ssh使用ssl中的rsa证书进行登录

2018-03-22

之前用谷歌虚拟主机搭了一个小机场，但是只当机场用，有点浪费，所以最近觉得应该把这个服务器用起来，ssh连接的时候遇到点小问题，所以记录下来

SSH

什么是SSH?
如果你经常玩linux，经常需要远程连接服务器，那么对于ssh应该很熟，关于具体原理可以参考另外一篇博文阮一峰的ssh原理，我觉得他讲的很通俗易懂。

遇到的问题

SSH一直连接不上
一直提示Pemission Denied(publickey)，可是我明明已经把rsa的公钥放到~/.ssh/authorized_keys 里面了，也把/etc/sshd_config的配置文件也配置了，但是最终还是失败，最后发现问题所在，就是允许密码登陆的地方给遗漏了，配置文件如下：

# Package generated configuration file
# See the sshd_config(5) manpage for details

# What ports, IPs and protocols we listen for
Port 22
# 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
#
# Google Compute Engine times out connections after 10 minutes of inactivity.
# Keep alive ssh connections by sending a packet every 2 minutes.
ClientAliveInterval 120

# Prevent reverse DNS lookups.
UseDNS no

ssh的配置文件存放在/etc/ssh/下，sshd_config是ssh服务器(也就是个人主机连接你的服务器，你对个人主机的限制)的配置文件，ssh_config是ssh客户端的配置文件，需要修改sshd_config，这样我才能实现远程连接到谷歌的这台主机，修改的地方如下：

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

把上面几处的值改成yes，然后把注释符号#去除，然后可以了。

添加本机的rsa公钥到主机上，实现无密码登陆

生成秘钥命令：

1	ssh-keygen

可以一直回车，对于私钥可以设置一个密码，进行加密，防止泄露
　　查看本机的rsa公钥:cat ~/ssh/id_rsa.pub，然后复制，粘贴到远程主机的~/.ssh/authorized_keys里面就可以了，最后实现无密码的登陆。

参考：
ssh原理