README

🔏 Stand-alone DKIM class to sign your emails with a 2048 bit private key hashed with SHA-256 algorithm.

Usage

Sample lines to import into your mail code to start signing with DKIM:

require_once __DIR__ . '/../vendor/autoload.php' ; // Autoload files using Composer autoload
use JVconseil\DkimPhpMailSignature\DKIMsign ;
use JVconseil\DkimPhpMailSignature\DKIMconfig ;

// init
$config = new DKIMconfig('/www/inc/config/jv-conseil/dkim-php-mail-signature/config.inc.php') ;
$sign = new DKIMsign(
 $config->private_key,
 $config->passphrase,
 $config->domain,
 $config->selector
) ;

// sign
$signed_headers = $sign->get_signed_headers($to, $subject, $message, $headers) ;

// send email
mail($to, $subject, $message, $signed_headers.$headers) ;

Installation

Step by Step guide to generate your encryption keys and populate them through your DNS records.

Installation & loading

DkimPhpMailSignature is available on Packagist (using semantic versioning), and installation via Composer is the recommended way to install DkimPhpMailSignature. Just add this line to your composer.json file:

"jv-conseil/dkim-php-mail-signature": "^1.0"

or run

composer require jv-conseil/dkim-php-mail-signature

Note that the vendor folder and the vendor/autoload.php script are generated by Composer; they are not part of DkimPhpMailSignature.

Make your own copy of config file

Before starting you should make a copy of folder config/ and store it outside your vendor/ Composer repository in a non-public area of your website e.g.:

/www/inc/config/jv-conseil/dkim-php-mail-signature/

Failing to do so will expose you to lose all your settings in case of a future Composer udpate.

Generate your Public & Private Encryption keys

In Terminal enter this command line to start working under the path of your config/ folder:

cd /www/inc/config/jv-conseil/dkim-php-mail-signature/

In Terminal enter this command line to generate a new private 2048 bit encryption key:

openssl genrsa -des3 -out private.pem 2048

Enter your Pass Phrase and save it for editing your config.inc.php file in the next step.

Then retrieve your public key:

openssl rsa -in private.pem -out public.pem -outform PEM -pubout

You can delete the two originals *.pem file keys stored in the config/ folder if they create a conflict in the creation process of your keys.

Edit your DNS with a new DKIM record

Access your registrar interface (e.g.: OVH.com) and create a new DKIM record to declare your public key:

selector._domainkey  IN TXT  ( "v=DKIM1;k=rsa;p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA0ekggNf9vuzzL4SlVc8QZyyqbEwR5bVTPC9cEZ8hFqTKOc7go180n3RZilYJZvveaxBkLCVJSTQaMPtKuSptY5au6Pi3AkFlizzhUJ80+0zgZXSGx7gfbginbRwhD+XdGOe9NXpo0PfrD6dEJ49Ytx4/nHB0TKiL227C0kGWb7RfWTVWccgJq4+kQb4l+4" "oDU5rGomSYK+zmMV13QTSETcJnoXhmjoJ30omyJfEXAsK5Ny0LJo8rWCucLD31BxHrM9/+M/Ye+TWxcrD2mRh5Jxqcnyj00/7kCnWeGPTftVKkAJBP3JMRqCNShLUchLhaz0qeXUtxAe9dx7ltr8042QIDAQAB;" )

DKIM works better with SPF and DMARC records, you should consider editing them too:

3600     IN TXT  "v=spf1 include:_spf.google.com ~all"
_dmarc   IN TXT  "v=DMARC1; p=quarantine; rua=mailto:me@yourdomain.name"

Further reading:

• Add DKIM domain key to domain DNS records
• Manage suspicious emails with DMARC
• Help prevent email spoofing with SPF records

Edit your Config File

Under config/config.sample.inc.php you will find a config file example to help you set your own details.

Now you can drop .sample in the filename and start editing it:

• domain: your domain name e.g: google.com
• selector: selector used in your DKIM DNS record, e.g.: selector._domainkey.MAIL_DKIM_DOMAIN
• passphrase: your pass phrase used to generate your keys e.g.: myPassPhrase.
• ... other parameters can be omitted.

Simple Use

Sample lines to import into your mail code to start signing with DKIM:

require_once __DIR__ . '/../vendor/autoload.php' ; // Autoload files using Composer autoload
use JVconseil\DkimPhpMailSignature\DKIMsign ;
use JVconseil\DkimPhpMailSignature\DKIMconfig ;

// init
$config = new DKIMconfig('/www/inc/config/jv-conseil/dkim-php-mail-signature/config.inc.php') ;

// set: this calls __set()
$config->domain = "mynewdomain.name" ;

// get: this calls __get()
$config->domain ; // => "mynewdomain.name" ;

Introducing DKIMmail class

📬 Stand-alone class to send DKIM signed emails with a 2048 bit private key hashed with SHA-256 algorithm.

// init
$mail = new DKIMmail('/www/inc/config/jv-conseil/dkim-php-mail-signature/config.inc.php') ;

// parameters
$mail->from    = "Sender" <sender@yourdomain.com> ;
$mail->to      = "Recipient" <recipient@yourdomain.com> ;
$mail->subject = "Your Mail Subject" ;
$mail->body    = "Your Mail Message." ;
$mail->attach("/path/to/your/attachment.jpg", "NameOfYourAttachment.jpg") ;

// send!
$mail->send() ;

Documentation

Documentation is available online, though it may not be quite up to date or match your version exactly.

You can generate API documentation by running phpdoc in the top-level folder of this project, and documentation will be generated in this folder:

php ~/vendor/bin/phpdoc -d ~/dkim-php-mail-signature/ -t ~/dkim-php-mail-signature/docs/

You will need to have phpDocumentor installed.

Sponsorship

If this project helps you reduce time to develop, you can give me a cup of coffee ☕️ :-)