How to run the sftp command with a password from Bash script?

Question

I need to transfer a log file to a remote host using sftp from a Linux host. I have been provided credentials for the same from my operations group. However, since I don't have control over other host, I cannot generate and share RSA keys with the other host.

So is there a way to run the sftp command (with the username/password provided) from inside the Bash script through a cron job?

I found a similar Stack Overflow question, Specify password to sftp in a Bash script, but there was no satisfactory answer to my problem.

Answer 1

You have a few options other than using public key authentication:

1. Use keychain
2. Use sshpass (less secured but probably that meets your requirement)
3. Use expect (least secured and more coding needed)

If you decide to give sshpass a chance here is a working script snippet to do so:

export SSHPASS=your-password-here
sshpass -e sftp -oBatchMode=no -b - sftp-user@remote-host << !
   cd incoming
   put your-log-file.log
   bye
!

---

Update: However do understand that using environment variables is also insecure as using command line option -p for passing password.

It is better to store and read password from a file like this using -f option:

echo 'your-password-here' > ~/.passwd
chmod 0400 ~/.passwd

sshpass -f ~/.passwd -e sftp -oBatchMode=no -b - sftp-user@remote-host << !
   cd incoming
   put your-log-file.log
   bye
!