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Since many of you are too lazy to read man pages, and instead prefer to ask us in #bash to read them for you, I'll even give a brief summary of the procedure here: Here is a brief summary of the procedure:


I want to automate an ssh (or scp, or sftp) connection, but I don't know how to send the password....


First of all, if you actually were to embed your password in a script somewhere, it would be visible to the entire world (or at least, anyone who can read files on your system). This would defeat the entire purpose of having a password on your remote account.

If you understand this and still want to continue, then the next thing you need to do is read and understand the man page for ssh-keygen(1). This will tell you how to generate a public/private key pair (in either RSA or DSA format), and how to use these keys to authenticate to the remote system without sending a password at all.

Here is a brief summary of the procedure:

ssh-keygen -t rsa
ssh me@remote "cat >> ~/.ssh/authorized_keys" < ~/.ssh/id_rsa.pub
ssh me@remote date     # should not prompt for passWORD,
                       # but your key may have a passPHRASE

If your key has a passphrase on it, and you want to avoid typing it every time, look into ssh-agent(1). It's beyond the scope of this document, though.

If you're being prompted for a password even with the public key inserted into the remote authorized_keys file, chances are you have a permissions problem on the remote system. Check every single directory in the full path leading up to the authorized_keys file and make sure they do not have world- or group-write privileges. E.g., if your home directory is /home/fred and /home has group "staff" write privileges, sshd will refuse to honor your key.

If that's not it, then make sure you didn't spell it authorised_keys. SSH uses the US spelling, authorized_keys.

If you really want to use a password instead of public keys, first have your head examined. Then, if you still want to use a password, use [http://expect.nist.gov/ expect(1)]. And don't ask us for help with it.

BashFAQ/069 (last edited 2019-04-11 12:53:15 by GreyCat)