SSH and SCP giving error

Question

I am doing the same steps (Perform SSH and SCP Without Entering Password on openSSH). But it keep asking password prompt while scp or 'ssh -l' command run. Same steps i did few days back, it was working fine, but now it is not working.

What i did was:

1. I have two machines LOCAL and REMOTE.
2. In both machines, I login in putty with root user.
3. In both machines, I checked 'ssh -V', i find same version same product in both.
4. in local, i run from /root/.ssh folder

ssh-keygen

i gave key file name as appkey. 5. it generated appkey, appkey.pub in /root/.ssh 6. In remote, i copied content of local appkey.pub and pasted in at the end of remote authorized_keys file. 7. In remote, i run

chmod 755 ~/.ssh chmod 644 ~/.ssh/authorized_keys

8. In local, i tried to run scp and 'ssh -l' commands, but it still asking passwords.
9. I tried other way also, instead of adding in authorized_keys file, i copied appkey.put to romote /root/.ssh folder

Answer 1

You need also to check your home permission to make sure that nobody can write to it. Otherwise strangers can rename your .ssh and create their own .ssh. I have this initial ssh setup which I created a few years ago and which helped many people:

#!/bin/csh -fx

chmod go-w ~
if (! -d ~/.ssh) then
   rm -rf ~/.ssh
   mkdir ~/.ssh
endif
chmod 700 ~/.ssh
cd ~/.ssh
touch authorized_keys
chmod 600 authorized_keys
rm -f id_rsa
# generate id_rsa and id_rsa.pub
ssh-keygen -t rsa -f id_rsa -P ""
cat id_rsa.pub >> authorized_keys
# for remote host:
# cat ~/.ssh/id_rsa.pub | ssh HOST 'cat >> ~/.ssh/authorized_keys'
# it is the same as:
# ssh-copy-id -i id_rsa.pub USER@HOST
# it will add mulptiple entries if called multiple times

I am not an expert in this, just collected pieces in Web. Something may be outdated but works in our environment.

Answer 2

did you try specifying which exact keyfile to use when you are issuing the ssh command from your local server as follows ?

ssh -i /root/.ssh/appkey -l remote_username remote_servername

otherwise, ssh assumes your private key name as you can see from the following excerpt from ssh man page.

 ...
 -i identity_file
     Selects a file from which the identity (private key) for RSA or
     DSA authentication is read.  The default is ~/.ssh/identity for
     protocol version 1, and ~/.ssh/id_rsa and ~/.ssh/id_dsa for pro-
     tocol version 2.  Identity files may also be specified on a per-
     host basis in the configuration file.  It is possible to have
     multiple -i options (and multiple identities specified in config-
     uration files).
  ...

Answer 3

Jackua, You solved my problem. it solved by doing like this:

1. Deleted existing .ssh(renamed as .ssh_bck) folder.
2. I did the same steps as you mentioned.
3. I used ssh-copy-id -i id_rsa.pub USER@HOST
4. To confirm with command 'ssh 'USER@HOST'' not asking for password.
5. run cat .ssh/authorized_keys To verify multiple entities or single entity exist in file.