sftp client authentication methods

Posted on 2009-05-04
Last Modified: 2013-12-09
I'm trying to connect to an sftp server, but am unable to do so through a bash script.  the server is expecting ssh key authentication by default and i'd like to do UserName/Password auth.  Is there a way i can specify the type of auth i want to use and if so what are some examples?  Such as:
sftp -oAuthenticationMethod=Password
sftp -oAuthenticationMethod=SSH_KEY

I've tried using the -o options, but am not sure i got the syntax right.
also, i interactivly try and connect to the sftp server it will prompt me for a password and when i enter it, it's just fine.
i'm running the bash script on Linux machine which is trying to connect to a sftp server running on windows machine.
Question by:nohurt
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 3
  • 3

Assisted Solution

mchkorg earned 130 total points
ID: 24302287
Just to be sure: you're not confused between sftp and ftps ?
- sftp is "FTP over SSH", it requires a SSH server
- ftps is "secured FTP", it requires a FTP server with SSL

What's your server software on Windows ?
LVL 28

Assisted Solution

lesouef earned 120 total points
ID: 24305005
the only I know to overcome this (avoid the interactive questions) is to use an answer file with the commands in it, as argument to ftp-s filename,
or use a .netrc file in your account root folder to store the account defaults

Author Comment

ID: 24307015
i'mtrying to connect to a partner who is hosting the sftp server on windows.  i'm not sure what server they are running.  they have asked that i connect to them using "sftp".  When i do that interactively from command line on a linux box, the sftp server prompts me for my password, i enter it and all is fine.  When i try and connect using (through a bash script):
expect << 'END' 2>&1 | tee -a $LogFile
set timeout 5
spawn sftp $env(UserID)@$env(HostToConnectTo)
expect "'s password: "
send -- "$env(Password) \r"
expect "sftp> "
send -- "cd $env(OutPutDir) \r"
expect "sftp> "
send -- "ls -l ../ \r"
expect "sftp> "
send "bye \r"
The partner has not "White listed" my ssh key on their server, so it doesn't work.  I would like to know if there is an option for sftp so that i can be very specific on sftp command line the use of authentication (password or ssh key).
Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

LVL 28

Assisted Solution

lesouef earned 120 total points
ID: 24307229
have you tried the old URL method:
or removing the password: mention, entering the password strait away after the login line? (I do that on ftp)
LVL 28

Assisted Solution

lesouef earned 120 total points
ID: 24310611
foud this also:
sftp [-1vC] [-A Password] [-b batchfile] [-L logfilename] [-osshopt=value] [user@]host[:file [file]]

The host must be given on the command line. The current interactive username will be used unless a user id is passed on the command line. This is done by adding the desired username to the hostname with the @ symbol. For example to connect to sftpserver as administrator, connect with

sftp administrator@sftpserver


 use the SSH1 protocol
 verbose mode for debugging
 use compression
A Password
 use password to logon to sftp server
b batchfile
 automation file - list desired commands to process after connected
L logfilename
 allows commands and responses to be logged to file logfilename
o sshoptions
 ssh client options

Accepted Solution

mchkorg earned 130 total points
ID: 24311607
If keyauthentication is enabled, it should work without asking anything.
Maybe try with scp. Sftp should be used as a ftp client, I mean : browsing directories and so on.
If you just want to transfer files over SSH, scp sound better:

scp user@host:/some/file some_local_destination


scp something_local user@host:/something

You can use "-r" for recurse and so on

AND: are you sure you public key is in the authorized_keys on server's side? If not, you might add it manually in a regular ssh session.

Author Comment

ID: 24382278
my authorized_key is in the file. If i "sftp" i get in just fine and am at the sftp> prompt.  But if i try and ssh or scp a file, it just hangs.  i'm not sure what's going on.

Assisted Solution

mchkorg earned 130 total points
ID: 24382844
authorized_key => authorized_keys

Please, copy/paste the ssh and scp command you enter

Author Closing Comment

ID: 31577899
it turns out that the ftp server i connect to has to accept my ssh key on their side manally in the sftp server.  i am not allowed to put a public ssh key on their server.

Featured Post

Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Envision that you are chipping away at another e-business site with a team of pundit developers and designers. Everything seems, by all accounts, to be going easily.
Since pre-biblical times, humans have sought ways to keep secrets, and share the secrets selectively.  This article explores the ways PHP can be used to hide and encrypt information.
Internet Business Fax to Email Made Easy - With eFax Corporate (, you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, fr…
The Email Laundry PDF encryption service allows companies to send confidential encrypted  emails to anybody. The PDF document can also contain attachments that are embedded in the encrypted PDF. The password is randomly generated by The Email Laundr…

688 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question