[Hadoop]SSH免密码登录以及失败解决方案

1. 创建ssh-key

这里我们采用rsa方式，使用如下命令：

   
   
   
   

    
    
    
    
xiaosi@xiaosi:~$ ssh-keygen -t rsa -f ~/.ssh/id_rsa
    
    
    
    
Generating public/private rsa key pair.
    
    
    
    
Created directory '/home/xiaosi/.ssh'.
    
    
    
    
Enter passphrase (empty for no passphrase): 
    
    
    
    
Enter same passphrase again: 
    
    
    
    
Your identification has been saved in /home/xiaosi/.ssh/id_rsa.
    
    
    
    
Your public key has been saved in /home/xiaosi/.ssh/id_rsa.pub.
    
    
    
    
The key fingerprint is:
    
    
    
    
SHA256:n/sFaAT94A/xxxxxxxxxxxxxxxxxxxxxxx xiaosi@xiaosi
    
    
    
    
The key's randomart image is:
    
    
    
    
+---[xxxxx]----+
    
    
    
    
|        o= .. .. |
    
    
    
    
|        o.= ..  .|
    
    
    
    
|         *.* o  .|
    
    
    
    
|        +.4.=E+..|
    
    
    
    
|       .SBo=. h+ |
    
    
    
    
|        ogo..oo. |
    
    
    
    
|          or +j..|
    
    
    
    
|          ...+o=.|
    
    
    
    
|          ... o=+|
    
    
    
    
+----[xxxxx]-----+
   
   
   
   

备注：

这里会提示输入pass phrase，一定不要输入任何字符，回车即可。

2. 生成authorized_keys文件

   
   
   
   

    
    
    
    
xiaosi@xiaosi:~$ cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
   
   
   
   

备注：

记得要把authorized_keys文件放到.ssh目录下，与rsa等文件放在一起，否则免登录失败，debug如下（ssh -vvv localhost进行调试，查找错误原因）：

    
    
    
    

     
     
     
     
xiaosi@xiaosi:~$ ssh -vvv localhost
     
     
     
     
OpenSSH_7.2p2 Ubuntu-4ubuntu1, OpenSSL 1.0.2g-fips  1 Mar 2016
     
     
     
     
debug1: Reading configuration data /etc/ssh/ssh_config
     
     
     
     
debug1: /etc/ssh/ssh_config line 19: Applying options for *
     
     
     
     
debug2: resolving "localhost" port 22
     
     
     
     
debug2: ssh_connect_direct: needpriv 0
     
     
     
     
debug1: Connecting to localhost [127.0.0.1] port 22.
     
     
     
     
debug1: Connection established.
     
     
     
     
debug1: identity file /home/xiaosi/.ssh/id_rsa type 1
     
     
     
     
debug1: key_load_public: No such file or directory
     
     
     
     
debug1: identity file /home/xiaosi/.ssh/id_rsa-cert type -1
     
     
     
     
debug1: key_load_public: No such file or directory
     
     
     
     
debug1: identity file /home/xiaosi/.ssh/id_dsa type -1
     
     
     
     
debug1: key_load_public: No such file or directory
     
     
     
     
debug1: identity file /home/xiaosi/.ssh/id_dsa-cert type -1
     
     
     
     
debug1: key_load_public: No such file or directory
     
     
     
     
debug1: identity file /home/xiaosi/.ssh/id_ecdsa type -1
     
     
     
     
debug1: key_load_public: No such file or directory
     
     
     
     
debug1: identity file /home/xiaosi/.ssh/id_ecdsa-cert type -1
     
     
     
     
debug1: key_load_public: No such file or directory
     
     
     
     
debug1: identity file /home/xiaosi/.ssh/id_ed25519 type -1
     
     
     
     
debug1: key_load_public: No such file or directory
     
     
     
     
debug1: identity file /home/xiaosi/.ssh/id_ed25519-cert type -1
     
     
     
     
debug1: Enabling compatibility mode for protocol 2.0
     
     
     
     
debug1: Local version string SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu1
     
     
     
     
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu1
     
     
     
     
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu1 pat OpenSSH* compat 0x04000000
     
     
     
     
debug2: fd 3 setting O_NONBLOCK
     
     
     
     
debug1: Authenticating to localhost:22 as 'xiaosi'
     
     
     
     
debug3: hostkeys_foreach: reading file "/home/xiaosi/.ssh/known_hosts"
     
     
     
     
debug3: record_hostkey: found key type ECDSA in file /home/xiaosi/.ssh/known_hosts:1
     
     
     
     
debug3: load_hostkeys: loaded 1 keys from localhost
     
     
     
     
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@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,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,aes128-cbc,aes192-cbc,aes256-cbc,3des-cbc
     
     
     
     
debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,aes192-cbc,aes256-cbc,3des-cbc
     
     
     
     
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@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-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@libssh.org
     
     
     
     
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 SHA256:378enl3ckhdpObP8fnsHr1EXz4d1q2Jde+jUplkub/Y
     
     
     
     
debug3: hostkeys_foreach: reading file "/home/xiaosi/.ssh/known_hosts"
     
     
     
     
debug3: record_hostkey: found key type ECDSA in file /home/xiaosi/.ssh/known_hosts:1
     
     
     
     
debug3: load_hostkeys: loaded 1 keys from localhost
     
     
     
     
debug1: Host 'localhost' is known and matches the ECDSA host key.
     
     
     
     
debug1: Found key in /home/xiaosi/.ssh/known_hosts:1
     
     
     
     
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
     
     
     
     
debug2: set_newkeys: mode 0
     
     
     
     
debug1: rekey after 134217728 blocks
     
     
     
     
debug1: SSH2_MSG_NEWKEYS received
     
     
     
     
debug2: key: /home/xiaosi/.ssh/id_rsa (0x5602df5e80c0)
     
     
     
     
debug2: key: /home/xiaosi/.ssh/id_dsa ((nil))
     
     
     
     
debug2: key: /home/xiaosi/.ssh/id_ecdsa ((nil))
     
     
     
     
debug2: key: /home/xiaosi/.ssh/id_ed25519 ((nil))
     
     
     
     
debug3: send packet: type 5
     
     
     
     
debug3: receive packet: type 7
     
     
     
     
debug1: SSH2_MSG_EXT_INFO received
     
     
     
     
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
     
     
     
     
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 gssapi-keyex,gssapi-with-mic,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: /home/xiaosi/.ssh/id_rsa
     
     
     
     
debug3: send_pubkey_test
     
     
     
     
debug3: send packet: type 50
     
     
     
     
debug2: we sent a publickey packet, wait for reply
     
     
     
     
debug3: receive packet: type 51
     
     
     
     
debug1: Authentications that can continue: publickey,password
     
     
     
     
debug1: Trying private key: /home/xiaosi/.ssh/id_dsa
     
     
     
     
debug3: no such identity: /home/xiaosi/.ssh/id_dsa: No such file or directory
     
     
     
     
debug1: Trying private key: /home/xiaosi/.ssh/id_ecdsa
     
     
     
     
debug3: no such identity: /home/xiaosi/.ssh/id_ecdsa: No such file or directory
     
     
     
     
debug1: Trying private key: /home/xiaosi/.ssh/id_ed25519
     
     
     
     
debug3: no such identity: /home/xiaosi/.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
     
     
     
     
xiaosi@localhost's password: 
    
    
    
    



3. 验证

   
   
   
   

    
    
    
    
xiaosi@xiaosi:~$ ssh localhost
    
    
    
    
The authenticity of host 'localhost (127.0.0.1)' can't be established.
    
    
    
    
ECDSA key fingerprint is SHA256:378enl3ckhdpObP8fnsHr1EXz4d1q2Jde+jUplkub/Y.
    
    
    
    
Are you sure you want to continue connecting (yes/no)? yes
    
    
    
    
Warning: Permanently added 'localhost' (ECDSA) to the list of known hosts.
    
    
    
    
sign_and_send_pubkey: signing failed: agent refused operation
    
    
    
    
xiaosi@localhost's password: 
   
   
   
   

4. authorized_keys权限

我们可以看到还是让我输入密码，很大可能是authorized_keys文件权限的问题，我们给该文件赋予一定权限：

   
   
   
   

    
    
    
    
xiaosi@xiaosi:~$ chmod 600 ~/.ssh/authorized_keys
   
   
   
   

再次验证：

   
   
   
   

    
    
    
    
xiaosi@xiaosi:~$ ssh localhost
    
    
    
    
Welcome to Ubuntu 16.04 LTS (GNU/Linux 4.4.0-24-generic x86_64)
    
    
    
    

    
    
    
    
 * Documentation:  https://help.ubuntu.com/
    
    
    
    

    
    
    
    
0 个可升级软件包。
    
    
    
    
0 个安全更新。
    
    
    
    

    
    
    
    
Last login: Thu Jun 16 08:05:50 2016 from 127.0.0.1
   
   
   
   

到此表示OK了。

备注：

或者第一次需要输入密码，以后再次登陆就不需要输入密码了。

有更明白的小伙伴可以指导一下。。。。。。