我无法通过 SSH 从一台主机连接到我的 Ubuntu 22.04 服务器。我可以从其他主机毫无问题地连接到该服务器。但是，当我尝试从该主机连接时：ssh -p 5435 -i ~/.ssh/id_ed25519 user@my_server.com -vvv
我得到：
OpenSSH_8.9p1 Ubuntu-3ubuntu0.10, OpenSSL 3.0.2 15 Mar 2022
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 *
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts' -> '/home/user/.ssh/known_hosts'
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts2' -> '/home/user/.ssh/known_hosts2'
debug2: resolving "my_server.com" port 5435
debug3: resolve_host: lookup my_server.com: 5435
debug3: ssh_connect_direct: entering
debug1: Connecting to my_server.com [xxx.xxx.xxx.xxx] port 5435.
debug3: set_sock_tos: set socket 3 IP_TOS 0x10
debug1: Connection established.
debug1: identity file /home/user/.ssh/id_rsa type -1
debug1: identity file /home/user/.ssh/id_rsa-cert type -1
debug1: identity file /home/user/.ssh/id_ecdsa type -1
debug1: identity file /home/user/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/user/.ssh/id_ecdsa_sk type -1
debug1: identity file /home/user/.ssh/id_ecdsa_sk-cert type -1
debug1: identity file /home/user/.ssh/id_ed25519 type 3
debug1: identity file /home/user/.ssh/id_ed25519-cert type -1
debug1: identity file /home/user/.ssh/id_ed25519_sk type -1
debug1: identity file /home/user/.ssh/id_ed25519_sk-cert type -1
debug1: identity file /home/user/.ssh/id_xmss type -1
debug1: identity file /home/user/.ssh/id_xmss-cert type -1
debug1: identity file /home/user/.ssh/id_dsa type -1
debug1: identity file /home/user/.ssh/id_dsa-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.9p1 Ubuntu-3ubuntu0.10
debug1: Remote protocol version 2.0, remote software version OpenSSH_8.9p1 Ubuntu-3ubuntu0.10
debug1: compat_banner: match: OpenSSH_8.9p1 Ubuntu-3ubuntu0.10 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to my_server.com:5435 as 'user'
debug3: put_host_port: [my_server.com]:5435
debug3: record_hostkey: found key type ED25519 in file /home/user/.ssh/known_hosts:1
debug3: load_hostkeys_file: loaded 1 keys from [my_server.com]:5435
debug1: load_hostkeys: fopen /home/user/.ssh/known_hosts2: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts2: No such file or directory
debug3: order_hostkeyalgs: have matching best-preference key type [email protected], using HostkeyAlgorithms verbatim
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,[email protected],diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,ext-info-c,[email protected]
debug2: host key algorithms: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected],rsa-sha2-512,rsa-sha2-256
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,[email protected],diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,[email protected]
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
debug3: kex_choose_conf: will use strict KEX ordering
debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: ssh-ed25519
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: SSH2_MSG_KEX_ECDH_REPLY received
debug1: Server host key: ssh-ed25519 SHA256:ChCUrM9ZYCR057q60M84kB6pAQa9bQ8ZEHVuw8g7/p0
debug3: put_host_port: [xxx.xxx.xxx.xxx]:5435
debug3: put_host_port: [my_server.com]:5435
debug3: record_hostkey: found key type ED25519 in file /home/user/.ssh/known_hosts:1
debug3: load_hostkeys_file: loaded 1 keys from [my_server.com]:5435
debug1: load_hostkeys: fopen /home/user/.ssh/known_hosts2: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts2: No such file or directory
debug1: Host '[my-server.com]:5435' is known and matches the ED25519 host key.
debug1: Found key in /home/user/.ssh/known_hosts:1
debug3: send packet: type 21
debug1: ssh_packet_send2_wrapped: resetting send seqnr 3
debug2: ssh_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: ssh_packet_read_poll2: resetting read seqnr 3
debug1: SSH2_MSG_NEWKEYS received
debug2: ssh_set_newkeys: mode 0
debug1: rekey in after 134217728 blocks
debug1: Will attempt key: /home/user/.ssh/id_rsa
debug1: Will attempt key: /home/user/.ssh/id_ecdsa
debug1: Will attempt key: /home/user/.ssh/id_ecdsa_sk
debug1: Will attempt key: /home/user/.ssh/id_ed25519 ED25519 SHA256:95gTIyyYHXV+UgGYTJiGgC5ulxp3jQoeHmhohQRbIPI
debug1: Will attempt key: /home/user/.ssh/id_ed25519_sk
debug1: Will attempt key: /home/user/.ssh/id_xmss
debug1: Will attempt key: /home/user/.ssh/id_dsa
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],[email protected]>
debug1: kex_input_ext_info: [email protected]=<0>
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
debug3: start over, passed a different list publickey
debug3: preferred gssapi-with-mic,keyboard-interactive,password
debug1: No more authentication methods to try.
[email protected]: Permission denied (publickey).
客户端似乎没有向服务器提供任何公钥。Offering public key:...之后应该有Authentications that can continue: publickey
该~/.ssh文件夹似乎具有正确的权限：
user@client:~$ ll .ssh
total 24
drwx------ 2 user user 4096 Oct 13 18:54 ./
drwxr-xr-x 8 user user 4096 Oct 12 12:13 ../
-rw------- 1 user user 96 Sep 14 16:50 authorized_keys
-rw------- 1 user user 411 Oct 12 11:42 id_ed25519
-rw-r--r-- 1 user user 96 Oct 12 11:42 id_ed25519.pub
-rw-r--r-- 1 user user 142 Oct 12 11:45 known_hosts
另外，我在密钥中启用了 ed25519：
$ ssh -Q key
ssh-ed25519
[email protected]
...
我的公钥在服务器的authorised_keys文件中，我仔细检查了本地文件id_ed25519.pub。它们是相同的。在服务器的日志中，我有：
$ tail -f /var/log/auth.log
Oct 13 19:19:53 my_server sshd[3131]: Connection closed by authenticating user user xxx.xxx.xxx.xxx port 39810 [preauth]
可能是什么问题？我重新安装了 ssh，但没用。我还生成并上传了一个新密钥 - 同样的错误。同样，我可以从至少 2 个其他主机使用同一用户连接到该服务器。
您可能已在客户端的某处
PubkeyAuthentication进行设置。no通常情况下：
publickey如果PubkeyAuthentication未设置/设置为，则应包括yes：但是，如果我
PubkeyAuthentication用以下方法覆盖no：检查您是否已在 中
PubkeyAuthentication设置为，或者：no~/.ssh/config/etc/ssh/ssh_config/etc/ssh/ssh_config.d/*pubkey您的首选身份验证方法中似乎没有。检查您的 ssh 配置文件（/etc/ssh/ssh_config和~/.ssh/config）中是否有选项PreferredAuthentications更改。另外，在服务器上检查
/etc/ssh/sshd_config是否PubkeyAcceptedKeyTypes包含ed25519，以及是否PubkeyAuthentication设置为yes（应该根据日志）。否则，您可以尝试新的 RSA 4096 密钥。