Set password-less ssh and linuxssh in linux

Set password-less ssh and linuxssh in linux

Ssh Configuration

Host A: 10.0.5.199

Host B: 10.0.5.198

You need to configure host A to log on to host A and host B without A password.

First, make sure that the firewall of all hosts is disabled.

Run the following command on host:

1. $ cd ~ /. Ssh

2. $ ssh-keygen-t rsa ------------------ press the Enter key until the generated key is saved in the. ssh/id_rsa file according to the default options.

3. $ cp id_rsa.pub authorized_keys

After this step, you can log on to the local machine without a password, that is, ssh localhost, without entering the password.

4. $ scp authorized_keys summer@10.0.5.198:/home/summer/. ssh ------ copy the generated authorized_keys file to host B.

5. $ chmod 600 authorized_keys

Go to the. ssh directory of host B and change the permission of the authorized_keys file.

(4 and 5 can merge one step, execute: $ ssh-copy-id-I summer@10.0.5.198)

 

After completing the preceding steps, you can initiate an ssh connection from the host a to the host a and B. You only need to enter the password for the first login and will not need it later.

 

Possible problems:

1. During ssh Login, the following error occurs: "Agent admitted failure to sign using the key".

Run: $ ssh-add

Forcibly Add the private key.

2. if no error message is displayed, you can enter A password to log on, but you cannot log on without A password on the connected host (for example, if A initiates an ssh connection to B, it will be on B) perform the following steps:

$ Chmod o-w ~ /

    $chmod 700 ~/.ssh

$ Chmod 600 ~ /. Ssh/authorized_keys

3. If you still cannot log on without a password after step 1, try the following:

$ Ps-Af | grep agent

Check whether the ssh proxy is enabled. If enabled, kill the proxy and run the following command to re-open an ssh proxy. If not, run the following command:

$ Ssh-agent

If the problem persists, run the following command to restart the ssh service.

$ Sudo service sshd restart

4. "cocould not open a connection to your authenticationh agent" prompt when executing ssh-add, but failed

For SSH password-less access in linux, follow the instructions on the Internet

Machine A creates A key
Ssh-keygen-t rsa copies the key of server A to server B.
Scp/root/. ssh/id_rsa.pub B _ip:/root/. ssh/authorized_keys2 enter the password, and the copy is complete. Machine B creates a key
Ssh-keygen-t rsa: copy the key of server B to a file.
Cat/root/. ssh/id_rsa.pub>/root/. ssh/authorized_keys2 copy the key file to machine.
Scp/root/. ssh/authorized_keys2 A_ip:/root/. ssh/authorized_keys2

Linux ssh password-less Login

You need to modify the watching symbol in the/etc/ssh/sshd_config file to remove the following three lines :#

Vi/etc/ssh/sshd_config remove the three rows #
RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile. ssh/authorized_keys
Restart the sshd service.