Estou desenvolvendo software em uma placa personalizada que roda Linux. Eu acesso esta placa através de ssh em uma conexão com fio. Eu tenho um adaptador USB-Ethernet na minha máquina e o cabo Ethernet se conecta a esta placa personalizada. Eu tinha chaves ssh configuradas para não precisar digitar uma senha todas as vezes. Tudo estava funcionando bem até que compartilhei a Internet com aquela placa e executei um git pull para atualizar o software nela. (Isso funcionou bem, aliás). Depois de alterar o endereço IP de volta para manual e colocar o IP antigo de volta, recebi um aviso sobre a alteração do host. Isso é da internet, então os ips não coincidem, mas era mais ou menos assim:
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ 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 RSA key sent by the remote host is
51:82:00:1c:7e:6f:ac:ac:de:f1:53:08:1c:7d:55:68.
Please contact your system administrator.
Add correct host key in /Users/isaacalves/.ssh/known_hosts to get rid of this message.
Offending RSA key in /Users/isaacalves/.ssh/known_hosts:12
RSA host key for 104.131.16.158 has changed and you have requested strict checking.
Host key verification failed.
Sempre me pedem a senha quando tento fazer o ssh, mesmo que não deva.A parte mais peculiaré que quando digito a senha ele não aceita. Como posso saber se é a senha correta? Porque estou usando a tela para fazer login serial na placa e efetuei login com essa senha através da tela. Posso acessar a placa então (host) através da tela, só que a tela é muito lenta e preciso fazer ssh para vscode e outras coisas.
Eu até desinstalei o cliente ssh da minha máquina e o reinstalei. Nada. Eu removi a pastaknown_hosts da minha máquina e isso não ajudou. O host pode fazer ssh para seu próprio endereço IP (não loopback), então acredito que ele está aceitando solicitações de ssh. (A menos que haja um curto-circuito e ele não esteja realmente usando ssh quando usa seu próprio IP. Mas acho que é).
Posso acessar os arquivos do host e do cliente, se necessário. Estou preso nisso há 3 dias por causa do meu trabalho, então qualquer ajuda seria muito apreciada. Postarei o máximo de coisas úteis que puder imaginar.
Tentativa SSH:
ellis77@CB461-EE10955:~/.ssh$ ssh [email protected] -vvv
OpenSSH_8.2p1 Ubuntu-4ubuntu0.2, OpenSSL 1.1.1f 31 Mar 2020
debug1: Reading configuration data /home/ellis77/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: include /etc/ssh/ssh_config.d/*.conf matched no files
debug1: /etc/ssh/ssh_config line 21: Applying options for *
debug2: resolve_canonicalize: hostname 169.254.132.152 is address
debug2: ssh_connect_direct
debug1: Connecting to 169.254.132.152 [169.254.132.152] port 22.
debug1: Connection established.
debug1: identity file /home/ellis77/.ssh/id_rsa type 0
debug1: identity file /home/ellis77/.ssh/id_rsa-cert type -1
debug1: identity file /home/ellis77/.ssh/id_dsa type -1
debug1: identity file /home/ellis77/.ssh/id_dsa-cert type -1
debug1: identity file /home/ellis77/.ssh/id_ecdsa type -1
debug1: identity file /home/ellis77/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/ellis77/.ssh/id_ecdsa_sk type -1
debug1: identity file /home/ellis77/.ssh/id_ecdsa_sk-cert type -1
debug1: identity file /home/ellis77/.ssh/id_ed25519 type -1
debug1: identity file /home/ellis77/.ssh/id_ed25519-cert type -1
debug1: identity file /home/ellis77/.ssh/id_ed25519_sk type -1
debug1: identity file /home/ellis77/.ssh/id_ed25519_sk-cert type -1
debug1: identity file /home/ellis77/.ssh/id_xmss type -1
debug1: identity file /home/ellis77/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.2p1 Ubuntu-4ubuntu0.2
debug1: Remote protocol version 2.0, remote software version OpenSSH_8.2p1 Ubuntu-4ubuntu0.2
debug1: match: OpenSSH_8.2p1 Ubuntu-4ubuntu0.2 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to 169.254.132.152:22 as 'root'
debug3: hostkeys_foreach: reading file "/home/ellis77/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/ellis77/.ssh/known_hosts:1
debug3: load_hostkeys: loaded 1 keys from 169.254.132.152
debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
debug1: SSH2_MSG_KEXINIT received
debug2: local client KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,ext-info-c
debug2: host key algorithms: [email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],ssh-ed25519,[email protected],rsa-sha2-512,rsa-sha2-256,ssh-rsa
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected],zlib
debug2: compression stoc: none,[email protected],zlib
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256
debug2: host key algorithms: rsa-sha2-512,rsa-sha2-256,ssh-rsa,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected]
debug2: compression stoc: none,[email protected]
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:DJTgdLuz5rpLWLc/y2M7YJMqKu8g77Orjn3CyoRreoU
debug3: hostkeys_foreach: reading file "/home/ellis77/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/ellis77/.ssh/known_hosts:1
debug3: load_hostkeys: loaded 1 keys from 169.254.132.152
debug1: Host '169.254.132.152' is known and matches the ECDSA host key.
debug1: Found key in /home/ellis77/.ssh/known_hosts:1
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey out after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey in after 134217728 blocks
debug1: Will attempt key: /home/ellis77/.ssh/id_rsa RSA SHA256:rk0afdhz18RlnxGQ0ejIyPKXNUnLvHDEv3BTu9u1kLY agent
debug1: Will attempt key: /home/ellis77/.ssh/id_dsa
debug1: Will attempt key: /home/ellis77/.ssh/id_ecdsa
debug1: Will attempt key: /home/ellis77/.ssh/id_ecdsa_sk
debug1: Will attempt key: /home/ellis77/.ssh/id_ed25519
debug1: Will attempt key: /home/ellis77/.ssh/id_ed25519_sk
debug1: Will attempt key: /home/ellis77/.ssh/id_xmss
debug2: pubkey_prepare: done
debug3: send packet: type 5
debug3: receive packet: type 7
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<ssh-ed25519,[email protected],ssh-rsa,rsa-sha2-256,rsa-sha2-512,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected]>
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,password
debug3: start over, passed a different list publickey,password
debug3: preferred 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 public key: /home/ellis77/.ssh/id_rsa RSA SHA256:rk0afdhz18RlnxGQ0ejIyPKXNUnLvHDEv3BTu9u1kLY agent
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,password
debug1: Trying private key: /home/ellis77/.ssh/id_dsa
debug3: no such identity: /home/ellis77/.ssh/id_dsa: No such file or directory
debug1: Trying private key: /home/ellis77/.ssh/id_ecdsa
debug3: no such identity: /home/ellis77/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: /home/ellis77/.ssh/id_ecdsa_sk
debug3: no such identity: /home/ellis77/.ssh/id_ecdsa_sk: No such file or directory
debug1: Trying private key: /home/ellis77/.ssh/id_ed25519
debug3: no such identity: /home/ellis77/.ssh/id_ed25519: No such file or directory
debug1: Trying private key: /home/ellis77/.ssh/id_ed25519_sk
debug3: no such identity: /home/ellis77/.ssh/id_ed25519_sk: No such file or directory
debug1: Trying private key: /home/ellis77/.ssh/id_xmss
debug3: no such identity: /home/ellis77/.ssh/id_xmss: No such file or directory
debug2: we did not send a packet, disable method
debug3: authmethod_lookup password
debug3: remaining preferred: ,password
debug3: authmethod_is_enabled password
debug1: Next authentication method: password
[email protected]'s password:
Depois de digitar a senha correta (que não deveria ser solicitada):
[email protected]'s password:
debug3: send packet: type 50
debug2: we sent a password packet, wait for reply
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,password
Permission denied, please try again.
[email protected]'s password:
Aqui está parte do arquivo sshd_config do host. Observe que a autenticação por senha está ativada no momento, mas eu a desliguei e reiniciei o serviço ssh e ele ainda a solicitou.
# This is the sshd server system-wide configuration file. See
# sshd_config(5) for more information.
# This sshd was compiled with PATH=/usr/local/sbin:/usr/local/bin:/usr/bin
# Logging
SyslogFacility AUTH
LogLevel VERBOSE
# Authentication:
#LoginGraceTime 2m
PermitRootLogin yes
#StrictModes yes
#AuthorizedPrincipalsFile none
#AuthorizedKeysCommand none
#AuthorizedKeysCommandUser nobody
# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
#HostbasedAuthentication no
# Change to yes if you don't trust ~/.ssh/known_hosts for
# HostbasedAuthentication
#IgnoreUserKnownHosts no
# Don't read the user's ~/.rhosts and ~/.shosts files
#IgnoreRhosts yes
# To disable tunneled clear text passwords, change to no here!
PasswordAuthentication yes
#PermitEmptyPasswords no
E por fim, a permissão de ambos os diretórios ssh: Cliente:
drwxrwxr-x 2 ellis77 ellis77 4096 Jun 17 10:08 .
drwxr-xr-x 27 ellis77 ellis77 4096 Jun 17 09:58 ..
-rw-r--r-- 1 ellis77 ellis77 0 Jun 17 10:07 config
-rw------- 1 ellis77 ellis77 2610 Jun 17 09:59 id_rsa
-rw------- 1 ellis77 ellis77 575 Jun 17 09:59 id_rsa.pub
-rw-r--r-- 1 ellis77 ellis77 222 Jun 17 10:08 known_hosts
Hospedar:
drwxr-xr-x 2 root root 4096 Sep 14 2020 .
drwxr-xr-x 38 root root 4096 Jun 15 13:01 ..
-rw-r--r-- 1 root root 525809 Aug 31 2020 moduli
-rw-r--r-- 1 root root 1484 Sep 15 2020 ssh_config
-rw------- 1 root root 1381 Sep 14 2020 ssh_host_dsa_key
-rw-r--r-- 1 root root 600 Sep 14 2020 ssh_host_dsa_key.pub
-rw------- 1 root root 505 Sep 14 2020 ssh_host_ecdsa_key
-rw-r--r-- 1 root root 172 Sep 14 2020 ssh_host_ecdsa_key.pub
-rw------- 1 root root 399 Sep 14 2020 ssh_host_ed25519_key
-rw-r--r-- 1 root root 92 Sep 14 2020 ssh_host_ed25519_key.pub
-rw------- 1 root root 2590 Sep 14 2020 ssh_host_rsa_key
-rw-r--r-- 1 root root 564 Sep 14 2020 ssh_host_rsa_key.pub
-rw-r--r-- 1 root root 3126
Desde já, obrigado. Ficarei feliz em fornecer qualquer outra coisa necessária.
Por último, para confirmar o IP do host:
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 169.254.132.152 netmask 255.255.0.0 broadcast 169.254.255.255
inet6 fe80::20a:35ff:fe00:122 prefixlen 64 scopeid 0x20<link>
ether 00:0a:35:00:01:22 txqueuelen 1000 (Ethernet)
RX packets 1 bytes 46 (46.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 381 bytes 16730 (16.3 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 27 base 0xb000
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1 (Local Loopback)
RX packets 212 bytes 18477 (18.0 KiB)
Editar: acabei de fazer login no SSH com meu laptop (sem chaves configuradas no meu laptop) e ele aceitou a senha. Então o problema parece estar na minha máquina de trabalho.
Responder1
Então foi muito bobo, mas sutil. Depois de compartilhar a Internet com a placa e executar o dhcpcd, configurei o endereço IP da conexão Ethernet USB de volta para o modo manual e configurei o endereço para 169.254.132.152...que era oigual ao tabuleiroEu estava tentando fazer SSH. Erro de novato. Precisa ser um endereço diferente de forma que seja o mesmo após o mascaramento com a máscara de rede... por exemplo 169.254.132.150. Então estamos na mesma máscara, mas não monopolizando o mesmo endereço. Isso explica por que eu consegui fazer ping e por que ele não aceitou minha "senha" porque eu estava fazendo ssh na minha conexão... não na minha placa.
Dica: Ao alterar o endereço IP da conexão, desconecte o USB e conecte-o novamente para que ele seja atualizado.