SSH Login with no password

English Network/Internet
#1

Hey everybody. I’m trying to set up passwordless SSH between two hosts but I’m having trouble authenticating. When I try to connect from the host I get the following:

matt@VidWebSatellite:~>ssh matt@192.168.59.134
Permission denied (publickey).

I generated the keys with “ssh-keygen -t rsa” and copied the contents of “~/.ssh/id_rsa.pub” to “/home/matt/.ssh/authorized_keys”. The .ssh directory is owned by matt:users and has 700 permissions. The authorized_keys file is owned by matt:users and has 600 permissions.

Here is the sshd_config from the server:

#	$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/bin:/bin:/usr/sbin:/sbin

# 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
LogLevel DEBUG3

# Authentication:

#LoginGraceTime 2m
#PermitRootLogin yes
#StrictModes yes
#MaxAuthTries 6
#MaxSessions 10

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 no
#PermitEmptyPasswords yes

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

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

# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes

# Set this to 'yes' to enable support for the deprecated 'gssapi' authentication
# mechanism to OpenSSH 3.8p1. The newer 'gssapi-with-mic' mechanism is included
# in this release. The use of 'gssapi' is deprecated due to the presence of 
# potential man-in-the-middle attacks, which 'gssapi-with-mic' is not susceptible to.
#GSSAPIEnableMITMAttack 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 yes

#AllowAgentForwarding yes
#AllowTcpForwarding yes
#GatewayPorts 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
#UseDNS yes
#PidFile /var/run/sshd.pid
#MaxStartups 10
#PermitTunnel no
#ChrootDirectory none

# no default banner path
#Banner none

# override default of no subsystems
Subsystem	sftp	/usr/lib/ssh/sftp-server

# This enables accepting locale enviroment variables LC_* LANG, see sshd_config(5).
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

# Example of overriding settings on a per-user basis
#Match User anoncvs
#	X11Forwarding no
#	AllowTcpForwarding no
#	ForceCommand cvs server

And here is the log of the connection attempt:

Aug  9 21:09:43 VidWebMaster sshd[13063]: debug3: fd 5 is not O_NONBLOCK
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: rexec start in 5 out 5 newsock 5 pipe 7 sock 8
Aug  9 21:09:43 VidWebMaster kernel: klogd 1.4.1, ---------- state change ----------
Aug  9 21:09:43 VidWebMaster sshd[13063]: debug1: Forked child 13518.
Aug  9 21:09:43 VidWebMaster sshd[13063]: debug3: send_rexec_state: entering fd = 8 config len 547
Aug  9 21:09:43 VidWebMaster sshd[13063]: debug3: ssh_msg_send: type 0
Aug  9 21:09:43 VidWebMaster sshd[13063]: debug3: send_rexec_state: done
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: inetd sockets after dupping: 3, 3
Aug  9 21:09:43 VidWebMaster sshd[13518]: Connection from 192.168.59.135 port 48904
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: Client protocol version 2.0; client software version OpenSSH_5.1
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: match: OpenSSH_5.1 pat OpenSSH*
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: Enabling compatibility mode for protocol 2.0
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: Local version string SSH-2.0-OpenSSH_5.1
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug2: fd 3 setting O_NONBLOCK
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug2: Network child is on pid 13519
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: preauth child monitor started
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_request_receive entering
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: monitor_read: checking request 0
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_answer_moduli: got parameters: 1024 1024 8192
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_request_send entering: type 1
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug2: monitor_read: 0 used once, disabling now
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_request_receive entering
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: monitor_read: checking request 4
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_answer_sign
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_answer_sign: signature 0xb80b6f60(143)
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_request_send entering: type 5
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug2: monitor_read: 4 used once, disabling now
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_request_receive entering
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: monitor_read: checking request 6
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_answer_pwnamallow
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: Trying to reverse map address 192.168.59.135.
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug2: parse_server_config: config reprocess config len 547
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_answer_pwnamallow: sending MONITOR_ANS_PWNAM: 1
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_request_send entering: type 7
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug2: monitor_read: 6 used once, disabling now
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_request_receive entering
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: monitor_read: checking request 45
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: PAM: initializing for "matt"
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: PAM: setting PAM_RHOST to "192.168.59.135"
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: PAM: setting PAM_TTY to "ssh"
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug2: monitor_read: 45 used once, disabling now
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_request_receive entering
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: monitor_read: checking request 3
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_answer_authserv: service=ssh-connection, style=
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug2: monitor_read: 3 used once, disabling now
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_request_receive entering
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: monitor_read: checking request 20
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_answer_keyallowed entering
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_answer_keyallowed: key_from_blob: 0xb80bba00
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: temporarily_use_uid: 1000/100 (e=0/0)
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: trying public key file /root/.ssh/authorized_keys
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: restore_uid: 0/0
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: temporarily_use_uid: 1000/100 (e=0/0)
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: trying public key file /root/.ssh/authorized_keys
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: restore_uid: 0/0
Aug  9 21:09:43 VidWebMaster sshd[13518]: Failed publickey for matt from 192.168.59.135 port 48904 ssh2
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_answer_keyallowed: key 0xb80bba00 is not allowed
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_request_send entering: type 21
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: mm_request_receive entering
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: do_cleanup
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug1: PAM: cleanup
Aug  9 21:09:43 VidWebMaster sshd[13518]: debug3: PAM: sshpam_thread_cleanup entering

Why is it looking in /root/.ssh/ for the authorized_keys file? What have I missed?

Cheers

#2

It would be because of this line that you modified in /etc/ssh/sshd_config:

AuthorizedKeysFile	~/.ssh/authorized_keys

Before you modified it, it was:

#AuthorizedKeysFile     .ssh/authorized_keys

which is to say, the default was already correct, it’s relative to the home directory. By changing it to ~/.ssh/authorized_keys, you made it equal to /root/.ssh/authorized_keys, because the user running sshd is root.

Public key authentication works with the out of the box /etc/ssh/sshd_config. You made it not work by too much interference. :wink: So put things in /etc/ssh/sshd_config back the way you found them and it will work. After that you may wish to add

PermitRootLogin no

and

AllowUsers matt

to tighten up security.

#3

You made it not work by too much interference.

Haha, story of my life. Thanks heaps, mate.

#4

where is your private key is stored?