(PHP Extension) Apple Keychain - Create RSA Signature

See more Apple Keychain Examples

Using an RSA private key stored in the Apple Keychain, create a signature by signing the SHA-256 hash of the provided string, then return the signature encoded in Base64 format.

Note: This example requires Chilkat v10.0.0 or greater.

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<?php

include("chilkat.php");
// Use "chilkat_9_5_0.php" for versions of Chilkat < 10.0.0

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

$cert = new CkCert();

// On MacOS and iOS, the LoadByCommonName function will search the Apple Keychain for the matching certificate.

// A digital certificate's Common Name (CN) is a field in the certificate that specifies the name of the entity the 
// certificate is issued to. It is often used to identify the domain name, hostname, or organization the certificate represents. 

// For example:
// - In an SSL/TLS certificate for a website, the CN typically contains the domain name (e.g., "www.example.com").
// - For certificates representing individuals or organizations, the CN might include the person's name or the organization's name.

// The CN is part of the certificate's Subject field and is crucial for verifying that the certificate corresponds 
// to the intended entity, especially in SSL/TLS communications.

$success = $cert->LoadByCommonName('Example, Inc.');
if ($success == false) {
    print $cert->lastErrorText() . "\n";
    exit;
}

$rsa = new CkRsa();
$success = $rsa->SetX509Cert($cert,true);
if ($success == false) {
    print $rsa->lastErrorText() . "\n";
    exit;
}

// Generate an RSA signature by signing the SHA-256 hash of the provided string, 
// then return the signature encoded in Base64 format.
$rsa->put_EncodingMode('base64');
$sigBase64 = $rsa->signStringENC('to be signed','sha256');
if ($rsa->get_LastMethodSuccess() == false) {
    print $rsa->lastErrorText() . "\n";
    exit;
}

print 'RSA Signature:' . "\n";
print $sigBase64 . "\n";

?>