Cannot accept ssh post, but id_rsa.pub is in authorized_keys

Question

/ Update: the problem is being clarified: the authorized keys could not be opened. /

I have an Ubuntu server in Virtualbox, and I try to log in to ssh, but every time asking for a password to enter, pubkey does not work.

Summary: Ubuntu 12.04.2 LTS Server in Vbox. Network configuration for host only. Static ip 192.168.56.10 Standard OpenSSH server. The id_rsa.pub host is added to the client's authorized_keys file.

g2ra@host :~$ cat .ssh/id_rsa.pub | ssh -p 22 g2ra@192.168.56.10 'cat >> .ssh/authorized_keys' 

~ / .ssh - correctly chmod.

 g2ra@host :~$ ll .ssh/ total 68 drwx------ 2 g2ra g2ra 4096 Apr 24 00:31 ./ drwx------ 81 g2ra g2ra 28672 Apr 24 09:37 ../ -rw------- 1 g2ra g2ra 1766 Mar 27 10:12 id_rsa -rw------- 1 g2ra g2ra 397 Mar 27 10:12 id_rsa.pub -rw------- 1 g2ra g2ra 1110 Apr 24 11:23 known_hosts 

Here is the debug message:

 ~$ ssh -v -l g2ra -p 22 192.168.56.10 OpenSSH_5.9p1 Debian-5ubuntu1.1, OpenSSL 1.0.1 14 Mar 2012 debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 19: Applying options for * debug1: Connecting to 192.168.56.10 [192.168.56.10] port 22. debug1: Connection established. debug1: identity file /home/g2ra/.ssh/id_rsa type 1 debug1: Checking blacklist file /usr/share/ssh/blacklist.RSA-2048 debug1: Checking blacklist file /etc/ssh/blacklist.RSA-2048 debug1: identity file /home/g2ra/.ssh/id_rsa-cert type -1 debug1: identity file /home/g2ra/.ssh/id_dsa type -1 debug1: identity file /home/g2ra/.ssh/id_dsa-cert type -1 debug1: identity file /home/g2ra/.ssh/id_ecdsa type -1 debug1: identity file /home/g2ra/.ssh/id_ecdsa-cert type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.9p1 Debian-5ubuntu1.1 debug1: match: OpenSSH_5.9p1 Debian-5ubuntu1.1 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.9p1 Debian-5ubuntu1.1 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: sending SSH2_MSG_KEX_ECDH_INIT debug1: expecting SSH2_MSG_KEX_ECDH_REPLY debug1: Server host key: ECDSA 00:00:00:87:00:0a:3d:e1:aa:78:ac:05:00:00:0e:00 debug1: Host '192.168.56.10' is known and matches the ECDSA host key. debug1: Found key in /home/g2ra/.ssh/known_hosts:5 debug1: ssh_ecdsa_verify: signature correct debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: SSH2_MSG_NEWKEYS received debug1: Roaming not allowed by server debug1: SSH2_MSG_SERVICE_REQUEST sent debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey,password debug1: Next authentication method: publickey debug1: Offering RSA public key: /home/g2ra/.ssh/id_rsa debug1: Authentications that can continue: publickey,password debug1: Trying private key: /home/g2ra/.ssh/id_dsa debug1: Trying private key: /home/g2ra/.ssh/id_ecdsa debug1: Next authentication method: password 

Here is my sshd configuration on a Ubuntu server in Vbox:

 Port 22 # Use these options to restrict which interfaces/protocols sshd will bind to #ListenAddress :: #ListenAddress 0.0.0.0 Protocol 2 # HostKeys for protocol version 2 HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_dsa_key HostKey /etc/ssh/ssh_host_ecdsa_key #Privilege Separation is turned on for security UsePrivilegeSeparation yes # Lifetime and size of ephemeral version 1 server key KeyRegenerationInterval 3600 ServerKeyBits 768 # Logging SyslogFacility AUTH LogLevel INFO # Authentication: LoginGraceTime 120 PermitRootLogin yes StrictModes yes RSAAuthentication yes PubkeyAuthentication yes AuthorizedKeysFile %h/.ssh/authorized_keys # Don't read the user ~/.rhosts and ~/.shosts files IgnoreRhosts yes # For this to work you will also need host keys in /etc/ssh_known_hosts RhostsRSAAuthentication no # similar for protocol version 2 HostbasedAuthentication no # Uncomment if you don't trust ~/.ssh/known_hosts for RhostsRSAAuthentication #IgnoreUserKnownHosts yes # To enable empty passwords, change to yes (NOT RECOMMENDED) PermitEmptyPasswords no # Change to yes to enable challenge-response passwords (beware issues with # some PAM modules and threads) ChallengeResponseAuthentication no # Change to no to disable tunnelled clear text passwords #PasswordAuthentication yes # Kerberos options #KerberosAuthentication no #KerberosGetAFSToken no #KerberosOrLocalPasswd yes #KerberosTicketCleanup yes # GSSAPI options #GSSAPIAuthentication no #GSSAPICleanupCredentials yes X11Forwarding yes X11DisplayOffset 10 PrintMotd no PrintLastLog yes TCPKeepAlive yes #UseLogin no #MaxStartups 10:30:60 #Banner /etc/issue.net # Allow client to pass locale environment variables AcceptEnv LANG LC_* Subsystem sftp /usr/lib/openssh/sftp-server # 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 

Update increased to DEBUG level in sshd config. On Ubuntu Server Vbox.

 grep 'ssh'/var/log/auth.log Apr 24 13:57:03 host sshd[19731]: debug1: Client protocol version 2.0; client software version OpenSSH_5.9p1 Debian-5ubuntu1.1 Apr 24 13:57:03 host sshd[19731]: debug1: match: OpenSSH_5.9p1 Debian-5ubuntu1.1 pat OpenSSH* Apr 24 13:57:03 host sshd[19731]: debug1: Enabling compatibility mode for protocol 2.0 Apr 24 13:57:03 host sshd[19731]: debug1: Local version string SSH-2.0-OpenSSH_5.9p1 Debian-5ubuntu1.1 Apr 24 13:57:03 host sshd[19731]: debug1: permanently_set_uid: 105/65534 [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: list_hostkey_types: ssh-rsa,ssh-dss,ecdsa-sha2-nistp256 [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: SSH2_MSG_KEXINIT sent [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: SSH2_MSG_KEXINIT received [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: kex: client->server aes128-ctr hmac-md5 none [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: kex: server->client aes128-ctr hmac-md5 none [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: expecting SSH2_MSG_KEX_ECDH_INIT [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: SSH2_MSG_NEWKEYS sent [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: expecting SSH2_MSG_NEWKEYS [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: SSH2_MSG_NEWKEYS received [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: KEX done [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: userauth-request for user g2ra service ssh-connection method none [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: attempt 0 failures 0 [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: PAM: initializing for "g2ra" Apr 24 13:57:03 host sshd[19731]: debug1: PAM: setting PAM_RHOST to "192.168.56.1" Apr 24 13:57:03 host sshd[19731]: debug1: PAM: setting PAM_TTY to "ssh" Apr 24 13:57:03 host sshd[19731]: debug1: userauth-request for user g2ra service ssh-connection method publickey [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: attempt 1 failures 0 [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: test whether pkalg/pkblob are acceptable [preauth] Apr 24 13:57:03 host sshd[19731]: debug1: Checking blacklist file /usr/share/ssh/blacklist.RSA-2048 Apr 24 13:57:03 host sshd[19731]: debug1: Checking blacklist file /etc/ssh/blacklist.RSA-2048 Apr 24 13:57:03 host sshd[19731]: debug1: temporarily_use_uid: 1000/1000 (e=0/0) Apr 24 13:57:03 host sshd[19731]: debug1: trying public key file /home/g2ra/.ssh/authorized_keys Apr 24 13:57:03 host sshd[19731]: debug1: Could not open authorized keys '/home/g2ra/.ssh/authorized_keys': No such file or directory Apr 24 13:57:03 host sshd[19731]: debug1: restore_uid: 0/0 Apr 24 13:57:03 host sshd[19731]: Failed publickey for g2ra from 192.168.56.1 port 51041 ssh2 Apr 24 13:57:07 host sshd[19731]: debug1: userauth-request for user g2ra service ssh-connection method password [preauth] Apr 24 13:57:07 host sshd[19731]: debug1: attempt 2 failures 1 [preauth] Apr 24 13:57:07 host sshd[19733]: pam_ecryptfs: Passphrase file wrapped Apr 24 13:57:08 host sshd[19731]: debug1: PAM: password authentication accepted for g2ra Apr 24 13:57:08 host sshd[19731]: debug1: do_pam_account: called Apr 24 13:57:08 host sshd[19731]: Accepted password for g2ra from 192.168.56.1 port 51041 ssh2 Apr 24 13:57:08 host sshd[19731]: debug1: monitor_read_log: child log fd closed Apr 24 13:57:08 host sshd[19731]: debug1: monitor_child_preauth: g2ra has been authenticated by privileged process Apr 24 13:57:08 host sshd[19731]: debug1: PAM: establishing credentials Apr 24 13:57:08 host sshd[19731]: pam_unix(sshd:session): session opened for user g2ra by (uid=0) Apr 24 13:57:09 host sshd[19731]: User child is on pid 19871 Apr 24 13:57:09 host sshd[19871]: debug1: SELinux support disabled Apr 24 13:57:09 host sshd[19871]: debug1: PAM: establishing credentials Apr 24 13:57:09 host sshd[19871]: debug1: permanently_set_uid: 1000/1000 Apr 24 13:57:09 host sshd[19871]: debug1: Entering interactive session for SSH2. Apr 24 13:57:09 host sshd[19871]: debug1: server_init_dispatch_20 Apr 24 13:57:09 host sshd[19871]: debug1: server_input_channel_open: ctype session rchan 0 win 1048576 max 16384 Apr 24 13:57:09 host sshd[19871]: debug1: input_session_request Apr 24 13:57:09 host sshd[19871]: debug1: channel 0: new [server-session] Apr 24 13:57:09 host sshd[19871]: debug1: session_new: session 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_open: channel 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_open: session 0: link with channel 0 Apr 24 13:57:09 host sshd[19871]: debug1: server_input_channel_open: confirm session Apr 24 13:57:09 host sshd[19871]: debug1: server_input_global_request: rtype [e-mail] want_reply 0 Apr 24 13:57:09 host sshd[19871]: debug1: server_input_channel_req: channel 0 request pty-req reply 1 Apr 24 13:57:09 host sshd[19871]: debug1: session_by_channel: session 0 channel 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_input_channel_req: session 0 req pty-req Apr 24 13:57:09 host sshd[19871]: debug1: Allocating pty. Apr 24 13:57:09 host sshd[19731]: debug1: session_new: session 0 Apr 24 13:57:09 host sshd[19731]: debug1: SELinux support disabled Apr 24 13:57:09 host sshd[19871]: debug1: session_pty_req: session 0 alloc /dev/pts/0 Apr 24 13:57:09 host sshd[19871]: debug1: server_input_channel_req: channel 0 request env reply 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_by_channel: session 0 channel 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_input_channel_req: session 0 req env Apr 24 13:57:09 host sshd[19871]: debug1: server_input_channel_req: channel 0 request env reply 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_by_channel: session 0 channel 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_input_channel_req: session 0 req env Apr 24 13:57:09 host sshd[19871]: debug1: server_input_channel_req: channel 0 request env reply 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_by_channel: session 0 channel 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_input_channel_req: session 0 req env Apr 24 13:57:09 host sshd[19871]: debug1: server_input_channel_req: channel 0 request env reply 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_by_channel: session 0 channel 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_input_channel_req: session 0 req env Apr 24 13:57:09 host sshd[19871]: debug1: server_input_channel_req: channel 0 request env reply 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_by_channel: session 0 channel 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_input_channel_req: session 0 req env Apr 24 13:57:09 host sshd[19871]: debug1: server_input_channel_req: channel 0 request env reply 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_by_channel: session 0 channel 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_input_channel_req: session 0 req env Apr 24 13:57:09 host sshd[19871]: debug1: server_input_channel_req: channel 0 request env reply 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_by_channel: session 0 channel 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_input_channel_req: session 0 req env Apr 24 13:57:09 host sshd[19871]: debug1: server_input_channel_req: channel 0 request env reply 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_by_channel: session 0 channel 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_input_channel_req: session 0 req env Apr 24 13:57:09 host sshd[19871]: debug1: server_input_channel_req: channel 0 request env reply 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_by_channel: session 0 channel 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_input_channel_req: session 0 req env Apr 24 13:57:09 host sshd[19871]: debug1: server_input_channel_req: channel 0 request env reply 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_by_channel: session 0 channel 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_input_channel_req: session 0 req env Apr 24 13:57:09 host sshd[19871]: debug1: server_input_channel_req: channel 0 request shell reply 1 Apr 24 13:57:09 host sshd[19871]: debug1: session_by_channel: session 0 channel 0 Apr 24 13:57:09 host sshd[19871]: debug1: session_input_channel_req: session 0 req shell Apr 24 13:57:09 host sshd[19872]: debug1: Setting controlling tty using TIOCSCTTY. 

Debug log Failed to open authorized keys / home / g 2ra / .ssh / authorized_keys: no such file or directory. Why?

Answer 1

The @ g1ra comment solves this problem if you have an encrypted home folder. Add it here for better visibility.

If you have an encrypted home directory, SSH cannot access your authorized_keys file because it is located in your encrypted home directory and will not be accessible until you authenticate. Therefore, SSH will by default authenticate with a password.

To solve this problem, create a folder outside your home with the name /etc/ssh/<username> (replace <username> with your actual username). This directory must have permissions of 755 and be owned by the user. Move the authorized_keys file to it. The authorized_keys file must have 644 permissions and must belong to the user.

Then edit the file / etc / ssh / sshd _config and add:

 AuthorizedKeysFile /etc/ssh/%u/authorized_keys 

Finally, restart ssh with:

 sudo service ssh restart 

The next time you connect to SSH, you do not need to enter a password.

Source: Ubuntu - SSH / OpenSSH / Keys

Answer 2

Generally, you should use ssh-copy-id instead of creating it manually.

Have you checked permissions for the .ssh and authorized_keys folders on the target machine? Maybe (caused by a manual cat) a file / folder was created with the standard umask, which is too "open" for SSH.

Answer 3

You can try updating ssh entries with ssh-add on both machines.