Problem with connecting to my PBX using SSH – ‘Authentication failed’ message although the password is correct?

Usually this issue appears if the sshd (SSH servers at Asterisk box) is not configured to support password authentication. Some SSH servers by default does not support password authentication. Please make sure that your SSH server supports it.

In other words, check that your sshd_config file contains the following line:
PasswordAuthentication yes

If you find it *exactly* like it is written above, without ‘#’ or any other characters – you are fine. If not, do the following:
vi /etc/ssh/sshd_config

and then change the following line from:
# PasswordAuthentication no

to

PasswordAuthentication yes

And last but not least, restart the sshd:
service sshd restart

It should work now.

In case this does not resolve the issue, you may try to setup SFTP on the Asterisk server in addition to the steps above. It helped some users.