Redhat Linux password fail on ssh

I am trying to ssh into my linux machine from my mac. If I am physically at the machine I can log in with my password just fine, but if I am sshing it refuses. I am getting: Permission denies (publickey,keyboard-interactive) I have previously been able to ssh in (last time was probably about a month ago) but all of a sudden I can’t access it any more. I thought that it might be caused by some changes that I recently made to system-auth, but I restored everything to what I believe was the original format:

#%PAM-1.0# This file is auto-generated.# User changes will be destroyed the next time authconfig is run.auth        required      pam_env.soauth        sufficient    pam_fprintd.soauth        sufficient    pam_unix.so nullok try_first_passauth        requisite     pam_succeed_if.so uid >= 500 quietauth        required      pam_deny.soaccount     required      pam_unix.soaccount     sufficient    pam_localuser.soaccount     sufficient    pam_succeed_if.so uid < 500 quietaccount     required      pam_permit.sopassword    requisite     pam_cracklib.so try_first_pass retry=3password    sufficient    pam_unix.so md5 shadow nullok try_first_pass use_authtokpassword    required      pam_deny.sosession     optional      pam_keyinit.so revokesession     required      pam_limits.sosession     [success=1 default=ignore] pam_succeed_if.so service in crond quiet use_uidsession     required      pam_unix.so

But I still could not ssh in. I tried removing my password all together and that didn’t seem to help either. It still asks and even entering an empty string (nothing) it still fails me out.

I checked the  sshd_config, at the suggestion of an answer below, and that does not seem to be the issue.

PermitEmptyPasswords yesPasswordAuthentication yesUsePAM yesChallengeResponseAuthentication noRSAAuthentication yesPubkeyAuthentication yesAuthorizedKeysFile      /home/%u/.ssh/authorized_keys

I haven’t actually looked into this file, before it was suggested, so I imagine most of it is probably still system defaults.

And I am still shut out through ssh.

Any advice?

Solution:

If you’re running Red Hat with Security Enchanced Linux enabled (SELinux), then you might be having a problem because SELinux is preventing sshd from reading $HOME/.ssh.  To make SELinux happy, you have to do

root@sshd-server# restorecon -Rv ~/.ssh

To see if you’re running with SELinux enabled use sestatus.  Here’s what it looks like if SELinux is enabled.

root@sshd-server# sestatusSELinux status:                 enabledSELinuxfs mount:                /selinuxCurrent mode:                   enforcingMode from config file:          enforcingPolicy version:                 24Policy from config file:        targeted

Note that you may also have to change the security context of the .ssh file.  Use the -Z switch to the ls command like:

ls -laZ ~/.ssh

Which may report a security context like system_u:object_r:default_t:s0.Then use the chcon command like:

chcon -R -v system_u:object_r:usr_t:s0 ~/.ssh/

Thanks to Massimo Ronca’s post titled “Fixing SELinux and passwordless SSH authentication”[1] for the chcon tip.

1- https://massimoronca.it/2017/03/14/fixing-selinux-and-passwordless-ssh-authentication.html