Problema: incompatibilidade de IP do host bastion em ~/.ssh/known_hosts
Eu tinha o arquivo known_hosts
antigo quando o endereço IP do bastião foi alterado ...
$ ssh 10.82.49.24
ssh_exchange_identification: Connection closed by remote host
Não me deu nenhuma informação. Olhando para a saída detalhada leva à mesma coisa:
$ ssh -v 10.82.49.24
OpenSSH_7.4p1, LibreSSL 2.5.0
debug1: Reading configuration data /Users/mdesales/.ssh/config
debug1: /Users/mdesales/.ssh/config line 1: Applying options for 10.82.*.*
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Executing proxy command: exec ssh -q -W 10.82.49.24:22 [email protected] -i ~/.ssh/xxxconfig-xxxx.pem
debug1: key_load_public: No such file or directory
debug1: identity file ~/.ssh/xxxconfig-xxxx.pem
debug1: key_load_public: No such file or directory
debug1: identity file ~/.ssh/xxxconfig-xxxx.pem-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.4
debug1: permanently_drop_suid: 1647059022
ssh_exchange_identification: Connection closed by remote host
Neste ponto, como é um proxy para outro host no bastião, eu vi o bastião sendo um problema:
$ ssh [email protected] -i ~/.ssh/xxxconfig-xxxx.pem
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the ECDSA key sent by the remote host is
SHA256:Z8X1UlIgQ94BKJ7NA/oQi7v0NL4IlFeO7Ou4j76Zphk.
Please contact your system administrator.
Add correct host key in /Users/mdesales/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /Users/mdesales/.ssh/known_hosts:238
ECDSA host key for [email protected] has changed and you have requested strict checking.
Host key verification failed.
Solução
Remover a entrada na linha 238 resolveu o problema ... Eu poderia ssh para o bastião e pude ssh para os hosts.
$ vim /Users/mdesales/.ssh/known_hosts
$ ssh [email protected] -i ~/.ssh/xxxconfig-xxxx.pem
The authenticity of host '[email protected] (34.x.x.y)' can't be established.
ECDSA key fingerprint is SHA256:Z8X1UlIgQ94BKJ7NA/oQi7v0NL4IlFeO7Ou4j76Zphk.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '[email protected] -i ~/.ssh/xxxconfig-xxxx.pem,34.213.y.x' (ECDSA) to the list of known hosts.
********************************************************************************
This is a private computer system containing information that is proprietary
and confidential to the owner of the system. Only individuals or entities
authorized by the owner of the system are allowed to access or use the system.
Any unauthorized access or use of the system or information is strictly
prohibited.
All violators will be prosecuted to the fullest extent permitted by law.
********************************************************************************
Last login: Wed Aug 2 20:35:55 2017 from 10.81.31.115
[ec2-user@ip-10-82-50-142 ~]$