Debian 10 Buster 中的 SSH 伺服器錯誤

無法sshd在 Debian 10 “Buster” 中連接，連接時出現如下錯誤：

$ ssh -p 2222 user@192.168.12.73
ssh_exchange_identification: read: Connection reset by peer

檢查這些服務，得到以下錯誤：

● sshd.service - OpenBSD Secure Shell server
  Loaded: loaded (/etc/systemd/system/sshd.service; enabled; vendor preset: enabled)
  Active: active (running) since Tue 2019-10-22 18:10:51 -03; 13min ago
 Process: 559 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=0/SUCCESS)
Main PID: 606 (sshd)
   Tasks: 1 (limit: 2304)
  Memory: 2.3M
  CGroup: /system.slice/sshd.service
          └─606 /usr/sbin/sshd -D

Oct 22 18:10:50 ffurtpc systemd[1]: Starting OpenBSD Secure Shell server...
Oct 22 18:10:51 ffurtpc sshd[606]: Server listening on 0.0.0.0 port 22.
Oct 22 18:10:51 ffurtpc sshd[606]: error: Bind to port 22 on :: failed: Address already in use.
Oct 22 18:10:51 ffurtpc systemd[1]: Started OpenBSD Secure Shell server.
Oct 22 18:14:26 ffurtpc sshd[1514]: Connection closed by authenticating user friedrich 192.168.12.73 port 49880 [preauth]
Oct 22 18:23:45 ffurtpc sshd[1583]: fatal: Missing privilege separation directory: /run/sshd

已經嘗試用xinetd包管理，設置為2222埠，而OpenBSD Secure Shell伺服器一直監聽22埠，如下：

● xinetd.service - LSB: Starts or stops the xinetd daemon.
  Loaded: loaded (/etc/init.d/xinetd; generated)
  Active: active (running) since Tue 2019-10-22 18:10:55 -03; 15min ago
    Docs: man:systemd-sysv-generator(8)
 Process: 722 ExecStart=/etc/init.d/xinetd start (code=exited, status=0/SUCCESS)
   Tasks: 1 (limit: 2304)
  Memory: 4.5M
  CGroup: /system.slice/xinetd.service
          └─755 /usr/sbin/xinetd -pidfile /run/xinetd.pid -stayalive -inetd_compat -inetd_ipv6

Oct 22 18:10:56 ffurtpc xinetd[755]: Reading included configuration file: /etc/xinetd.d/echo-udp [file=/etc/xinetd.d/echo-udp] [line=26]
Oct 22 18:10:56 ffurtpc xinetd[755]: Reading included configuration file: /etc/xinetd.d/servers [file=/etc/xinetd.d/servers] [line=14]
Oct 22 18:10:56 ffurtpc xinetd[755]: Reading included configuration file: /etc/xinetd.d/services [file=/etc/xinetd.d/services] [line=13]
Oct 22 18:10:56 ffurtpc xinetd[755]: Reading included configuration file: /etc/xinetd.d/sshd [file=/etc/xinetd.d/sshd] [line=13]
Oct 22 18:10:56 ffurtpc xinetd[755]: Reading included configuration file: /etc/xinetd.d/time [file=/etc/xinetd.d/time] [line=16]
Oct 22 18:10:56 ffurtpc xinetd[755]: Reading included configuration file: /etc/xinetd.d/time-udp [file=/etc/xinetd.d/time-udp] [line=28]
Oct 22 18:10:56 ffurtpc xinetd[755]: 2.3.15.3 started with libwrap loadavg labeled-networking options compiled in.
Oct 22 18:10:56 ffurtpc xinetd[755]: Started working: 1 available service
Oct 22 18:14:22 ffurtpc sshd[1512]: Connection closed by authenticating user friedrich 192.168.12.73 port 35954 [preauth]
Oct 22 18:23:43 ffurtpc sshd[1582]: fatal: Missing privilege separation directory: /run/sshd

有任何想法嗎？

這裡有類似的錯誤，看起來sshd是啟動時創建/run/sshd目錄失敗，所以在這里通過腳本進行管理，如下：

sshddir在以下內容中創建一個腳本/etc/init.d/：

#!/bin/sh

### BEGIN INIT INFO
# Provides:          sshddir
# Required-Start:    $all
# Required-Stop:     $network
# Should-Start:      $network
# Default-Start:     3 4 5
# Default-Stop:      0 1 2 6
# Short-Description: Sshd /run/sshd Directory
# Description:       Intended to create /run/sshd directory for Sshd.
### END INIT INFO

mkdir -p /run/sshd

chmod -R 755 /run/sshd

$ sudo chmod 755 /etc/init.d/sshddir

$ sudo update-rc.d sshddir defaults

這樣，可能會重新啟動並訪問它。

引用自：https://unix.stackexchange.com/questions/548209