Secure SSH, CVS, SCP without Password Prompt

For the old version of this homepage I have used CVS to update the websites. I have done this via SSH, which is pretty secure but has the annoying disadvantage of asking for a password for each operation. If you can trust the security of your client computer, there is a way to get rid of the password altogehter, without loosing security:

1. Suppose the domain name of your server is server, and your login name loginname.

2. On the client, generate a public and private key.

   ssh-keygen -C loginname@server -t dsa
   

   When asked for a password, simply press return. The private key is stored in ~/.ssh/id_dsa, and the public key in ~/.ssh/id_dsa.pub. Never give the private key away!

3. Copy the public file to the server with

   scp ~/.ssh/id_dsa.pub loginname@server:~/
   

4. Login on the server with

   ssh loginname@server
   

   append the copied file to ~/.ssh/authorized_keys with

   cat ~/id_dsa.pub >>~/.ssh/authorized_keys
   

5. If you want to enable this features on other servers, just repeat step 3 on each of the servers.

That’s it! If you have done everything correctly, the next time you login via SSH or use CVS over SSH, you will not need to enter a password yet you have a secure connenction.