SSH实现双向认证
SSH实现双向认证
由于经常需要使用scp在两台机器间拷贝文件，每次都输入密码太麻烦，于是按下面的步骤配置了一下，再使用ssh或scp登录远程机器时就不需输入密码了：
A主机：192.168.100.82 B主机：192.168.100.83
Linux/Unix双机建立信任
1.在A机生成证书
在A机root用户或其他用户下执行ssh-keygen命令，在需要输入的地方，直接回车，生成建立安全信任关系的证书。
[root@localhost ~]#ssh-keygen -t rsa
注意：在程序提示输入passphrase时直接输入回车，表示无证书密码。
上述命令将生成私钥证书id_rsa和公钥证书id_rsa.pub，存放在用户家目录的.ssh子目录中.
2.查看~/.ssh生成密钥的文件
[root@localhost ~]# ll /root/.ssh/ total 8 -rw------- 1 root root 1675 Apr 27 15:55 id_rsa -rw-r--r-- 1 root root 400 Apr 27 15:55 id_rsa.pub
3.A对B建立信任关系
将A主机的公钥证书id_rsa.pub复制到机器B主机的root家目录的.ssh子目录中，同时将文件名更换为authorized_keys，此时需要输入B主机的root用户密码（还未建立信任关系）。建立了客户端到服务器端的信任关系后，客户端就可以不用再输入密码，就可以从服务器端拷贝数据了。
scp -r -P 22 /root/.ssh/id_rsa.pub root@192.168.100.83:/root/.ssh/authorized_keys
如果做单向认证，这里已经可以实现A到B的免秘钥上传下载了.
4.B对A建立信任关系
在B机上执行同样的操作，建立B对A的信任关系。
[root@localhost ~]#ssh-keygen -t rsa root@localhost ~]# ll /root/.ssh/ total 8 -rw-r--r-- 1 root root 1678 Apr 27 15:59 authorized_keys -rw------- 1 root root 1675 Apr 27 15:55 id_rsa -rw-r--r-- 1 root root 400 Apr 27 15:55 id_rsa.pub
将B主机的公钥证书id_rsa.pub复制到机器A主机的root家目录的.ssh子目录中，同时将文件名更换为authorized_keys
scp -r -P 22 /root/.ssh/id_rsa.pub root@192.168.100.82:/root/.ssh/authorized_keys
这样A和B主机就可以互相传文件而不需要密码了.
如果连接反应慢，请修改以下两参数
/etc/ssh/sshd_config GSSAPIAuthentication no UseDNS no
重启sshd
service sshd restart
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二.使用ssh-keygen和ssh-copy-id三步实现SSH无密码登录
由于上面这样复制文件很麻烦，以下给出更为方便的方法，在做单向ssh认证时都在本端计算机进行， 即使用ssh-copy-id进行操作，它可以直接在对端生成authorized_keys文件.
[user1@localhost ~]$ ssh-keygen -t rsa Generating public/private rsa key pair. Enter file in which to save the key (/home/user1/.ssh/id_rsa): Created directory '/home/user1/.ssh'. Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/user1/.ssh/id_rsa. Your public key has been saved in /home/user1/.ssh/id_rsa.pub. The key fingerprint is: da:e3:f0:2b:93:47:15:4d:a1:dc:68:00:07:ec:41:87 user1@localhost The key's randomart image is: +--[ RSA 2048]----+ | o+++ oo. | | Eo o.+. | | . . =.. | | . .. | | S. | | o. | | ooo | | ++.. | | ++. | +-----------------+ [user1@localhost ~]$ ssh-copy-id -i .ssh/id_rsa.pub "-p 6168 user1@192.168.3.192" The authenticity of host '[192.168.3.192]:6168 ([192.168.3.192]:6168)' can't be established. RSA key fingerprint is 8d:8c:22:67:68:f7:ad:1e:83:f3:4c:d4:32:d8:53:d6. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '[192.168.3.192]:6168' (RSA) to the list of known hosts. user1@192.168.3.192's password: Now try logging into the machine, with "ssh '-p 6168 user1@192.168.3.192'", and check in: .ssh/authorized_keys to make sure we haven't added extra keys that you weren't expecting. [user1@localhost ~]$ #这样就会自动在192.168.3.192远端机器的.ssh目录下创建authorized_keys文件.
#!/bin/bash if [ ! -f ~/.ssh/id_rsa ];then ssh-keygen -t rsa -P "" -f ~/.ssh/id_rsa else echo "id_rsa has created ..." fi
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