(PHP Extension) RSAES-OAEP Encrypt String with AES-128 Content Encryption and SHA256

Encrypts a string using RSAES-OAEP with SHA256 and AES-128 content encryption to produce PKCS7 output (base64 encoded).

Note: This example requires Chilkat v9.5.0.67 or greater.

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 requires the Chilkat Crypt API to have been previously unlocked.
// See Unlock Chilkat Crypt for sample code.

// First build a string to be encrypted
$sb = new CkStringBuilder();
$i = 1;
while ($i < 25) {
    $sb->AppendInt($i);
    $sb->Append(' the quick brown fox jumped over the lazy dog.\r\n');
    $i = $i + 1;
}

print $sb->getAsString() . "\n";

// The string to be encrypted looks like this:

// 1 the quick brown fox jumped over the lazy dog.
// 2 the quick brown fox jumped over the lazy dog.
// 3 the quick brown fox jumped over the lazy dog.
// 4 the quick brown fox jumped over the lazy dog.
// 5 the quick brown fox jumped over the lazy dog.
// 6 the quick brown fox jumped over the lazy dog.
// ...

// Load a digital certificate. 
// We don't need the private key for encryption.
// Only the public key is needed (which is included in a certificate).
$cert = new CkCert();
$success = $cert->LoadFromFile('qa_data/rsaes-oaep/cert.pem');
if ($success != true) {
    print $cert->lastErrorText() . "\n";
    exit;
}

$crypt = new CkCrypt2();

// Tell the crypt object to use the certificate.
$crypt->SetEncryptCert($cert);

// Indicate that we want PKI encryption (i.e. public-key infrastructure)
// to produce a CMS message (Cryptographic Message Syntax/PKCS7),
// that is be created with RSAES-OAEP padding, SHA256, and AES-128 for the
// bulk encryption.
$crypt->put_CryptAlgorithm('pki');
$crypt->put_Pkcs7CryptAlg('aes');
$crypt->put_KeyLength(128);
$crypt->put_OaepHash('sha256');
$crypt->put_OaepPadding(true);

// Also, don't forget to be specific about the character encoding (byte representation) of the
// string to be encrypted.
$crypt->put_Charset('utf-8');

// Now indicate that the PKCS7 output is to be returned in the base64 encoding.
$crypt->put_EncodingMode('base64');

$base64Pkcs7 = $crypt->encryptStringENC($sb->getAsString());
if ($crypt->get_LastMethodSuccess() != true) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

// Show the output
print $base64Pkcs7 . "\n";

// This base64 can be copy-and-pasted into the form at http://lapo.it/asn1js/
// to verify that all the chosen algorithms were indeed used.

print 'OK.' . "\n";

?>