Arch Linux

tomfitzyuk

Member

Registered: 2005-12-30

Posts: 89

Passwordless SSH isn't working for me : [Solved]

Hey,

I'm trying to setup passwordless SSH.

My server, bsdserver, is running OpenBSD. My client, tomscomputer, is running Arch Linux.

When I try to login through SSH, it returns:

~ :: ssh -v -v -v tom@bsdserver
OpenSSH_4.3p2, OpenSSL 0.9.8c 05 Sep 2006
debug1: Reading configuration data /etc/ssh/ssh_config
debug2: ssh_connect: needpriv 0
debug1: Connecting to bsdserver [192.168.0.4] port 22.
debug1: Connection established.
debug3: Not a RSA1 key file /home/tom/.ssh/id_dsa.
debug2: key_type_from_name: unknown key type '-----BEGIN'
debug3: key_read: missing keytype
debug2: key_type_from_name: unknown key type 'Proc-Type:'
debug3: key_read: missing keytype
debug2: key_type_from_name: unknown key type 'DEK-Info:'
debug3: key_read: missing keytype
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug2: key_type_from_name: unknown key type '-----END'
debug3: key_read: missing keytype
debug1: identity file /home/tom/.ssh/id_dsa type 2
debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3
debug1: match: OpenSSH_4.3 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_4.3
debug2: fd 3 setting O_NONBLOCK
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib@openssh.com,zlib
debug2: kex_parse_kexinit: none,zlib@openssh.com,zlib
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib@openssh.com
debug2: kex_parse_kexinit: none,zlib@openssh.com
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: mac_init: found hmac-md5
debug1: kex: server->client aes128-cbc hmac-md5 none
debug2: mac_init: found hmac-md5
debug1: kex: client->server aes128-cbc hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: dh_gen_key: priv key bits set: 132/256
debug2: bits set: 515/1024
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug3: check_host_in_hostfile: filename /home/tom/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 1
debug3: check_host_in_hostfile: filename /home/tom/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 1
debug1: Host 'bsdserver' is known and matches the RSA host key.
debug1: Found key in /home/tom/.ssh/known_hosts:1
debug2: bits set: 493/1024
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /home/tom/.ssh/id_dsa (0x8091e88)
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug3: start over, passed a different list publickey,password,keyboard-interactive
debug3: preferred publickey,keyboard-interactive
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering public key: /home/tom/.ssh/id_dsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug2: we did not send a packet, disable method
debug3: authmethod_lookup keyboard-interactive
debug3: remaining preferred:
debug3: authmethod_is_enabled keyboard-interactive
debug1: Next authentication method: keyboard-interactive
debug2: userauth_kbdint
debug2: we sent a keyboard-interactive packet, wait for reply
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug3: userauth_kbdint: disable: no info_req_seen
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
Permission denied (publickey,password,keyboard-interactive).
~ ::

Here's some useful information:
ls tomscomputer:~tom/.ssh/

~ :: ls -lah ~tom/.ssh/
total 24K
drwx------  2 tom users 4.0K 2006-09-09 00:00 .
drwx--x--x 30 tom users 8.0K 2006-09-09 00:21 ..
-r--------  1 tom users  736 2006-09-08 23:28 id_dsa
-rw-r--r--  1 tom users  606 2006-09-08 23:28 id_dsa.pub
-rw-r--r--  1 tom users  403 2006-09-08 23:27 known_hosts

ls bsdserver:~tom/.ssh/

-bash-3.1$ ls -lah ~tom/.ssh/
total 12
drwx------  2 tom  tom   512B Sep  9 02:20 .
drwxr-xr-x  7 tom  tom   512B Sep  9 03:00 ..
-rw-------  1 tom  tom   606B Sep  9 02:31 authorized_keys

cat bsdserver:/etc/ssh/sshd_config

-bash-3.1$ cat /etc/ssh/sshd_config
#       $OpenBSD: sshd_config,v 1.73 2005/12/06 22:38:28 reyk Exp $

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

# 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
#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
#LogLevel INFO

# Authentication:

LoginGraceTime 2m
PermitRootLogin no
#StrictModes yes
MaxAuthTries 6

RSAAuthentication yes
DSAAuthentication 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

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

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

# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes

#AllowTcpForwarding yes
#GatewayPorts 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
#UseDNS yes
PidFile /var/run/sshd.pid
#MaxStartups 10
#PermitTunnel no

# no default banner path
#Banner /some/path

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

cat tomscomputer:/etc/ssh/ssh_config

#    $OpenBSD: ssh_config,v 1.21 2005/12/06 22:38:27 reyk Exp $

# This is the ssh client system-wide configuration file.  See
# ssh_config(5) for more information.  This file provides defaults for
# users, and the values can be changed in per-user configuration files
# or on the command line.

# Configuration data is parsed as follows:
#  1. command line options
#  2. user-specific file
#  3. system-wide file
# Any configuration value is only changed the first time it is set.
# Thus, host-specific definitions should be at the beginning of the
# configuration file, and defaults at the end.

# Site-wide defaults for some commonly used options.  For a comprehensive
# list of available options, their meanings and defaults, please see the
# ssh_config(5) man page.

# Host *
#   ForwardAgent no
#   ForwardX11 no
#   RhostsRSAAuthentication no
   RSAAuthentication yes
   PasswordAuthentication no
#   HostbasedAuthentication no
#   BatchMode no
#   CheckHostIP yes
#   AddressFamily any
#   ConnectTimeout 0
#   StrictHostKeyChecking ask
#   IdentityFile ~/.ssh/identity
#   IdentityFile ~/.ssh/id_rsa
   IdentityFile ~/.ssh/id_dsa
#   Port 22
#   Protocol 2,1
#   Cipher 3des
#   Ciphers aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc
#   EscapeChar ~
#   Tunnel no
#   TunnelDevice any:any
#   PermitLocalCommand no

Proof I have copied over my public key correctly

~ :: sshfs tom@bsdserver:/home/tom mnt/
tom@bsdserver's password:
~ :: diff mnt/.ssh/authorized_keys ~tom/.ssh/id_dsa.pub
~ ::

Does anybody have any idea why this isn't this working?

If there's somebody who has passwordless SSH working, it'd be great if they post their setup similar to how I have

Thanks,
Tom

allucid

Member

Registered: 2006-01-06

Posts: 259

Re: Passwordless SSH isn't working for me : [Solved]

Looks like you are trying to do RSA authetication but you created a DSA keypair.

This is a guess, I would assume SSH should autodetect what type of key you are using.

tomfitzyuk

Member

Registered: 2005-12-30

Posts: 89

Re: Passwordless SSH isn't working for me : [Solved]

Looks like you are trying to do RSA authetication but you created a DSA keypair.

This is a guess, I would assume SSH should autodetect what type of key you are using.

I searched 'man sshd_config' for DSA and nothing was found...

RSAAuthentication only applies to protocol version 1, so I guess I needn't bother enabling (since only protocol version 2 is enabled).

I think PubkeyAuthentication is the important one.

I think the vital information in the debugging information is:

debug1: Next authentication method: publickey
debug1: Trying private key: /home/tom/.ssh/identity
debug3: no such identity: /home/tom/.ssh/identity
debug1: Trying private key: /home/tom/.ssh/id_rsa
debug3: no such identity: /home/tom/.ssh/id_rsa
debug1: Offering public key: /home/tom/.ssh/id_dsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey,password,keyboard-interactive

It sends the public key packet, but then never gets a reply, why so?

tomfitzyuk

Member

Registered: 2005-12-30

Posts: 89

Re: Passwordless SSH isn't working for me : [Solved]

I ran sshd in debug mode:

/usr/sbin/sshd -d

And it seems that sshd was trying to read /root/.ssh/authorized_keys despite how:

-bash-3.1$ grep AuthorizedKeysFile /etc/ssh/sshd_config
AuthorizedKeysFile ~/.ssh/authorized_keys
-bash-3.1$

... and I was logging in as tom.

Changing:

AuthorizedKeysFile ~/.ssh/authorized_keys

to:

/home/tom/.ssh/authorized_keys

caused it to start working...

Obviously this isn't the problem free, but this problem is more specific.

Since my host is running OpenBSD, this is no longer an Arch issue.

tomfitzyuk

Member

Registered: 2005-12-30

Posts: 89

Re: Passwordless SSH isn't working for me : [Solved]

Solved it by commenting out AuthorizedKeysFile in /etc/ssh/sshd_config

It must have expanded ~/.ssh/authorized_keys to /root/.ssh/authorized_keys

Since the default setting was ~/.ssh/authorized_keys sshd was able to handle it properly.

All sorted now