sshd服务启动失败问题

 查看/etc/ssh/ssh_host_ed25519_key权限是755，其他用户也有访问权限，修改该文件权限为600后，重启sshd服务成功

启动后，发现/etc/ssh/ssh_host_rsa_key和/etc/ssh/ssh_host_ecdsa_key文件也是755权限，也需要修改为600权限

# systemctl status sshd.service
* sshd.service - OpenSSH server daemon
   Loaded: loaded (/usr/lib/systemd/system/sshd.service; enabled; vendor preset: enabled)
   Active: active (running) since Tue 2021-06-15 20:51:35 CST; 3min 53s ago
     Docs: man:sshd(8)
           man:sshd_config(5)
 Main PID: 127264 (sshd)
   CGroup: /system.slice/sshd.service
           `-127264 sshd: /usr/sbin/sshd -D [listener] 0 of 10-100 startups

Jun 15 20:53:59 localhost.localdomain sshd[15771]: error: Permissions 0755 for '/etc/ssh/ssh_host_rsa_key' are too open.
Jun 15 20:53:59 localhost.localdomain sshd[15771]: error: It is required that your private key files are NOT accessible by others.
Jun 15 20:53:59 localhost.localdomain sshd[15771]: error: This private key will be ignored.
Jun 15 20:53:59 localhost.localdomain sshd[15771]: error: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Jun 15 20:53:59 localhost.localdomain sshd[15771]: error: @         WARNING: UNPROTECTED PRIVATE KEY FILE!          @
Jun 15 20:53:59 localhost.localdomain sshd[15771]: error: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Jun 15 20:53:59 localhost.localdomain sshd[15771]: error: Permissions 0755 for '/etc/ssh/ssh_host_ecdsa_key' are too open.
Jun 15 20:53:59 localhost.localdomain sshd[15771]: error: It is required that your private key files are NOT accessible by others.
Jun 15 20:53:59 localhost.localdomain sshd[15771]: error: This private key will be ignored.
Jun 15 20:54:01 localhost.localdomain sshd[15771]: Accepted password for root from 10.56.55.44 port 64206 ssh2

参考链接：

https://blog.csdn.net/fly_520/article/details/79991229