[X2Go-Dev] X2go Mac client and Red Hat 7 server

Mon May 11 18:44:18 CEST 2015

> if my previous message with the $(which sshd) line didn't produce any
>useful debug output, here's something else you could try.  However, if
>you *did* get debug output from
> that previous step, there's no need to try the following as well.  These
>are mainly connectivity tests.
> On the client's commandline, execute:
> ssh -L18935:128.149.23.102:22 128.149.23.102
> If that connects, leave the ssh session running.

Client connects and I¹m able to authenticate.

> Then, change your X2GoClient session to point to
> 127.0.0.1:18935 instead of 128.149.23.102:22
> Try and see if it connects.
> (Expected result: Protocol mismatch error message)

2015-05-11 09:28:59.009 x2goclient[21467:1656748] modalSession has been
exited prematurely - check for a reentrant call to endModalSession:
x2go-INFO-8> "Starting connection to server: 127.0.0.1:18935"
x2go-ERROR-2> "Connection Error(Cannot connect to 127.0.0.1:18935):
Protocol mismatch: "

> Close X2GoClient, close the SSH session, then repeat it like this:
> ssh -L18935:127.0.0.1:22 128.149.23.102
> #           ^^^^^^^^^ note the different IP here
> Try and see if it connects. (Expected result: Protocol mismatch error
>message)

x2go-INFO-8> "Starting connection to server: 127.0.0.1:18935"
x2go-ERROR-2> "Connection Error(Cannot connect to 127.0.0.1:18935):
Protocol mismatch: "

> Again, close X2GoClient, close the SSH session.
> Repeat with
> ssh -L18935:127.0.0.1:18935 128.149.23.102
> #                     ^^^^^ note the different port number here

Able to connect and authenticate

> verify that an SSHD is listening on the server by using the command
> netstat -ant | grep ':18935' | wc -l
> on the *server*. It should return a number greater than 0.

Returned 0

> Now, try to connect X2GoClient using 127.0.0.1:18935 again.

2015-05-11 09:36:04.970 x2goclient[21660:1659334] modalSession has been
exited prematurely - check for a reentrant call to endModalSession:
x2go-INFO-8> "Starting connection to server: 127.0.0.1:18935"
x2go-ERROR-2> "Connection Error(Cannot connect to 127.0.0.1:18935):
Connection refused"

On 5/11/15, 9:16 AM, "Real, Elizabeth (392K)"
<Elizabeth.Real at jpl.nasa.gov> wrote:

>See my replies below:
>
>> When using "sudo sshd -ddd -p 18935" like suggested by Mihai, I'm
>> getting "sshd re-exec requires execution with an absolute path" and
>> the shell prompt returns.
>
>I got this last Friday and figured the absolute path
>
>> Which means there is no SSHD running on port 18935.  (Verifiable with
>> "netstat -ant | grep ':18935' | wc -l" - that should return a number
>> greater than 0 if SSHD is running on Port 18935.)
>
>Returned the number 2
>
>> sudo $(which sshd) -ddd -p 18935
>> Leave that commandline window open, important debug information will
>>appear there.
>
># $(which sshd) -ddd -p 18935
>debug2: load_server_config: filename /etc/ssh/sshd_config
>debug2: load_server_config: done config len = 848
>debug2: parse_server_config: config /etc/ssh/sshd_config len 848
>debug3: /etc/ssh/sshd_config:28 setting HostKey /etc/ssh/ssh_host_rsa_key
>debug3: /etc/ssh/sshd_config:30 setting HostKey
>/etc/ssh/ssh_host_ecdsa_key
>debug3: /etc/ssh/sshd_config:42 setting SyslogFacility AUTHPRIV
>debug3: /etc/ssh/sshd_config:44 setting LogLevel VERBOSE
>debug3: /etc/ssh/sshd_config:56 setting MaxAuthTries 5
>debug3: /etc/ssh/sshd_config:64 setting AuthorizedKeysFile
>.ssh/authorized_keys
>debug3: /etc/ssh/sshd_config:73 setting RhostsRSAAuthentication yes
>debug3: /etc/ssh/sshd_config:76 setting HostbasedAuthentication yes
>debug3: /etc/ssh/sshd_config:82 setting IgnoreRhosts no
>debug3: /etc/ssh/sshd_config:87 setting PasswordAuthentication yes
>debug3: /etc/ssh/sshd_config:91 setting ChallengeResponseAuthentication
>yes
>debug3: /etc/ssh/sshd_config:102 setting GSSAPIAuthentication yes
>debug3: /etc/ssh/sshd_config:104 setting GSSAPICleanupCredentials yes
>debug3: /etc/ssh/sshd_config:120 setting UsePAM yes
>debug3: /etc/ssh/sshd_config:126 setting X11Forwarding yes
>debug3: /etc/ssh/sshd_config:133 setting UsePrivilegeSeparation sandbox
>    
>debug3: /etc/ssh/sshd_config:149 setting Banner /etc/banners/sshd
>debug3: /etc/ssh/sshd_config:152 setting AcceptEnv LANG LC_CTYPE
>LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES
>debug3: /etc/ssh/sshd_config:153 setting AcceptEnv LC_PAPER LC_NAME
>LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT
>debug3: /etc/ssh/sshd_config:154 setting AcceptEnv LC_IDENTIFICATION
>LC_ALL LANGUAGE
>debug3: /etc/ssh/sshd_config:155 setting AcceptEnv XMODIFIERS
>debug3: /etc/ssh/sshd_config:158 setting Subsystem sftp
>/usr/libexec/openssh/sftp-server
>debug1: sshd version OpenSSH_6.4, OpenSSL 1.0.1e-fips 11 Feb 2013
>debug3: Incorrect RSA1 identifier
>debug1: read PEM private key done: type RSA
>debug3: Incorrect RSA1 identifier
>debug3: Could not load "/etc/ssh/ssh_host_rsa_key" as a RSA1 public key
>debug1: private host key: #0 type 1 RSA
>debug3: Incorrect RSA1 identifier
>debug1: read PEM private key done: type ECDSA
>debug3: Incorrect RSA1 identifier
>debug3: Could not load "/etc/ssh/ssh_host_ecdsa_key" as a RSA1 public key
>debug1: private host key: #1 type 3 ECDSA
>debug1: rexec_argv[0]='/sbin/sshd'
>debug1: rexec_argv[1]='-ddd'
>debug1: rexec_argv[2]='-p'
>debug1: rexec_argv[3]='18935'
>debug3: oom_adjust_setup
>Set /proc/self/oom_score_adj from 0 to -1000
>debug2: fd 3 setting O_NONBLOCK
>debug1: Bind to port 18935 on 0.0.0.0.
>Server listening on 0.0.0.0 port 18935.
>debug2: fd 4 setting O_NONBLOCK
>debug3: sock_set_v6only: set socket 4 IPV6_V6ONLY
>debug1: Bind to port 18935 on ::.
>Server listening on :: port 18935.
>
>
>> With that window open, try connecting with X2GoClient to
>>128.149.23.102:18935.
>% /Applications/x2goclient.app/Contents/MacOS/x2goclient ; exit;
>x2go-INFO-1> "Starting x2goclient..."
>x2go-WARNING-1> "Can't load translator: :/i18n/x2goclient_en_us"
>x2go-WARNING-2> "Can't load translator: :/i18n/qt_en_US"
>x2go-INFO-3> "Started  x2goclient."
>Object::connect: No such slot SessionWidget::slot_emitSettings()
>Object::connect: No such slot SessionWidget::slot_emitSettings()
>Object::connect: No such signal SessionWidget::directRDP(bool)
>Object::connect: No such signal
>SessionWidget::settingsChanged(QString,QString,QString)
>2015-05-11 09:15:19.797 x2goclient[21241:1652401] modalSession has been
>exited prematurely - check for a reentrant call to endModalSession:
>x2go-INFO-8> "Starting connection to server: 128.149.23.102:18935"
>x2go-ERROR-2> "Connection Error(Cannot connect to 128.149.23.102:18935):
>Connection refused"
>
>
>
>
>
>On 5/11/15, 9:05 AM, "Real, Elizabeth (392K)"
><Elizabeth.Real at jpl.nasa.gov> wrote:
>
>>Here are the outputs from RH7 server and Mac client:
>>
>>RH7 server:
>># /usr/sbin/sshd -ddd -p 18935
>>debug2: load_server_config: filename /etc/ssh/sshd_config
>>debug2: load_server_config: done config len = 848
>>debug2: parse_server_config: config /etc/ssh/sshd_config len 848
>>debug3: /etc/ssh/sshd_config:28 setting HostKey /etc/ssh/ssh_host_rsa_key
>>debug3: /etc/ssh/sshd_config:30 setting HostKey
>>/etc/ssh/ssh_host_ecdsa_key
>>debug3: /etc/ssh/sshd_config:42 setting SyslogFacility AUTHPRIV
>>debug3: /etc/ssh/sshd_config:44 setting LogLevel VERBOSE
>>debug3: /etc/ssh/sshd_config:56 setting MaxAuthTries 5
>>debug3: /etc/ssh/sshd_config:64 setting AuthorizedKeysFile
>>.ssh/authorized_keys
>>debug3: /etc/ssh/sshd_config:73 setting RhostsRSAAuthentication yes
>>debug3: /etc/ssh/sshd_config:76 setting HostbasedAuthentication yes
>>debug3: /etc/ssh/sshd_config:82 setting IgnoreRhosts no
>>debug3: /etc/ssh/sshd_config:87 setting PasswordAuthentication yes
>>debug3: /etc/ssh/sshd_config:91 setting ChallengeResponseAuthentication
>>yes
>>debug3: /etc/ssh/sshd_config:102 setting GSSAPIAuthentication yes
>>debug3: /etc/ssh/sshd_config:104 setting GSSAPICleanupCredentials yes
>>debug3: /etc/ssh/sshd_config:120 setting UsePAM yes
>>debug3: /etc/ssh/sshd_config:126 setting X11Forwarding yes
>>debug3: /etc/ssh/sshd_config:133 setting UsePrivilegeSeparation sandbox		
>>debug3: /etc/ssh/sshd_config:149 setting Banner /etc/banners/sshd
>>debug3: /etc/ssh/sshd_config:152 setting AcceptEnv LANG LC_CTYPE
>>LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES
>>debug3: /etc/ssh/sshd_config:153 setting AcceptEnv LC_PAPER LC_NAME
>>LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT
>>debug3: /etc/ssh/sshd_config:154 setting AcceptEnv LC_IDENTIFICATION
>>LC_ALL LANGUAGE
>>debug3: /etc/ssh/sshd_config:155 setting AcceptEnv XMODIFIERS
>>debug3: /etc/ssh/sshd_config:158 setting Subsystem
>>sftp	/usr/libexec/openssh/sftp-server
>>debug1: sshd version OpenSSH_6.4, OpenSSL 1.0.1e-fips 11 Feb 2013
>>debug3: Incorrect RSA1 identifier
>>debug1: read PEM private key done: type RSA
>>debug3: Incorrect RSA1 identifier
>>debug3: Could not load "/etc/ssh/ssh_host_rsa_key" as a RSA1 public key
>>debug1: private host key: #0 type 1 RSA
>>debug3: Incorrect RSA1 identifier
>>debug1: read PEM private key done: type ECDSA
>>debug3: Incorrect RSA1 identifier
>>debug3: Could not load "/etc/ssh/ssh_host_ecdsa_key" as a RSA1 public key
>>debug1: private host key: #1 type 3 ECDSA
>>debug1: rexec_argv[0]='/usr/sbin/sshd'
>>debug1: rexec_argv[1]='-ddd'
>>debug1: rexec_argv[2]='-p'
>>debug1: rexec_argv[3]='18935'
>>debug3: oom_adjust_setup
>>Set /proc/self/oom_score_adj from 0 to -1000
>>debug2: fd 3 setting O_NONBLOCK
>>debug1: Bind to port 18935 on 0.0.0.0.
>>Server listening on 0.0.0.0 port 18935.
>>debug2: fd 4 setting O_NONBLOCK
>>debug3: sock_set_v6only: set socket 4 IPV6_V6ONLY
>>debug1: Bind to port 18935 on ::.
>>Server listening on :: port 18935.
>>
>>
>>Mac client:
>>% ssh -p 18935 root at joey
>>ssh: connect to host joey port 18935: Connection refused
>>
>>________________________________________
>>From: Real, Elizabeth (392K)
>>Sent: Thursday, May 07, 2015 3:23 PM
>>To: Mihai Moldovan; x2go-dev at lists.x2go.org
>>Subject: Re: [X2Go-Dev] X2go Mac client and Red Hat 7 server
>>
>>RH7 server: setup  debug and set sshd port 18935
>>
>>Client: configured x2goclient to connect to port 18935 but got connection
>>refused
>>x2go-INFO-8> "Starting connection to server: 128.149.23.102:18935"
>>x2go-ERROR-2> "Connection Error(Cannot connect to 128.149.23.102:18935):
>>Connection refused"
>>
>>
>>
>>On 5/7/15, 12:41 PM, "Mihai Moldovan" <ionic at ionic.de> wrote:
>>
>>>On 06.05.2015 11:55 PM, Real, Elizabeth (392K) wrote:
>>>> Any other ideas?
>>>
>>>No new information and you have done nothing wrong.
>>>
>>>Looks like you will need to get your hands dirty.
>>>
>>>Please start sshd manually as root on the RH 7 machine:
>>>
>>>sudo sshd -ddd -p 18935
>>>
>>>It should be running in the foreground, outputting debug information and
>>>listening on port 18935 (feel free to change this to whatever you feel
>>>suitable,
>>>it doesn't matter as long it as the port is unused and not colling with
>>>anything
>>>else you might use.
>>>
>>>Then, configure x2goclient to connect to that port and start a session.
>>>
>>>You should see additional debug information printed by sshd... hopefully
>>>hinting
>>>at what might have gone awry.
>>>
>>>
>>>
>>>Mihai
>>>
>>
>