CODEWITHSUNDEEP
bashshellunixsshscripting
mosab
mosab

Reputation: 207

Auto answer ssh-copy-id in shell script

I'm writting a shell script and I want to automate login into a remote machine using ssh-copy-id, so manually when I print :

ssh-copy-id -i /root/.ssh/id_rsa $2@$4 -p $3 | echo $1

$1 refer to password, $2 refer to username, $3 refer to port, and $4 refer to ip, It is ok with that, the problem is that I have to automate inserting password after : 

ssh-copy-id -i /root/.ssh/id_rsa $2@$4 -p $3

I add this "| printf $1", but it does not work it shows "password:" in the screen and still wait for the password .. I hope you understand me and thank you.

Upvotes: 2

Views: 9222

Answers (2)

Brian Chan
Brian Chan

Reputation: 170

2020 / Mac OS X:

Install sshpass (original answer)

brew install hudochenkov/sshpass/sshpass

Run ssh-copy-id using sshpass and with the password as an arg

sshpass -p $1 ssh-copy-id -i ~/PATH/TO/KEY $2@$4 -p $3

If you want to turn off strict host checking as well, use the -o flag, which is passed to the underlying ssh:

sshpass -p hunter2 ssh-copy-id -o StrictHostKeyChecking=no -i ~/PATH/TO/KEY $2@$4 -p $3

I tried the solution by @redneb, and installed setsid through util-linux by following this answer, but kept receiving a password denied.

I found this strategy to work for uploading my SSH key while setting up multiple raspberry pis in successino. In my script, I also run ssh-keygen -R raspberrypi.local each time too, to avoid the The ECDSA host key for raspberrypi.local has changed error.

Upvotes: 1

redneb
redneb

Reputation: 23850

As @Leon pointed out, you had the pipeline backwards. But even if you do it with the correct order, it will still not work because ssh-copy-id (and all other programs from openssh) do not read passwords from their stdin. The solution is to use the $SSH_ASKPASS environment variable. You can do that as follows: first, create an auxiliary script, say /var/tmp/ssh-pass.sh (actually find a better name than that), with the following contents:

#!/bin/sh                                                                    
echo "$PASS"

Then you can use the following command to accomplish what you've asked for:

PASS="$1" SSH_ASKPASS="/var/tmp/ssh-pass.sh" setsid -w ssh-copy-id -i /root/.ssh/id_rsa "$2"@"$4" -p "$3"

Explanation: we use setsid -w to disassociate the ssh-copy-id process from the currently used terminal. That forces ssh-copy-id to run the executable specified in the $SSH_ASKPASS in order to obtain the password. We have specified our own script in that variable, so ssh-copy-id will execute just that. Now the script is supposed to provide the password to ssh-copy-id by printing it to its stdout. We use the $PASS variable to the password to the script, so the script just prints that variable.

Upvotes: 3

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