Client does not support authentication protocol
Luego de agregar un nuevo usuario MySQL he tenido el siguiente problema al intentar conectarme a la DB usando PHP4:
Client does not support authentication protocol requested by server;
consider upgrading MySQL client
Buscando llego a: http://dev.mysql.com/doc/refman/5.0/en/password-hashing.html
El problema
The password hashing mechanism was updated in MySQL 4.1 to provide better security and to reduce the risk of passwords being intercepted. However, this new mechanism is understood only by MySQL 4.1 (and newer) servers and clients, which can result in some compatibility problems.
Hace un tiempo pasé de la versión 4 a la 4.1. Resulta que ahora el hash correspondiente a las passwords se realiza utilizando un nuevo algoritmo que genera un hash de 41 bytes frente al viejo de 16 bytes.
Antes de la versión 4.1 la función
devolvía un hash de 16 bytes:
mysql> SELECT PASSWORD('mypass');
+--------------------+
| PASSWORD('mypass') |
+--------------------+
| 6f8c114b58f2ce9e |
+--------------------+
A partir de la versión 4.1 la función
devuelve un hash de 41 bytes:
mysql> SELECT PASSWORD('mypass');
+-------------------------------------------+
| PASSWORD('mypass') |
+-------------------------------------------+
| *6C8989366EAF75BB670AD8EA7A7FC1176A95CEF4 |
+-------------------------------------------+
Solución
Según: Common Problems with MySQL and PHP.
Error: Client does not support authentication protocol: This is most often encountered when trying to use the older mysql extension with MySQL 4.1.1 and later. Possible solutions are: downgrade to MySQL 4.0; switch to PHP 5 and the newer mysqli extension; or configure the MySQL server with –old-passwords. (See Section A.2.3, “Client does not support authentication protocol”, for more information.)
Otra solución
La función
devuelve el viejo hash de 16 bytes:
mysql> SET PASSWORD FOR 'some_user'@'some_host' = OLD_PASSWORD('newpwd');
