# SSH免密无法登录 时间：2025年8月8日 ------ 记录一次SSH免密无法登录处理过程 ## 现象 提交git仓代码时发现需要输入密码，检查git公钥私钥正常，怀疑gitea bug，删除gitea账户的密钥后，仍失败 ![image-20250808001918017](C:\Users\85749\AppData\Roaming\Typora\typora-user-images\image-20250808001918017.png) ## 排查过程 1、查看本机密钥权限是否存在异常 ``` root@VM-2-16-ubuntu:~/.ssh# ll total 24 drwx------ 2 root root 4096 Aug 7 23:56 ./ drwx------ 25 root root 4096 Aug 7 23:51 ../ -rw------- 1 root root 777 Dec 13 2024 authorized_keys -rw------- 1 root root 411 Nov 19 2024 id_ed25519 ###权限正常600 -> 411 -rw-r--r-- 1 root root 101 Nov 19 2024 id_ed25519.pub -rw-r--r-- 1 root root 142 Aug 7 23:56 known_hosts ``` 2、查看本机公钥私钥是否匹配 ``` root@VM-2-16-ubuntu:~/.ssh# cat id_ed25519.pub ssh-ed25519 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA root@VM-2-16-ubuntu ssh-keygen -y -f ~/.ssh/id_ed25519 ssh-ed25519 AAAAAAAAAAAAAAAAAAAAAAAAAA root@VM-2-16-ubuntu ###密钥结果匹配，本机无异常 ``` 3、查看本机debug日志 ``` root@VM-2-16-ubuntu:~/.ssh# ssh -vT -i ~/.ssh/id_ed25519 git@git.lzcwy.cn OpenSSH_9.6p1 Ubuntu-3ubuntu13.5, OpenSSL 3.0.13 30 Jan 2024 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 * debug1: Connecting to git.lzcwy.cn [82.157.64.204] port 22. debug1: Connection established. debug1: identity file /root/.ssh/id_ed25519 type 3 debug1: identity file /root/.ssh/id_ed25519-cert type -1 debug1: Local version string SSH-2.0-OpenSSH_9.6p1 Ubuntu-3ubuntu13.5 debug1: Remote protocol version 2.0, remote software version OpenSSH_9.6p1 Ubuntu-3ubuntu13.13 debug1: compat_banner: match: OpenSSH_9.6p1 Ubuntu-3ubuntu13.13 pat OpenSSH* compat 0x04000000 debug1: Authenticating to git.lzcwy.cn:22 as 'git' debug1: load_hostkeys: fopen /root/.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: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: algorithm: sntrup761x25519-sha512@openssh.com debug1: kex: host key algorithm: ssh-ed25519 debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: compression: none debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: compression: none debug1: expecting SSH2_MSG_KEX_ECDH_REPLY debug1: SSH2_MSG_KEX_ECDH_REPLY received debug1: Server host key: ssh-ed25519 SHA256:KeQo88NlFRuNnUykhPUh2o0dyWazhH9OIvIPklUD4w4 debug1: load_hostkeys: fopen /root/.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 'git.lzcwy.cn' is known and matches the ED25519 host key. debug1: Found key in /root/.ssh/known_hosts:1 debug1: ssh_packet_send2_wrapped: resetting send seqnr 3 debug1: rekey out after 134217728 blocks debug1: SSH2_MSG_NEWKEYS sent debug1: Sending SSH2_MSG_EXT_INFO debug1: expecting SSH2_MSG_NEWKEYS debug1: ssh_packet_read_poll2: resetting read seqnr 3 debug1: SSH2_MSG_NEWKEYS received debug1: rekey in after 134217728 blocks debug1: SSH2_MSG_EXT_INFO received debug1: kex_ext_info_client_parse: server-sig-algs= debug1: kex_ext_info_check_ver: publickey-hostbound@openssh.com=<0> debug1: kex_ext_info_check_ver: ping@openssh.com=<0> debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: SSH2_MSG_EXT_INFO received debug1: kex_ext_info_client_parse: server-sig-algs= debug1: Authentications that can continue: publickey,password debug1: Next authentication method: publickey debug1: Will attempt key: /root/.ssh/id_ed25519 ED25519 SHA256:w2mqdrO/ZGBBofMzBXHkEIyuoSudfgtF3rTr5Tlr6eE explicit debug1: Offering public key: /root/.ssh/id_ed25519 ED25519 SHA256:w2mqdrO/ZGBBofMzBXHkEIyuoSudfgtF3rTr5Tlr6eE explicit debug1: Authentications that can continue: publickey,password debug1: Next authentication method: password git@git.lzcwy.cn's password: ###debug1: Offering public key: /root/.ssh/id_ed25519 ED25519 说明本机可以识别到密钥并正确发送，查看对端日志 ``` 4、查看对端ssh日志 ``` root@VM-24-13-ubuntu:/home/ubuntu# tail -f /var/log/auth.log 2025-08-07T23:50:16.251031+08:00 localhost sshd[553036]: User git not allowed because account is locked ###账号被锁定了 ``` 5、查看账号状态 ``` root@VM-24-13-ubuntu:/home/ubuntu# passwd -S git git L 2024-12-31 -1 -1 -1 -1 ###L为被Lock，解锁账号 ``` 6、解锁账号恢复 ``` usermod -p 密码 git ```