How to respond to password prompt when using SCP in a shell script?

Question

First of all, I am well aware of that there are many of questions regarding this topic. I have read them, but still could figure out an appropriate answer for my situation.

I would like to scp the entire ~/cs###/assign1 dir from local to school home dir with a shell script. My question is, is there a way in my script to wait for the password prompt, and then simulate key board event to 'type' in my password?

here is a really detailed guide of how to set up the key

This question sounds exactly like your situation: http://stackoverflow.com/questions/50096/how-to-pass-password-to-scp — innaM, Sep 22 '09 at 20:21
Note that the answers to the putative duplicate question do not mention 'ssh keys' as is mentioned by BZ. — Jonathan Leffler, Sep 22 '09 at 20:49
I was hoping that there could be a solution using only simple shell or unix commands. — derrdji, Sep 22 '09 at 20:50
Possible duplicate of [How to pass password to scp?](https://stackoverflow.com/questions/50096/how-to-pass-password-to-scp) — Jim Fell, Feb 15 '19 at 16:55

score 17 · Answer 1 · answered Dec 19 '12 at 15:20

17

Use "sshpass"!

#!/bin/bash
sshpass -p "password" scp -r /some/local/path user@example.com:/some/remote/path

answered Dec 19 '12 at 15:20

KevinS

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`sshpass` looks interesting. Working on a system that won’t work well with SSH keys so this will do. Thanks! – Giacomo1968 Feb 02 '14 at 07:46

score 11 · Accepted Answer · answered Sep 22 '09 at 20:08

11

Are ssh keys not allowed? That would be a better solution.

answered Sep 22 '09 at 20:08

BZ.

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score 4 · Answer 3 · answered Sep 22 '09 at 20:08

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I don't think you can easily do that. What you can do is using public key authentication instead.

Something along these lines

ssh-keygen -t rsa
ssh school mkdir .ssh/
cat ~/.ssh/id_rsa.pub | ssh school "cat >>.ssh/authorized_keys"

(or dsa).

But hey, it's not serverfault, is it? ;-)

answered Sep 22 '09 at 20:08

Michael Krelin - hacker

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The server and everything was setup by school, I have no control of the setting at that end – derrdji Sep 22 '09 at 20:09
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These settings are in your home directory. – Michael Krelin - hacker Sep 22 '09 at 20:11

score 4 · Answer 4 · answered Sep 22 '09 at 20:10

4

Consider using keys, or an external library.

I don't think it's possible otherwise (I hope I'm not wrong), as it imposes automatic brute force intrusion and sniffing of passwords.

There are libraries that can do what you want (use the SFTP protocol, not calling scp), such as libssh.

Again, I highly recommend keys.

answered Sep 22 '09 at 20:10

LiraNuna

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C'mon, automating brute force attacks can be done using libraries as well ;-) – Michael Krelin - hacker Sep 22 '09 at 20:12

score 3 · Answer 5 · answered Sep 22 '09 at 20:53

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I agree that you should use keys. But expect can automate the interactive aspect of the process IF you want to hardcode your password in a plain-text script file.

answered Sep 22 '09 at 20:53

glenn jackman

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score 2 · Answer 6 · answered Sep 22 '09 at 20:14

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Something like this - http://code.google.com/p/enchanter/ ?

answered Sep 22 '09 at 20:14

cms

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score 1 · Answer 7 · answered Sep 22 '09 at 20:21

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You don't say which platform you are using at home and at school. Assuming Linux, Cygwin or OS/X you have several options:

Public key authentication if it hasn't been turned off at the server
ssh-agent and ssh-add to enter your password once per session

For option (1), you would

generate a keypair at home using ssh-keygen, with no passphrase on the private key. Note that omitting a passphrase is probably not a good idea if other people use the same computer, but your objective was to get around having to type in the password.
upload the PUBLIC key to your school account and place it in ~/.ssh/authorized_keys
Use scp with the "-i identityfile" option, where identityfile is the full path to your private key. Or, add an entry to .ssh/config (see the man pages)

For the second option, ssh-agent allows you to cache your password in a local process one time per session. You set an expiration time

answered Sep 22 '09 at 20:21

Jim Garrison

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Of multiple solutions in multiple answers, this is the only one worked for me. Copied the contents of my `id_rsa.pub` file to the remote's `~/.ssh/authorized_keys` directory and now I can `scp -i` and no manual password is required! – ysap Jan 28 '22 at 09:21
And as a side bonus - no manual password is required for the `ssh` sessions as well (which is kind'a the same thing, but was a nice surprise). When logging in to a remote machine multiple times a day, this is a time saver. – ysap Jan 28 '22 at 09:25
I just found out that `scp` works w/o the need for the `-i identityfile`. Looks like ssh takes care of the key matching once both sides are configured correctly. I guess ssh looks at the local `~/.ssh` directory for `id_rsa.pub` by default?? – ysap Jan 28 '22 at 20:30

score 1 · Answer 8 · answered Oct 20 '17 at 07:12

Once you set up ssh-keygen as explained here, you can do

scp -i ~/.ssh/id_rsa /local/path/to/file remote@ip.com:/path/in/remote/server/

where id_rsa is the local key generated in the ssh-keygen setup.

If you want to lessen typing each time, you can modify your .bash_profile file and put

alias remote_scp='scp -i ~/.ssh/id_rsa /local/path/to/file remote@ip.com:/path/in/remote/server/

Then from your terminal do source ~/.bash_profile. Afterwards if you type remote_scp in your terminal it should run the scp command without password.

score 0 · Answer 9 · answered Sep 22 '09 at 20:11

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If you can mount the directory from a Windows machine (e.g. via AFS, NFS or SMB which my university's Windows labs all did), you can use pscp with the -pw switch.

answered Sep 22 '09 at 20:11

i_am_jorf

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score 0 · Answer 10 · answered Sep 22 '09 at 20:11

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Why not just use the "-r" option to copy it recursively? Or use rsync instead?

You could also use public key authentication, which requires no help on their end as long as you have an actual user account. See this

answered Sep 22 '09 at 20:11

kenm

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score 0 · Answer 11 · edited Oct 14 '15 at 00:25

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As many have already said that using ssh keys would be the safest and best way. If anyone else is still wondering around and searching for help, in Ubuntu help there is a fast and straight forward way to use ssh keys.

edited Oct 14 '15 at 00:25

Jonathan Cast

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answered Oct 13 '15 at 23:21

Karls

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score 0 · Answer 12 · answered Nov 17 '18 at 04:48

I found no way to do this on our systems automatically - I ssh into one device, and then ssh to the next device, and on both, I cannot install any other software. So I can only use existing shell script commands. I can either copy all the files of a type with, such as *.png, or one by one in my script file, having to enter the password for each individual file. The one thing I did that was helpful was to type the password into a file, cut it, and be able to paste it to each prompt for each file.

How to respond to password prompt when using SCP in a shell script?

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