SSH password transmission

[Kadir]

I need to do teams on the remote server. To this end, a team is calling:

 ssh root@ip 'echo 123'

It'd be all right, but I have to pass the password to the same team. It's necessary to use this team in Qt because of qt, I can't catch the password request and introduce it.

system("ssh root@" TARGET_IP " 'echo 123'");

Where to dig?

---

The key's on the server, but the Qt team. system("ssh root@" TARGET_IP " 'echo 123'"); Makes such mistakes:

ssh_askpass: exec(/usr/libexec/ssh-askpass): No such file or directory
ssh_askpass: exec(/usr/libexec/ssh-askpass): No such file or directory
ssh_askpass: exec(/usr/libexec/ssh-askpass): No such file or directory
ssh_askpass: exec(/usr/libexec/ssh-askpass): No such file or directory
Received disconnect from 192.168.5.161: 2: Too many authentication failures
Disconnected from 192.168.5.161

---

To the team. root@ip 'echo 123' He asks the password anyway. The key lies in the derictor. /root/.ssh♪

[yajahira]

On the server, any editor, vim /etc/ssh/sshd_config

  RSAAuthentication yes
  PasswordAuthentication no /указать NO
   HostKey /root/.ssh/rsa_key.pub  /указать путь к ключу