Ssh
樹莓派 SSH 登錄後立即關閉連接
我啟用了 ssh 並在我的 pi 上工作（我多次使用它）。
到今天為止，它在我輸入密碼後立即開始關閉連接。
我試圖通過以下方式獲取 ID：
ssh pi@XXX.XXX.XXX.XXX id卻一無所獲。
這是-vvv日誌：
OpenSSH_7.6p1, LibreSSL 2.6.2 debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 48: Applying options for * debug2: ssh_connect_direct: needpriv 0 debug1: Connecting to XXX.XXX.XXX.XXX port 22. debug1: Connection established. debug1: key_load_public: No such file or directory debug1: identity file /Users/gio/.ssh/id_rsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /Users/gio/.ssh/id_rsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /Users/gio/.ssh/id_dsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /Users/gio/.ssh/id_dsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /Users/gio/.ssh/id_ecdsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /Users/gio/.ssh/id_ecdsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /Users/gio/.ssh/id_ed25519 type -1 debug1: key_load_public: No such file or directory debug1: identity file /Users/gio/.ssh/id_ed25519-cert type -1 debug1: Local version string SSH-2.0-OpenSSH_7.6 debug1: Remote protocol version 2.0, remote software version OpenSSH_7.4p1 Raspbian-10+deb9u1 debug1: match: OpenSSH_7.4p1 Raspbian-10+deb9u1 pat OpenSSH* compat 0x04000000 debug3: fd 5 is O_NONBLOCK debug1: Authenticating to XXX.XXX.XXX.XXX:22 as 'pi' debug3: hostkeys_foreach: reading file "/Users/gio/.ssh/known_hosts" debug3: record_hostkey: found key type ECDSA in file /Users/gio/.ssh/known_hosts:23 debug3: load_hostkeys: loaded 1 keys from XXX.XXX.XXX.XXX debug3: order_hostkeyalgs: prefer hostkeyalgs: ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,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,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,ext-info-c debug2: host key algorithms: ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519-cert-v01@openssh.com,ssh-rsa-cert-v01@openssh.com,ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: compression ctos: none,zlib@openssh.com,zlib debug2: compression stoc: none,zlib@openssh.com,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,curve25519-sha256@libssh.org,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,diffie-hellman-group14-sha1 debug2: host key algorithms: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519 debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: compression ctos: none,zlib@openssh.com debug2: compression stoc: none,zlib@openssh.com 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: chacha20-poly1305@openssh.com MAC: <implicit> compression: none debug1: kex: client->server cipher: chacha20-poly1305@openssh.com 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:DnP87WARo4OBChrMsVUrmJSOtXfTex+1QWp8poAKmYE debug3: hostkeys_foreach: reading file "/Users/gio/.ssh/known_hosts" debug3: record_hostkey: found key type ECDSA in file /Users/gio/.ssh/known_hosts:23 debug3: load_hostkeys: loaded 1 keys from XXX.XXX.XXX.XXX debug1: Host 'XXX.XXX.XXX.XXX' is known and matches the ECDSA host key. debug1: Found key in /Users/gio/.ssh/known_hosts:23 debug3: send packet: type 21 debug2: set_newkeys: mode 1 debug1: rekey 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 after 134217728 blocks debug2: key: /Users/gio/.ssh/id_rsa (0x0) debug2: key: /Users/gio/.ssh/id_dsa (0x0) debug2: key: /Users/gio/.ssh/id_ecdsa (0x0) debug2: key: /Users/gio/.ssh/id_ed25519 (0x0) 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,ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521> 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 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: Trying private key: /Users/gio/.ssh/id_rsa debug3: no such identity: /Users/gio/.ssh/id_rsa: No such file or directory debug1: Trying private key: /Users/gio/.ssh/id_dsa debug3: no such identity: /Users/gio/.ssh/id_dsa: No such file or directory debug1: Trying private key: /Users/gio/.ssh/id_ecdsa debug3: no such identity: /Users/gio/.ssh/id_ecdsa: No such file or directory debug1: Trying private key: /Users/gio/.ssh/id_ed25519 debug3: no such identity: /Users/gio/.ssh/id_ed25519: 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 pi@XXX.XXX.XXX.XXX's password: debug3: send packet: type 50 debug2: we sent a password packet, wait for reply Connection closed by XXX.XXX.XXX.XXX port 22
原來問題是由低電壓引起的。換了電源，重啟了pi，問題就解決了。
允許登錄的 ssh-server 設備。
如果使用者不被允許登錄，伺服器只是斷開連接而不給出詳細的原因（這可能有助於黑客）。
查看 raspberry 上的 /var/log/auth 以了解原因。