ubuntu18 sshd_config文件

sshd_config文件是OpenSSH服务器的配置文件，位于/etc/ssh/目录下。下面是一个Ubuntu 18的sshd_config文件的示例：

# Package generated configuration file
# See /usr/share/doc/openssh-server/README.Debian for more information

# Authentication:
LoginGraceTime 120
PermitRootLogin without-password
StrictModes yes

# Change to yes to enable challenge-response passwords (beware issues with
# some PAM modules and threads)
ChallengeResponseAuthentication no

# Uncomment to enable PubkeyAuthentication
PubkeyAuthentication yes

# Don't read the user's ~/.rhosts and ~/.shosts files
IgnoreRhosts yes

# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
RhostsRSAAuthentication no

# Uncomment if you don't trust ~/.ssh/known_hosts for RhostsRSAAuthentication
#IgnoreUserKnownHosts yes

# To enable empty passwords, change to yes (NOT RECOMMENDED)
PermitEmptyPasswords no

# Change to yes to enable default ubuntu shell behavior
# (This is not necessary for SSH protocol version 2, but it may be useful
# in some situations to enable Protocol 1)
#PermitTunnel no

# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
# be allowed through the ChallengeResponseAuthentication and
# PasswordAuthentication.  Depending on your PAM configuration,
# PAM authentication via ChallengeResponseAuthentication may bypass
# the setting of "PermitRootLogin without-password".
# If you just want the PAM account and session checks to run without
# PAM authentication, then enable this but set PasswordAuthentication
# and ChallengeResponseAuthentication to 'no'.
UsePAM yes

# Accept locale-related environment variables
AcceptEnv LANG LC_*

#Subsystem sftp /usr/lib/openssh/sftp-server
Subsystem sftp internal-sftp

Match Group sftpusers
     ChrootDirectory /home/%u
     ForceCommand internal-sftp
     AllowTcpForwarding no
     X11Forwarding no

请注意，这只是一个示例，实际上可能根据您的系统和需求有所不同。在修改此文件之前，请确保您了解每个选项的含义，并且备份原始文件以防止意外更改。