It took me a while to find out the correct way how to sign and encrypt data with these functions.
I needed that to communicate with German Health Insurance Providers as part of a DiGA. Maybe someone finds that useful.
<?php
function signAndEncrypt(string $rawData): string
{
$tempDir = __DIR__ . '/tmp';
$tempfileOriginal = tempnam($tempDir, 'original');
$tempfileSigned = tempnam($tempDir, 'signed');
$tempfileEncrypted = tempnam($tempDir, 'signedEncrypted');
file_put_contents($tempfileOriginal, $rawData);
$recipientsCertificateFile = __DIR__ . '/recipientsCertificate.pem';
$recipientsCertificate = file_get_contents($recipientsCertificateFile);
$myCertificate = file_get_contents(__DIR__ . '/my.crt');
$myPrivateKey = openssl_pkey_get_private(
file_get_contents(__DIR__ . '/my.prv.key.pem')
);
openssl_cms_sign(
input_filename: $tempfileOriginal,
output_filename: $tempfileSigned,
certificate: $myCertificate,
private_key: $myPrivateKey,
headers: [],
encoding: OPENSSL_ENCODING_DER,
);
openssl_cms_encrypt(
input_filename: $tempfileSigned,
output_filename: $tempfileEncrypted,
certificate: $recipientsCertificate,
headers: [],
flags: OPENSSL_CMS_BINARY | OPENSSL_CMS_NOSIGS | OPENSSL_CMS_NOVERIFY,
encoding: OPENSSL_ENCODING_DER,
cipher_algo: OPENSSL_CIPHER_AES_256_CBC
);
return file_get_contents($tempfileEncrypted);
}
