Estou tentando conectar-me a um servidor SSH com o qual eu consegui me conectar no passado, mas usando diferentes versões do cliente OpenSSH.
A partir de um cliente Cygwin OpenSSH_6.6.1, OpenSSL 1.0.1g 7 Apr 2014 , passando por um proxy Squid usando saca-rolhas, estou conectando bem a um servidor Ubuntu 13.10 OpenSSH_6.2p2 Ubuntu-6ubuntu0.3 intermediário usando um agente encaminhado para ignorar um firewall que impede o acesso direto ao servidor de destino.
Consigo me conectar bem com outros servidores SSH por meio desse servidor intermediário, que descarta problemas de configuração ou permissões de agentes encaminhados.
A única diferença que eu posso dizer com o servidor de destino que falha é que ele executa uma versão antiga do Debian usando OpenSSH_4.3 que não foi atualizado por vários anos, embora eu pudesse me conectar a ele há alguns meses (antes de atualizar o servidor intermediário após o bug heartbleed) e antes de atualizar meu cliente Cygwin.
Existe algum problema de incompatibilidade de protocolo conhecido entre os agentes de usuário recentes e antigos do OpenSSH?
A conexão do servidor intermediário ao servidor de destino ( s1.hidden.com @63.82.7.10 nos rastreamentos abaixo) falha sem nenhuma mensagem de erro e depois que o servidor de destino relatou a aceitação da minha chave pública encaminhada e o servidor intermediário enviou essa chave pública. / p>
No rastreio abaixo, a conexão com o servidor intermediário e a tentativa de conexão com o servidor de destino têm opções -vvv , o que explica channel 1 mensagens de depuração envolvendo o agente encaminhado (os endereços são editados):
[...]
debug2: we sent a publickey packet, wait for reply
debug1: Server accepts key: pkalg ssh-rsa blen 279
debug2: input_userauth_pk_ok: fp 46:83:33:00:28:48:b2:3c:b1:3f:60:bb:62:80:cc:d2
debug3: sign_and_send_pubkey: RSA 46:83:33:00:28:48:b2:3c:b1:3f:60:bb:62:80:cc:d2
debug2: channel 1: rcvd eof
debug2: channel 1: output open -> drain
debug2: channel 1: obuf empty
debug2: channel 1: close_write
debug2: channel 1: output drain -> closed
debug1: channel 1: FORCE input drain
debug2: channel 1: ibuf empty
debug2: channel 1: send eof
debug2: channel 1: input drain -> closed
debug2: channel 1: send close
Connection closed by 63.82.7.10
root@intermediate-server: ~
$ debug3: channel 1: will not send data after close
debug2: channel 1: rcvd close
debug3: channel 1: will not send data after close
debug2: channel 1: is dead
debug2: channel 1: garbage collecting
debug1: channel 1: free: authentication agent connection, nchannels 2
debug3: channel 1: status: The following connections are open:
#0 client-session (t4 r0 i0/0 o0/0 fd 3/6 cc -1)
#1 authentication agent connection (t4 r2 i3/0 o3/0 fd 8/8 cc -1)
Em um servidor de destino que é bem-sucedido, posso ver:
debug2: channel 1: input drain -> closed
debug2: channel 1: send close
debug1: Authentication succeeded (publickey).
Em vez disso, no servidor com falha:
debug2: channel 1: input drain -> closed
debug2: channel 1: send close
Connection closed by 63.82.7.10
Tudo parece ser diferente das versões e endereços do OpenSSH.
Aqui está o rastreio fullvvv do servidor intermediário para o servidor de destino:
OpenSSH_6.2p2 Ubuntu-6ubuntu0.3, OpenSSL 1.0.1e 11 Feb 2013
debug1: Reading configuration data /root/.ssh/config
debug1: /root/.ssh/config line 1: Applying options for s1
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to s1.hidden.com [63.82.7.10] port 2222.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /root/.ssh/id_rsa type -1
debug1: identity file /root/.ssh/id_rsa-cert type -1
debug1: identity file /root/.ssh/id_dsa type -1
debug1: identity file /root/.ssh/id_dsa-cert type -1
debug1: identity file /root/.ssh/id_ecdsa type -1
debug1: identity file /root/.ssh/id_ecdsa-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.2p2 Ubuntu-6ubuntu0.3
debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3
debug1: match: OpenSSH_4.3 pat OpenSSH_4*
debug2: fd 3 setting O_NONBLOCK
debug3: put_host_port: [s1.hidden.com]:2222
debug3: load_hostkeys: loading entries for host "[s1.hidden.com]:2222" from file "/root/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /root/.ssh/known_hosts:4
debug3: load_hostkeys: loaded 1 keys
debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],[email protected],ssh-rsa
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: [email protected],[email protected],ssh-rsa,[email protected],[email protected],[email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-dss
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,[email protected],[email protected],aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,[email protected],[email protected],aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-md5,hmac-sha1,[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-md5,hmac-sha1,[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,[email protected],zlib
debug2: kex_parse_kexinit: none,[email protected],zlib
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,[email protected],aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,[email protected],aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,[email protected]
debug2: kex_parse_kexinit: none,[email protected]
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: mac_setup: found hmac-md5
debug1: kex: server->client aes128-ctr hmac-md5 none
debug2: mac_setup: found hmac-md5
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: dh_gen_key: priv key bits set: 135/256
debug2: bits set: 507/1024
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Server host key: RSA b0:07:f4:ce:c7:00:e2:54:23:1c:45:7f:d9:61:41:8a
debug3: put_host_port: [63.82.7.10]:2222
debug3: put_host_port: [s1.hidden.com]:2222
debug3: load_hostkeys: loading entries for host "[s1.hidden.com]:2222" from file "/root/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /root/.ssh/known_hosts:4
debug3: load_hostkeys: loaded 1 keys
debug3: load_hostkeys: loading entries for host "[63.82.7.10]:2222" from file "/root/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /root/.ssh/known_hosts:5
debug3: load_hostkeys: loaded 1 keys
debug1: Host '[s1.hidden.com]:2222' is known and matches the RSA host key.
debug1: Found key in /root/.ssh/known_hosts:4
debug2: bits set: 535/1024
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: client_input_channel_open: ctype [email protected] rchan 2 win 65536 max 16384
debug2: fd 8 setting O_NONBLOCK
debug3: fd 8 is O_NONBLOCK
debug1: channel 1: new [authentication agent connection]
debug1: confirm [email protected]
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /home/jvincent/.ssh/id_rsa (0xb8485070),
debug2: key: /root/.ssh/id_rsa ((nil)),
debug2: key: /root/.ssh/id_dsa ((nil)),
debug2: key: /root/.ssh/id_ecdsa ((nil)),
debug1: Authentications that can continue: publickey,password
debug3: start over, passed a different list publickey,password
debug3: preferred gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/jvincent/.ssh/id_rsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Server accepts key: pkalg ssh-rsa blen 279
debug2: input_userauth_pk_ok: fp 46:83:33:00:28:48:b2:3c:b1:3f:60:bb:62:80:cc:d2
debug3: sign_and_send_pubkey: RSA 46:83:33:00:28:48:b2:3c:b1:3f:60:bb:62:80:cc:d2
debug2: channel 1: rcvd eof
debug2: channel 1: output open -> drain
debug2: channel 1: obuf empty
debug2: channel 1: close_write
debug2: channel 1: output drain -> closed
debug1: channel 1: FORCE input drain
debug2: channel 1: ibuf empty
debug2: channel 1: send eof
debug2: channel 1: input drain -> closed
debug2: channel 1: send close
Connection closed by 63.82.7.10
root@intermediate-server: ~
$ debug3: channel 1: will not send data after close
debug2: channel 1: rcvd close
debug3: channel 1: will not send data after close
debug2: channel 1: is dead
debug2: channel 1: garbage collecting
debug1: channel 1: free: authentication agent connection, nchannels 2
debug3: channel 1: status: The following connections are open:
#0 client-session (t4 r0 i0/0 o0/0 fd 3/6 cc -1)
#1 authentication agent connection (t4 r2 i3/0 o3/0 fd 8/8 cc -1)
A maneira de depurar esses problemas é obter um canal / sessão secundária para o servidor e, em seguida, iniciar %código% e verifique a saída do sshd para obter informações melhores. O culpado em minhas experiências:
'which sshd' -d -p 2222
$HOME e $HOME/.ssh , sshd podem ser pedantes com isso. (No entanto, não suspeito que este, como apepared os servidores aceitou as chaves) NOTA: você parece ter "ssh -vv" em execução no servidor intermediário, pois as mensagens de depuração *: após o prompt $ indicam o intermediário - > target exited, mas agora você tem alguns verbos / depuração intermediários de origem > também intercalados com as informações de depuração que você está procurando / em.