问题
如何在3台linux服务器之间为非 root 用户创建无需密码的 ssh 连接。
当用户user1在linux服务器之间进行ssh连接时，如何设置不需要密码？
在服务器3上执行类似的操作
要使用普通用户在多台Linux计算机之间创建无密码ssh身份验证，请确保下面这两个权限设置正确，否则无密码ssh身份验证将无法工作。
authorized_keys 文件的权限 600
.ssh目录的权限 700
在服务器1上 设置无需密码的连接
在服务器1上执行
以user1的身份登录
[user1@server1 ~]$ssh-keygen -t rsa Generating public/private rsa key pair. Enter file in which to save the key (/home/user1/.ssh/id_rsa): Created directory '/home/user1/.ssh'. Enter passphrase (empty for no passphrase): [Press ENTER for EMPTY password] Enter same passphrase again: [Press ENTER for EMPTY password] Your identification has been saved in /home/user1/.ssh/id_rsa. Your public key has been saved in /home/user1/.ssh/id_rsa.pub. The key fingerprint is: 81:bf:d5:03:3f:a1:a4:81:27:b5:61:e4:e6:17:b9:a0 user1@server1.example The key's randomart image is: +--[ RSA 2048]----+ | .= | | * o . | | + O = . | | B * B . | | E S = = | | + o | | . | | | | | +-----------------+
通过上面的命令，我们使用RSA类型的身份验证创建了一对公钥和私钥。
现在要创建一个无密码的ssh连接，我们需要将id_rsa.pub复制到远程服务器上，即：server2和server3
[user1@server1 ~]$ssh-copy-id user1@server2 The authenticity of host 'server2 (192.168.1.11)' can't be established. RSA key fingerprint is de:75:8a:ff:26:1b:b5:82:61:36:9c:44:d2:57:3c:9e. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added 'server2,192.168.1.11' (RSA) to the list of known hosts. user1@server2's password: [Give password for user1]
现在，尝试使用“ssh”登录到计算机user1@server2“，并检查：
.ssh/authorized_keys
以确保我们没有添加另外的密钥。
[user1@server1 ~]$ssh-copy-id user1@server3 The authenticity of host 'server3 (192.168.1.12)' can't be established. RSA key fingerprint is 98:61:fb:91:8b:10:29:e1:b2:db:fd:52:6d:79:d7:1a. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added 'server3,192.168.1.12' (RSA) to the list of known hosts. user1@server3's password: [Give password for user1]
现在，尝试使用“ssh”登录到计算机user1@server3“，并检查：
.ssh/authorized_keys
以确保我们没有添加另外的密钥。
注意：确保对授权密钥的权限为600。
通过以上步骤，我们已经成功地创建了从
服务器 1 ------> 服务器 2
服务器 1 ------> 服务器 3
的无密码身份验证。
在服务器2上 设置无需密码的连接
在服务器2上执行
以user1的身份登录
[user1@server2 ~]$ssh-keygen -t rsa Generating public/private rsa key pair. Enter file in which to save the key (/home/user1/.ssh/id_rsa): Enter passphrase (empty for no passphrase): [Press ENTER for EMPTY password] Enter same passphrase again: [Press ENTER for EMPTY password] 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: 8f:0d:bc:8c:fc:d1:38:1a:b3:be:7a:8d:fc:8d:0d:1e user1@server2.example The key's randomart image is: +--[ RSA 2048]----+ | | | | | | | . | | S | | . o O | | .=oE + | | +B.O | | .+=o= o | +-----------------+
通过上面的命令，我们使用RSA类型的身份验证创建了一对公钥和私钥。
现在要创建一个无密码的ssh连接，我们需要将id_rsa.pub复制到远程服务器上，即：server1和server3
[user1@server2 ~]$ssh-copy-id user1@server1 The authenticity of host 'server1 (192.168.1.6)' can't be established. RSA key fingerprint is b8:36:c1:38:01:db:cc:89:b1:a9:b8:f7:f7:a8:17:ef. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added 'server1,192.168.1.6' (RSA) to the list of known hosts. user1@server1's password: [Give password for user1]
现在，尝试使用“ssh”登录到计算机user1@server1“，并检查：
.ssh/authorized_keys
以确保我们没有添加另外的密钥。
[user1@server2 ~]$ssh-copy-id user1@server3 The authenticity of host 'server3 (192.168.1.12)' can't be established. RSA key fingerprint is 98:61:fb:91:8b:10:29:e1:b2:db:fd:52:6d:79:d7:1a. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added 'server3,192.168.1.12' (RSA) to the list of known hosts. user1@server3's password: [Give password for user1]
现在，尝试使用“ssh”登录到计算机user1@server3“，并检查：
.ssh/authorized_keys
以确保我们没有添加另外的密钥。
通过以上步骤，我们已经成功地创建了从
服务器 2 ------> 服务器 1
服务器 2 ------> 服务器 3
的无密码身份验证。
准备工作
用户 user1 应该存在于所有 3 个 Linux 机器上
服务器详情
server1.example
IP 192.168.1.6
server2.example
IP 192.168.1.11
server3.example
IP 192.168.1.12