無密碼登錄僅適用於伺服器上直接呼叫的 sshd

對於經典的 ssh 密鑰問題，我已經完成了盡可能多的錯誤修復：我已經“正確”設置了我的公鑰和私鑰，但無密碼登錄仍然不起作用。細節 ：

首先，我知道沒有人想閱讀另一個權限問題：

~$ ls -lhd $HOME
drwx------. 28 mrkelly mrkelly 4.0K May 13 16:23 /mnt/driveB/mrkelly
~$ ls -lhd $HOME/.ssh
drwx------. 2 mrkelly mrkelly 4.0K May 13 15:37 /mnt/driveB/mrkelly/.ssh
~$ ls -lh $HOME/.ssh
total 24K
-rwx------. 1 mrkelly mrkelly 1.7K May 13 15:37 authorized_keys
-rwx------. 1 mrkelly mrkelly  668 May 13 15:20 id_dsa
-rwx------. 1 mrkelly mrkelly  625 May 13 15:20 id_dsa.pub
-rwx------. 1 mrkelly mrkelly 1.7K May 13 15:11 id_rsa
-rwx------. 1 mrkelly mrkelly  417 May 13 15:11 id_rsa.pub
-rwx------. 1 mrkelly mrkelly  980 May 13 14:57 known_hosts
/$ ll -d /
dr-xr-xr-x. 17 root root 4.0K May 14 12:21 /
/$ ll -d /mnt
drwxr-xr-x. 4 root root 4.0K Nov 18 04:33 /mnt
/$ ll -d /mnt/driveB
drwxr-xr-x. 4 root root 4.0K May 13 17:31 /mnt/driveB
~$ uname -a 
Linux action-jackson.stanford.edu 3.19.7-200.fc21.x86_64 #1 SMP Thu May 7 22:00:21 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

在閱讀了 SELinux 在此類情況下是常見的反派之後，我禁用了它：

~$ sudo systemctl status selinux 
● selinux.service
  Loaded: not-found (Reason: No such file or directory)
  Active: inactive (dead)

我是主機上的管理員，所以我使用一個終端作為 sshd 伺服器端服務，一個作為客戶端。

首先，工作版本：

• 主機終端（sshd 已被禁用）：

~$ sudo /usr/sbin/sshd -d   
debug1: sshd version OpenSSH_6.6.1, OpenSSL 1.0.1k-fips 8 Jan 2015
debug1: key_parse_private2: missing begin marker
debug1: read PEM private key done: type RSA
debug1: private host key: #0 type 1 RSA
debug1: key_parse_private2: missing begin marker
debug1: read PEM private key done: type ECDSA
debug1: private host key: #1 type 3 ECDSA
debug1: private host key: #2 type 4 ED25519
debug1: rexec_argv[0]='/usr/sbin/sshd'
debug1: rexec_argv[1]='-d'
Set /proc/self/oom_score_adj from 0 to -1000
debug1: Bind to port 22 on 0.0.0.0.
Server listening on 0.0.0.0 port 22.
debug1: Bind to port 22 on ::.
Server listening on :: port 22.

（我們一直在這裡，直到使用“客戶端”終端登錄，然後：）

debug1: Server will not fork when running in debugging mode.
debug1: rexec start in 5 out 5 newsock 5 pipe -1 sock 8
debug1: inetd sockets after dupping: 3, 3
Connection from 127.0.0.1 port 49966 on 127.0.0.1 port 22
debug1: Client protocol version 2.0; client software version OpenSSH_6.6.1
debug1: match: OpenSSH_6.6.1 pat OpenSSH_6.6.1* compat 0x04000000
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.6.1
debug1: SELinux support enabled [preauth]
debug1: ssh_selinux_change_context: setting context from 'unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023' to 'unconfined_u:unconfined_r:sshd_net_t:s0-s0:c0.c1023' [preauth]
debug1: permanently_set_uid: 74/74 [preauth]
debug1: list_hostkey_types: ssh-rsa,ecdsa-sha2-nistp256,ssh-ed25519 [preauth]
debug1: SSH2_MSG_KEXINIT sent [preauth]
debug1: SSH2_MSG_KEXINIT received [preauth]
debug1: kex: client->server aes128-ctr hmac-md5-etm@openssh.com none [preauth]
debug1: kex: server->client aes128-ctr hmac-md5-etm@openssh.com none [preauth]
debug1: kex: curve25519-sha256@libssh.org need=16 dh_need=16 [preauth]
debug1: kex: curve25519-sha256@libssh.org need=16 dh_need=16 [preauth]
debug1: expecting SSH2_MSG_KEX_ECDH_INIT [preauth]
debug1: SSH2_MSG_NEWKEYS sent [preauth]
debug1: expecting SSH2_MSG_NEWKEYS [preauth]
debug1: SSH2_MSG_NEWKEYS received [preauth]
debug1: KEX done [preauth]
debug1: userauth-request for user mrkelly service ssh-connection method none [preauth]
debug1: attempt 0 failures 0 [preauth]
debug1: PAM: initializing for "mrkelly"
debug1: PAM: setting PAM_RHOST to "localhost.localdomain"
debug1: PAM: setting PAM_TTY to "ssh"
debug1: userauth-request for user mrkelly service ssh-connection method publickey [preauth]
debug1: attempt 1 failures 0 [preauth]
debug1: test whether pkalg/pkblob are acceptable [preauth]
debug1: temporarily_use_uid: 1000/1000 (e=0/0)
debug1: trying public key file /mnt/driveB/mrkelly/.ssh/authorized_keys
debug1: fd 4 clearing O_NONBLOCK
Found matching RSA key: d7:9e:aa:54:63:d7:2d:87:d3:b1:0e:83:3b:70:27:d4
debug1: restore_uid: 0/0
Postponed publickey for mrkelly from 127.0.0.1 port 49966 ssh2 [preauth]
debug1: userauth-request for user mrkelly service ssh-connection method publickey [preauth]
debug1: attempt 2 failures 0 [preauth]
debug1: temporarily_use_uid: 1000/1000 (e=0/0)
debug1: trying public key file /mnt/driveB/mrkelly/.ssh/authorized_keys
debug1: fd 4 clearing O_NONBLOCK
Found matching RSA key: d7:9e:aa:54:63:d7:2d:87:d3:b1:0e:83:3b:70:27:d4
debug1: restore_uid: 0/0
debug1: ssh_rsa_verify: signature correct
debug1: do_pam_account: called
Accepted publickey for mrkelly from 127.0.0.1 port 49966 ssh2: RSA d7:9e:aa:54:63:d7:2d:87:d3:b1:0e:83:3b:70:27:d4
debug1: monitor_child_preauth: mrkelly has been authenticated by privileged process
debug1: monitor_read_log: child log fd closed
debug1: SELinux support enabled
debug1: PAM: establishing credentials
User child is on pid 8196
debug1: PAM: establishing credentials
debug1: permanently_set_uid: 1000/1000
debug1: Entering interactive session for SSH2.
debug1: server_init_dispatch_20
debug1: server_input_channel_open: ctype session rchan 0 win 1048576 max 16384
debug1: input_session_request
debug1: channel 0: new [server-session]
debug1: session_new: session 0
debug1: session_open: channel 0
debug1: session_open: session 0: link with channel 0
debug1: server_input_channel_open: confirm session
debug1: server_input_global_request: rtype no-more-sessions@openssh.com want_reply 0
debug1: server_input_channel_req: channel 0 request x11-req reply 1
debug1: session_by_channel: session 0 channel 0
debug1: session_input_channel_req: session 0 req x11-req
debug1: channel 1: new [X11 inet listener]
debug1: channel 2: new [X11 inet listener]
debug1: server_input_channel_req: channel 0 request pty-req reply 1
debug1: session_by_channel: session 0 channel 0
debug1: session_input_channel_req: session 0 req pty-req
debug1: Allocating pty.
debug1: session_new: session 0
debug1: SELinux support enabled
debug1: session_pty_req: session 0 alloc /dev/pts/4
debug1: server_input_channel_req: channel 0 request env reply 0
debug1: session_by_channel: session 0 channel 0
debug1: session_input_channel_req: session 0 req env
debug1: server_input_channel_req: channel 0 request env reply 0
debug1: session_by_channel: session 0 channel 0
debug1: session_input_channel_req: session 0 req env
debug1: server_input_channel_req: channel 0 request shell reply 1
debug1: session_by_channel: session 0 channel 0
debug1: session_input_channel_req: session 0 req shell
Starting session: shell on pts/4 for mrkelly from 127.0.0.1 port 49966
debug1: Setting controlling tty using TIOCSCTTY.

• 客戶端：

~$ ssh -v `whoami`@localhost
OpenSSH_6.6.1, OpenSSL 1.0.1k-fips 8 Jan 2015
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 56: Applying options for *
debug1: Connecting to localhost [127.0.0.1] port 22.
debug1: Connection established.
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_rsa type 1
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_rsa-cert type -1
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_dsa type 2
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_dsa-cert type -1
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_ecdsa type -1
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_ecdsa-cert type -1
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_ed25519 type -1
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.6.1
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6.1
debug1: match: OpenSSH_6.6.1 pat OpenSSH_6.6.1* compat 0x04000000
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5-etm@openssh.com none
debug1: kex: client->server aes128-ctr hmac-md5-etm@openssh.com none
debug1: kex: curve25519-sha256@libssh.org need=16 dh_need=16
debug1: kex: curve25519-sha256@libssh.org need=16 dh_need=16
debug1: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ECDSA 8d:cb:f2:94:da:97:7b:0d:ee:e6:bb:8e:3f:41:ae:d8
debug1: Host 'localhost' is known and matches the ECDSA host key.
debug1: Found key in /mnt/driveB/mrkelly/.ssh/known_hosts:3
debug1: ssh_ecdsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /mnt/driveB/mrkelly/.ssh/id_rsa
debug1: Server accepts key: pkalg ssh-rsa blen 279
debug1: key_parse_private2: missing begin marker
debug1: read PEM private key done: type RSA
debug1: Authentication succeeded (publickey).
Authenticated to localhost ([127.0.0.1]:22).
debug1: channel 0: new [client-session]
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug1: Requesting X11 forwarding with authentication spoofing.
debug1: Sending environment.
debug1: Sending env LANGUAGE = 
debug1: Sending env LANG = en_US.UTF-8
Last login: Wed May 13 15:58:17 2015 from localhost.localdomain
Environment:
 LANGUAGE=
 LANG=en_US.UTF-8
 USER=mrkelly
 LOGNAME=mrkelly
 HOME=/mnt/driveB/mrkelly
 PATH=/usr/local/bin:/usr/bin
 MAIL=/var/mail/mrkelly
 SHELL=/bin/zsh
 SSH_CLIENT=127.0.0.1 49967 22
 SSH_CONNECTION=127.0.0.1 49967 127.0.0.1 22
 SSH_TTY=/dev/pts/4
 TERM=xterm-256color
 DISPLAY=localhost:11.0
 SELINUX_ROLE_REQUESTED=
 SELINUX_LEVEL_REQUESTED=
 SELINUX_USE_CURRENT_RANGE=
 XDG_SESSION_ID=21
 XDG_RUNTIME_DIR=/run/user/1000
 XDG_SEAT=seat0
 XDG_VTNR=1
Running /usr/bin/xauth remove unix:11.0
/usr/bin/xauth add unix:11.0 MIT-MAGIC-COOKIE-1 62951eb22f06d56df8189ee23126a19e

（工作，無密碼登錄）

現在，我們重新啟動 sshd.service 並顯示非工作版本。

• 主機終端

sudo systemctl start sshd

• 客戶端

~$ ssh -v `whoami`@localhost
OpenSSH_6.6.1, OpenSSL 1.0.1k-fips 8 Jan 2015
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 56: Applying options for *
debug1: Connecting to localhost [127.0.0.1] port 22.
debug1: Connection established.
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_rsa type 1
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_rsa-cert type -1
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_dsa type 2
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_dsa-cert type -1
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_ecdsa type -1
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_ecdsa-cert type -1
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_ed25519 type -1
debug1: identity file /mnt/driveB/mrkelly/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.6.1
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6.1
debug1: match: OpenSSH_6.6.1 pat OpenSSH_6.6.1* compat 0x04000000
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5-etm@openssh.com none
debug1: kex: client->server aes128-ctr hmac-md5-etm@openssh.com none
debug1: kex: curve25519-sha256@libssh.org need=16 dh_need=16
debug1: kex: curve25519-sha256@libssh.org need=16 dh_need=16
debug1: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ECDSA 8d:cb:f2:94:da:97:7b:0d:ee:e6:bb:8e:3f:41:ae:d8
debug1: Host 'localhost' is known and matches the ECDSA host key.
debug1: Found key in /mnt/driveB/mrkelly/.ssh/known_hosts:3
debug1: ssh_ecdsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /mnt/driveB/mrkelly/.ssh/id_rsa
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: Offering DSA public key: /mnt/driveB/mrkelly/.ssh/id_dsa
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: Trying private key: /mnt/driveB/mrkelly/.ssh/id_ecdsa
debug1: Trying private key: /mnt/driveB/mrkelly/.ssh/id_ed25519
debug1: Next authentication method: keyboard-interactive
Password: 

（就在那裡）。

最後說幾句：我最近不得不重新格式化安裝驅動器，並且我正在使用儲存在另一個驅動器上的文件夾。重新安裝 Fedora 21 時，我被迫在該驅動器上創建主目錄，但在為其他驅動器創建掛載點後，我將使用者帳戶切換為指向舊主目錄的備份版本。

編輯：無密碼登錄也可以使用以下呼叫：

/usr/sbin/sshd -D

（沒有守護程序，但沒有調試消息）

/usr/shbin/sshd

（我猜這是一個臨時的解決方法，因為這確實呼叫了守護程序）

EDIT2：sudo journalctl -u sshd之後的輸出sudo systemctl restart sshd（日誌記錄級別 debug3）

我的送出有字元限制，所以我將連結到帶有輸出的 Dropbox 中的純文字文件。

感謝您的任何幫助，您可以提供！

這是一個 SELinux 問題，由您的主目錄位於一個奇怪的位置引起。你為禁用它所做的事情，沒有。SELinux 不是服務，systemctl status selinux只是告訴你*（* “未找到（原因：沒有這樣的文件或目錄） ”）。

您可以執行setenforce permissive或以其他方式禁用 SELinux，但這就像只是因為您曾經放錯了房門鑰匙而將門從您的房子上拆下來。跑步chcon -t ssh_home_t ~/.ssh/應該這樣做。

我怎麼知道？因為那是我係統~/.ssh上文件的類型。但是我可以從包中安裝，然後執行以生成手冊頁，其中記錄了實際的策略。sepolicy``policycoreutils-devel``sepolicy manpage -t ssh_d``ssh_selinux.8

真的，我最建議忘記所有這些，只需將驅動器安裝在/home而不是/mnt/driveB，然後執行restorecon -R -v /home。

引用自：https://unix.stackexchange.com/questions/203286