OCI: SSH Password login fails on OL9 “Connection closed by authenticating user port [preauth]“

APPLIES TO

Oracle Cloud Infrastructure
Linux x86-64 

Symptom 

On OL9 instance, enabled password authentication for SSHD service but still the SSH connections doesnot perform password authentication and fails with key authentication permission denied. 

 $ ssh -vvv testuser@<x.x.x.x> 
debug2: we did not send a packet, disable method 
debug1: No more authentication methods to try. 
testuser@x.x.x.x: Permission denied (publickey,gssapi-keyex,gssapi-with-mic). 

 

$ grep -i Passwordauthentication /etc/ssh/sshd_config 
PasswordAuthentication yes 

Cause 

 OL9 SSHD includes a system wide configuration that restrict the password authentication in OCI Linux images. 

 <<snip>> 

/etc/ssh/sshd_config 

 

# To modify the system-wide sshd configuration, create a  *.conf  file under