Shell Programming and Scripting

Hi,

I'm using Ubuntu 10.04 LTS.

I checked the set up of passwordless authentication in this way: .When i excecuted the above command it din't ask me for any password. So i thought it might be passwordless authentication is set up alreday.Am i verifying the passwordless authentication in a right way?

Where can i find the logs related to sftp or ssh. I searched bfor /var/log/secure but dint find it.

Also executing the sftp caommands manually to transfer the file from remote to local not giving any error but the thing is asking for the password as passwordless authentication is not properly set.

When i write the bash script where in i used sftp commands to transfer the file. Here also i'm not getting any error and file is being transferred sucessfully but asking for the password due to authentication.

So how can i set the passwordless authentication and verify it.
One more query is if i go for passwordless authentication does it affect other things as multiple users are using the same ubuntu machine and alos hadoop is installed on this machine. So enabling passwordless authentication will affect other things or it is only applicable for my work?
I'm bit confused here.

Thanks,
Shree

---------- Post updated 06-10-14 at 01:30 AM ---------- Previous update was 06-09-14 at 11:46 PM ----------

Hi,

I got the steps to create passwordless login to a remote machine from local machine.
Below are the steps:

Code:

localserver# mkdir ~/.ssh
localserver# cd ~/.ssh
localserver# ssh-keygen -t rsalocalserver# ssh user@<remoteserver_ip>
Password: 
localserver# ssh user@<remoteserver_ip> mkdir -p .ssh
localserver# cat .ssh/id_rsa.pub | ssh user@<remoteserver_ip> 'cat >> .ssh/authorized_keys'
localserver# ssh user@<remoteserver_ip> "chmod 700 .ssh; chmod 640 .ssh/authorized_keys"
localserver# ssh user@<remoteserver_ip>

In the above steps, in which location do i need to create the ssh directory on local and remote machine.I already have ssh directory on this path /etc/ssh both on local and remote machines. So do i need to create ssh directory in the differen tlocation or do i need to use the ssh directory already existing?In case if i use the existiong ssh directory does it overwrite the existing contents with new contents? Please clarify the above queries.

Thanks,Shree

If you want to run that using your ID, create '.ssh' folder in your home directory
else, create in the respective application / functional ID's home directory

Hi Srini, I dint get "If you want to run that using your ID, create '.ssh' folder in your home directory" . Here ID in the sense?I'm accessing ubuntu using putty.

I mean user (username)

One more query is can we have multiple ssh directories one created under root user in the path /etc/ssh and other created using user user in the path /home/user/ssh ? Do they conflict each other?

In my case i have ssh folder created under /etc and under ssh i have the following files:
So after login to user useranme can i excecute the $ssh-keygen -t rsa command inside /etc/ssh folder? So doing this will overwrite the existing ssh_host_rsa_key.pub file or it will make a new public key entry at the end of the file?

So, the public key needs to be accepted on the server by the user you are connecting to. You seem to have the instructions to do this. Can you sign on without a password as that user?:-

Code:

ssh user@host

If it prompts for a password, do you know it? If so, put it in then have a look on the remote server at the permissions for the .ssh directory in that users home directory and the files within it. It must be owned by the account you've logged on as and it's best to keep them all as RW only to that owner, with no other access. The .ssh directory itself will need to have RWX though.

Note that the /etc/ssh is for the overall service, not your login certificates. Using ssh-keygen will (by default) work on or create the .ssh directory in your home directory.



Robin

Hi,

I tried generating public and private keys on local machine. Also copied the id_rsa.pub to the remote machine and renamed to authorized_keys.

Also set the permissions to the .ssh and authorized_keys as below:
chmod 640 authorized_keys
chmod 700 .ssh

But still when i do :
$ssh remoteserver@<ip>, it is asking for the password. The passwordless login is not yet enabled.Not getting where it's going wrong.

Thanks

---------- Post updated at 04:06 AM ---------- Previous update was at 03:47 AM ----------

Hi,

I'm able to transfer the file from remote machine to loac server with passwordless login.

Thank you.