O login SSH leva 15 segundos
Eu tenho dois dispositivos:
- WSL para Windows em execução: OpenSSH_7.6p1 Ubuntu-4ubuntu0.5, OpenSSL 1.0.2n 7 de dezembro de 2017
- Raspbian em execução: OpenSSH_7.9p1 Raspbian-10 + deb10u2, OpenSSL 1.1.1d 10 de setembro de 2019
E um servidor centos 8.
O primeiro (WSL), leva 15 segundos para fazer login no servidor, seja por senha ou chave pública. Raspbian é imediato. Eu uso o ip para conectar de ambos os dispositivos.
Eu configurei o log daemon ssh do servidor para debug3 e não consegui ver muita diferença entre os 2 logins, vejo o atraso de 15 segundos aqui:
Oct 17 09:13:20 localhost sshd[2080]: debug3: userauth_finish: failure partial=0 next methods="publickey,gssapi-keyex,gssapi-with-mic,password" [preauth]
Oct 17 09:13:20 localhost sshd[2080]: debug3: send packet: type 51 [preauth]
Oct 17 09:13:20 localhost sshd[1979]: debug2: channel 0: rcvd adjust 50867
Oct 17 09:13:36 localhost sshd[2080]: debug3: receive packet: type 50 [preauth]
Oct 17 09:13:36 localhost sshd[2080]: debug1: userauth-request for user marco service ssh-connection method publickey [preauth]
Alguma pista sobre o que devo procurar?
Esta é a saída ssh -vvv, adicionei timestamp
[2021-10-21 19:53:13] debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
[2021-10-21 19:53:13] debug3: start over, passed a different list publickey,gssapi-keyex,gssapi-with-mic,password
[2021-10-21 19:53:13] debug3: preferred gssapi-with-mic,publickey,keyboard-interactive,password
[2021-10-21 19:53:13] debug3: authmethod_lookup gssapi-with-mic
[2021-10-21 19:53:13] debug3: remaining preferred: publickey,keyboard-interactive,password
[2021-10-21 19:53:13] debug3: authmethod_is_enabled gssapi-with-mic
[2021-10-21 19:53:13] debug1: Next authentication method: gssapi-with-mic
[2021-10-21 19:53:22] debug1: Unspecified GSS failure. Minor code may provide more information
[2021-10-21 19:53:22] No Kerberos credentials available (default cache: FILE:/tmp/krb5cc_1000)
[2021-10-21 19:53:22]
[2021-10-21 19:53:22]
[2021-10-21 19:53:33] debug1: Unspecified GSS failure. Minor code may provide more information
[2021-10-21 19:53:33] No Kerberos credentials available (default cache: FILE:/tmp/krb5cc_1000)
[2021-10-21 19:53:33]
[2021-10-21 19:53:33]
[2021-10-21 19:53:33] debug2: we did not send a packet, disable method
[2021-10-21 19:53:33] debug3: authmethod_lookup publickey
[2021-10-21 19:53:33] debug3: remaining preferred: keyboard-interactive,password
[2021-10-21 19:53:33] debug3: authmethod_is_enabled publickey
[2021-10-21 19:53:33] debug1: Next authentication method: publickey
[2021-10-21 19:53:33] debug1: Offering public key: /home/marco/.ssh/id_rsa RSA SHA256:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
[2021-10-21 19:53:33] debug3: send packet: type 50
[2021-10-21 19:53:34] debug2: we sent a publickey packet, wait for reply
[2021-10-21 19:53:34] debug3: receive packet: type 51
[2021-10-21 19:53:34] debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
[2021-10-21 19:53:34] debug1: Trying private key: /home/marco/.ssh/id_dsa
[2021-10-21 19:53:34] debug3: no such identity: /home/marco/.ssh/id_dsa: No such file or directory
[2021-10-21 19:53:34] debug1: Trying private key: /home/marco/.ssh/id_ecdsa
[2021-10-21 19:53:34] debug3: no such identity: /home/marco/.ssh/id_ecdsa: No such file or directory
[2021-10-21 19:53:34] debug1: Trying private key: /home/marco/.ssh/id_ecdsa_sk
[2021-10-21 19:53:34] debug3: no such identity: /home/marco/.ssh/id_ecdsa_sk: No such file or directory
[2021-10-21 19:53:34] debug1: Trying private key: /home/marco/.ssh/id_ed25519
[2021-10-21 19:53:34] debug3: no such identity: /home/marco/.ssh/id_ed25519: No such file or directory
[2021-10-21 19:53:34] debug1: Trying private key: /home/marco/.ssh/id_ed25519_sk
[2021-10-21 19:53:34] debug3: no such identity: /home/marco/.ssh/id_ed25519_sk: No such file or directory
[2021-10-21 19:53:34] debug1: Trying private key: /home/marco/.ssh/id_xmss
[2021-10-21 19:53:34] debug3: no such identity: /home/marco/.ssh/id_xmss: No such file or directory
[2021-10-21 19:53:34] debug2: we did not send a packet, disable method
[2021-10-21 19:53:34] debug3: authmethod_lookup password
[2021-10-21 19:53:34] debug3: remaining preferred: ,password
[2021-10-21 19:53:34] debug3: authmethod_is_enabled password
[2021-10-21 19:53:34] debug1: Next authentication method: password
Responder1
Tente desabilitar GSSAPIAuthentication. Edite o sshd_configarquivo no WSL e mude GSSAPIAuthenticationde yespara no.
sudo nano /etc/ssh/sshd_config
Salve as alterações e reinicie o daemon SSH.
sudo systemctl restart sshd
Fonte: Vislumbre técnico