Wann sollte ich sshd_config verwenden?
Nutze sie, um eine fehlende Default-Datei wiederherzustellen, zu prüfen, was ausgeliefert wurde, oder sie gegen deine aktuelle OpenSSH-Config zu diffen.
# $OpenBSD: sshd_config,v 1.104 2021/07/02 05:11:21 dtucker Exp $ # This is the sshd server system-wide configuration file. See # sshd_config(5) for more information. # This sshd was compiled with PATH=/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin # The strategy used for options in the default sshd_config shipped with # OpenSSH is to specify options with their default value where # possible, but leave them commented. Uncommented options override the # default value. # To modify the system-wide sshd configuration, create a *.conf file under # /etc/ssh/sshd_config.d/ which will be automatically included below Include /etc/ssh/sshd_config.d/*.conf # If you want to change the port on a SELinux system, you have to tell # SELinux about this change. # semanage port -a -t ssh_port_t -p tcp #PORTNUMBER # #Port 22 #AddressFamily any #ListenAddress 0.0.0.0 #ListenAddress :: #HostKey /etc/ssh/ssh_host_rsa_key #HostKey /etc/ssh/ssh_host_ecdsa_key #HostKey /etc/ssh/ssh_host_ed25519_key # Ciphers and keying #RekeyLimit default none # Logging #SyslogFacility AUTH #LogLevel INFO # Authentication: #LoginGraceTime 2m #PermitRootLogin prohibit-password #StrictModes yes #MaxAuthTries 6 #MaxSessions 10 #PubkeyAuthentication yes # The default is to check both .ssh/authorized_keys and .ssh/authorized_keys2 # but this is overridden so installations will only check .ssh/authorized_keys AuthorizedKeysFile .ssh/authorized_keys #AuthorizedPrincipalsFile none #AuthorizedKeysCommand none #AuthorizedKeysCommandUser nobody # For this to work you will also need host keys in /etc/ssh/ssh_known_hosts #HostbasedAuthentication no # Change to yes if you don't trust ~/.ssh/known_hosts for # HostbasedAuthentication #IgnoreUserKnownHosts no # Don't read the user's ~/.rhosts and ~/.shosts files #IgnoreRhosts yes # To disable tunneled clear text passwords, change to no here! #PasswordAuthentication yes #PermitEmptyPasswords no # Change to no to disable s/key passwords #KbdInteractiveAuthentication yes # Kerberos options #KerberosAuthentication no #KerberosOrLocalPasswd yes #KerberosTicketCleanup yes #KerberosGetAFSToken no #KerberosUseKuserok yes # GSSAPI options #GSSAPIAuthentication no #GSSAPICleanupCredentials yes #GSSAPIStrictAcceptorCheck yes #GSSAPIKeyExchange no #GSSAPIEnablek5users 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 KbdInteractiveAuthentication and # PasswordAuthentication. Depending on your PAM configuration, # PAM authentication via KbdInteractiveAuthentication 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 KbdInteractiveAuthentication to 'no'. # WARNING: 'UsePAM no' is not supported in RHEL and may cause several # problems. #UsePAM no #AllowAgentForwarding yes #AllowTcpForwarding yes #GatewayPorts no #X11Forwarding no #X11DisplayOffset 10 #X11UseLocalhost yes #PermitTTY yes #PrintMotd yes #PrintLastLog yes #TCPKeepAlive yes #PermitUserEnvironment no #Compression delayed #ClientAliveInterval 0 #ClientAliveCountMax 3 #UseDNS no #PidFile /var/run/sshd.pid #MaxStartups 10:30:100 #PermitTunnel no #ChrootDirectory none #VersionAddendum none # no default banner path #Banner none # override default of no subsystems Subsystem sftp /usr/libexec/openssh/sftp-server # Example of overriding settings on a per-user basis #Match User anoncvs # X11Forwarding no # AllowTcpForwarding no # PermitTTY no # ForceCommand cvs server
curl https://exampleconfig.com/api/v1/config/original/277e5f0fbf35f80cfcc17db55bbaa93e?hint=sshd_config
wget -O sshd_config https://exampleconfig.com/api/v1/config/original/277e5f0fbf35f80cfcc17db55bbaa93e?hint=sshd_config
<prompt><role>DevOps agent</role><source url='https://exampleconfig.com/api/v1/config/original/277e5f0fbf35f80cfcc17db55bbaa93e?hint=sshd_config' /><config><app>OpenSSH</app><os>CentOS Stream 9</os><location>/etc/ssh/sshd_config</location><lines>130</lines><md5>277e5f0fbf35f80cfcc17db55bbaa93e</md5><sha256>4ea32326a179469529c2905630c6d61eb3ffa518e09112390de61096b00da0d9</sha256></config></prompt>
Füge es in Claude, ChatGPT oder einen anderen KI-Assistenten ein.
sudo apk add openssh-server
sudo apt update && sudo apt install openssh-server
sudo yum install openssh-server
sudo apt update && sudo apt install openssh-server
Wann sollte ich sshd_config verwenden?
Nutze sie, um eine fehlende Default-Datei wiederherzustellen, zu prüfen, was ausgeliefert wurde, oder sie gegen deine aktuelle OpenSSH-Config zu diffen.
Wie stelle ich die Defaults von OpenSSH wieder her?
Lad die Datei runter, sichere die aktuelle in /etc/ssh/sshd_config, ersetze sie und lade OpenSSH neu oder starte es neu.
Ist sshd_config für den produktiven Einsatz geeignet?
Das ist der Hersteller-Default für CentOS Stream 9. Nimm sie als Basis und prüf Security- und Performance-Einstellungen, bevor du sie produktiv nutzt.
Wie unterscheidet sich das von anderen OS-Versionen?
Defaults variieren je nach Distro und Version. Diese Version passt zu CentOS Stream 9.
Kann ich das fürs Troubleshooting von OpenSSH nutzen?
Ja. Diff es gegen deine Version, finde Abweichungen und stell nur die Teile wieder her, die du brauchst.