Para desativar a senha auth, defini os seguintes valores em sshd_config
ChallengeResponseAuthentication no
PasswordAuthentication no
UsePAM no
Quando tento fazer login com minha chave privada, obtenho
Permission denied (publickey).
Se eu alterar UsePAM para yes , posso fazer o login usando minha chave privada. Por quê?
Estou me conectando a um host Ubuntu 12.04 de 64 bits da OSX
ssh -i ~/.ssh/deploy -l deploy localhost -p 2222 -v
aqui está o verboso ssh output:
OpenSSH_5.9p1, OpenSSL 0.9.8r 8 Feb 2011
debug1: Reading configuration data /Users/<user>/.ssh/config
debug1: Reading configuration data /etc/ssh_config
debug1: /etc/ssh_config line 20: Applying options for *
debug1: Connecting to localhost [127.0.0.1] port 2222.
debug1: Connection established.
debug1: identity file /Users/<user>/.ssh/deploy type 1
debug1: identity file /Users/<user>/.ssh/deploy-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.9p1 Debian-5ubuntu1
debug1: match: OpenSSH_5.9p1 Debian-5ubuntu1 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.9
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
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
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Server host key: RSA 50:db:75:ba:11:2f:43:c9:ab:14:40:6d:7f:a1:ee:e3
debug1: Host '[localhost]:2222' is known and matches the RSA host key.
debug1: Found key in /Users/<user>/.ssh/known_hosts:2
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /Users/<user>/.ssh/key1
debug1: Authentications that can continue: publickey
debug1: Offering RSA public key: /Users/<user>/.ssh/deploy
debug1: Authentications that can continue: publickey
debug1: No more authentication methods to try.
Permission denied (publickey).
Sem o PAM (Pluggable Authentication Module) é necessária uma configuração ssh mais complicada para autenticar. Você está procurando por isso, na verdade:
# grep Password /etc/ssh/sshd_config
PermitEmptyPasswords no
PasswordAuthentication no
Isso desativará o login com senha. Verifique se você definiu as configurações de chave pública corretamente.
Sua conta de usuário está bloqueada? Você pode desbloquear a conta de usuário
passwd -u username
ou bloquear a conta do usuário, mas ativar o PAM:
ChallengeResponseAuthentication no
PasswordAuthentication no
UsePAM yes