Encrypt using public key, decrypt using private key.
Use this to store stuff in your database: Unless someone
has your private key, the database contents are useless.
Also, use this for sending to a specific individual: Get
their public key, encrypt the message, only they can use
their private key to decode it.
<?php
echo "Source: $source";
$fp=fopen("/path/to/certificate.crt","r");
$pub_key=fread($fp,8192);
fclose($fp);
openssl_get_publickey($pub_key);
openssl_public_encrypt($source,$crypttext,$pub_key);
echo "String crypted: $crypttext";
$fp=fopen("/path/to/private.key","r");
$priv_key=fread($fp,8192);
fclose($fp);
$res = openssl_get_privatekey($priv_key,$passphrase);
openssl_private_decrypt($crypttext,$newsource,$res);
echo "String decrypt : $newsource";
?>