I was trying to setup Hadoop and was stumbled on passwordless ssh to localhost. I am getting a password prompt when trying to connect using ssh username@hostname format. But there is no problem connecting to the machine like ssh localhost or ssh hostname.com. Tried ssh-copy-id user@hostname but it did not work. Using CentOS 6.3 as normal user, I neither have root access or am a sudoer so editing any files like sshd_config is not possible (not even cat the sshd_config file contents). I hope the user login is possible since I can do login without password to localhost, right? Please advise, Here is the ssh debug output. [[email protected] ~]$ ssh -v [email protected] OpenSSH_5.3p1, OpenSSL 1.0.0-fips 29 Mar 2010 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug1: Connecting to hostname.com [::1] port 22. debug1: Connection established. debug1: identity file /home/user/.ssh/identity type -1 debug1: identity file /home/user/.ssh/id_rsa type -1 debug1: identity file /home/user/.ssh/id_dsa type 2 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3 debug1: match: OpenSSH_5.3 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.3 debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: server->client aes128-ctr hmac-md5 none debug1: kex: client->server aes128-ctr hmac-md5 none debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP debug1: SSH2_MSG_KEX_DH_GEX_INIT sent debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY debug1: Host 'hostname.com' is known and matches the RSA host key. debug1: Found key in /home/user/.ssh/known_hosts:1 debug1: ssh_rsa_verify: signature correct debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: SSH2_MSG_NEWKEYS received debug1: SSH2_MSG_SERVICE_REQUEST sent debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password debug1: Next authentication method: gssapi-keyex debug1: No valid Key exchange context debug1: Next authentication method: gssapi-with-mic debug1: Unspecified GSS failure. Minor code may provide more information Credentials cache file '/tmp/krb5cc_500' not found debug1: Unspecified GSS failure. Minor code may provide more information Credentials cache file '/tmp/krb5cc_500' not found debug1: Unspecified GSS failure. Minor code may provide more information debug1: Unspecified GSS failure. Minor code may provide more information debug1: Next authentication method: publickey debug1: Offering public key: /home/user/.ssh/id_dsa debug1: Server accepts key: pkalg ssh-dss blen 434 Agent admitted failure to sign using the key. debug1: Trying private key: /home/user/.ssh/identity debug1: Trying private key: /home/user/.ssh/id_rsa debug1: Next authentication method: password [email protected]'s password: