I created two ssh keys for my two server.
One is Ubuntu 18.04.3 and the other is CentOS 7.7.1908.
I use putty to connect. Connection to Ubuntu was successful, but CentOS refused our key.
Centos authorized_keys had the same mode as ubuntu authorized_keys
-rw-rw-r-- 1 danny danny 398 1月 8 09:52 authorized_keys
I found that CentOS needed the permissions set to 644 or 600, because in sshd_config, StrictModes default value is yes.
chmod 644 ~/.ssh/authorized_keys
but Ubuntu server didn't refused our key.
My question is two OS check file modes and ownership are different?
======= CentOS /var/log/secure==================
Jan 9 18:33:12 localhost sshd[57020]: Authentication refused: bad ownership or modes for file /home/danny/.ssh/authorized_keys
======add ls -ld / /home /home/danny /home/danny/.ssh======
Ubuntu:
danny@danny-ubuntu:~/.ssh$ ls -ld / /home /home/danny /home/danny/.ssh
drwxr-xr-x 24 root root 4096 1月 5 21:59 /
drwxr-xr-x 4 root root 4096 1月 9 13:33 /home
drwxr-xr-x 22 danny danny 4096 1月 9 13:14 /home/danny
drwx------ 2 danny danny 4096 1月 9 17:23 /home/danny/.ssh
CentOS:
[danny@localhost .ssh]$ ls -ld / /home /home/danny /home/danny/.ssh
dr-xr-xr-x. 17 root root 224 7月 29 2018 /
drwxr-xr-x. 3 root root 19 7月 29 2018 /home
drwx------. 10 danny danny 240 1月 9 13:12 /home/danny
drwx------. 2 danny danny 150 1月 9 17:23 /home/danny/.ssh
-rw-rw-r--are acceptable because you are the only member of the group that has read/write access. You need to look at the permissions for the directories above. Please add the result of this to your question -ls -ld / /home /home/danny /home/danny/.ssh/var/log/auth.logforssh-related failures -grep sshd /var/log/auth.log. You'll probably see the cause of the error documented (for example,Jan 9 12:33:34 centos sshd[29954]: Authentication refused: bad ownership or modes for directory /home/danny).Authentication refused: bad ownership or modes for directory /home/danny