ssh免密登录失败

╰半橙微兮° 2022-04-16 02:36 772阅读 0赞

**前言**

本来要在服务器上安装docker-machine，然后管理其他云服务器的docker容器的，结果到了ssh免密登录这一步，一直走不通。下面把我遇到的问题，记录下。

注：docker-machine安装可参考文章：[https://blog.csdn.net/wfs1994/article/details/80658555][https_blog.csdn.net_wfs1994_article_details_80658555]

**ssh免密登录**

由于，要管理其他的云服务器的docker，所以需要用ssh免密登录到其余的云服务器（主服务器192.168.20.200，远程服务器192.168.20.201）。如下：

ssh-keygen -t rsa

ssh-copy-id 192.168.20.201

然后输入192.168.20.201的密码，提示ok了，于是测试下

ssh 192.168.20.201

结果还是需要输入密码。

**google一下**

出现这种奇葩问题，果断，先google一下。结果大部分都说是权限问题，然后我按照教程说的修改了192.168.20.201下root目录及下面的.ssh文件夹的权限，还是不行。

于是用ssh -v 192.168.20.201看一下日志：

OpenSSH_7.4p1, OpenSSL 1.0.2k-fips  26 Jan 2017
    debug1: Reading configuration data /etc/ssh/ssh_config
    debug1: /etc/ssh/ssh_config line 58: Applying options for *
    debug1: Connecting to 192.168.20.201 [192.168.20.201] port 22.
    debug1: Connection established.
    debug1: permanently_set_uid: 0/0
    debug1: identity file /root/.ssh/id_rsa type 1
    debug1: key_load_public: No such file or directory
    debug1: identity file /root/.ssh/id_rsa-cert type -1
    debug1: key_load_public: No such file or directory
    debug1: identity file /root/.ssh/id_dsa type -1
    debug1: key_load_public: No such file or directory
    debug1: identity file /root/.ssh/id_dsa-cert type -1
    debug1: key_load_public: No such file or directory
    debug1: identity file /root/.ssh/id_ecdsa type -1
    debug1: key_load_public: No such file or directory
    debug1: identity file /root/.ssh/id_ecdsa-cert type -1
    debug1: key_load_public: No such file or directory
    debug1: identity file /root/.ssh/id_ed25519 type -1
    debug1: key_load_public: No such file or directory
    debug1: identity file /root/.ssh/id_ed25519-cert type -1
    debug1: Enabling compatibility mode for protocol 2.0
    debug1: Local version string SSH-2.0-OpenSSH_7.4
    debug1: Remote protocol version 2.0, remote software version OpenSSH_7.4
    debug1: match: OpenSSH_7.4 pat OpenSSH* compat 0x04000000
    debug1: Authenticating to 192.168.20.201:22 as 'root'
    debug1: SSH2_MSG_KEXINIT sent
    debug1: SSH2_MSG_KEXINIT received
    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
    debug1: kex: curve25519-sha256 need=64 dh_need=64
    debug1: kex: curve25519-sha256 need=64 dh_need=64
    debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
    debug1: Server host key: ecdsa-sha2-nistp256 SHA256:wORn5yWtd8wO3XfFm11Wu6iNezHNRT5QKxowGHZyCT0
    debug1: Host '192.168.20.201' is known and matches the ECDSA host key.
    debug1: Found key in /root/.ssh/known_hosts:1
    debug1: rekey after 134217728 blocks
    debug1: SSH2_MSG_NEWKEYS sent
    debug1: expecting SSH2_MSG_NEWKEYS
    debug1: SSH2_MSG_NEWKEYS received
    debug1: rekey after 134217728 blocks
    debug1: SSH2_MSG_EXT_INFO received
    debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
    debug1: SSH2_MSG_SERVICE_ACCEPT received
    debug1: Authentications that can continue: gssapi-keyex,gssapi-with-mic,password
    debug1: Next authentication method: gssapi-keyex
    debug1: No valid Key exchange context
    debug1: Next authentication method: gssapi-with-mic
    debug1: Unspecified GSS failure.  Minor code may provide more information
    No Kerberos credentials available (default cache: KEYRING:persistent:0)
    
    debug1: Unspecified GSS failure.  Minor code may provide more information
    No Kerberos credentials available (default cache: KEYRING:persistent:0)
    
    debug1: Next authentication method: password

发现ssh确实是几种认证方式都失败了，直接到了需要密码登录，如下：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21hcXVlYWxvbmU_size_16_color_FFFFFF_t_70][]

那这是什么原因造成的呢？

结果发现认证方式只有gssapi-keyex,gssapi-with-mic,password，并没有publickey。

那肯定是192.168.20.201这台服务器上的sshd配置有问题。

于是登录192.168.20.201这台服务器，看了下sshd配置

搜索PubkeyAuthentication，结果发现这项被注释了。放开注释，重启sshd：service sshd restart。

再用ssh远程登录这台服务器，ok了。

[https_blog.csdn.net_wfs1994_article_details_80658555]: https://blog.csdn.net/wfs1994/article/details/80658555
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21hcXVlYWxvbmU_size_16_color_FFFFFF_t_70]: /images/20220416/f03a84e2ef9e4859a9eaeea3963e062a.png