通过中间主机的 SSH 仅在 myuser@mymac 上失败，但在其他地方有效

Question

我无法在我的 macbook 上使用我的用户通过 ssh 连接到我的数据中心节点之一。这是最近出现的问题，从几周前开始就非常有用了。

奇怪的是，这只会影响我计算机上的用户，但我能够从以下位置建立连接：

• 同一台机器上的不同用户，使用相同的 ssh 密钥并且没有任何 .ssh/config 规则。
• 不同的服务器，运行 macos 或 ubuntu，具有相同或不同的 ssh 密钥。

在我的计算机上使用我的用户名和相同的密钥，我可以：

• 连接网关主机
• 使用 VPN 直接连接到节点（不幸的是，这不是一个长期的解决方案）

我对这个错误感到很困惑。你能帮我定位问题吗？

查看日志，与网关的连接已建立，但无法连接到节点。在客户端：

? ~ ? ssh -v -J gatekeeper@gateway ubuntu@node -i ~/.ssh/id_rsa 
OpenSSH_7.3p1, LibreSSL 2.4.1
[...]
debug1: Authentication succeeded (publickey).
Authenticated to gateway ([35.156.248.245]:22).
debug1: channel_connect_stdio_fwd node:22
debug1: channel 0: new [stdio-forward]
debug1: getpeername failed: Bad file descriptor
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug1: pledge: network
debug1: client_input_global_request: rtype keepalive@openssh.com want_reply 1
debug1: client_input_global_request: rtype keepalive@openssh.com want_reply 1
debug1: client_input_global_request: rtype keepalive@openssh.com want_reply 1
debug1: client_input_global_request: rtype keepalive@openssh.com want_reply 1
debug1: client_input_global_request: rtype keepalive@openssh.com want_reply 1
debug1: client_input_global_request: rtype keepalive@openssh.com want_reply 1
debug1: client_input_global_request: rtype keepalive@openssh.com want_reply 1
debug1: client_input_global_request: rtype keepalive@openssh.com want_reply 1
channel 0: open failed: connect failed: Connection timed out
stdio forwarding failed
ssh_exchange_identification: Connection closed by remote host

在网关端：

admin@gateway:~$ grep -e "\[7669\]" -e "\[7739\]" /var/log/auth.log
Mar 13 11:01:20 gateway sshd[7669]: Set /proc/self/oom_score_adj to 0
Mar 13 11:01:20 gateway sshd[7669]: rexec line 32: Deprecated option PermitBlacklistedKeys
Mar 13 11:01:20 gateway sshd[7669]: Connection from <laptop-out-ip> port 62113 on <gateway-ip> port 22
Mar 13 11:01:20 gateway sshd[7669]: Postponed publickey for gatekeeper from <laptop-out-ip> port 62113 ssh2 [preauth]
Mar 13 11:01:20 gateway sshd[7669]: Accepted publickey for gatekeeper from <laptop-out-ip> port 62113 ssh2: RSA 8d:7e:9c:53:11:c9:4d:b3:67:7b:ae:04:03:8f:e2:71
Mar 13 11:01:20 gateway sshd[7669]: pam_unix(sshd:session): session opened for user gatekeeper by (uid=0)
Mar 13 11:01:20 gateway sshd[7669]: User child is on pid 7739
Mar 13 11:03:27 gateway sshd[7739]: error: connect_to <node-ip> port 22: failed.
Mar 13 11:03:28 gateway sshd[7739]: Connection closed by <laptop-out-ip>
Mar 13 11:03:28 gateway sshd[7739]: Transferred: sent 2252, received 2864 bytes
Mar 13 11:03:28 gateway sshd[7739]: Closing connection to <laptop-out-ip> port 62113
Mar 13 11:03:28 gateway sshd[7669]: pam_unix(sshd:session): session closed for user gatekeeper

在节点端，日志中没有条目。

网关的 ssd_config：

# ssh service configuration

AcceptEnv
AddressFamily inet
AllowAgentForwarding yes
AllowGroups
AllowTcpForwarding no
AllowUsers gatekeeper
AuthorizedKeysFile %h/.ssh/authorized_keys
ChallengeResponseAuthentication no
Ciphers aes128-ctr,aes192-ctr,aes256-ctr
ClientAliveCountMax 3
ClientAliveInterval 15
Compression delayed
DenyGroups
DenyUsers
GSSAPIAuthentication no
GatewayPorts no
HostKey /etc/ssh/ssh_host_dsa_key
HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_ecdsa_key
HostbasedAuthentication no
KerberosAuthentication no
ListenAddress 0.0.0.0:22
LogLevel VERBOSE
LoginGraceTime 60
MaxAuthTries 6
MaxSessions 10
MaxStartups 30
PasswordAuthentication no
PermitBlacklistedKeys no
PermitRootLogin no
PermitTunnel no
PermitUserEnvironment no
PidFile /var/run/sshd.pid
PrintLastLog yes
PrintMotd no
Protocol 2
PubkeyAuthentication yes
RSAAuthentication no
RhostsRSAAuthentication no
StrictModes yes
SyslogFacility AUTH
TCPKeepAlive yes
UseDNS no
UseLogin no
UsePAM yes
UsePrivilegeSeparation yes
X11Forwarding no

Match User gatekeeper
AllowTcpForwarding yes
AllowAgentForwarding no
X11Forwarding no

Answer 1

最后我终于能够找到问题的根源。我可以通过不采购 iterm2 shell 集成或只是将其更新到最新版本来使问题消失。这可能与使用鱼壳有关。

我没有进一步深入研究这个问题，如果有人感兴趣请告诉我。