为什么只有一个用户对ssh密码提出质疑？

为什么我要为密码挑战？ 只有一个用户？ 不是其他的？ 密钥没有validationssh连接吗？

Authentication succeeded (keyboard-interactive). 

来自本地主机的完整日志：

 thufir@doge:~$ thufir@doge:~$ ssh [e-mail] -vvvvv OpenSSH_7.2p2 Ubuntu-4ubuntu1, OpenSSL 1.0.2g 1 Mar 2016 debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 19: Applying options for * debug2: resolving "fqdn.example.com" port 22 debug2: ssh_connect_direct: needpriv 0 debug1: Connecting to fqdn.example.com [xxx.xxx.xxx.xxx] port 22. debug1: Connection established. debug1: identity file /home/thufir/.ssh/id_rsa type 1 debug1: key_load_public: No such file or directory debug1: identity file /home/thufir/.ssh/id_rsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/thufir/.ssh/id_dsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/thufir/.ssh/id_dsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/thufir/.ssh/id_ecdsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/thufir/.ssh/id_ecdsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/thufir/.ssh/id_ed25519 type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/thufir/.ssh/id_ed25519-cert type -1 debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu1 debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu2.1 debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu2.1 pat OpenSSH* compat 0x04000000 debug2: fd 3 setting O_NONBLOCK debug1: Authenticating to fqdn.example.com:22 as 'thufir' debug3: hostkeys_foreach: reading file "/home/thufir/.ssh/known_hosts" debug3: record_hostkey: found key type ECDSA in file /home/thufir/.ssh/known_hosts:1 debug3: load_hostkeys: loaded 1 keys from fqdn.example.com debug3: order_hostkeyalgs: prefer hostkeyalgs: [e-mail],[e-mail],[e-mail],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521 debug3: send packet: type 20 debug1: SSH2_MSG_KEXINIT sent debug3: receive packet: type 20 debug1: SSH2_MSG_KEXINIT received debug2: local client KEXINIT proposal debug2: KEX algorithms: [e-mail],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,ext-info-c debug2: host key algorithms: [e-mail],[e-mail],[e-mail],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[e-mail],[e-mail],ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa debug2: ciphers ctos: [e-mail],aes128-ctr,aes192-ctr,aes256-ctr,[e-mail],[e-mail],aes128-cbc,aes192-cbc,aes256-cbc,3des-cbc debug2: ciphers stoc: [e-mail],aes128-ctr,aes192-ctr,aes256-ctr,[e-mail],[e-mail],aes128-cbc,aes192-cbc,aes256-cbc,3des-cbc debug2: MACs ctos: [e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: MACs stoc: [e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: compression ctos: none,[e-mail],zlib debug2: compression stoc: none,[e-mail],zlib debug2: languages ctos: debug2: languages stoc: debug2: first_kex_follows 0 debug2: reserved 0 debug2: peer server KEXINIT proposal debug2: KEX algorithms: [e-mail],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1 debug2: host key algorithms: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519 debug2: ciphers ctos: [e-mail],aes128-ctr,aes192-ctr,aes256-ctr,[e-mail],[e-mail] debug2: ciphers stoc: [e-mail],aes128-ctr,aes192-ctr,aes256-ctr,[e-mail],[e-mail] debug2: MACs ctos: [e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: MACs stoc: [e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: compression ctos: none,[e-mail] debug2: compression stoc: none,[e-mail] debug2: languages ctos: debug2: languages stoc: debug2: first_kex_follows 0 debug2: reserved 0 debug1: kex: algorithm: [e-mail] debug1: kex: host key algorithm: ecdsa-sha2-nistp256 debug1: kex: server->client cipher: [e-mail] MAC:  compression: none debug1: kex: client->server cipher: [e-mail] MAC:  compression: none debug3: send packet: type 30 debug1: expecting SSH2_MSG_KEX_ECDH_REPLY debug3: receive packet: type 31 debug1: Server host key: ecdsa-sha2-nistp256 SHA256:IdFVo/3ets3QiQ+cZoW9EYN1BYCTok8We6mqR8yiV0E debug3: hostkeys_foreach: reading file "/home/thufir/.ssh/known_hosts" debug3: record_hostkey: found key type ECDSA in file /home/thufir/.ssh/known_hosts:1 debug3: load_hostkeys: loaded 1 keys from fqdn.example.com debug3: hostkeys_foreach: reading file "/home/thufir/.ssh/known_hosts" debug3: record_hostkey: found key type ECDSA in file /home/thufir/.ssh/known_hosts:2 debug3: load_hostkeys: loaded 1 keys from xxx.xxx.xxx.xxx debug1: Host 'fqdn.example.com' is known and matches the ECDSA host key. debug1: Found key in /home/thufir/.ssh/known_hosts:1 debug3: send packet: type 21 debug2: set_newkeys: mode 1 debug1: rekey after 134217728 blocks debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug3: receive packet: type 21 debug2: set_newkeys: mode 0 debug1: rekey after 134217728 blocks debug1: SSH2_MSG_NEWKEYS received debug2: key: /home/thufir/.ssh/id_rsa (0x5617a39bdaa0), agent debug2: key: /home/thufir/.ssh/id_dsa ((nil)) debug2: key: /home/thufir/.ssh/id_ecdsa ((nil)) debug2: key: /home/thufir/.ssh/id_ed25519 ((nil)) debug3: send packet: type 5 debug3: receive packet: type 7 debug1: SSH2_MSG_EXT_INFO received debug1: kex_input_ext_info: server-sig-algs= debug3: receive packet: type 6 debug2: service_accept: ssh-userauth debug1: SSH2_MSG_SERVICE_ACCEPT received debug3: send packet: type 50 debug3: receive packet: type 51 debug1: Authentications that can continue: publickey,keyboard-interactive debug3: start over, passed a different list publickey,keyboard-interactive debug3: preferred gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive debug3: authmethod_lookup publickey debug3: remaining preferred: keyboard-interactive debug3: authmethod_is_enabled publickey debug1: Next authentication method: publickey debug1: Offering RSA public key: /home/thufir/.ssh/id_rsa debug3: send_pubkey_test debug3: send packet: type 50 debug2: we sent a publickey packet, wait for reply debug3: receive packet: type 51 debug1: Authentications that can continue: publickey,keyboard-interactive debug1: Trying private key: /home/thufir/.ssh/id_dsa debug3: no such identity: /home/thufir/.ssh/id_dsa: No such file or directory debug1: Trying private key: /home/thufir/.ssh/id_ecdsa debug3: no such identity: /home/thufir/.ssh/id_ecdsa: No such file or directory debug1: Trying private key: /home/thufir/.ssh/id_ed25519 debug3: no such identity: /home/thufir/.ssh/id_ed25519: No such file or directory debug2: we did not send a packet, disable method debug3: authmethod_lookup keyboard-interactive debug3: remaining preferred: debug3: authmethod_is_enabled keyboard-interactive debug1: Next authentication method: keyboard-interactive debug2: userauth_kbdint debug3: send packet: type 50 debug2: we sent a keyboard-interactive packet, wait for reply debug3: receive packet: type 60 debug2: input_userauth_info_req debug2: input_userauth_info_req: num_prompts 1 Password: debug3: send packet: type 61 debug3: receive packet: type 60 debug2: input_userauth_info_req debug2: input_userauth_info_req: num_prompts 0 debug3: send packet: type 61 debug3: receive packet: type 52 debug1: Authentication succeeded (keyboard-interactive). Authenticated to fqdn.example.com ([xxx.xxx.xxx.xxx]:22). debug1: channel 0: new [client-session] debug3: ssh_session2_open: channel_new: 0 debug2: channel 0: send open debug3: send packet: type 90 debug1: Requesting [e-mail] debug3: send packet: type 80 debug1: Entering interactive session. debug1: pledge: network debug3: receive packet: type 80 debug1: client_input_global_request: rtype [e-mail] want_reply 0 debug3: receive packet: type 91 debug2: callback start debug2: fd 3 setting TCP_NODELAY debug3: ssh_packet_set_tos: set IP_TOS 0x10 debug2: client_session2_setup: id 0 debug2: channel 0: request pty-req confirm 1 debug3: send packet: type 98 debug1: Sending environment. debug3: Ignored env XDG_VTNR debug3: Ignored env XDG_SESSION_ID debug3: Ignored env CLUTTER_IM_MODULE debug3: Ignored env XDG_GREETER_DATA_DIR debug3: Ignored env SESSION debug3: Ignored env GPG_AGENT_INFO debug3: Ignored env SHELL debug3: Ignored env TERM debug3: Ignored env VTE_VERSION debug3: Ignored env QT_LINUX_ACCESSIBILITY_ALWAYS_ON debug3: Ignored env WINDOWID debug3: Ignored env OLDPWD debug3: Ignored env UPSTART_SESSION debug3: Ignored env GNOME_KEYRING_CONTROL debug3: Ignored env GTK_MODULES debug3: Ignored env USER debug3: Ignored env LS_COLORS debug3: Ignored env QT_ACCESSIBILITY debug3: Ignored env XDG_SESSION_PATH debug3: Ignored env XDG_SEAT_PATH debug3: Ignored env SSH_AUTH_SOCK debug3: Ignored env DEFAULTS_PATH debug3: Ignored env XDG_CONFIG_DIRS debug3: Ignored env PATH debug3: Ignored env DESKTOP_SESSION debug3: Ignored env QT_IM_MODULE debug3: Ignored env QT_QPA_PLATFORMTHEME debug3: Ignored env XDG_SESSION_TYPE debug3: Ignored env PWD debug3: Ignored env JOB debug3: Ignored env XMODIFIERS debug3: Ignored env GNOME_KEYRING_PID debug1: Sending env LANG = en_CA.UTF-8 debug2: channel 0: request env confirm 0 debug3: send packet: type 98 debug3: Ignored env GDM_LANG debug3: Ignored env MANDATORY_PATH debug3: Ignored env IM_CONFIG_PHASE debug3: Ignored env COMPIZ_CONFIG_PROFILE debug3: Ignored env GDMSESSION debug3: Ignored env SESSIONTYPE debug3: Ignored env GTK2_MODULES debug3: Ignored env HOME debug3: Ignored env XDG_SEAT debug3: Ignored env SHLVL debug3: Ignored env LANGUAGE debug3: Ignored env GNOME_DESKTOP_SESSION_ID debug3: Ignored env UPSTART_INSTANCE debug3: Ignored env UPSTART_EVENTS debug3: Ignored env XDG_SESSION_DESKTOP debug3: Ignored env LOGNAME debug3: Ignored env COMPIZ_BIN_PATH debug3: Ignored env QT4_IM_MODULE debug3: Ignored env XDG_DATA_DIRS debug3: Ignored env DBUS_SESSION_BUS_ADDRESS debug3: Ignored env LESSOPEN debug3: Ignored env INSTANCE debug3: Ignored env UPSTART_JOB debug3: Ignored env XDG_RUNTIME_DIR debug3: Ignored env DISPLAY debug3: Ignored env XDG_CURRENT_DESKTOP debug3: Ignored env GTK_IM_MODULE debug3: Ignored env LESSCLOSE debug3: Ignored env XAUTHORITY debug3: Ignored env _ debug2: channel 0: request shell confirm 1 debug3: send packet: type 98 debug2: callback done debug2: channel 0: open confirm rwindow 0 rmax 32768 debug3: receive packet: type 99 debug2: channel_input_status_confirm: type 99 id 0 debug2: PTY allocation request accepted on channel 0 debug2: channel 0: rcvd adjust 2097152 debug3: receive packet: type 99 debug2: channel_input_status_confirm: type 99 id 0 debug2: shell request accepted on channel 0 Welcome to Ubuntu 16.04.1 LTS (GNU/Linux 4.4.0-53-generic x86_64) * Documentation: https://help.ubuntu.com * Management: https://landscape.canonical.com * Support: https://ubuntu.com/advantage Get cloud support with Ubuntu Advantage Cloud Guest: http://www.ubuntu.com/business/services/cloud 0 packages can be updated. 0 updates are security updates. Last login: Mon Jan 9 19:31:03 2017 from yyy.yyy.yyy.yyy thufir@ip-xxx-xxx-xxx-xxx:~$ thufir@ip-xxx-xxx-xxx-xxx:~$ thufir@ip-xxx-xxx-xxx-xxx:~$ exit logout debug3: receive packet: type 98 debug1: client_input_channel_req: channel 0 rtype exit-status reply 0 debug3: receive packet: type 98 debug1: client_input_channel_req: channel 0 rtype [e-mail] reply 0 debug2: channel 0: rcvd eow debug2: channel 0: close_read debug2: channel 0: input open -> closed debug3: receive packet: type 96 debug2: channel 0: rcvd eof debug2: channel 0: output open -> drain debug2: channel 0: obuf empty debug2: channel 0: close_write debug2: channel 0: output drain -> closed debug3: receive packet: type 97 debug2: channel 0: rcvd close debug3: channel 0: will not send data after close debug2: channel 0: almost dead debug2: channel 0: gc: notify user debug2: channel 0: gc: user detached debug2: channel 0: send close debug3: send packet: type 97 debug2: channel 0: is dead debug2: channel 0: garbage collecting debug1: channel 0: free: client-session, nchannels 1 debug3: channel 0: status: The following connections are open: #0 client-session (t4 r0 i3/0 o3/0 fd -1/-1 cc -1) debug3: send packet: type 1 Connection to fqdn.example.com closed. Transferred: sent 2992, received 4028 bytes, in 4.6 seconds Bytes per second: sent 644.6, received 867.8 debug1: Exit status 0 thufir@doge:~$ 

远程ssh配置：

 ubuntu@ip-xxx-xx-x-xx:~$ cat /etc/ssh/sshd_config # Package generated configuration file # See the sshd_config(5) manpage for details # What ports, IPs and protocols we listen for Port 22 # Use these options to restrict which interfaces/protocols sshd will bind to #ListenAddress :: #ListenAddress 0.0.0.0 Protocol 2 # HostKeys for protocol version 2 HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_dsa_key HostKey /etc/ssh/ssh_host_ecdsa_key HostKey /etc/ssh/ssh_host_ed25519_key #Privilege Separation is turned on for security UsePrivilegeSeparation yes # Lifetime and size of ephemeral version 1 server key KeyRegenerationInterval 3600 ServerKeyBits 1024 # Logging SyslogFacility AUTH LogLevel INFO # Authentication: LoginGraceTime 120 #PermitRootLogin prohibit-password PermitRootLogin no StrictModes yes RSAAuthentication yes PubkeyAuthentication yes #AuthorizedKeysFile %h/.ssh/authorized_keys # 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_known_hosts RhostsRSAAuthentication no # similar for protocol version 2 HostbasedAuthentication 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 challenge-response passwords (beware issues with # some PAM modules and threads) ChallengeResponseAuthentication yes # Change to no to disable tunnelled clear text passwords PasswordAuthentication no # Kerberos options #KerberosAuthentication no #KerberosGetAFSToken no #KerberosOrLocalPasswd yes #KerberosTicketCleanup yes # GSSAPI options #GSSAPIAuthentication no #GSSAPICleanupCredentials yes X11Forwarding yes X11DisplayOffset 10 PrintMotd no PrintLastLog yes TCPKeepAlive yes #UseLogin no #MaxStartups 10:30:60 #Banner /etc/issue.net # Allow client to pass locale environment variables AcceptEnv LANG LC_* Subsystem sftp /usr/lib/openssh/sftp-server # 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 AllowUsers thufir ubuntu DenyUsers root ubuntu@ip-xxx-xx-x-xx:~$ 

然而，用户ubuntu可以在不提示输入密码的情况下 ssh。 为什么？ 不，我没有创建第三个用户，看看会发生什么（还）。

这是在AWS实例上。 ubuntu用户是默认用户。

**非详细登录：

 thufir@doge:~$ thufir@doge:~$ ssh [e-mail] Permission denied (publickey). thufir@doge:~$ 

**

Answer 1

Fromm ssh-vvv ssh服务器正在使用键盘交互式。

首先确保您可以使用密钥登录。

然后，编辑sshd_config并将以下内容设置为no

 PasswordAuthentication no KbdInteractiveAuthentication no ChallengeResponseAuthentication no 

并重新启动ssh服务器。