SSH AUTHENTIFACTION ISSUE - sshd

I am a newbie to embedded networking. I want to set arm board as a ssh server .From other boards(client boards connected in the network), I need to connect to this server board.
I have downloaded the openssh and cross compiled it for arm successfully.
I have used default sshd_config file and run sshd command in arm-board.
Command
"ssh-keygen -t rsa -f /usr/local/etc/ssh_host_rsa_key -N "" "
is used to genrate key.
My doubt is where can I set the username and password, so that I can login from a remote client using ssh command. I didn't find any document regarding this...?

Using ssh you are logging in as a normal system user. So you should add user using useradd command. You can change password using passwd command.

Related

Host key verification failed. in docker

I wanted to launch the jenkins which is installed through docker automatically in browser.. im working on windows os. in docker base os is ubuntu.. then i used solution from this link1.now im getting following error when i ssh using -v command i find that "read_passphrase: can't open /dev/tty: No such device or address"
by going through many websites i have created ssh file through windows using gitbash it contains id_rsa,id_rsa.pub,known_hosts files.
Now what should i do to launch the jenkins file in browser which is build using docker
I'm just going to address the error message you pasted for now.
ssh is trying to get keyboard input for the passphrase on your private key, but can't open the terminal correctly. Are you running the ssh command directly in the terminal, or from a script? If not, try running ssh directly. If you need to run ssh from a script:
Maybe try with keys that don't have a passphrase.
If you can use ssh-agent: Run eval $(ssh-agent), then run ssh-add and enter your passphrase. ssh will no longer prompt for a passphrase now.

Need to Run batch script in UNIX server and display the output through vbscript

I am currently developing the new VBScript to execute the Shell (through Putty software) in UNIX server,
Set shell = WScript.CreateObject("WScript.Shell")
shell.Exec D:\Putty.exe hostname -l username -pw password 1.sh
I am getting connection refused error.
when I run the below command without my script (1.sh)
shell.Exec D:\Putty.exe hostname -l username -pw password
Connection is getting established without any issues.
Also, I just wanted to extract the output, once extracted, the session should get closed automatically.
This doesn't work in putty.exe. Putty has however a dedicated program to do these kind of things, it's called plink.exe - there you can pass commands and read the output just as you would expect, and your example should work just like you specified it.
PuTTY Link: command-line connection utility
Release 0.63
Usage: plink [options] [user#]host [command]
("host" can also be a PuTTY saved session name)
Options:
-V print version information and exit
-pgpfp print PGP key fingerprints and exit
-v show verbose messages
-load sessname Load settings from saved session
-ssh -telnet -rlogin -raw -serial
force use of a particular protocol
-P port connect to specified port
-l user connect with specified username
-batch disable all interactive prompts
The following options only apply to SSH connections:
-pw passw login with specified password
-D [listen-IP:]listen-port
Dynamic SOCKS-based port forwarding
-L [listen-IP:]listen-port:host:port
Forward local port to remote address
-R [listen-IP:]listen-port:host:port
Forward remote port to local address
-X -x enable / disable X11 forwarding
-A -a enable / disable agent forwarding
-t -T enable / disable pty allocation
-1 -2 force use of particular protocol version
-4 -6 force use of IPv4 or IPv6
-C enable compression
-i key private key file for authentication
-noagent disable use of Pageant
-agent enable use of Pageant
-m file read remote command(s) from file
-s remote command is an SSH subsystem (SSH-2 only)
-N don't start a shell/command (SSH-2 only)
-nc host:port
open tunnel in place of session (SSH-2 only)
-sercfg configuration-string (e.g. 19200,8,n,1,X)
Specify the serial configuration (serial only)

How to transfer a file using sftp in UNIX

I want to transfer a .png file from a directory on my computer to a directory on a remote server.
I have to use SFTP to secure the file and transfer mode. And I already have a UNIX script (.ksh) file to copy the files in the normal mode. How do I implement the transfer in SFTP mode?
Use sftp instead of whatever command you are using in your .ksh script. See sftp man for reference.
You may also want to look at scp secure copy - scp man.
EDIT
sftp is mostly for interactive operations, you need to specify host you want to connect to:
sftp example.com
you will be prompted for username and passsword, and the interactive session will begin..
Although it can be used in scripts, the scp is much more easy to use:
scp /path/to/localfile user#host:/path/to/dest
you will be prompted for password..
Edit 2
Both scp and sftp use ssh as underlying protocol, see this and this
The best way to setup them to run from scripts is to setup passwordless authentication using keys. See this and this. I use this extensively on my servers.. After you setup keys, you can run
scp -i private-key-file /path/to/local/file user#host:/path/to/remote
sftp -oIdentityFile=private-key-file -b batch-file user#host
If you want to authenticate with password, you may try the expect package. The simplest script may look like this:
#!/usr/bin/expect
spawn sftp -b batch-file user#host
expect "*?assword:*"
send "pasword\n"
interact
See this, this and this for more info.
Send commands through sftp on one line:
Make a file and save it as my_batch_file:
cd /root
get blah.txt
bye
Run this to execute your batch file:
eric#dev /home/el $ sftp root#10.30.25.15 < my_batch_file
Connecting to 10.30.25.15...
Password:
sftp> cd /root
sftp> get blah.txt
Fetching /root/blah.txt to blah.txt
sftp> bye
The file is transferred
That moved the blah.txt from remote computer to local computer.
If you don't want to specify a password, do this:
How to run the sftp command with a password from Bash script?
Or if you want to do it the hacky insecure way, use bash and expect:
#!/bin/bash
expect -c "
spawn sftp username#your_host
expect \"Password\"
send \"your_password_here\r\"
interact "
You may need to install expect, change the wording of 'Password' to lowercase 'p' to match what your prompt receives. The problems here is that it exposes your password in plain text in the file as well as in the command history. Which nearly defeats the purpose of having a password in the first place.

sftp code required with out prompting for a password

Working code for ftp is as follows
#!/bin/sh
HOST='host ip address'
USER='yourid'
PASSWD='yourpw'
FILE='output_file.csv'
ftp -n $HOST <<END
quote USER $USER
quote PASS $PASSWD
put $FILE
quit
END
exit 0
This is a working ftp code for file transfer. What modification have to be done in this code to make it a Working SFTP code?
If you are mentioning SFTP [Secure FTP]. then you would require to generate the sftp keys (or the ssh keys) and exchange with the remote target server. They needs to be placed in the .ssh folder on remote machine. This would ensure password-less connectivity between the 2 hosts.
Then just issue the command
$ sftp remoteUser#host
You would get logged into the remote machine. You need to amend the code accordingly as you won't need the password now.

ssh login without any prompt

I have to login more then 150 sever and execute some unix commands.
The problem is, if I create a script which will run from one server and ssh login to 150 server and execute cmds and exit.
How can i login with any password prompt.
due to some reason i should not use ssh-keygen public and private key method , or use of some extra tool with bash line like "expect".
is there any normal way to do login through ssh in single command consisting username/password#servername like we have option in sqlplus and ftp.
There is a utility called sshpass that allows you to specify a password in the commandline.
Under Ubuntu/Debian install by using sudo apt-get install sshpass
sshpass -p 'abcedf' ssh joe#myserver.domain.com "df > ~/test; cat ~/test; rm ~/test;"
hope this helps
You can try setting up either ~/.shosts or /etc/ssh/shosts.equiv on each of your remote hosts. See man ssh under "AUTHENTICATION" for details.

Resources