Linux下配置ssh无密码登陆

mkdir ~/.ssh
chmod 700 ~/.ssh
ssh-keygen -t rsa
ssh-keygen -t dsa
然后，在节点 dbtest1 执行以下命令
cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
ssh dbtest2 cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
ssh dbtest2 cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
scp ~/.ssh/authorized_keys dbtest2:~/.ssh/authorized_keys

节点1：
node1:~ #cd /root
node1:~ # mkdir .ssh
node1:~ # chmod 700 .ssh
node1:~ # ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
b0:1d:73:0a:99:2a:ee:ce:cd:5f:de:e5:db:c9:ab:6e [MD5] root@node1
The key's randomart image is:
+--[ RSA 2048]----+
| |
| o |
| = o . |
| . = = |
| . . . S |
| . . |
| . . . |
| o o o . oEo . |
| .+ o.. . .o=o=. |
+--[MD5]----------+
node1:~ # ssh-keygen -t dsa
Generating public/private dsa key pair.
Enter file in which to save the key (/root/.ssh/id_dsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_dsa.
Your public key has been saved in /root/.ssh/id_dsa.pub.
The key fingerprint is:
9c:93:19:6b:df:bd:f3:01:b6:82:be:32:0c:ee:b0:68 [MD5] root@node1
The key's randomart image is:
+--[ DSA 1024]----+
| |
| |
| . |
| . * |
| S o |
| . . o....o |
| .. o ....... |
| E. o. +. . ...|
|.. ... oo. .o.|
+--[MD5]----------+
node1:~ #

节点2
node2:~ # cd /root
node2:~ # mkdir .ssh
node2:~ # chmod 700 .ssh/
node2:~ # ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
f2:ca:0c:73:98:04:55:69:48:1a:9a:a8:8e:0c:96:0c [MD5] root@node2
The key's randomart image is:
+--[ RSA 2048]----+
| ..oo.. |
|.o +. o |
|E o . |
|+ .. |
|o+ . . S |
|* . o o |
|.o = . . |
| * . |
| + |
+--[MD5]----------+
node2:~ # ssh-keygen -t dsa
Generating public/private dsa key pair.
Enter file in which to save the key (/root/.ssh/id_dsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_dsa.
Your public key has been saved in /root/.ssh/id_dsa.pub.
The key fingerprint is:
6a:c4:e1:cc:bb:c7:32:51:5c:96:49:46:24:df:86:ad [MD5] root@node2
The key's randomart image is:
+--[ DSA 1024]----+
| .+=o |
| +=+ |
| .. oo + |
| = .o o |
| *.S E |
| ..o |
| +o |
| .o.o |
| .+ |
+--[MD5]----------+
node2:~ #

同步authorized_key

node1:~/.ssh # cat id_rsa.pub >>authorized_keys
node1:~/.ssh # cat id_dsa.pub >>authorized_keys
node1:~/.ssh # ssh node2 cat /root/.ssh/id_rsa.pub >> authorized_keys
The authenticity of host 'node2 (10.0.0.31)' can't be established.
ECDSA key fingerprint is b4:30:1b:97:e9:75:1e:e2:2c:85:91:2a:76:85:77:ce [MD5].
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'node2,10.0.0.31' (ECDSA) to the list of known hosts.
Password:
node1:~/.ssh # ssh node2 cat /root/.ssh/id_dsa.pub >> authorized_keys
Password:
node1:~/.ssh # scp authorized_keys node2:/root/.ssh/
Password:
authorized_keys 100% 1984 1.9KB/s 00:00
node1:~/.ssh #
测试
node1:~/.ssh # ssh node2 date
Sat May 9 05:40:58 CST 2015
node1:~/.ssh #
node2:~ # ssh node1 date
Sat May 9 05:41:03 CST 2015
node2:~ #