ssh和ssh-copy-id以及批量多机无密码登陆详解

ssh  root@ip  -p端口号

[root@localhost .ssh]# ssh-keygen  -t ecdsa
Generating public/private ecdsa key pair.
Enter file in which to save the key (/root/.ssh/id_ecdsa): 按回车键或设置密钥的存储路径
Enter passphrase (empty for no passphrase): 直接按回车键或设置密钥的密码
Enter same passphrase again: 再次按回车键或设置密钥的密码
Your identification has been saved in /root/.id_ecdsa.
Your public key has been saved id_ecdsa.pub.
The key fingerprint is:
SHA256:yMZjxaP0yC2OQrRPEexfsbMweSPVVEvK88cvqUGA root@localhost.localdomain
The key's randomart image is:
+---[ECDSA 256]---+
|   ..   ..oo.o   |
|    .. .o+oo+    |
|  ... .oEo=o     |
| . ..*=O*o +     |
|  o ..%*S+o .    |
| . o =.o.. . .   |
|  . o . .   o    |
|   .     . .     |
|         .o      |
+----[SHA256]-----+
[root@localhost .ssh]# ll
total 8
-rw------- 1 root root 227 Jun 10 23:55 id_ecdsa         #私钥
-rw-r--r-- 1 root root 188 Jun 10 23:55 id_ecdsa.pub　　  #公钥

[root@localhost yum.repos.d]# ssh-copy-id  -i /root/.ssh/id_ecdsa.pub  root@192.168.123.218
/usr/bin/id: INFO: Source of key(s) to be installed: "/root/.ssh/id_ecdsa.pub"
The authenticity of host 192.168.123.218 (192.168.123.218)' cant be established.
ECDSA key fingerprint is SHA256:Qh+4R5mpwlU6kK3bf0k53ngm+WpKKnfvL1ZJo+YM3ic.
ECDSA key fingerprint is MD5:d2:76:6d:33:45:e1:23:83:13:aa:10:ce:f7:1f:9f:32.
Are you sure you want to continue connecting (yes/no)? yes   #输入yes
/usr/bin/id: INFO: attempting to log in with the new key(s),to filter out any that are already installed
/usr/bin/id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@123.218s password:   #填入密码

Number of key(s) added: 1

Now try logging into the machine,with:   ssh 'root@192.168.123.218'
and check to make sure that only the key(s) you wanted were added.

打开/etc/ssh_config文件：
找到：
# StrictHostKeyChecking ask
修改为
StrictHostKeyChecking no

#!/bin/bash
#检查本地是否有密钥文件，没有则添加。
./sshkeygen.exp
#循环取出ip和密码
for i in $(cat ./hosts )
do
    #取出ip和密码
    IP=$(echo ${i}" |awk -F:" {print $1}')
    PW=$({print $2})
    #将本地的公钥复制到远程主机
    ./sshcopy.exp $IP  $PW
    #将脚本sshkeygen.exp复制到远程主机
    scp -p ./sshkeygen.exp   $IP:/root/
    #远程主机安装expect
    ssh root@$IP yum install expect -y 
    #远程主机创建密钥文件
    /root/sshkeygen.exp&
    #将远程主机的公钥添加到本地authorized_keys文件
    cat ~/.ssh/*.pub" >>./authorized_keys
done
#将本地的公钥复制到远程主机
hosts)

     IP=$()
　　　#将本地主机的公钥文件添加到authorized_keys文件
?? ? cat ~/.ssh/*.pub >>./authorized_keys
     scp ./authorized_keys $IP:~/.done 

#!/usr/bin/expect -d  
set ip [lindex $argv 0]
set pw [lindex $argv ]
set timeout 60
spawn id $ip
expect {
#*yes/no" {send yesr"; exp_continue}
#如果上面这行注释了，我们需要在/etc/ssh_config 将# StrictHostKeyChecking ask 修改为 StrictHostKeyChecking no。
password:$pwr}
}
expect eof

#!/usr/bin/expect -d
set timeout 90ssh-keygen
expect {
.ssh/id_rsar;exp_continue}
Overwrite (y/n)? exit
Enter passphraseEnter same passphrase again:}
}
expect eof

149.28.244.75:*p8V1xG{7)%sQV!
245.101:K(1q@jsvM@UVZtk