private function direct_sodium($pri, $pub, $atpay_pub, $nonce, $message)
{
$secret = new \sodium\secret_key();
$secret->load(base64_decode($pub), base64_decode($pri), false);
$atpay = new \sodium\public_key();
$atpay->load(base64_decode($atpay_pub), false);
$boxer = new \sodium\crypto();
return $boxer->box($message, $nonce, $atpay, $secret);
}
try {
$c = new \sodium\crypto();
// Create a secret key
$alice_secret = $c->keypair();
// Create public key
$alice_public = new \sodium\public_key();
// Load binary key from alice_secret (pbin), false: expect binary, not key in hex
$alice_public->load($alice_secret->pbin, false);
// Alice's friend Bob
$bob_secret = $c->keypair();
// Create public key from bob_secret (pbin)
$bob_public = new \sodium\public_key();
$bob_public->load($bob_secret->pbin, false);
// Alice's message to Bob
$message = "Now Jesus did many other signs in the presence of the disciples,";
$message .= "which are not written in this book; but these are written so that";
$message .= "you may believe that Jesus is the Christ, the Son of God, and that";
$message .= "by believing you may have life in his name. (ESV, John 20:30:31)";
// Create a nonce
$nonce = new \sodium\nonce();
// Every call to $nonce->next() generates a new nonce! Important for crypto_box
// Use Bob's public key to send to Bob
$encrypted_text = $c->box($message, $nonce->next(), $bob_public, $alice_secret);
// Bob receives the $encrypted_text and 24 bytes nonce->nbin from Alice via the network
$nonce_from_alice = $nonce->nbin;
$bob_nonce = new \sodium\nonce();
$message_decrypted = $c->box_open($encrypted_text, $bob_nonce->set_nonce($nonce_from_alice, true), $alice_public, $bob_secret);
echo "Messages encrypted/decrypted\n";
} catch (\sodium\crypto_exception $e) {
syslog(LOG_ERR, sprintf("Error: %s:%s : (%s) %s\n%s\n", $e->getFile(), $e->getLine(), $e->getCode(), $e->getMessage(), $e->getTraceAsString()));
}