Estoy desarrollando software en una placa personalizada que ejecuta Linux. Accedo a esta placa a través de ssh en una conexión por cable. Tengo un adaptador USB-Ethernet en mi máquina y luego el cable Ethernet se conecta a esta placa personalizada. Tenía claves ssh configuradas para no tener que escribir una contraseña cada vez. Todo funcionaba bien hasta que compartí Internet con esa placa y ejecuté un git pull para actualizar el software. (Eso funcionó bien por cierto). Después de cambiar la dirección IP a manual y restablecer la IP anterior, recibí una advertencia sobre el cambio de host. Esto es de Internet, por lo que las IP no coinciden, pero se veía así:
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ 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.
Me siguen pidiendo la contraseña cuando intento hacer ssh aunque no debería.La parte más peculiar.es que cuando escribo la contraseña no la acepta. ¿Cómo sé que es la contraseña correcta? Porque estoy usando la pantalla para conectarme en serie a la placa y he iniciado sesión con esa contraseña a través de la pantalla. Puedo acceder al tablero y luego (host) a través de la pantalla, es solo que la pantalla es muy lenta y necesito ssh para vscode y otras cosas.
Incluso desinstalé el cliente ssh en mi máquina y lo reinstalé. Nada. Eliminé la carpetaknown_hosts de mi máquina y no sirvió de nada. El host puede enviar ssh a su propia dirección IP (no loopback), por lo que creo que acepta solicitudes ssh. (A menos que haya un cortocircuito allí y en realidad no esté usando ssh cuando usa su propia IP. Pero creo que sí).
Puedo acceder a los archivos del host y del cliente si es necesario. He estado estancado en esto durante 3 días por mi trabajo, por lo que cualquier ayuda sería muy apreciada. Publicaré tantas cosas útiles como se me ocurran.
Intento 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:
Después de escribir la contraseña correcta (que no debería solicitar):
[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:
Aquí hay parte del archivo sshd_config del host. Tenga en cuenta que la autenticación de contraseña está actualmente activada, pero la desactivé y reinicié el servicio ssh y todavía la solicitó.
# 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
Y por último, el permiso de ambos directorios 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
Anfitrión:
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
Gracias de antemano. Estaré encantado de proporcionarte cualquier otra cosa que necesites.
Por último, para confirmar la IP del 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: simplemente inicié sesión en SSH con mi computadora portátil (sin claves configuradas en mi computadora portátil) y aceptó la contraseña. Entonces el problema parece estar en mi máquina de trabajo.
Respuesta1
Entonces fue muy tonto pero sutil. Después de compartir Internet con la placa y ejecutar dhcpcd, configuré la dirección IP de la conexión Ethernet USB nuevamente al modo manual y configuré la dirección en 169.254.132.152... que era laigual que el tableroEstaba intentando ingresar por SSH. Error de principiante. Tiene que ser una dirección diferente de manera que sea la misma después de enmascararla con la máscara de red... por ejemplo 169.254.132.150. Entonces estamos con la misma máscara pero no acaparando la misma dirección. Esto explica por qué podía hacer ping y por qué no aceptaba mi "contraseña" porque estaba ingresando a mi conexión... no a mi placa.
Consejo: cuando cambie la dirección IP de la conexión, asegúrese de desconectar su USB y volver a enchufarlo para que se actualice.