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
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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).
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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.

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