PHP Extension

Select the RSA Signature Scheme for Signed Email

Demonstrates the Chilkat Email.SigningAlg property, which selects the signature algorithm used when sending signed (PKCS#7) email. The default is PKCS1-v1_5; set it to RSASSA-PSS (or simply pss) to use the RSASSA-PSS scheme. This applies only when signing with an RSA private key — it has no effect for ECC or DSA keys, and the chosen scheme must be supported by the private-key provider. This example selects RSASSA-PSS.

Background: There are two common ways to build an RSA signature. The older PKCS1-v1_5 scheme is deterministic and still widely used, while RSASSA-PSS adds randomized "salt" to the padding, giving it a stronger security proof and making it the modern recommendation. This property picks the padding scheme for the signature; it is distinct from SigningHashAlg, which chooses the hash function (such as SHA-256) that the scheme signs.

Chilkat PHP Extension Downloads

Download Chilkat for PHP Extension

PHP Extension

<?php

include("chilkat.php");

//  Demonstrates the Email.SigningAlg property, which selects the signature scheme used
//  when sending signed (PKCS#7) email.  The default is PKCS1-v1_5.  Set it to RSASSA-PSS
//  (or simply "pss") to use the RSASSA-PSS scheme.  This applies only to RSA signing.

$email = new CkEmail();

//  Use the RSASSA-PSS signature scheme instead of the default PKCS1-v1_5.
$email->put_SigningAlg('RSASSA-PSS');

print 'SigningAlg = ' . $email->signingAlg() . "\n";

?>