|
|
$publickey = file_get_contents($publickeyfile);
|
|
} else {
|
|
//Create a 2048-bit RSA key with an SHA256 digest
|
|
$pk = openssl_pkey_new(
|
|
[
|
|
'digest_alg' => 'sha256',
|
|
'private_key_bits' => 2048,
|
|
'private_key_type' => OPENSSL_KEYTYPE_RSA,
|
|
]
|
|
);
|
|
//Save private key
|
|
openssl_pkey_export_to_file($pk, $privatekeyfile);
|
|
//Save public key
|
|
$pubKey = openssl_pkey_get_details($pk);
|
|
$publickey = $pubKey['key'];
|
|
file_put_contents($publickeyfile, $publickey);
|
|
$privatekey = file_get_contents($privatekeyfile);
|
|
}
|
|
echo "Private key (keep this private!):\n\n" . $privatekey;
|
|
echo "\n\nPublic key:\n\n" . $publickey;
|
|
|
|
//Prepare public key for DNS, e.g.
|
|
//phpmailer._domainkey.example.com IN TXT "v=DKIM1; h=sha256; t=s; p=" "MIIBIjANBg...oXlwIDAQAB"...
|
|
$dnskey = "$selector._domainkey.$domain IN TXT";
|
|
$dnsvalue = '"v=DKIM1; h=sha256; t=s; p=" ';
|
|
//Some DNS servers don't like ;(semi colon) chars unless backslash-escaped
|
|
$dnsvalue2 = '"v=DKIM1\; h=sha256\; t=s\; p=" ';
|
|
|
|
//Strip and split the key into smaller parts and format for DNS
|
|
//Many DNS systems don't like long TXT entries
|
|
//but are OK if it's split into 255-char chunks
|
|
//Remove PEM wrapper
|
|
$publickey = preg_replace('/^-+.*?-+$/m', '', $publickey);
|
|
//Strip line breaks
|
|
$publickey = str_replace(["\r", "\n"], '', $publickey);
|
|
//Split into chunks
|
|
$keyparts = str_split($publickey, 253); //Becomes 255 when quotes are included
|
|
//Quote each chunk
|
|
foreach ($keyparts as $keypart) {
|
|
$dnsvalue .= '"' . trim($keypart) . '" ';
|
|
$dnsvalue2 .= '"' . trim($keypart) . '" ';
|
|
}
|
|
echo "\n\nDNS key:\n\n" . trim($dnskey);
|
|
echo "\n\nDNS value:\n\n" . trim($dnsvalue);
|
|
echo "\n\nDNS value (with escaping):\n\n" . trim($dnsvalue2);
|