mySQL connection string through SSH tunnel without password

问题

I've been given SSH access to a server running mySQL. My access is authenticated through my public key, with no further password required.

Using Putty, I am able to SSH to the server using my private key, log directly into the mySQL database via the command-line tools and run SQL directly. I'm looking to emulate this through a C# service (forwarding port 3306 through the SSH connection), unfortunately all the connection strings listed at http://www.connectionstrings.com/mysql/ require a password.

My rough-and-ready code so far, using MySql.Data and SSH.NET:

  PrivateKeyFile file = new PrivateKeyFile(@" [ path to private key ]");
  using (var client = new SshClient(" [ server ] ", "ubuntu", file))
  {

      var port = new ForwardedPortLocal(3306, "localhost", 3306);
      client.AddForwardedPort (port);
      client.Connect();

      var connection = new MySqlConnection(
           "server=localhost;database=[database];uid=ubuntu;"
      );
      MySqlCommand command = connection.CreateCommand();
      MySqlDataReader Reader;
      command.CommandText = "select * from sample";
      connection.Open();
      Reader = command.ExecuteReader();
      while (Reader.Read())
      {
          string thisrow = "";
          for (int i = 0; i < Reader.FieldCount; i++)
              thisrow += Reader.GetValue(i).ToString() + ",";
          Console.Write(thisrow);
      }
      connection.Close();
      client.Disconnect();
 }

Running the code without the SshClient section, talking to a database on the local network (with a known username and password), is working perfectly. With the SshClient section in, and with a breakpoint once the tunnel has been set up, I can telnet to localhost:3306 and get a response back from mySQL.

However, the following error is thrown on the connection.Open() line:

Authentication to host 'localhost' for user 'ubuntu' using method 'mysql_native_password' failed with message: Access denied for user 'ubuntu'@'localhost' (using password: YES)

So ... what connection string do I need? Or have I missed something subtle elsewhere?

回答1:

MySQL is able to deny logins if they are connecting from the wrong host. Maybe you did not allow ubuntu to connect from localhost?

https://dev.mysql.com/doc/refman/5.1/en/connection-access.html

回答2:

The problem turned out to be related to the SSH tunnel itself; creating the tunnel using Putty instead and removing all the code that runs before the line:

  var connection = new MySqlConnection(
       "server=localhost;database=[database];uid=ubuntu;"
  );

now succeeds.

Two lessons learnt:

It is allowable to omit the password if mySQL does not require one.
mySQL's error messages could do with being more explicit.

来源：https://stackoverflow.com/questions/18498955/mysql-connection-string-through-ssh-tunnel-without-password

标签

mysql

ssh

connection-string