OpenSSL¶
The OpenSSL Project develops and maintains the OpenSSL software - a robust, commercial-grade, full-featured toolkit for general-purpose cryptography and secure communication.
The library is integrated into PHP as an extension. It provides a lot of functions and features to the language.
<?php
// Example from php.net documentation
// $data is assumed to contain the data to be signed
// fetch private key from file and ready it
$pkeyid = openssl_pkey_get_private("file://src/openssl-0.9.6/demos/sign/key.pem");
// compute signature
openssl_sign($data, $signature, $pkeyid);
// free the key from memory
openssl_free_key($pkeyid);
?>
See also Encryption using PHP and OpenSSL
Related : Cryptography, libsodium