Tramp ssh Authentication Problem.

Tramp ssh Authentication Problem.

[Ian Barton]

I am having some problems with Tramp logging in to remote servers. In
my ~/.ssh/config I have:

Host blacky.wilkesley.net
      IdentityFile ~/.ssh/id_rsa_blacky_linode
Host wilkesley.org
     IdentityFile ~/.ssh/id_rsa_linode_ian

I can login to  either host using ssh wilkesley.org or ssh
blacky.wilkesley.org. However, tramp logs in OK to wilkesley.org, but
*not* to blacky.wilkesley.net.

If I use the following minimal init file:

(setq tramp-shell-prompt-pattern "^[^$>\n]*[#$%>]*\\(\[[0-9;]*[a-zA-Z] 
*\\)*")
(eval-after-load 'tramp '(setenv "SHELL" "/bin/bash"))
(setq tramp-default-method "ssh")
(setq tramp-verbose 10)

I get the following in the Tramp log when I try to login to
blacky.wilkesley.net:

08:52:15.819432 tramp-process-one-action (5) # Looking for regexp 
"\(^.*\([pP]assword\|[pP]assphrase\).*:? *\)\'" from remote shell
08:52:15.819650 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.819878 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.820211 tramp-process-one-action (5) # Looking for regexp 
"\(^.*\(Connection \(?:\(?:clo\|refu\)sed\)\|Host key verification 
failed\.\|Login \(?:[Ii]ncorrect\)\|N\(?:ame or service not known\|o 
supported authentication methods left to try!\)\|Permission 
denied\|\(?:Sorry, try again\|Timeout, server not 
responding\)\.\).*\|^.*\(Received signal [0-9]+\).*\)\'" from remote shell
08:52:15.820469 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.820697 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.820936 tramp-process-one-action (5) # Looking for regexp "\(^[^#$%>
]*[#$%>] *\)\'" from remote shell
08:52:15.821198 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.821426 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.821635 tramp-process-one-action (5) # Looking for regexp "\(^[^$>
]*[#$%>]*\([[0-9;]*[a-zA-Z] *\)*\)\'" from remote shell
08:52:15.821866 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.822092 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.822339 tramp-process-one-action (5) # Looking for regexp 
"\(\(Are you sure you want to continue connecting (yes/no)\?\)\s-*\)\'" 
from remote shell
08:52:15.822574 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.822799 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.823010 tramp-process-one-action (5) # Looking for regexp 
"\(\(\(?:Store key in cache\? (y/\|Update cached key\? (y/n, Return 
cancels connectio\)n)\)\s-*\)\'" from remote shell
08:52:15.823245 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.823502 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.823690 tramp-process-one-action (5) # Looking for regexp 
"\(\(TERM = (.*)\|Terminal type\? \[.*\]\)\s-*\)\'" from remote shell
08:52:15.823906 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.824101 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.824277 tramp-process-one-action (5) # Looking for regexp 
"\(\)\'" from remote shell
08:52:15.824489 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.838558 tramp-get-connection-property (7) # check-remote-echo nil
08:52:15.838773 tramp-process-one-action (5) # Call 
`tramp-action-process-alive'
08:52:15.838968 tramp-accept-process-output (10) # *tramp/ssh 
blacky.wilkesley.net* run
08:52:16.757812 tramp-accept-process-output (10) #
#$ Last login: Sun Jun  8 08:51:51 2014 from 46.33.134.31
08:52:16.758055 tramp-process-one-action (5) # Looking for regexp 
"\(.*ogin\( .*\)?: *\)\'" from remote shell
08:52:16.758317 tramp-get-connection-property (7) # check-remote-echo nil
08:52:16.758556 tramp-get-connection-property (7) # check-remote-echo nil
08:52:16.758985 tramp-process-one-action (5) # Looking for regexp 
"\(^.*\([pP]assword\|[pP]assphrase\).*:? *\)\'" from remote shell
08:52:16.759223 tramp-get-connection-property (7) # check-remote-echo nil
08:52:16.759454 tramp-get-connection-property (7) # check-remote-echo nil
08:52:16.759688 tramp-process-one-action (5) # Looking for regexp 
"\(^.*\(Connection \(?:\(?:clo\|refu\)sed\)\|Host key verification 
failed\.\|Login \(?:[Ii]ncorrect\)\|N\(?:ame or service not known\|o 
supported authentication methods left to try!\)\|Permission 
denied\|\(?:Sorry, try again\|Timeout, server not 
responding\)\.\).*\|^.*\(Received signal [0-9]+\).*\)\'" from remote shell

For some reason it looks as thought the host key verification is
failing, but I can't see why.

Ian.

Re: Tramp ssh Authentication Problem.

[Ian Barton]

On 08/06/14 09:09, Ian Barton wrote:
> I am having some problems with Tramp logging in to remote servers. In
> my ~/.ssh/config I have:
>
> Host blacky.wilkesley.net
>       IdentityFile ~/.ssh/id_rsa_blacky_linode
> Host wilkesley.org
>      IdentityFile ~/.ssh/id_rsa_linode_ian
>
> I can login to  either host using ssh wilkesley.org or ssh
> blacky.wilkesley.org. However, tramp logs in OK to wilkesley.org, but
> *not* to blacky.wilkesley.net.
>
> If I use the following minimal init file:
>
> (setq tramp-shell-prompt-pattern "^[^$>\n]*[#$%>]*\\(\[[0-9;]*[a-zA-Z]
> *\\)*")
> (eval-after-load 'tramp '(setenv "SHELL" "/bin/bash"))
> (setq tramp-default-method "ssh")
> (setq tramp-verbose 10)
>
> I get the following in the Tramp log when I try to login to
> blacky.wilkesley.net:
>
> 08:52:15.819432 tramp-process-one-action (5) # Looking for regexp
> "\(^.*\([pP]assword\|[pP]assphrase\).*:? *\)\'" from remote shell
> 08:52:15.819650 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.819878 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.820211 tramp-process-one-action (5) # Looking for regexp
> "\(^.*\(Connection \(?:\(?:clo\|refu\)sed\)\|Host key verification
> failed\.\|Login \(?:[Ii]ncorrect\)\|N\(?:ame or service not known\|o
> supported authentication methods left to try!\)\|Permission
> denied\|\(?:Sorry, try again\|Timeout, server not
> responding\)\.\).*\|^.*\(Received signal [0-9]+\).*\)\'" from remote shell
> 08:52:15.820469 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.820697 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.820936 tramp-process-one-action (5) # Looking for regexp
> "\(^[^#$%>
> ]*[#$%>] *\)\'" from remote shell
> 08:52:15.821198 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.821426 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.821635 tramp-process-one-action (5) # Looking for regexp "\(^[^$>
> ]*[#$%>]*\([[0-9;]*[a-zA-Z] *\)*\)\'" from remote shell
> 08:52:15.821866 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.822092 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.822339 tramp-process-one-action (5) # Looking for regexp
> "\(\(Are you sure you want to continue connecting (yes/no)\?\)\s-*\)\'"
> from remote shell
> 08:52:15.822574 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.822799 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.823010 tramp-process-one-action (5) # Looking for regexp
> "\(\(\(?:Store key in cache\? (y/\|Update cached key\? (y/n, Return
> cancels connectio\)n)\)\s-*\)\'" from remote shell
> 08:52:15.823245 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.823502 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.823690 tramp-process-one-action (5) # Looking for regexp
> "\(\(TERM = (.*)\|Terminal type\? \[.*\]\)\s-*\)\'" from remote shell
> 08:52:15.823906 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.824101 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.824277 tramp-process-one-action (5) # Looking for regexp
> "\(\)\'" from remote shell
> 08:52:15.824489 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.838558 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:15.838773 tramp-process-one-action (5) # Call
> `tramp-action-process-alive'
> 08:52:15.838968 tramp-accept-process-output (10) # *tramp/ssh
> blacky.wilkesley.net* run
> 08:52:16.757812 tramp-accept-process-output (10) #
> #$ Last login: Sun Jun  8 08:51:51 2014 from 46.33.134.31
> 08:52:16.758055 tramp-process-one-action (5) # Looking for regexp
> "\(.*ogin\( .*\)?: *\)\'" from remote shell
> 08:52:16.758317 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:16.758556 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:16.758985 tramp-process-one-action (5) # Looking for regexp
> "\(^.*\([pP]assword\|[pP]assphrase\).*:? *\)\'" from remote shell
> 08:52:16.759223 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:16.759454 tramp-get-connection-property (7) # check-remote-echo nil
> 08:52:16.759688 tramp-process-one-action (5) # Looking for regexp
> "\(^.*\(Connection \(?:\(?:clo\|refu\)sed\)\|Host key verification
> failed\.\|Login \(?:[Ii]ncorrect\)\|N\(?:ame or service not known\|o
> supported authentication methods left to try!\)\|Permission
> denied\|\(?:Sorry, try again\|Timeout, server not
> responding\)\.\).*\|^.*\(Received signal [0-9]+\).*\)\'" from remote shell
>
> For some reason it looks as thought the host key verification is
> failing, but I can't see why.
>
> Ian.
>

A bit more information. Here is the log from the serer when tramp fails 
to login:

Jun 08 12:41:28 blacky.wilkesley.net sshd[19722]: Set 
/proc/self/oom_score_adj to 0
Jun 08 12:41:28 blacky.wilkesley.net sshd[19722]: Connection from 
46.33.134.31 port 51580 on 178.79.179.180 port 22
Jun 08 12:41:29 blacky.wilkesley.net sshd[19722]: reverse mapping 
checking getaddrinfo for dsl-fixed-46-33-134-31.interdsl.co.uk 
[46.33.134.31] failed - POSSIBLE BREAK-IN ATTEMPT!
Jun 08 12:41:29 blacky.wilkesley.net sshd[19722]: Postponed publickey 
for ian from 46.33.134.31 port 51580 ssh2 [preauth]
Jun 08 12:41:29 blacky.wilkesley.net sshd[19722]: Accepted publickey for 
ian from 46.33.134.31 port 51580 ssh2: RSA 
d2:4d:8c:36:40:84:7e:b1:d5:3a:39:37:fe:2f:31:1e
Jun 08 12:41:29 blacky.wilkesley.net sshd[19722]: 
pam_unix(sshd:session): session opened for user ian by (uid=0)

It appears that the public key is accepted OK, but Tramp just hangs. The 
sshd config file is identical on the server that works and the one that 
doesn't.

Ian.

Re: Tramp ssh Authentication Problem.

[Michael Albinus]

Ian Barton <lists@wilkesley.net> writes:

> It appears that the public key is accepted OK, but Tramp just
> hangs. The sshd config file is identical on the server that works and
> the one that doesn't.

Likely, there is a problem with your prompt. Use tramp-verbose 10, and
show the debug buffer.

> Ian.

Best regards, Michael.

Re: Tramp ssh Authentication Problem.

[Ian Barton]

On 08/06/14 16:15, Michael Albinus wrote:
> Ian Barton <lists@wilkesley.net> writes:
>
>> It appears that the public key is accepted OK, but Tramp just
>> hangs. The sshd config file is identical on the server that works and
>> the one that doesn't.
>
> Likely, there is a problem with your prompt. Use tramp-verbose 10, and
> show the debug buffer.
>
>> Ian.
>
> Best regards, Michael.
>

You were right. The actual prompt looks the same on both computers. 
However, I tried copying .zshrc from the computer that worked to the one 
that didn't and now I can connect via Tramp OK.

I thought that .zshrc was the same on both computers, but obviously it 
wasn't. Time to run diff and find out what the problem is.

Ian.

Re: Tramp ssh Authentication Problem.

[Michael Albinus]

Ian Barton <ian@wilkesley.net> writes:

> I thought that .zshrc was the same on both computers, but obviously it
> wasn't. Time to run diff and find out what the problem is.

Good luck. With zsh, it is often the zle which runs into problems with
Tramp. I've written some hints in the Tramp manual how to manage it.

> Ian.

Best regards, Michael.

Re: Tramp ssh Authentication Problem.

[zwz]

Nice. Can you give the link of your hints?

Also, I got the problem when I tried to use tramp:
sudo: no tty present and no askpass program specified

I have installed openssh-askpass.

Michael Albinus <michael.albinus@gmx.de> writes:

> Ian Barton <ian@wilkesley.net> writes:
>
>> I thought that .zshrc was the same on both computers, but obviously it
>> wasn't. Time to run diff and find out what the problem is.
>
> Good luck. With zsh, it is often the zle which runs into problems with
> Tramp. I've written some hints in the Tramp manual how to manage it.
>
>> Ian.
>
> Best regards, Michael.

Re: Tramp ssh Authentication Problem.

[Michael Albinus]

zwz <zhangweize@gmail.com> writes:

> Nice. Can you give the link of your hints?

It's in the FAQ section of the Tramp manual. Eval

(info "(tramp) Frequently Asked Questions")

> Also, I got the problem when I tried to use tramp:
> sudo: no tty present and no askpass program specified

Well, how to you use sudo? From your local machine, or do you hop onto
another machine (via Tramp), and apply sudo there?

> I have installed openssh-askpass.

Usually, you could instruct sudo to use your askpass program by setting
the environment variable $SUDO_ASKPASS. See the man page of sudo(8).

Best regards, Michael.

Re: Tramp ssh Authentication Problem.

[zwz]

Thank you, Michael.

I use sudo on my local machine with C-x C-f /sudo::

Now I start Emacs by SUDO_ASKPASS=openssh-askpass Emacs -q.
There is no message in *tramp/sudo...* buffer, but it still does not
prompt for my password.


Michael Albinus <michael.albinus@gmx.de> writes:

> zwz <zhangweize@gmail.com> writes:
>
>> Nice. Can you give the link of your hints?
>
> It's in the FAQ section of the Tramp manual. Eval
>
> (info "(tramp) Frequently Asked Questions")
>
>> Also, I got the problem when I tried to use tramp:
>> sudo: no tty present and no askpass program specified
>
> Well, how to you use sudo? From your local machine, or do you hop onto
> another machine (via Tramp), and apply sudo there?
>
>> I have installed openssh-askpass.
>
> Usually, you could instruct sudo to use your askpass program by setting
> the environment variable $SUDO_ASKPASS. See the man page of sudo(8).
>
> Best regards, Michael.

Re: Tramp ssh Authentication Problem.

[Michael Albinus]

zwz <zhangweize@gmail.com> writes:

> Now I start Emacs by SUDO_ASKPASS=openssh-askpass Emacs -q.
> There is no message in *tramp/sudo...* buffer, but it still does not
> prompt for my password.

Apply (setq tramp-verbose 10) prior to the connection. There will be a
buffer *debug tramp/sudo...* which shall tell us what happens.

Best regards, Michael.

Re: Tramp ssh Authentication Problem.

[zwz]

Thank you for your hint.

I now start Emacs with: SUDO_ASKPASS=/usr/bin/qt4-ssh-askpass emacs -q.
And then I apply (setq tramp-verbose 10).
With C-x C-f /sudo::<enter>, it prompts for user/password.
After I input my account and password, it just hangs there...

So I hit C-g, and I find hundreds lines of messages in the debug buffer.
It seems to be some loop there. Here is just the last one loop of messages:

;; GNU Emacs: 24.3.1 Tramp: 2.2.6-24.3 -*- mode: outline; -*-
...
12:47:56.780848 tramp-process-one-action (5) # Call `tramp-action-process-alive'
12:47:56.781476 tramp-accept-process-output (10) # *tramp/sudo root@myhost* run
12:47:57.783128 tramp-accept-process-output (10) #
exec sudo -u root -s -H -p Password:
Unable to load library icui18n "Cannot load library icui18n: (icui18n: cannot open shared object file: No such
file or directory)"
Sorry, try again.
Unable to load library icui18n "Cannot load library icui18n: (icui18n: cannot open shared object file: No such
file or directory)"
12:47:57.784193 tramp-process-one-action (5) # Looking for regexp "\(.*ogin\( .*\)?: *\)\'" from remote shell
12:47:57.785256 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.786172 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.795342 tramp-process-one-action (5) # Looking for regexp "\(^.*\([pP]assword\|[pP]assphrase\).*:.?
*\)\'" from remote shell
12:47:57.795957 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.796405 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.797148 tramp-process-one-action (5) # Looking for regexp "\(^.*\(Connection
\(?:\(?:clo\|refu\)sed\)\|Host key verification failed\.\|Login \(?:[Ii]ncorrect\)\|N\(?:ame or service not
known\|o supported authentication methods left to try!\)\|Permission denied\|\(?:Sorry, try again\|Timeout,
server not responding\)\.\).*\|^.*\(Received signal [0-9]+\).*\)\'" from remote shell
12:47:57.797684 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.798120 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.799167 tramp-process-one-action (5) # Looking for regexp "\(^[^#$%>
]*[#$%>] *\)\'" from remote shell
12:47:57.799645 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.800078 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.800613 tramp-process-one-action (5) # Looking for regexp "\(\(?:^\|.\)[^]#$%>
]*#?[]#$%>] *\(.\[[0-9;]*[a-zA-Z] *\)*\)\'" from remote shell
12:47:57.801051 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.801485 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.802579 tramp-process-one-action (5) # Looking for regexp "\(\(Are you sure you want to continue
connecting (yes/no)\?\)\s-*\)\'" from remote shell
12:47:57.803401 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.804152 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.804822 tramp-process-one-action (5) # Looking for regexp "\(\(\(?:Store key in cache\? (y/\|Update
cached key\? (y/n, Return cancels connectio\)n)\)\s-*\)\'" from remote shell
12:47:57.805331 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.805865 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.806335 tramp-process-one-action (5) # Looking for regexp "\(\(TERM = (.*)\|Terminal type\?
\[.*\]\)\s-*\)\'" from remote shell
12:47:57.806783 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.807220 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.807667 tramp-process-one-action (5) # Looking for regexp "\(\)\'" from remote shell
12:47:57.847724 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.848247 tramp-get-connection-property (7) # check-remote-echo nil
12:47:57.848672 tramp-process-one-action (5) # Call `tramp-action-process-alive'
12:47:57.849177 tramp-accept-process-output (10) # *tramp/sudo root@myhost* run
12:47:58.482404 tramp-accept-process-output (3) # Opening connection for root@myhost using sudo...done
12:47:58.529563 tramp-file-name-handler (1) # Interrupt received in
operation (expand-file-name /sudo:: nil)


Michael Albinus <michael.albinus@gmx.de> writes:

> zwz <zhangweize@gmail.com> writes:
>
>> Now I start Emacs by SUDO_ASKPASS=openssh-askpass Emacs -q.
>> There is no message in *tramp/sudo...* buffer, but it still does not
>> prompt for my password.
>
> Apply (setq tramp-verbose 10) prior to the connection. There will be a
> buffer *debug tramp/sudo...* which shall tell us what happens.
>
> Best regards, Michael.