execute rsync command from shell without prompt for passphrase - shell

I have rsync a repository with a remote server and currently, we have passphrase for the security key. How can add the passphrase in the rsync command without a prompt

Look at man rsync:
You can avoid the password prompt by setting the environment variable
RSYNC_PASSWORD to the password you want to use or using the --password-file option. This may be useful when scripting rsync.

Related

Run multiple rsync commands via ssh and only enter ssh passphrase once

I am syncing multiple folders between an iMac and Synology NAS via multiple rsync calls contained in a script. How to I add ssh with a private/public key and passphrase such that I only have to enter the passphrase once when the script is run but have all the rsync commands utilize the secure ssh tunnel?
rsync -rtv --chmod=Du=rwx,Dgo=rx,Fu=rw,Fgo=r --delete --exclude='.*' /Users/Username/FolderName/ username#ipaddress::Foldername/
This is the template for each rsync call with with no ssh. The folder name is different in each rsync call.
I can generate the ssh private/public keys with a passphrase and upload the public key to the NAS and incorporate it into authorized_keys file. I understand the syntax to add ssh to the rsync commands. I have no idea how via a script only enter the passphrase once for the 7 rsync commands that run in the script.
Any input that would point me in the right direction would be appreciated.
If you're using SSH keys for scripting, you don't want to use a passphrase. OpenSSH doesn't provide a way to enter passphrases except on a TTY, and the only way to use a TTY to enter a passphrase is to use something like Expect to handle the passphrase entry, which is needlessly complex.
Instead, you should use filesystem permissions and, if necessary, a dedicated user to control access to the keys.

bash: input password automatically

I want to sync some files from a remote server to local system. Because the files are large, it may last for several hours, so i want to run it as nohup:
nohup rsync -r <user>#<remote>:<dir> <local-dir> &
The problem is that it prompted for the password of the remote server, but after i typed the password, the bash just said
-bash: mypassword: command not found
I have also tried the --password-file option, but seems the --password-file is not for SSH account, it's for rsync service.
Could someone tell me how to input password automatically while keeping the nohup.
you don't want to input a password for that kind of use case. But you can use a ssh key (ssh-keygen -f ~/.ssh/id_rsa_that_key) protected by a password, and use ssh-add ~/.ssh/id_rsa_that_key to keep that password in cache. And indeed it's not programmer related...
From the manpage:
Some modules on the remote daemon may require authentication. If so, you will receive a password prompt when you connect. You can avoid the password prompt by setting the environment variable RSYNC_PASSWORD to the password you want to use or using the --password-file option. This may be useful when scripting rsync.
WARNING: On some systems environment variables are visible to all users. On those systems using --password-file is recommended.
It seems to me that your error is because you're assigning the password into a variable and it is being interpreted as a command by your bash script.
Try to set the above environment variable, remove "mypassword" from your bash script and give it another try!

SSH in shell script with password

I want to write one shell script like
command1
ssh vivek#remotehost
fire command on remote host
Now I have password in pass.txt . But when I change stdin with file. It is not reading password from file.
script.sh < password.txt
It is prompting for the password in place of reading password from the file.
What I am doing wrong ?
Second problem is that shell script don't shows the command fired. Is there a way , I can show fired command from it ?
Note :
I don't have key based access on remote system. I can only use password based login for ssh.
You can use ssh-agent or expect (the programing language) to do this.
OpenSSH ssh does not reads the password from stdin but from /dev/tty. That's why you have to use Expect or some other similar tool to automate it.
plink is another client, also available for Linux/Unix that accepts the password as a parameter on the command line... though that has some ugly security implications.
Okay, just to mention yet another option: sshpass is a tool developed for exactly the task of "fooling" regular openssh client to accept password non-interactively.

Specify password to sftp in a Bash script [duplicate]

This question already has answers here:
How to run the sftp command with a password from Bash script?
(12 answers)
Closed 7 years ago.
I am trying to write a script to back up a file over SFTP. The problem is, it requires a password, and I see no way to manually specify a password to SFTP. I've heard about requiring no password by using public keys, but that requires being able to ssh into the remote server and modify some configuration files, which I cannot do.
Currently my solution is to use cURL, but that is insecure (uses normal FTP). I also looked at the .netrc file, but that seems to be for FTP instead of SFTP. How do I manually specify a password for sftp?
Lftp allows specifying passwords for both ftp and sftp and does not require public keys at all. Your sh sync script may look like this:
#!/bin/sh
# Define folders
THEFOLDER='/mnt/my/folder'
# List files
THEFILES=`ls -p $THEFOLDER | grep -v "/"`
for file in $THEFILES
do
echo "Processing $file"
lftp -u login,password -e "put $THEFOLDER/$file;quit" theftp/sub/folder
done
cURL can support sftp, as documented by the manual:
USING PASSWORDS
FTP
To ftp files using name+passwd, include them in the URL like:
curl ftp://name:passwd#machine.domain:port/full/path/to/file
or specify them with the -u flag like
curl -u name:passwd ftp://machine.domain:port/full/path/to/file
FTPS
It is just like for FTP, but you may also want to specify and use
SSL-specific options for certificates etc.
Note that using FTPS:// as prefix is the "implicit" way as described in the
standards while the recommended "explicit" way is done by using FTP:// and
the --ftp-ssl option.
SFTP / SCP
This is similar to FTP, but you can specify a private key to use instead of
a password. Note that the private key may itself be protected by a password
that is unrelated to the login password of the remote system. If you
provide a private key file you must also provide a public key file.
You might also want to consider using python (the paramiko module), as it can quickly be called from the shell.
Install the Module
pip install paramiko
Example FTP Upload Script
import paramiko
username = 'my_username'
password = 'my_password'
transport = paramiko.Transport((server, 22))
transport.connect(username=username, password=password)
sftp = paramiko.SFTPClient.from_transport(transport)
local_filename = '/tmp/filename'
remote_filename = 'MyFiles/temp.txt'
sftp.put( local_filename, remote_filename )
Bash program to wait for sftp to ask for a password then send it along:
#!/bin/bash
expect -c "
spawn sftp username#your_host
expect \"assword\"
send \"your_password_here\r\"
interact "
Put that in a file called sftp_autologin.sh. The \r sends an to sftp to execute the command. I don't include the 'p' in password because on some systems it's uppercase, others lowercase. expect spawns the sftp command. Waits for the string 'assword' to be seen and sends a command. Then ends.
To get this to work:
Install expect, I'm using 5.44.1.15
Make sure you can sftp to your box in interactive mode and supply a password.
Make sure this bash script has executable permissions.
Then run it:
chmod +x sftp_autologin.sh
./sftp_autologin.sh
It should drop you into the sftp commandline without prompting you for a password.
Is it insecure?
It's about the most unsecure command you can run. It exposes the password to the commandline history, to anyone else who can read 'ps' output, and basically defeats the entire purpose of passwords all together.
But hey what's another log on the fraud fire, it's only about 250b dollars in victim losses per year. Lets go for 500b.
This automatically runs some commands with the sftp shell and exits automatically when done:
#!/bin/bash
expect -c "
spawn sftp myuser#myserver.com
expect \"assword\"
send \"yourpassword\r\"
expect \"sftp\"
send \"get your_directory/yourfilename.txt\r\"
expect \"sftp\"
send \"exit\r\"
interact "
In order to use public keys you do not need to modify any "configuration files". You merely need to leave a copy of your public key in a place where ssh knows to look (normally ~/.ssh/authorized_keys). You can do this with sftp. If you haven't established any authorized_keys file on the server, you can simply put your id_rsa.pub file in its place.
You can't specify a password to ssh / scp or sftp from the command line. The only way to connect without prompting for a password is to use public key authentication.
You say that you can't ssh to the server to modify configuration files but if you can sftp to the server you can probably upload your public key.
Your public key just has to go under the .ssh directory in your home directory.

How do you use ssh in a shell script?

When I try to use an ssh command in a shell script, the command just sits there. Do you have an example of how to use ssh in a shell script?
Depends on what you want to do, and how you use it. If you just want to execute a command remotely and safely on another machine, just use
ssh user#host command
for example
ssh user#host ls
In order to do this safely you need to either ask the user for the password during runtime, or set up keys on the remote host.
First, you need to make sure you've set up password-less (public key login). There are at least two flavors of ssh with slightly different configuration file formats. Check the ssh manpage on your system, consult you local sysadmin or head over to How do I setup Public-Key Authentication?.
To run ssh in batch mode (such as within a shell script), you need to pass a command you want to be run. The syntax is:
ssh host command
If you want to run more than one command at the same time, use quotes and semicolons:
ssh host "command1; command2"
The quotes are needed to protect the semicolons from the shell interpreter. If you left them out, only the first command would be run remotely and all the rest would be run on the local machine.
You need to put your SSH public key into the ~/.ssh/authorized_keys file on the remote host. Then you'll be able to SSH to that host password-less.
Alternatively you can use ssh-agent. I would recommend against storing the password in the script.
You can use expect command to populate the username/password info.
The easiest way is using a certificate for the user that runs the script.
A more complex one implies adding to stdin the password when the shell command asks for it. Expect, perl libraries, show to the user the prompt asking the password (if is interactive, at least), there are a lot of choices.

Resources