vim /usr/lib/systemd/system/sshd.service [Unit] Description=OpenSSH server daemon Documentation=man:sshd(8) man:sshd_config(5) After=network.target sshd-keygen.service Wants=sshd-keygen.service [Service] Type=notify EnvironmentFile=/etc/sysconfig/sshd ExecStart=/usr/sbin/sshd -d -D $OPTIONS // 添加-d ExecReload=/bin/kill -HUP $MAINPID KillMode=process Restart=on-failure RestartSec=42s [Install] WantedBy=multi-user.target
然后重启服务
systemctl daemon-reload systemctl restart sshd
查看系统日志
journalctl -xe -u sshd -f 在另开一个终端,使用ssh登录不同用户就会看到debug信息 -- Subject: Unit sshd.service has finished start-up -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit sshd.service has finished starting up. -- -- The start-up result is done. Jul 02 15:26:52 prophet268 sshd[27633]: debug1: private host key #1: ecdsa-sha2-nistp256 SHA256:cNmWmzJVrXuESZXn75p+5vaYwcRdTgn3A+EorcM+k2Y Jul 02 15:26:52 prophet268 sshd[27633]: debug1: private host key #2: ssh-ed25519 SHA256:hH55TxiE+wxkXJGnbipDvFdyHZSAkV5XZxM22L3pIkc Jul 02 15:26:52 prophet268 sshd[27633]: debug1: rexec_argv[0]='/usr/sbin/sshd' Jul 02 15:26:52 prophet268 sshd[27633]: debug1: rexec_argv[1]='-d' Jul 02 15:26:52 prophet268 sshd[27633]: debug1: rexec_argv[2]='-D' Jul 02 15:26:52 prophet268 sshd[27633]: debug1: Set /proc/self/oom_score_adj from 0 to -1000 Jul 02 15:26:52 prophet268 sshd[27633]: debug1: Bind to port 22 on 0.0.0.0. Jul 02 15:26:52 prophet268 sshd[27633]: Server listening on 0.0.0.0 port 22. Jul 02 15:26:52 prophet268 sshd[27633]: debug1: Bind to port 22 on ::. Jul 02 15:26:52 prophet268 sshd[27633]: Server listening on :: port 22. Jul 02 15:28:58 prophet268 sshd[27633]: debug1: Server will not fork when running in debugging mode. Jul 02 15:28:58 prophet268 sshd[27633]: debug1: rexec start in 5 out 5 newsock 5 pipe -1 sock 8 Jul 02 15:28:58 prophet268 sshd[27633]: rexec line 42: Deprecated option RSAAuthentication Jul 02 15:28:58 prophet268 sshd[27633]: debug1: sshd version OpenSSH_7.4, OpenSSL 1.0.2k-fips 26 Jan 2017 Jul 02 15:28:58 prophet268 sshd[27633]: debug1: inetd sockets after dupping: 3, 3 Jul 02 15:28:58 prophet268 sshd[27633]: Connection from ::1 port 45036 on ::1 port 22 Jul 02 15:28:58 prophet268 sshd[27633]: debug1: private host key #0: ssh-rsa SHA256:R8GeBmf5SzJ22r7wpGyUuXhYQnhxPyVNZHQShdjAldI Jul 02 15:28:58 prophet268 sshd[27633]: debug1: private host key #1: ecdsa-sha2-nistp256 SHA256:cNmWmzJVrXuESZXn75p+5vaYwcRdTgn3A+EorcM+k2Y Jul 02 15:28:58 prophet268 sshd[27633]: debug1: private host key #2: ssh-ed25519 SHA256:hH55TxiE+wxkXJGnbipDvFdyHZSAkV5XZxM22L3pIkc Jul 02 15:28:58 prophet268 sshd[27633]: debug1: Client protocol version 2.0; client software version OpenSSH_7.4 Jul 02 15:28:58 prophet268 sshd[27633]: debug1: match: OpenSSH_7.4 pat OpenSSH* compat 0x04000000 Jul 02 15:28:58 prophet268 sshd[27633]: debug1: Local version string SSH-2.0-OpenSSH_7.4 Jul 02 15:28:58 prophet268 sshd[27633]: debug1: Enabling compatibility mode for protocol 2.0 Jul 02 15:28:58 prophet268 sshd[27633]: debug1: SELinux support enabled [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: permanently_set_uid: 74/74 [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: list_hostkey_types: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519 [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: SSH2_MSG_KEXINIT sent [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: SSH2_MSG_KEXINIT received [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: kex: algorithm: curve25519-sha256 [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: kex: host key algorithm: ecdsa-sha2-nistp256 [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: kex: curve25519-sha256 need=64 dh_need=64 [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: kex: curve25519-sha256 need=64 dh_need=64 [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: expecting SSH2_MSG_KEX_ECDH_INIT [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: rekey after 134217728 blocks [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: SSH2_MSG_NEWKEYS sent [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: expecting SSH2_MSG_NEWKEYS [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: SSH2_MSG_NEWKEYS received [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: rekey after 134217728 blocks [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: KEX done [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: userauth-request for user root service ssh-connection method none [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: attempt 0 failures 0 [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: reprocess config line 42: Deprecated option RSAAuthentication Jul 02 15:28:58 prophet268 sshd[27633]: debug1: PAM: initializing for "root" Jul 02 15:28:58 prophet268 sshd[27633]: debug1: PAM: setting PAM_RHOST to "localhost" Jul 02 15:28:58 prophet268 sshd[27633]: debug1: PAM: setting PAM_TTY to "ssh" Jul 02 15:28:58 prophet268 sshd[27633]: debug1: userauth-request for user root service ssh-connection method publickey [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: attempt 1 failures 0 [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: userauth_pubkey: test whether pkalg/pkblob are acceptable for RSA SHA256:TstxdnvVdWV4TzqSNnhHDhTZWzNPoUeTn7DXHgbCVPQ [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: temporarily_use_uid: 0/0 (e=0/0) Jul 02 15:28:58 prophet268 sshd[27633]: debug1: trying public key file /root/.ssh/authorized_keys Jul 02 15:28:58 prophet268 sshd[27633]: debug1: fd 4 clearing O_NONBLOCK Jul 02 15:28:58 prophet268 sshd[27633]: debug1: restore_uid: 0/0 Jul 02 15:28:58 prophet268 sshd[27633]: Failed publickey for root from ::1 port 45036 ssh2: RSA SHA256:TstxdnvVdWV4TzqSNnhHDhTZWzNPoUeTn7DXHgbCVPQ Jul 02 15:28:58 prophet268 sshd[27633]: debug1: userauth-request for user root service ssh-connection method publickey [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: attempt 2 failures 1 [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: userauth_pubkey: test whether pkalg/pkblob are acceptable for DSA SHA256:K1gn5Xw0/Lodi/6sPHlmTsEFulyjSjjlhx4zii6NLiE [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: temporarily_use_uid: 0/0 (e=0/0) Jul 02 15:28:58 prophet268 sshd[27633]: debug1: trying public key file /root/.ssh/authorized_keys Jul 02 15:28:58 prophet268 sshd[27633]: debug1: fd 4 clearing O_NONBLOCK Jul 02 15:28:58 prophet268 sshd[27633]: debug1: restore_uid: 0/0 Jul 02 15:28:58 prophet268 sshd[27633]: Failed publickey for root from ::1 port 45036 ssh2: DSA SHA256:K1gn5Xw0/Lodi/6sPHlmTsEFulyjSjjlhx4zii6NLiE Jul 02 15:28:58 prophet268 sshd[27633]: debug1: userauth-request for user root service ssh-connection method publickey [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: attempt 3 failures 2 [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: userauth_pubkey: test whether pkalg/pkblob are acceptable for ECDSA SHA256:ITZJ9Rv6EGeKXqjlU1kYwlxshel9fcBb3WnESEmr6KI [preauth] Jul 02 15:28:58 prophet268 sshd[27633]: debug1: temporarily_use_uid: 0/0 (e=0/0) Jul 02 15:28:58 prophet268 sshd[27633]: debug1: trying public key file /root/.ssh/authorized_keys Jul 02 15:28:58 prophet268 sshd[27633]: debug1: fd 4 clearing O_NONBLOCK Jul 02 15:28:58 prophet268 sshd[27633]: debug1: restore_uid: 0/0 Jul 02 15:28:58 prophet268 sshd[27633]: Failed publickey for root from ::1 port 45036 ssh2: ECDSA SHA256:ITZJ9Rv6EGeKXqjlU1kYwlxshel9fcBb3WnESEmr6KI Jul 02 15:29:01 prophet268 sshd[27633]: debug1: userauth-request for user root service ssh-connection method password [preauth] Jul 02 15:29:01 prophet268 sshd[27633]: debug1: attempt 4 failures 3 [preauth] Jul 02 15:29:02 prophet268 sshd[27633]: debug1: PAM: password authentication accepted for root Jul 02 15:29:02 prophet268 sshd[27633]: debug1: do_pam_account: called Jul 02 15:29:02 prophet268 sshd[27633]: Accepted password for root from ::1 port 45036 ssh2 Jul 02 15:29:02 prophet268 sshd[27633]: debug1: monitor_child_preauth: root has been authenticated by privileged process Jul 02 15:29:02 prophet268 sshd[27633]: debug1: monitor_read_log: child log fd closed Jul 02 15:29:02 prophet268 sshd[27633]: debug1: temporarily_use_uid: 0/0 (e=0/0) Jul 02 15:29:02 prophet268 sshd[27633]: debug1: ssh_gssapi_storecreds: Not a GSSAPI mechanism Jul 02 15:29:02 prophet268 sshd[27633]: debug1: restore_uid: 0/0 Jul 02 15:29:02 prophet268 sshd[27633]: debug1: SELinux support enabled Jul 02 15:29:02 prophet268 sshd[27633]: debug1: PAM: establishing credentials
来源:https://www.cnblogs.com/magic-chenyang/p/11121031.html