Very Computer

by **Computer Perso** » Wed, 03 Dec 2003 04:47:21

Hi,

I want to use sftp in a cron job (shell script) so obvously I do not want to
have to interactively enter a password. I have seen solutions such as using
expect (nah) and setting up rsa keys and the like..

Anyone know what the best method of doing this is (in their opinion)? And if
so, do you know where I can find step by step instructions of how to carry
this out :) rtfm is not what I am looking for as a response..

Thanks!

by **Dr. David Kirk** » Wed, 03 Dec 2003 12:39:47

> Hi,

> I want to use sftp in a cron job (shell script) so obvously I do not want to
> have to interactively enter a password. I have seen solutions such as using
> expect (nah) and setting up rsa keys and the like..

> Anyone know what the best method of doing this is (in their opinion)? And if
> so, do you know where I can find step by step instructions of how to carry
> this out :) rtfm is not what I am looking for as a response..

> Thanks!

You want to use scp (secure copy) to copy the files, not sftp.

Here's an example of me copying the file 'ww' from host 'sparrow' to
host 'webserver2' and putting it in /tmp.

webserver2: HP-UX 11 system.
ww 100% |*****************************| 375
00:00

When you run ssh-keygen on 'sparrow' to create public and private
keys, you need to enter nothing for a passphase. Then append the
public key (id_dsa.pub or similar) from host 'sparrow' to the file
$HOME/.ssh/authorized_keys on the host 'webserver2'

(if $HOME/.ssh/authorized_keys does not exist, just copy the public
key. You can have multiple public keys all in the one 'authorized_key'
file).

This is secure but it does rely on nobody being able to get the
private part of the key.

If a passphrase was entered when entering using ssh-keygen, then the
private part of the key would not be sufficient to allow the file
copy, as the passphrase would need to be entered too. Obviously that
is impossible if you want to do it non-interactively, so you must have
a null passphrase.

Dr. David Kirkby

by **Dr. David Kirk** » Wed, 03 Dec 2003 13:08:59

> Hi,

> I want to use sftp in a cron job (shell script) so obvously I do not want to
> have to interactively enter a password. I have seen solutions such as using
> expect (nah) and setting up rsa keys and the like..

> Anyone know what the best method of doing this is (in their opinion)? And if
> so, do you know where I can find step by step instructions of how to carry
> this out :) rtfm is not what I am looking for as a response..

> Thanks!

Just to say the file containing the keys should be called
'authorized_keys' and not authorized_key as I said once in my post.
That was a typo.

This public-key/private-key takes a bit of getting one's head around,
but once you do, it is fairly simple. The file id_dsa.pub I used is
the default name for the public key of the type 'dsa', which you
generate with

ssh-keygen -t dsa
(this takes a while, then enter RETURN for the passphrase).

If you use the ssh from www.ssh.com, rather than openssh, then there
are differences in the file names, which adds to the confusion. There
are other issues too, so its best to stick to openssh, on which Sun's
ssh in Solaris 9 is based.

I hope that is a bit more a reply than 'rtfm', but releasitically you
do need to read the documentation.

BTW, There is a newsgroup devoted specifically to ssh.

Dr. David Kirkby.

by **Proud Gay Male Anthony Mandi** » Wed, 03 Dec 2003 13:08:23

> Hi,

> I want to use sftp in a cron job (shell script) so obvously I do not want to
> have to interactively enter a password. I have seen solutions such as using
> expect (nah) and setting up rsa keys and the like..

> Anyone know what the best method of doing this is (in their opinion)? And if
> so, do you know where I can find step by step instructions of how to carry
> this out :) rtfm is not what I am looking for as a response..

No 'expect' and you won't read the SSH book?

Lazy Canadian.

Very Computer

sftp non interactive session

sftp non interactive session

sftp non interactive session

sftp non interactive session

sftp non interactive session