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Asked: 2012-02-06 03:25:55 +0800 CST

How do I setup seamless SSH access on centOS 5.7?

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Well I haven't had to do this before until now, but I created an account on a remote server purely for shared git repo access and now need to setup seamless logins via ssh on each dev machine. I have read several articles on this, however I do no have a .ssh folder on the account of the created user so can not install the client key in the authorized_keys file. Do I just create these folder&files in order to be able to install the key because I don't think it'll be that simple. I am following this link for the tutorial and below is the sshd_config file as it stands at the moment. (currently password authenticated logins). Thanks for any pointers.

    # This is the sshd server system-wide configuration file.  See
# sshd_config(5) for more information.

# This sshd was compiled with PATH=/usr/local/bin:/bin:/usr/bin

# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented.  Uncommented options change a
# default value.

#Port 22
#Protocol 2,1
Protocol 2
#AddressFamily any
#ListenAddress 0.0.0.0
#ListenAddress ::

# HostKey for protocol version 1
#HostKey /etc/ssh/ssh_host_key
# HostKeys for protocol version 2
#HostKey /etc/ssh/ssh_host_rsa_key
#HostKey /etc/ssh/ssh_host_dsa_key

# Lifetime and size of ephemeral version 1 server key
#KeyRegenerationInterval 1h
#ServerKeyBits 768

# Logging
# obsoletes QuietMode and FascistLogging
#SyslogFacility AUTH
SyslogFacility AUTHPRIV
#LogLevel INFO

# Authentication:

#LoginGraceTime 2m
PermitRootLogin no
#StrictModes yes
#MaxAuthTries 6

RSAAuthentication yes
#PubkeyAuthentication yes
AuthorizedKeysFile      .ssh/authorized_keys

# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
#RhostsRSAAuthentication no
# similar for protocol version 2
#HostbasedAuthentication no
# Change to yes if you don't trust ~/.ssh/known_hosts for
# RhostsRSAAuthentication and HostbasedAuthentication
#IgnoreUserKnownHosts no
# Don't read the user's ~/.rhosts and ~/.shosts files
#IgnoreRhosts yes

# To disable tunneled clear text passwords, change to no here!
#PasswordAuthentication yes
#PermitEmptyPasswords no
PasswordAuthentication yes

# Change to no to disable s/key passwords
#ChallengeResponseAuthentication yes
ChallengeResponseAuthentication no

# Kerberos options
#KerberosAuthentication no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes
#KerberosGetAFSToken no

# GSSAPI options
#GSSAPIAuthentication no
GSSAPIAuthentication yes
#GSSAPICleanupCredentials yes
GSSAPICleanupCredentials yes

# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
# be allowed through the ChallengeResponseAuthentication mechanism.
# Depending on your PAM configuration, this may bypass the setting of
# PasswordAuthentication, PermitEmptyPasswords, and
# "PermitRootLogin without-password". If you just want the PAM account and
# session checks to run without PAM authentication, then enable this but set
# ChallengeResponseAuthentication=no
#UsePAM no
UsePAM yes

# Accept locale-related environment variables
AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES
AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT
AcceptEnv LC_IDENTIFICATION LC_ALL
#AllowTcpForwarding yes
#GatewayPorts no
#X11Forwarding no
X11Forwarding no
#X11DisplayOffset 10
#X11UseLocalhost yes
#PrintMotd yes
#PrintLastLog yes
#TCPKeepAlive yes
#UseLogin no
#UsePrivilegeSeparation yes
#PermitUserEnvironment no
#Compression delayed
#ClientAliveInterval 0
#ClientAliveCountMax 3
#ShowPatchLevel no
#UseDNS yes
#PidFile /var/run/sshd.pid
#MaxStartups 10
#PermitTunnel no
#ChrootDirectory none

# no default banner path
#Banner /some/path

# override default of no subsystems
Subsystem       sftp    /usr/libexec/openssh/sftp-server
ssh ssh-keys

2 Answers

  1. Yes, it (almost) is that simple. As the account on the ssh server, run:

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

    Where id_dsa.pub is a public key from one of the client machines.

    For safety, you might want to do something like chmod 700 ~/.ssh, though it should be OK for authorized_keys use. Make sure your private key (and your .ssh directory) has restrictive permissions.

    If you have problems, run ssh with the -v option on the client to get the debug info, and then look at the server's ssh log (maybe /var/log/auth.log or /var/log/secure or something like that, depending on distro).

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  2. Best Answer

    much easier way

    on your source box, make sure you have a key generated, if not, run ssh-keygen to generate one (ex: ssh-keygen -b 1024 -t rsa -q)

    then run ssh-copy-id -i .ssh/id_rsa.pub user@host

    this will do all of the authorized_keys nonsense for you. On older distributions, though, the ssh-copy-id command doesnt exist and you have to do the other method that was previously suggested.

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