Unable to login after creating user on CentOS

laredotornado · 08-26-2012, 02:20 PM

Hi,

I'm using CentOS and having trouble creating a user. Specifically, after creating the user and changing the password, I'm unable to login with the password I assigned (I'm cutting and pasting it to assure I'm not committing any typo's). What else do I need to do to activate a user? Here's what I'm trying ...

Code:

[myuser@remote-server ~]$ sudo useradd builduser
[sudo] password for myuser: 
[myuser@remote-server ~]$ sudo passwd builduser
Changing password for user builduser.
New password: 
Retype new password: 
passwd: all authentication tokens updated successfully.
[myuser@remote-server ~]$ ssh builduser@localhost
buildser@localhost's password: 
Permission denied, please try again.

Thanks, - Dave

sag47 · 08-26-2012, 03:13 PM

There shouldn't be much more to do. What does your /etc/ssh/sshd_config say?

Also you might want to

Code:

tail -f /var/log/secure

While you're attempting to log in to see if there are any server side errors.

Additionally you can turn up the verbosity of the ssh client to see what client side errors are being output.

Code:

ssh -vvvv builduser@localhost

TobiSGD · 08-26-2012, 04:03 PM

If I remember correctly, useradd does not create a /home-directory for the new user by default and you have not used the -d option. Does a /home-directory for the new user exist?

laredotornado · 08-27-2012, 08:37 AM

Tailing the log revealed that my user was not listed in the "AllowUsers" line of the /etc/ssh/sshd_config file, so I edited that line and added ...

Code:

AllowUsers user1 user2 myuser builduser

but still when attempting to login to localhost, I got this error in the logs …

Code:

Aug 27 13:30:42 myserver sudo: myuser : TTY=pts/0 ; PWD=/home/myuser ; USER=root ; COMMAND=/usr/bin/vim /etc/ssh/sshd_config
Aug 27 13:31:07 myserver sshd[20951]: User builduser from localhost not allowed because not listed in AllowUsers
Aug 27 13:31:07 myserver sshd[20952]: input_userauth_request: invalid user builduser
Aug 27 13:31:11 myserver sshd[20951]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=localhost  user=builduser
Aug 27 13:31:12 myserver sshd[20951]: Failed password for invalid user builduser from 127.0.0.1 port 38465 ssh2

Does the AllowUser setting not take effect right away? Is there another setting to adjust? The client side code looks like ...

Code:

[myuser@myserver ~]$ ssh -vvvv builduser@localhost
OpenSSH_5.3p1, OpenSSL 1.0.0j-fips 10 May 2012
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to localhost [127.0.0.1] port 22.
debug1: Connection established.
debug1: identity file /home/myuser/.ssh/identity type -1
debug1: identity file /home/myuser/.ssh/id_rsa type -1
debug1: identity file /home/myuser/.ssh/id_dsa type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3
debug1: match: OpenSSH_5.3 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.3
debug2: fd 3 setting O_NONBLOCK
debug1: SSH2_MSG_KEXINIT sent
debug3: Wrote 792 bytes for a total of 813
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,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-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,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-sha256,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-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,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_setup: found hmac-md5
debug1: kex: server->client aes128-ctr hmac-md5 none
debug2: mac_setup: found hmac-md5
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug3: Wrote 24 bytes for a total of 837
debug2: dh_gen_key: priv key bits set: 119/256
debug2: bits set: 529/1024
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug3: Wrote 144 bytes for a total of 981
debug3: check_host_in_hostfile: filename /home/myuser/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 1
debug1: Host 'localhost' is known and matches the RSA host key.
debug1: Found key in /home/myuser/.ssh/known_hosts:1
debug2: bits set: 546/1024
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
debug3: Wrote 16 bytes for a total of 997
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug3: Wrote 48 bytes for a total of 1045
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /home/myuser/.ssh/identity ((nil))
debug2: key: /home/myuser/.ssh/id_rsa ((nil))
debug2: key: /home/myuser/.ssh/id_dsa ((nil))
debug3: Wrote 64 bytes for a total of 1109
debug1: Authentications that can continue: publickey,password
debug3: start over, passed a different list publickey,password
debug3: preferred gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/myuser/.ssh/identity
debug3: no such identity: /home/myuser/.ssh/identity
debug1: Trying private key: /home/myuser/.ssh/id_rsa
debug3: no such identity: /home/myuser/.ssh/id_rsa
debug1: Trying private key: /home/myuser/.ssh/id_dsa
debug3: no such identity: /home/myuser/.ssh/id_dsa
debug2: we did not send a packet, disable method
debug3: authmethod_lookup password
debug3: remaining preferred: ,password
debug3: authmethod_is_enabled password
debug1: Next authentication method: password
builduser@localhost's password: 
debug3: packet_send2: adding 48 (len 62 padlen 18 extra_pad 64)
debug2: we sent a password packet, wait for reply
debug3: Wrote 144 bytes for a total of 1253
debug1: Authentications that can continue: publickey,password
Permission denied, please try again.

sag47 · 08-27-2012, 09:21 AM

When you modified AllowUser did you restart sshd?

laredotornado · 08-27-2012, 09:27 AM

Oops, no. I restarted and everything works now. Thanks, -

sag47 · 08-27-2012, 10:38 AM

You're welcome, please mark the thread as solved under thread tools at the top of the thread.

Also another way to go about resolving your problem is by specifying a group, e.g. sshusers. I recommend doing this so you can separate shell users from regular users.

Add AllowGroups to your sshd_config.

Code:

AllowGroups sshusers

And then you can add the group to your user,

Code:

groupadd sshusers
usermod -a -G sshusers user1

Additionally, if you don't care to specify an sshusers group for each user and simply want any user you create to have ssh access then you can allow the users group. In that case, you can use the following in sshd_config.

Code:

AllowGroups users

SAM