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25

Both keys and passwords have their pros and cons. The reason that "howtos" and the like advise using the SSH key is that they find their cons less worrisome than passwords' cons. SSH keys are long and complex, far more than any password could be. But as you state, they don't have expiry, and they sit on disk where they can be stolen from. On the other ...


14

With passwords, then the password is sent to the server, so the safety of the password is relative to how well the server protects whatever it uses to verify passwords (e.g. the /etc/shadow file). When you use an SSH key, then your private key remains on the client side, and no secret value is ever sent to the server. Even if the server is under hostile ...


3

If what I am understanding in your update, if your can provide the same entropy in your passwords vs keys, than as far as its security it's moot. You could make tthe case that keys are better because it would provide a better "user experience" because your not typing in passwords every time. I think more to your original point, we are discussing the ...


3

You should be safe from ssh side, but there are other vectors as well, like dhclient-script. By the way, you are only really "vulnerable" through SSH if you have users with restricted access (e.g. chroot or sftp-only). If all your users have full shell access, then even though they may run commands using this exploit, they could do that anyway.


2

You're correct, as far as I can tell. If AcceptEnv is not set then a remote client cannot get the SSH server to process any environment variable. Note that you can execute a command through SSH as an authenticated client and get that command to load up your crafted environment variable. So if you have any setuid/setgid binary running a Bash script, this ...


1

As noted in the comments, you seem to be misusing your private key. Your private key should only be held locally. That is, on the hard drive of the computer you're currently sitting at. You mentioned that the private key is located on several locations from where I upload/download data I gather you connect to one of this servers, do some work, and ...


1

I guess you use SSH-keys as authentication? Reauthentication and key exchanges happens all the time during the SSH protocol, so having a Active session is secure enough. Another thing is confirmation, eg, you want that the user really wants to commit a action that might be irreversible. Lets say deleting something. To solve this problem, I would suggest ...


1

A keyfile is an element of a PKI. I mean it is heavy to manage and is intended to be used for a long time period and and be deployed on a large infrastructure whereas an OTP, by definition, is useful for one session only and it is somehow a lightweight but robust solution for simple lightweight applications because as soon as someone finds your OTP it is no ...


1

Native certificate-based authentication is available in unmodified upstream OpenSSH. It is not, however, based on x.509. First, generate your CA: ssh-keygen -f ssh-ca Next, install your CA key in .authorized_keys with a cert-authority prefix: echo "cert-authority $(<ssh-ca.pub)" >>.ssh/authorized_keys From that point, whenever a key is ...


1

The best you could do is use a ssh connection to work on those files. If that is not an option you should try to make it possible. If ssh is really not possible you should check the following: use https with a valid certificate (without that password will be send as plain text!) your .htaccess uses a strong password (otherwise it might be brute forced) ...


1

Let's say that you have hypothetical known_hosting_keys entries for both nsa.gov and github.com. Now evil.net both infiltrates github.com and also obtains MITM-level control over your internet connection/DNS. Now you ssh into nsa.gov, and evil.net presents you with stolen github.com credentials, and your ssh client cycles through your known_hosting_keys ...



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