SSHD Gives error could not open Authorized Keys, although permissions seem correct
I'm unable to login to SSH because of the following error in /var/log/secure (according to the debug logs):
Dec 19 18:01:05 hostname sshd: debug1: trying public key file /root/.ssh/authorized_keys Dec 19 18:01:05 hostname sshd: debug1: Could not open authorized keys '/root/.ssh/authorized_keys': Permission denied
I have the following permissions set on root
chmod 700 ~/.ssh chmod 600 ~/.ssh/authorized_keys chmod go-wrx ~
ls -lah gives the following output for those directories:
drwx------. 6 root root 4.0K Dec 19 17:46 root drwx------. 2 root root 4.0K Dec 19 17:41 .ssh -rw-------. 1 root root 416 Dec 19 17:12 authorized_keys
I know the key I'm using is correct, as I just setup another server with it without any problems.
I'm running: CentOS release 6.4 (Final)
I've added my sshd config in case there's something misconfigured in there that might be causing the issue:
# $OpenBSD: sshd_config,v 1.80 2008/07/02 02:24:18 djm Exp $ # 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 #AddressFamily any #ListenAddress 0.0.0.0 #ListenAddress :: # Disable legacy (protocol version 1) support in the server for new # installations. In future the default will change to require explicit # activation of protocol 1 Protocol 2 # 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 1024 # Logging # obsoletes QuietMode and FascistLogging #SyslogFacility AUTH SyslogFacility AUTHPRIV LogLevel DEBUG # Authentication: #LoginGraceTime 2m PermitRootLogin yes StrictModes no #MaxAuthTries 6 #MaxSessions 10 RSAAuthentication yes PubkeyAuthentication yes AuthorizedKeysFile .ssh/authorized_keys #AuthorizedKeysCommand none #AuthorizedKeysCommandRunAs nobody # 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 #KerberosUseKuserok yes # GSSAPI options #GSSAPIAuthentication no GSSAPIAuthentication yes #GSSAPICleanupCredentials yes GSSAPICleanupCredentials yes #GSSAPIStrictAcceptorCheck yes #GSSAPIKeyExchange no # 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 and # PasswordAuthentication. Depending on your PAM configuration, # PAM authentication via ChallengeResponseAuthentication may bypass # the setting of "PermitRootLogin without-password". # If you just want the PAM account and session checks to run without # PAM authentication, then enable this but set PasswordAuthentication # and ChallengeResponseAuthentication to '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 LANGUAGE AcceptEnv XMODIFIERS #AllowAgentForwarding yes #AllowTcpForwarding yes #GatewayPorts no #X11Forwarding no X11Forwarding yes #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 no #PidFile /var/run/sshd.pid #MaxStartups 10:30:100 #PermitTunnel no #ChrootDirectory none # no default banner path #Banner none # override default of no subsystems Subsystem sftp /usr/libexec/openssh/sftp-server # Example of overriding settings on a per-user basis #Match User anoncvs # X11Forwarding no # AllowTcpForwarding no # ForceCommand cvs server
Any ideas would be much appreciated.
If the permissions are correct, SELinux might still be preventing sshd from opening the file.
Try fixing the labels inside the .ssh directory (and maybe $HOME):
restorecon -FRvv ~/.ssh
(I'm intentionally not suggesting disabling SELinux or setting it to the permissive mode.)
I was struggling to use key authentication as well.
Could not open authorized keys '/home/myUserName/.ssh/authorized_keys2': Permission denied
Had checked all the above things when I ended up here (first link on google). I realize that this is an old post but I will add it here in case somebody else has the same problem as me and end up here.
I had owner of the authorized_keys file to "root", so changing it with:
chown myUserName authorized_keys2
Solved it for me.
In case if SELinux enabled:
$ getenforce Enforcing
to temporary enable pub-key ssl login to non-standard user home directory location run:
$ sudo chcon -t ssh_home_t /srv/jenkins/.ssh/authorized_keys /srv/jenkins/.ssh $ ls -ldZ /srv/jenkins/.ssh/authorized_keys /srv/jenkins/.ssh/ drwxr-xr-x. jenkins jenkins system_u:object_r:ssh_home_t:s0 /srv/jenkins/.ssh/ -rw-r--r--. jenkins jenkins system_u:object_r:ssh_home_t:s0 /srv/jenkins/.ssh/authorized_keys
See https://linux.die.net/man/8/ssh_selinux for the details.
To make SELinux settings permanent run:
$ sudo semanage fcontext -a -t ssh_home_t /srv/jenkins/.ssh/authorized_keys $ sudo semanage fcontext -a -t ssh_home_t /srv/jenkins/.ssh $ sudo restorecon -R -v /srv/jenkins/.ssh/
You hit this if you are on modern RHEL, Oracle Linux, CentOS.
Check the /home directory permissions. It should be
- drwxr-xr-x. 9 root root 113 Jun 28 22:57 home
and then your home directory detail:
- drwxr----- 5 user group 124 May 18 17:00 User drwx------ 2 user group 29 May 18 12:05 .ssh -rw------- 1 user group 2235 Jun 28 23:09 authorized_keys
My error messages in logs
/var/log/secure > sshd: error: Received disconnect from X.X.X.X: 14: No supported authentication methods available [preauth]
On client side
ssh user@X.X.X.X Permission denied (publickey). ssh -vvv user@X.X.X.X ... debug2: we did not send a packet, disable method debug1: No more authentication methods to try. Permission denied (publickey). On server side
service sshd stop
run sshd debug mode:
... debug1: trying public key file /home/USER/.ssh/authorized_keys debug1: Could not open authorized keys '/home/USER/.ssh/authorized_keys': Permission denied ...
A couple ideas to check:
- Can you cat authorized_keys? What does the file look like?
- Is your sshd configured to allow root login? This is generally frowned upon,
- Are you doing it as root or as a sudoer?
Don't do chmod on ~/.ssh/.... Try to write the exact path: /root/.ssh/..., since sometimes (when using su etc), the ~ can be setup incorrectly. Check and post the permissions again for the full path without using ~ in the command.
Once you are absolutely sure the permissions are OK, check if your sshd is actually running under user root: ps -A u | grep sshd.
A couple of things to double-check:
- Are you sure you copied the PUBLIC key to the authorized_keys, not the private key? :-)
- Do cat -tv authorized_keys. Any ^M characters at the end of each line? Do a dos2unix on authorized_keys
- Did you restart the ssh daemon after making configuration changes?
I encountered this same issue and got it solved by changing both .ssh and authorized_keys's owner at the same time: chown MyUsername:Myusername .ssh chown MyUsername:Myusername .ssh/authorized_keys
Thanks to @niclaslindgren.
And BTW, it's no matter with whether there is ^M in authorized_keys or not, I had tested and proved it, it works with both the ways