Here is what I know:
echo "password" | sudo SOME_COMMAND
The above mentioned command will log in as root directly in Bash shell and run SOME_COMMAND.
What I am trying to do:
I want to perform same task, but from a remote machine. For that I want to pass the password as a variable via an SSH command. Something like this:
ssh -o PASSWORD=password user#hostA 'echo $PASSWORD | sudo SOME_COMMAND'
(Reference: When ssh'ing, how can I set an environment variable on the server that changes from session to session?)
But it doesn't pass the $PASSWORD variable.
How can I do it?
Simple summary:
Here is what I want to do:
I want to pass a variable to remote host when I log in through SSH so I can access it in the remote host script.
You can use the sshpass utility to do this task.
But this is not a secure way; your password is not in an encrypted format.
Reference: sshpass: Login To SSH Server / Provide SSH Password Using A Shell Script
You should not use sudo and ssh in one line. Here is a discussion and solution that I was answering yesterday on Super User.
To pass a variable though a pipe you can do the following...
echo "Hello, World!" | ssh USER#HOST cat
Other methods would be passing files via scp or rsync.
I am running a test script where files needs to be copied to the target embedded system.But when this command of copying the files to remote target system is run from the script I was prompted for the administrator password of the Target Board.How can I automate the script in such a way that the script will pick the password by itself(from within the script) and I don't have to put the password manually every-time i run the script.
Snippet form the script is as below :
scp test.file1 <Target ip-address>:/home/bot21/test/.
Password is prompted when the above command is run.
The right way to do this is with key-based authentication.
Read about it here.
If that link ever breaks, just google it: "ssh passwordless" or "ssh key authentication". Despite Toby's comment, I think linking to or instructing how to search it yourself is better than repeating what others can say better and in more depth than I can.
Use the -i option. Manpage says:
-i identity_file
Selects the file from which the identity (private key) for public
key authentication is read. This option is directly passed to
ssh(1).
That is do :
scp -i /path/to/identity_file test.file1 <Target ip-address>:/home/bot21/test/
The process of creating the identity file is well described [ here ].
The access-permissions for the identity file should be configured in such a way that potential users in your system who may access this file should be able to read it. Also mind that these users should be able to traverse the path ie /path/to in our example to reach the file
You can use sshpass to pass the password to the scp. Something like
sshpass -p passw0rd scp test.file1 <Target ip-address>:/home/bot21/test/
But as already mentioned, using the keys is recommended. I added the following notes to SO Documentation before it was retired.
Connecting from script using password
When you really need to script ssh connection, piping the password into the ssh command does not work (echo passw0rd | ssh host). It is because the password is not read from standard input, but directly from TTY (teleprinter, teletypewriter, Teletype for historical reasons).
But there is sshpass tool which works around this problem. It can read the password from parameter, file or environment variable. But note that none of these options does not satisfy the security requirements for a passwords!
$ sshpass -p passw0rd ssh host
$ sshpass -f /secret/filename ssh host
$ SSHPASS=passw0rd sshpass -e ssh host
The command line options can be seen by other users in ps (during runtime it is masked, but not during start time and you can't rely on it):
... 23624 6216 pts/5 Ss Aug30 0:00 \_ /bin/bash
... 12812 1988 pts/5 S+ 08:50 0:00 | \_ sshpass -p passw0rd ssh host
... 45008 5796 pts/15 Ss+ 08:50 0:00 | \_ ssh host
Note, that environemnet variables of a process are also accessible by other processes on the system using /proc/PID/environ file.
Finally, storing the password in the file might look like the best possible idea, but still using keys as described in the other examples is preferred way to use ssh.
How can you make SSH read the password from stdin, which it doesn't do by default?
based on this post you can do:
Create a command which open a ssh session using SSH_ASKPASS (seek SSH_ASKPASS on man ssh)
$ cat > ssh_session <<EOF
export SSH_ASKPASS="/path/to/script_returning_pass"
setsid ssh "your_user"#"your_host"
EOF
NOTE: To avoid ssh to try to ask on tty we use setsid
Create a script which returns your password (note echo "echo)
$ echo "echo your_ssh_password" > /path/to/script_returning_pass
Make them executable
$ chmod +x ssh_session
$ chmod +x /path/to/script_returning_pass
try it
$ ./ssh_session
Keep in mind that ssh stands for secure shell, and if you store your user, host and password in plain text files you are misleading the tool an creating a possible security gap
You can use sshpass which is for example in the offical debian repositories. Example:
$ apt-get install sshpass
$ sshpass -p 'password' ssh username#server
You can't with most SSH clients. You can work around it with by using SSH API's, like Paramiko for Python. Be careful not to overrule all security policies.
Distilling this answer leaves a simple and generic script:
#!/bin/bash
[[ $1 =~ password: ]] && cat || SSH_ASKPASS="$0" DISPLAY=nothing:0 exec setsid "$#"
Save it as pass, do a chmod +x pass and then use it like this:
$ echo mypass | pass ssh user#host ...
If its first argument contains password: then it passes its input to its output (cat) otherwise it launches whatver was presented after setting itself as the SSH_ASKPASS program.
When ssh encounters both SSH_ASKPASS AND DISPLAY set, it will launch the program referred to by SSH_ASKPASS, passing it the prompt user#host's password:
An old post reviving...
I found this one while looking for a solution to the exact same problem, I found something and I hope someone will one day find it useful:
Install ssh-askpass program (apt-get, yum ...)
Set the SSH_ASKPASS variable (export SSH_ASKPASS=/usr/bin/ssh-askpass)
From a terminal open a new ssh connection without an undefined TERMINAL variable (setsid ssh user#host)
This looks simple enough to be secure but did not check yet (just using in a local secure context).
Here we are.
FreeBSD mailing list recommends the expect library.
If you need a programmatic ssh login, you really ought to be using public key logins, however -- obviously there are a lot fewer security holes this way as compared to using an external library to pass a password through stdin.
a better sshpass alternative is :
https://github.com/clarkwang/passh
I got problems with sshpass, if ssh server is not added to my known_hosts sshpass will not show me any message, passh do not have this problem.
I'm not sure the reason you need this functionality but it seems you can get this behavior with ssh-keygen.
It allows you to login to a server without using a password by having a private RSA key on your computer and a public RSA key on the server.
http://www.linuxproblem.org/art_9.html
I want to transfer some files from my local to remote, like github does it. I want to happend it very smooth like in shell script. I tried creating one shell script which automates the process of ssh authentication without password but for first time it exposes my remote server password. I dont want to do it that way. Like in git we can't see their server password. Is there any possible way that we can do ?
I used this article script to automate ssh login. http://www.techpaste.com/2013/04/shell-script-automate-ssh-key-transfer-hosts-linux/
As i mentioned, you can use the scp command, like this:
scp /local_dir/some*.xml remote_user#remote_machine:/var/www/html
This requires that you need connect to the remote machine without password, only with ssh key-authentication.
Here is a link: http://linuxproblem.org/art_9.html to help you.
The important steps: (automatic login from host A / user a to Host B / user b.)
a#A:~> ssh-keygen -t rsa
a#A:~> ssh b#B mkdir -p .ssh
a#A:~> cat .ssh/id_rsa.pub | ssh b#B 'cat >> .ssh/authorized_keys'
I know it is not recommended, but is it at all possible to pass the user's password to scp?
I'd like to copy a file via scp as part of a batch job and the receiving server does, of course, need a password and, no, I cannot easily change that to key-based authentication.
Use sshpass:
sshpass -p "password" scp -r user#example.com:/some/remote/path /some/local/path
or so the password does not show in the bash history
sshpass -f "/path/to/passwordfile" scp -r user#example.com:/some/remote/path /some/local/path
The above copies contents of path from the remote host to your local.
Install :
ubuntu/debian
apt install sshpass
centos/fedora
yum install sshpass
mac w/ macports
port install sshpass
mac w/ brew
brew install https://raw.githubusercontent.com/kadwanev/bigboybrew/master/Library/Formula/sshpass.rb
just generate a ssh key like:
ssh-keygen -t rsa -C "your_email#youremail.com"
copy the content of ~/.ssh/id_rsa.pub
and lastly add it to the remote machines ~/.ssh/authorized_keys
make sure remote machine have the permissions 0700 for ~./ssh folder and 0600 for ~/.ssh/authorized_keys
If you are connecting to the server from Windows, the Putty version of scp ("pscp") lets you pass the password with the -pw parameter.
This is mentioned in the documentation here.
curl can be used as a alternative to scp to copy a file and it supports a password on the commandline.
curl --insecure --user username:password -T /path/to/sourcefile sftp://desthost/path/
You can script it with a tool like expect (there are handy bindings too, like Pexpect for Python).
You can use the 'expect' script on unix/terminal
For example create 'test.exp' :
#!/usr/bin/expect
spawn scp /usr/bin/file.txt root#<ServerLocation>:/home
set pass "Your_Password"
expect {
password: {send "$pass\r"; exp_continue}
}
run the script
expect test.exp
I hope that helps.
You may use ssh-copy-id to add ssh key:
$which ssh-copy-id #check whether it exists
If exists:
ssh-copy-id "user#remote-system"
Here is an example of how you do it with expect tool:
sub copyover {
$scp = Expect->spawn("/usr/bin/scp ${srcpath}/$file $who:${destpath}/$file");
$scp->expect(30,"ssword: ") || die "Never got password prompt from $dest:$!\n";
print $scp 'password' . "\n";
$scp->expect(30,"-re",'$\s') || die "Never got prompt from parent system:$!\n";
$scp->soft_close();
return;
}
Nobody mentioned it, but Putty scp (pscp) has a -pw option for password.
Documentation can be found here: https://the.earth.li/~sgtatham/putty/0.67/htmldoc/Chapter5.html#pscp
Once you set up ssh-keygen as explained above, you can do
scp -i ~/.ssh/id_rsa /local/path/to/file remote#ip.com:/path/in/remote/server/
If you want to lessen typing each time, you can modify your .bash_profile file and put
alias remote_scp='scp -i ~/.ssh/id_rsa /local/path/to/file remote#ip.com:/path/in/remote/server/
Then from your terminal do source ~/.bash_profile. Afterwards if you type remote_scp in your terminal it should run the scp command without password.
Here's a poor man's Linux/Python/Expect-like example based on this blog post: Upgrading simple shells to fully interactive
TTYs. I needed this for old machines where I can't install Expect or add modules to Python.
Code:
(
echo 'scp jmudd#mysite.com:./install.sh .'
sleep 5
echo 'scp-passwd'
sleep 5
echo 'exit'
) |
python -c 'import pty; pty.spawn("/usr/bin/bash")'
Output:
scp jmudd#mysite.com:install.sh .
bash-4.2$ scp jmudd#mysite.com:install.sh .
Password:
install.sh 100% 15KB 236.2KB/s 00:00
bash-4.2$ exit
exit
Make sure password authentication is enabled on the target server. If it runs Ubuntu, then open /etc/ssh/sshd_config on the server, find lines PasswordAuthentication=no and comment all them out (put # at the start of the line), save the file and run sudo systemctl restart ssh to apply the configuration. If there is no such line then you're done.
Add -o PreferredAuthentications="password" to your scp command, e.g.:
scp -o PreferredAuthentications="password" /path/to/file user#server:/destination/directory
make sure you have "expect" tool before, if not, do it
# apt-get install expect
create the a script file with following content. (# vi /root/scriptfile)
spawn scp /path_from/file_name user_name_here#to_host_name:/path_to
expect "password:"
send put_password_here\n;
interact
execute the script file with "expect" tool
# expect /root/scriptfile
copy files from one server to other server ( on scripts)
Install putty on ubuntu or other Linux machines. putty comes with pscp. we can copy files with pscp.
apt-get update
apt-get install putty
echo n | pscp -pw "Password#1234" -r user_name#source_server_IP:/copy_file_path/files /path_to_copy/files
For more options see pscp help.
Using SCP non interactively from Windows:
Install the community Edition of netcmdlets
Import Module
Use Send-PowerShellServerFile -AuthMode password -User MyUser -Password not-secure -Server YourServer -LocalFile C:\downloads\test.txt -RemoteFile C:\temp\test.txt for sending File with non-interactive password
In case if you observe a strict host key check error then use -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null options.
The complete example is as follows
sshpass -p "password" scp -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null root#domain-name.com:/tmp/from/psoutput /tmp/to/psoutput
You can use below steps. This works for me!
Step1-
create a normal file suppose "fileWithScpPassword" which contains the ssh password for the destination server.
Step2- use sshpaas -f followed by password file name and then normal scp command.
sshpass -f "fileWithScpPassword" scp /filePathToUpload user#ip:/destinationPath/
One easy way I do this:
Use the same scp cmd as you use with ssh keys i.e
scp -C -i <path_to opens sshkey> <'local file_path'> user#<ip_address_VM>: <'remote file_path’>
for transferring file from local to remote
but instead of providing the correct <path_to_opensshkey>, use some garbage path. Due to wrong key path you will be asked for password instead and you can simply pass the password now to get the work done!
An alternative would be add the public half of the user's key to the authorized-keys file on the target system. On the system you are initiating the transfer from, you can run an ssh-agent daemon and add the private half of the key to the agent. The batch job can then be configured to use the agent to get the private key, rather than prompting for the key's password.
This should be do-able on either a UNIX/Linux system or on Windows platform using pageant and pscp.
All the solutions mentioned above can work only if you the app installed or you should have the admin rights to install except or sshpass.
I found this very useful link to simply start the scp in Background.
$ nohup scp file_to_copy user#server:/path/to/copy/the/file > nohup.out 2>&1
https://charmyin.github.io/scp/2014/10/07/run-scp-in-background/
I found this really helpful answer here.
rsync -r -v --progress -e ssh user#remote-system:/address/to/remote/file /home/user/
Not only you can pass there the password, but also it will show the progress bar when copying. Really awesome.