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fourstring
V2EX  ›  Linux

Ubuntu14.04 普通用户无法通过 sshkey 登陆

  •  
  •   fourstring · 2016-08-09 17:51:17 +08:00 · 5710 次点击
    这是一个创建于 3029 天前的主题,其中的信息可能已经有所发展或是发生改变。

    如题。目前的基本情况是:

    本地:

    • OS:OS X 10.11.6
    • 用户名:fourstring

    服务器:

    • OS:Ubuntu14.04 x64 LTS
    • 用户名:git(想要建立 git 远程仓库)

    我新建了 git 用户,然后在/home/git下建立.ssh目录,设置权限为git:git 0700,并在.ssh目录下运行ssh-keygen,生成公私钥,将公钥命名为authorized_keys,设置权限git:git 0600。将私钥复制回本地,本地建立 ssh 配置,并且授予私钥权限 0600 。

    之后,尝试使用 ssh 命令连接服务器,连接被拒绝。

    我做的几点排查:

    • auth.log 没有任何验证失败信息
    • /etc/ssh/sshd_config中已经设置了
    RSAAuthentication yes
    PubkeyAuthentication yes
    AuthorizedKeysFile      %h/.ssh/authorized_keys
    
    • 确认各个文件权限完全正确
    • git 用户没有加入 /sbin/nologin(测试用)
    • 由于是 ubuntu 不存在 selinux
    • root 用户可以正常登陆

    运行ssh hexo(配置中的 Host 名) -vvv信息如下:

    OpenSSH_6.9p1, LibreSSL 2.1.8
    debug1: Reading configuration data /Users/fourstring/.ssh/config
    debug1: /Users/fourstring/.ssh/config line 1: Applying options for hexo
    debug1: Reading configuration data /etc/ssh/ssh_config
    debug1: /etc/ssh/ssh_config line 21: Applying options for *
    debug2: ssh_connect: needpriv 0
    debug1: Connecting to xxx port xxx.
    debug1: Connection established.
    debug1: identity file /Users/fourstring/.ssh/hexo type 1
    debug1: key_load_public: No such file or directory
    debug1: identity file /Users/fourstring/.ssh/hexo-cert type -1
    debug1: Enabling compatibility mode for protocol 2.0
    debug1: Local version string SSH-2.0-OpenSSH_6.9
    debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.6
    debug1: match: OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.6 pat OpenSSH_6.6.1* compat 0x04000000
    debug2: fd 3 setting O_NONBLOCK
    debug1: Authenticating to xxx as 'git'
    debug3: put_host_port: xxx
    debug3: hostkeys_foreach: reading file "/Users/fourstring/.ssh/known_hosts"
    debug3: record_hostkey: found key type ECDSA in file /Users/fourstring/.ssh/known_hosts:22
    debug3: load_hostkeys: loaded 1 keys from xxx
    debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
    debug1: SSH2_MSG_KEXINIT sent
    debug1: SSH2_MSG_KEXINIT received
    debug2: kex_parse_kexinit: [email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
    debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected],[email protected],[email protected],[email protected],ssh-ed25519,ssh-rsa,ssh-dss
    debug2: kex_parse_kexinit: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
    debug2: kex_parse_kexinit: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
    debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1,[email protected],[email protected],[email protected],[email protected],hmac-md5,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
    debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1,[email protected],[email protected],[email protected],[email protected],hmac-md5,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
    debug2: kex_parse_kexinit: none,[email protected],zlib
    debug2: kex_parse_kexinit: none,[email protected],zlib
    debug2: kex_parse_kexinit:
    debug2: kex_parse_kexinit:
    debug2: kex_parse_kexinit: first_kex_follows 0
    debug2: kex_parse_kexinit: reserved 0
    debug2: kex_parse_kexinit: [email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
    debug2: kex_parse_kexinit: ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ssh-ed25519
    debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,[email protected],[email protected],[email protected],aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
    debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,[email protected],[email protected],[email protected],aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
    debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-md5,hmac-sha1,[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
    debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-md5,hmac-sha1,[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
    debug2: kex_parse_kexinit: none,[email protected]
    debug2: kex_parse_kexinit: none,[email protected]
    debug2: kex_parse_kexinit:
    debug2: kex_parse_kexinit:
    debug2: kex_parse_kexinit: first_kex_follows 0
    debug2: kex_parse_kexinit: reserved 0
    debug1: kex: server->client [email protected] <implicit> none
    debug1: kex: client->server [email protected] <implicit> none
    debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
    debug1: Server host key: ecdsa-sha2-nistp256 SHA256:jGsXPrH3Cl2EWrBRzd4rr72jDeWKugYGPySGAMFL1mU
    debug3: put_host_port: xxx
    debug3: put_host_port: xxx
    debug3: hostkeys_foreach: reading file "/Users/fourstring/.ssh/known_hosts"
    debug3: record_hostkey: found key type ECDSA in file /Users/fourstring/.ssh/known_hosts:22
    debug3: load_hostkeys: loaded 1 keys from xxx
    debug3: hostkeys_foreach: reading file "/Users/fourstring/.ssh/known_hosts"
    debug3: record_hostkey: found key type ECDSA in file /Users/fourstring/.ssh/known_hosts:22
    debug3: load_hostkeys: loaded 1 keys from xxx
    debug1: Host 'xxx' is known and matches the ECDSA host key.
    debug1: Found key in /Users/fourstring/.ssh/known_hosts:22
    debug2: set_newkeys: mode 1
    debug1: SSH2_MSG_NEWKEYS sent
    debug1: expecting SSH2_MSG_NEWKEYS
    debug2: set_newkeys: mode 0
    debug1: SSH2_MSG_NEWKEYS received
    debug1: SSH2_MSG_SERVICE_REQUEST sent
    debug2: service_accept: ssh-userauth
    debug1: SSH2_MSG_SERVICE_ACCEPT received
    debug2: key: /Users/fourstring/.ssh/hexo (0x7f9f3b013d70), explicit
    debug1: Authentications that can continue: publickey
    debug3: start over, passed a different list publickey
    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: Offering RSA public key: /Users/fourstring/.ssh/hexo
    debug3: send_pubkey_test
    debug2: we sent a publickey packet, wait for reply
    debug1: Authentications that can continue: publickey
    debug2: we did not send a packet, disable method
    debug1: No more authentication methods to try.
    Permission denied (publickey).
    

    最离奇的是以我自己的了解,我竟然没有从中看出任何连接被拒绝的信息。。。

    另外,查找资料说本地用户名须和远程要登陆的用户名一致,但我的实际体验中并非如此。我的root用户就是本地生成sshkey上传到服务器,可以正常登陆。而且从我描述的流程中,可以看出我是在服务器上生成的key然后下载到本地的。

    还望各位大神不吝赐教,感谢!

    34 条回复    2018-04-09 13:08:43 +08:00
    sopato
        1
    sopato  
       2016-08-09 18:09:32 +08:00
    看看 /var/log/auth.log 输出了什么信息给你,根据那个错误信息来检查排错一下呗。
    shenqi
        2
    shenqi  
       2016-08-09 18:09:51 +08:00
    不知道。围观下,坐等其他人的回答。

    我觉得是露珠描述不清楚。
    ipeony
        3
    ipeony  
       2016-08-09 18:21:35 +08:00 via Android
    private key 没加载好?正常是启个 agent ,然后 ssh-add 吧
    finian
        4
    finian  
       2016-08-09 18:34:16 +08:00
    1. 远程 sshd 改完配置重启了吗?
    2. 本地私钥是这个 /Users/fourstring/.ssh/hexo 对吗?
    wweir
        5
    wweir  
       2016-08-09 19:05:23 +08:00
    对 $HOME 目录的权限也有要求,验了么?
    之前搞 docker 把 /root 目录共享了一下,也是 ssh 方面出了一大堆问题
    fourstring
        6
    fourstring  
    OP
       2016-08-09 19:11:36 +08:00
    @sopato auth.log 没有任何错误……而且我还运行过 tail -f /var/run/auth.log ,在连接失败时该日志没有任何变化
    fourstring
        7
    fourstring  
    OP
       2016-08-09 19:11:54 +08:00
    @shenqi 您觉得是哪里描述不清楚呢?请指出
    crazycen
        8
    crazycen  
       2016-08-09 19:12:26 +08:00 via iPhone
    .ssh 目录不需要手动建立,还有,确认你生成 key 的方式是否正确。这是最基本功能,也不可能会出问题!
    fourstring
        9
    fourstring  
    OP
       2016-08-09 19:14:15 +08:00
    @ipeony .ssh 目录下 config 文件是用 IdentifyFile 选项加载 privatekey 么?如果是的话我应该没有配置错。
    另外和能正常登陆的 root 用户的-vvv 比较了一下,好像就只有 debug 信息的最后几行,正常的是
    debug2: we sent a publickey packet, wait for reply
    之后就收到 auth succeed 的回复然后进入 shell
    fourstring
        10
    fourstring  
    OP
       2016-08-09 19:14:57 +08:00
    @finian 实际上我没有改过配置,那个配置是默认就有的。我也尝试过重启 sshd ,没有效果。私钥是这个,没有出错。
    fourstring
        11
    fourstring  
    OP
       2016-08-09 19:16:06 +08:00
    @wweir 我用的是 adduser 命令添加用户,自动建立了主目录,刚刚又去检查了一下,$HOME 的权限是正确的
    fourstring
        12
    fourstring  
    OP
       2016-08-09 19:16:40 +08:00
    @crazycen 请问.ssh 目录不手动建立该如何建立呢?另外生成 key 的方式是不是运行 ssh-keygen 命令?
    crazycen
        13
    crazycen  
       2016-08-09 19:20:51 +08:00
    larsenlouis
        14
    larsenlouis  
       2016-08-09 19:21:11 +08:00
    普通用户能用密码登录吗?普通用户的 Home 加密了?如果普通用户 home 目录加密,本机没有登录的情况下, Home 目录没有挂载,只能密码登录。而 root 用户的 home 目录不在加密的目录里。
    oxoxoxox
        15
    oxoxoxox  
       2016-08-09 19:27:10 +08:00
    远端 server 的 authorized_keys 权限设置为 644 试试看呢?
    fourstring
        16
    fourstring  
    OP
       2016-08-09 19:29:17 +08:00
    @larsenlouis 密码可以登录。我用 adduser 命令添加的用户,应该不会自动加密吧? root 是可以正常访问 git 用户的$home 目录的
    fourstring
        17
    fourstring  
    OP
       2016-08-09 19:31:41 +08:00
    @oxoxoxox 这个刚刚尝试了一下,貌似并没有什么用。。。/var/run/auth.log 里也没有报权限错误
    larsenlouis
        18
    larsenlouis  
       2016-08-09 19:33:05 +08:00
    @fourstring 加密 home 是安装 ubuntu 系统时选的,你看看 /etc/fstab 有没有 encryptfs 的载点, root 可以正常访问时用 ssh 还是服务器本地,当时服务器本地有没有普通用户登录?
    fourstring
        19
    fourstring  
    OP
       2016-08-09 19:36:08 +08:00
    @larsenlouis 对,安装 ubuntu 的时候确实会送这个。问题是我是 VPS 啊。。。 root 用 ssh 可以正常访问的。我都进不去服务器本地- -
    larsenlouis
        20
    larsenlouis  
       2016-08-09 19:38:54 +08:00
    @fourstring 有些供应商会在虚拟机的控制台上模拟本地终端,你用普通用户登录后用`w`命令看看有没有 tty 的 session
    fourstring
        21
    fourstring  
    OP
       2016-08-09 19:41:44 +08:00
    @larsenlouis 没有啊- -都是 pts ?
    larsenlouis
        22
    larsenlouis  
       2016-08-09 20:04:18 +08:00
    @fourstring 贴一下本地的.ssh/config 和 服务器的 sshd_config
    实在不知道是什么问题 这个时候就要 sudo apt remove openssh-server --purge && rm -rf ~/.ssh/,祭出此文,重装。 https://help.ubuntu.com/community/SSH/OpenSSH/Keys

    客户端本地生成密匙, ssh-copy-id(不知道 macOS 有没有)上传 publickey ,再改本地.ssh/config ,再改服务器 sshd_config 关闭密码登录和禁止 root 登录,最后装上 fail2ban 。
    fourstring
        23
    fourstring  
    OP
       2016-08-09 20:07:02 +08:00
    @larsenlouis sshd_config:
    # Package generated configuration file
    # See the sshd_config(5) manpage for details

    # What ports, IPs and protocols we listen for
    Port 63842
    # Use these options to restrict which interfaces/protocols sshd will bind to
    #ListenAddress ::
    #ListenAddress 0.0.0.0
    Protocol 2
    # HostKeys for protocol version 2
    HostKey /etc/ssh/ssh_host_rsa_key
    HostKey /etc/ssh/ssh_host_dsa_key
    HostKey /etc/ssh/ssh_host_ecdsa_key
    HostKey /etc/ssh/ssh_host_ed25519_key
    #Privilege Separation is turned on for security
    UsePrivilegeSeparation yes

    # Lifetime and size of ephemeral version 1 server key
    KeyRegenerationInterval 3600
    ServerKeyBits 1024

    # Logging
    SyslogFacility AUTH
    LogLevel INFO

    # Authentication:
    LoginGraceTime 120
    PermitRootLogin yes
    StrictModes yes

    RSAAuthentication yes
    PubkeyAuthentication yes
    AuthorizedKeysFile %h/.ssh/authorized_keys

    # Don't read the user's ~/.rhosts and ~/.shosts files
    IgnoreRhosts yes
    # For this to work you will also need host keys in /etc/ssh_known_hosts
    RhostsRSAAuthentication no
    # similar for protocol version 2
    HostbasedAuthentication no
    # Uncomment if you don't trust ~/.ssh/known_hosts for RhostsRSAAuthentication
    #IgnoreUserKnownHosts yes

    # To enable empty passwords, change to yes (NOT RECOMMENDED)
    PermitEmptyPasswords no

    # Change to yes to enable challenge-response passwords (beware issues with
    # some PAM modules and threads)
    ChallengeResponseAuthentication no

    # Change to no to disable tunnelled clear text passwords
    PasswordAuthentication no

    # Kerberos options
    #KerberosAuthentication no
    #KerberosGetAFSToken no
    #KerberosOrLocalPasswd yes
    #KerberosTicketCleanup yes

    # GSSAPI options
    #GSSAPIAuthentication no
    #GSSAPICleanupCredentials yes

    X11Forwarding yes
    X11DisplayOffset 10
    PrintMotd no
    PrintLastLog yes
    TCPKeepAlive yes
    #UseLogin no

    #MaxStartups 10:30:60
    #Banner /etc/issue.net

    # Allow client to pass locale environment variables
    AcceptEnv LANG LC_*

    Subsystem sftp /usr/lib/openssh/sftp-server

    # Set this to 'yes' to enable PAM authentication, account processing,
    # and session processing. If this is enabled, PAM authentication will
    # be allowed through the ChallengeResponseAuthentication and
    # PasswordAuthentication. Depending on your PAM configuration,
    # PAM authentication via ChallengeResponseAuthentication may bypass
    # the setting of "PermitRootLogin without-password".
    # If you just want the PAM account and session checks to run without
    # PAM authentication, then enable this but set PasswordAuthentication
    # and ChallengeResponseAuthentication to 'no'.
    UsePAM yes

    ssh config :
    Host hexo
    HostName xxx
    Port 63842
    User git
    IdentityFile ~/.ssh/hexo
    fourstring
        24
    fourstring  
    OP
       2016-08-09 20:07:40 +08:00
    @larsenlouis 另外由客户端生成密钥和服务端生成密钥都试过,均失败
    abmin521
        25
    abmin521  
       2016-08-09 20:15:28 +08:00 via Android
    试一下 ssh localhost ?
    fourstring
        26
    fourstring  
    OP
       2016-08-09 20:20:46 +08:00
    @abmin521 为什么要这么用。。。?是在服务器上么?
    abmin521
        27
    abmin521  
       2016-08-09 20:22:24 +08:00 via Android
    @fourstring 不是服务器 要登陆 root 的机器 有些服务器可能有限制
    abmin521
        28
    abmin521  
       2016-08-09 20:22:49 +08:00 via Android
    看错了 是服务器
    hsyu53
        29
    hsyu53  
       2016-08-09 20:33:25 +08:00 via Android
    印象中是在本地生产密钥,再将公钥拷贝到服务端
    larsenlouis
        30
    larsenlouis  
       2016-08-09 20:36:08 +08:00
    @fourstring UserPAM 之后放 subsystem ,而且 subsystem 在配置最后,没有其他配置。应该是这个的问题,另外 sftp 组里有哪些用户?
    fourstring
        31
    fourstring  
    OP
       2016-08-09 20:44:57 +08:00
    @larsenlouis 我刚刚用 VNC 连接,开启 sshd -d 看了一下 debug 信息,还请您看一下?(只有图片,没法复制出来- -)

    另外按您说的那样改了,也没有用= =
    fourstring
        32
    fourstring  
    OP
       2016-08-09 20:50:42 +08:00
    @larsenlouis ヾ(。`Д´。)!被这个问题坑了一下午,我有点想爆粗口了。。。
    我在服务端又重新生成了一对密钥,然后把私钥下载回本地,一开始仍然失败。
    当我把私钥名字从 hexo 改掉之后……连上了!连上了!神 TM 连上了……
    abmin521
        33
    abmin521  
       2016-08-09 21:22:50 +08:00 via Android
    呵呵 上面的当我没说
    winstars
        34
    winstars  
       2018-04-09 13:08:43 +08:00
    @fourstring #32 同学,我也是一样的问题,私钥名改掉是什么意思?
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