Cybersecurity

I'm stumped on an issue I'm having with RSA key based SSH logons.

I have 30 servers in a database cluster. They are all Red Hat Enterprise Linux Server release 6.4.

I want to be able to run a command on all of them from any one of them using SSH.

I generated private and public keys on each of them, pasted all the public keys together into an authorized_keys file and copied that file into ~/.ssh on each of the servers. I then wrote a script to run a command on each of the servers and it runs without prompting for a password on 29 out of the 30. On that one, it prompts for a password every time.

I thought maybe I just messed something up with my copying and pasting, so I went through the entire process again, and ended up wtih the same results. For some reason, I just can't get this one server to use it's authorized_keys file. I tried running the script from other servers in the group and it always fails on the same one. I also tried generating a key using Putty on my workstation and added it to the authorized_keys files on a few of the servers (including the problem one.) Putty failed to connect to that one server, but worked fine on all the others also.

I tried going through the whole process again with a different user ID, and it worked fine on all 30 servers. So it seems to be a problem isolated to that one user ID on the one server.

I'm out of ideas on what else to check or where to look for differences. Does anyone have any suggestions for things to check?

Thanks!

I suggest not using putty generated keys in debugging this situation since there is an issue of key conversion between putty clients and unix servers. Things to try...compare the successful case against the failed case by turning on verbose options see...Debug SSH at the Maximum Verbosity Level | commandlinefu.com