I have the pam_authentication plugin installed on a MySQL 5.5.19 server. I log in without issue from the command line and also from MySQL Workbench. When trying to log in with Toad for MySQL 18.104.22.1683 I get the following error.
MySQL Database Error: Client does not support authentication protocol requested by server; consider upgrading MySQL client
I also tried connecting with an SSH connection and using the MySQL libraries. In that case I get the following error.
Devart.Data.MySql.ClientLibraryLoadException Unable to load libmysql.dll. Stack Trace: at Devart.Data.MySql.am.b.a() at Devart.Data.MySql.l.d() at Devart.Data.MySql.bp..ctor() at Devart.Data.MySql.l..ctor() at Devart.Data.MySql.MySqlInternalConnection.Connect(MySqlConnection owner, String userId, String password, String host, String database, Int32 port, Int32 connectionTimeout, MySqlProtocol protocol, Boolean compress, Boolean clientInteractive) at Devart.Data.MySql.MySqlInternalConnection..ctor(o connectionOptions, MySqlConnection owner) at Devart.Data.MySql.ar.a(u A_0, Object A_1, DbConnectionBase A_2) at Devart.Common.DbConnectionFactory.a(DbConnectionBase A_0, u A_1) at Devart.Common.DbConnectionFactory.a(DbConnectionBase A_0) at Devart.Common.DbConnectionClosed.Open(DbConnectionBase outerConnection) at Devart.Common.DbConnectionBase.Open() at Devart.Data.MySql.MySqlConnection.Open() at Quest.Toad.Db.Connection.OpenConnection(IDbConnection connection) at Quest.Toad.MySQL.MySQLConnection.OpenConnection(IDbConnection connection) at Quest.Toad.Db.Connection.AllocConnection() at Quest.Toad.Db.Connection.Connect(Boolean notify) at Quest.Toad.Db.Provider.BackgroundConnector.CreateBackgroundConnection()
System.BadImageFormatException An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B) Stack Trace: at Devart.Data.MySql.am.b.mysql_get_client_info() at Devart.Data.MySql.am.b.a()
I solved this problem by downloading the 32bit version of MySQL 5.5.19 for Windows and copying the libMySQL.dll to the Toad installation directory. I then added this path to my user PATH environment variable. In my case it was located at C:\Program Files (x86)\Quest Software\Toad for MySQL Freeware 6.0.
As with the previous post I still needed to use an SSH connection and check Use MySQL libraries.