Note: The comment is displayed when a passphrase-protected key is used for client authentication. AndreBorie, unfortunately the client can't be trusted. I have a bad habit of either missing the first or last character. Doesn't using a password with a ssh key also prevent someone else using your key when connecting to a remote machine that already has your public key? The passphrase is used for encrypting the key, so that it cannot be used even if someone obtains the private key file. Not having a password on your key isn't the end of the world, here are 3 ideas to try and help you secure yourself a little better despite this. Also I have not found something like this ssh-keygen. Maybe even better is the following example, since it doesn't ask for input: -P specifies the passphrase to use, an unprotected key opens with an empty passphrase.
Is there any way around that like setting the keys for them, retaining the public key and for them and asking them to change the password for example? Unprotected keys can also be used by an attacker who has remote access to the client to jump to remote access to the network. The converted key is created using the same base file name with an added. I have this format in my private key. The key derivation is done using a hash function. If viewing the log file doesn't quickly lead you to a resolution, I suggest posting a new question since this is a great generalized question which does include the specific details from the log file, so that more specific directions can be provided. But isn't this a bit insecure, anyone who where to gain access to my console would be able to log in to remote systems using your keys. Then you should just be able to ssh between the source and the destination with no passwords.
The security of this is different from using a password-encrypted public key. I know of no way for a server to be able to tell if the keys being presented to it were protected with a passphrase, which is the most useful place to be able to leverage that sort of info. They also allow using strict host key checking, which means that the clients will outright refuse a connection if the host key has changed. However, in enterprise environments, the location is often different. Since having the keys and their passphrases sitting around on disk is essentially equivalent to having a plaintext key, you may as well do that and save yourself some trouble. Use this option in combination with -e.
I could provide a passphrase via the command line argument -N thepassphrase, so to keep the prompt from appearing. I prefer to have plausible deniability when it comes to credentials, therefore I would not like to store users private keys or even know what they are. This maximizes the use of the available randomness. It's optional because you can choose to accept the risk of having it not encrypted in storage. Or what if I lost my key, the finder would be able to access every system on which I installed my public key. Any serious DevOps will only ssh by key file.
I though the password was useful for the situation where a remote server only allows authenticated ssh access ie. So every time you want to use your key with ssh, you'll have to enter this passphrase. An attacker with access to your system will not be able to read the private key, because it's encrypted. Thus, there would be relatively little extra protection for automation. Am I typing some command incorretly? Our recommendation is to collect randomness during the whole installation of the operating system, save that randomness in a random seed file. This option creates the initial passphrase when you generate a new key.
You may also want to ensure that it does not get backed up, since then making off with one of your backup tapes is an easy way to break in. Changed keys are also reported when someone tries to perform a man-in-the-middle attack. You cannot determine if a private key is passphrase protected by examining a public key. If specified, login is allowed only for user names that match one of the patterns. I ran into this problem the other day.
We would recommend always using it with 521 bits, since the keys are still small and probably more secure than the smaller keys even though they should be safe as well. The encrypted information includes passwords and private keys. If passphrase is lost, you can't decript the key so access to it is lost until you recover the passphrase. This is what I want to achieve in a script like this:! Up to a point, a larger key size improves security. The cost is rather small.
Commonly used values are: - rsa for keys - dsa for keys - ecdsa for keys -i Input When ssh-keygen is required to access an existing key, this option designates the file. The statements about relative security are only guidelines, of course; your circumstances will dictate which is the right trade-off. It Should Be Hard to Guess A good passphrase should have at least 15, preferably 20 characters and be difficult to guess. This does nothing more than configuring your key so that you have to enter a passphrase to use it. This is not to say it can't ever be the right choice; you just have to know what you're doing. I believe ssh-agent goes away when the shell does, so this should be scripted upon startup for maximum convenience. However there's always trade-off's with security.