authentication has been revamp.

Current implementation was requiring authentication plugin that are have multiple step to begin with iAuthMoreData, but that's only required for "caching_sha2_password" and "sha256_password" plugins.
Additionally, now permits multi-authentication (in mariadb: https://mariadb.com/kb/en/create-user/#identified-viawith-authentication_plugin / mysql: https://dev.mysql.com/doc/refman/8.0/en/multifactor-authentication.html)

goal is to add MariaDB main authentication plugins (like parsec, PAM, GSSAPI, ...)

Author: rusher

AUTHORS

@@ -37,6 +37,7 @@ Daniel Montoya <dsmontoyam at gmail.com>
 Daniel Nichter <nil at codenode.com>
 Daniël van Eeden <git at myname.nl>
 Dave Protasowski <dprotaso at gmail.com>
+Diego Dupin <diego.dupin at gmail.com>
 Dirkjan Bussink <d.bussink at gmail.com>
 DisposaBoy <disposaboy at dby.me>
 Egor Smolyakov <egorsmkv at gmail.com>

README.md

@@ -534,6 +534,17 @@ See [context support in the database/sql package](https://golang.org/doc/go1.8#d
 > The `QueryContext`, `ExecContext`, etc. variants provided by `database/sql` will cause the connection to be closed if the provided context is cancelled or timed out before the result is received by the driver.
 
 
+### Authentication Plugin System
+
+The driver implements a pluggable authentication system that supports various authentication methods used by MySQL and MariaDB servers. The built-in authentication plugins include:
+
+- `mysql_native_password` - The default MySQL authentication method
+- `caching_sha2_password` - Default authentication method in MySQL 8.0+
+- `mysql_clear_password` - Cleartext authentication (requires `allowCleartextPasswords=true`)
+- `mysql_old_password` - Old MySQL authentication (requires `allowOldPasswords=true`)
+- `sha256_password` - SHA256 authentication
+- `client_ed25519` - MariaDB Ed25519 authentication
+
 ### `LOAD DATA LOCAL INFILE` support
 For this feature you need direct access to the package. Therefore you must change the import path (no `_`):
 ```go