(PHP Extension) Generate RSA Key and Export to PKCS1 / PKCS8

PHP Extension example code showing how to generate an RSA public/private key and save to PKCS1 and PKCS8 format files. In a PKCS1 or PKCS8 formatted file, the key is stored in binary ASN.1 format (and ASN.1 is itself written according to DER -- Distinguished Encoding Rules). A PEM file simply contains the binary ASN.1 base64 encoded and delimited by BEGIN/END lines. PKCS1 format files are never encrypted. PKCS8 can be encrypted or unencrypted. Public keys are never encrypted (there is no need). Private keys *should* always be encrypted - unless perhaps the unencrypted private key is obtained and itself stored in some sort of secure place.

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

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

$rsa = new CkRsa();

// Generate a 2048-bit key.  Chilkat RSA supports
// key sizes ranging from 512 bits to 8192 bits.
$success = $rsa->GenerateKey(2048);
if ($success != true) {
    print $rsa->lastErrorText() . "\n";
    exit;
}

// Get the public and private key parts:
// pubKey is a CkPublicKey
$pubKey = $rsa->ExportPublicKeyObj();
// privKey is a CkPrivateKey
$privKey = $rsa->ExportPrivateKeyObj();

// Get the public key as a PKCS8 PEM string
$pubKeyPem = $pubKey->getPem(false);
print $pubKeyPem . "\n";

// Get the public key in PKCS8 format, in a Base64 encoded string.
$pubKeyPkcs8Base64 = $pubKey->getEncoded(false,'base64');
print $pubKeyPkcs8Base64 . "\n";

// Get the public key in PKCS1 format, in a Base64 encoded string.
$pubKeyPkcs1Base64 = $pubKey->getEncoded(true,'base64');
print $pubKeyPkcs1Base64 . "\n";

// Get the private key in a PKCS8 PEM string.
$privKeyPem = $privKey->getPkcs8Pem();
print $privKeyPem . "\n";

// Get the private key in a PKCS8 encrypted PEM string.
$privKeyEncPem = $privKey->getPkcs8EncryptedPem('myPassword');
print $privKeyEncPem . "\n";

// Get the private key in PKCS1 Base64 format
$privKeyPkcs1Base64 = $privKey->getPkcs1ENC('base64');
print $privKeyPkcs1Base64 . "\n";

// Get the private key in PKCS8 Base64 format
$privKeyPkcs8Base64 = $privKey->getPkcs8ENC('base64');
print $privKeyPkcs8Base64 . "\n";

// Save to PKCS1 / PKCS8 / PEM files...

// Save the public key to PKCS8 binary DER
$success = $pubKey->SaveDerFile(false,'pubKey_pkcs8.der');

// Save the public key to PKCS1 binary DER
$success = $pubKey->SaveDerFile('pubKey_pkcs1.der');

// Save the private key to unencrypted binary PKCS1 DER.
// Note: PKCS1 is never found in an encrypted format. 
$success = $privKey->SavePkcs1File('privKey_pkcs1.der');

// Save the private key to unencrypted binary PKCS8
$success = $privKey->SavePkcs8File('privKey_pkcs8.der');

// Save the private key to encrypted binary PKCS8
$success = $privKey->SavePkcs8EncryptedFile('myPassword','privKey_enc_pkcs8.der');

// Save the private key to unencrypted PKCS8 PEM
$success = $privKey->SavePkcs8PemFile('privKey.pem');

// Save the private key to encrypted PKCS8 PEM
$success = $privKey->SavePkcs8EncryptedPemFile('myPassword','privKey_enc.pem');


?>