After entering you passphrase twice the program will print the key fingerprint, which is some kind of hashing used to distinguish different keys, followed by the default key comment more on key comments later. This is something that is easily done via a terminal using ssh-keygen on Mac and Linux, however on Windows… this tool is not easily accessible to the non-technical person. The key password protects against a different threat. My goal is to outline the steps needed so you can start using key-based authentication on your Mac. A full run through of those options is well outside the scope of this gist.
It is best to replace it. This might be a bug in Transmit. The Terminal window opens with the command line prompt displaying the name of your machine and your username. They'll be able to add it to your user account's list of authorized keys and that will enable you to log in without typing a password. In my understanding, that should not be a problem as long as the key is valid and meets the specification.
You should see your server and terminal prompt after pressing enter. You generally work on multiple servers per project. Extracting the public key You'll want to be able to send the public key to other people and leave it on other computers without risking your private key. If you create a passphrase-less key just make sure you only put it on trusted hosts as it may compromise the remote machine if the key falls to the wrong hands. The ssh-keygen utility prompts you for a passphrase. A good passphrase, as I said before, should be at least 10 characters long, and consist of random upper and lower case letters, numbers and symbols.
Passphrases Passphrases allow you to prevent unauthorized usage of your key by meaning of protecting the key itself by a password. Also, if you set a key password, you will be asked to supply it before you can access the key. After executing the command it may take some time to generate the keys as the program waits for enough entropy to be gathered to generate random numbers. While the passphrase boosts the security of the key, under some conditions you may want to leave it empty. You won't have to type it in regularly so generate it with your password vault. If you pass an incorrect password or cypher then an error will be displayed. The number after the -b specifies the key length in bits.
If you are going to public your key for example on your website so that other people can verify the authorship of files attributed to you then you'll want to distribute it in another format. Posted by Travis Tidwell Sep 6 th, 2013. Longer keys provide greater security however there is diminishing returns as key length increases. I usually use a randomly generated passphrase, as this kind is considered the most secure. Also, increasing the key length also increases computational costs exponentially by the cube of the change, so 2048 is 8x more demanding than 1024-bit. You should not be giving it to the root account.
Make sure to use a very strong, unique, random password for this file. Would using a larger key 2048 or even 4096 bits increase overhead? I'd recommend just making a tarball and delivering it through normal methods email, sftp, dropbox, whatever. Deleting the old connection and creating a new one seems to always work. When you execute this command, the ssh-keygen utility prompts you to indicate where to store the key. Doing it the hard way This method involves creating the keys as a bundle, exporting the public key and manually setting the permssions on all of the paths.
That way, if your Mac workstation is ever compromised, you minimise the risk of access to servers used for past projects where your account has been inadvertently left active. While passphraseless keys are very useful for scripts just remember to only use them at trusted machines. I will also explain how to maintain those keys by changing their associated comments and more importantly by changing the passphrases using this handy utility. You may want to use smaller keys for slower hardware or if you find yourself frequently reconnecting due to bad connections during a session for better performance. Repeatedly entering secure long random passwords is becoming a hassle. Is it possible that one system is setup not to accept keys shorter than X even if they are valid under the standard? While you can simply select the default, it might be a good idea to create a key file specifically for each project. This is a phone, after all.
Leaving the passphrase empty allows you to use the key from within scripts, for example to transfer a file via scp. If you want to use very long keys then you'll have to split it into several short messages, encrypt them independently, and then concatinate them into a single long string. I find it useful to keep a copy in my. Typically you want to ensure the private key is chmod 600, andd the public key is chmod 644. Decrypting the password will require reversing the technique: splitting the file into smaller chuncks, decrypting them independently, and then concatinating those into the original password key file. Apparently, this is not enough although many say it is.
You should make sure that the key can only be read by you and not by any other user for security reasons. No one will ever ask you for it and if so, simply ignore them - they are trying to steal it. A good passphrase should be at least 10 characters long. Find the Terminal application in the Utilities window. End Notes Feel free to share your public key, as its name suggests, it should be public. It cannot be used to derive the private key so there is no risk in sharing it.