/**
* Derive an encryption key from a password and a salt
*
* @param string $password
* @param string $salt
* @param int $type
* @return array|\ParagonIE\Halite\Key
* @throws CryptoException\InvalidFlags
*/
public static function deriveFromPassword($password, $salt, $type = self::CRYPTO_SIGN)
{
if (Key::doesNotHaveFlag($type, Key::ASYMMETRIC)) {
throw new CryptoException\InvalidKey('An asymmetric key type must be passed to KeyPair::generate()');
}
if (Key::hasFlag($type, Key::SIGNATURE)) {
$key = SignatureSecretKey::deriveFromPassword($password, $salt, Key::CRYPTO_SIGN);
$keypair = new SignatureKeyPair($key[0]);
return $keypair;
}
throw new CryptoException\InvalidKey('You must specify encryption or authentication flags.');
}
