RSA is the most common kind of keypair generation. Other popular ways of generating RSA public key / private key pairs include PuTTYgen and ssh-keygen. 1 Generate an RSA keypair with a 2048 bit private key 2 Extracting the public key from an RSA keypair. Before you can create your CSR, you need to create your Java keystore. Your Java keystore contains your private key. Run the following command to create your 2048 bit Java keystore: keytool -genkey -alias myalias -keyalg RSA –keysize 2048 -keystore c:yoursite.keystore. How to generate encryption keys. On macOS and on Linux, you should open the terminal program and execute the commands displayed below: Create a 2048-bit RSA private key. Don’t share this key with anyone, use it only in the EDD FastSpring plugin settings. This key will be used to encrypt the orders. In the Number of bits in a generated key box, enter 2048. Click Generate to generate a public/private key pair. As the key is being generated, move the mouse around the blank area as directed. (Optional) Enter a passphrase for the private key in the Key passphrase box and reenter it in the Confirm passphrase box.
This tutorial series will teach you how to use GPG in Linux terminal. I will not tell you a bunch of theory to overwhelm you. Instead, I show you quick and dirty examples to get you started, and explain the basic theory along the way.
This is part 1 of this series. At the end of this post, you should be able to generate your own public/private keypair and a revocation certificate. This certificate is used to revoke your public/private keypair when your private key is compromised or you forget the passphrase for your private key.
GPG can be used for encryption and for signing. This software is pre-installed on most Linux distributions. Currently the stable version is GPG 2.0. I’m using the modern version GPG 2.2 on Arch Linux.
Check Your GPG Version
First Let’s check out the version of GPG on your system and some interesting tidbits. Run the following command.
As you can see, I’m using GPG 2.2.8, which is the latest version. We also know that the configuration directory is ~/.gnupg, which will hold our public/private key files. The default option file is ~/.gnupg/gpg.conf and ~/.gnupg/dirmngr.conf. It also tells us what algorithms are supported.
If you look closely, you can see that the insecure hash algorithm SHA1 is still supported in version 2.2.8 SHA1 is obsolete and you don’t want to use it to generate signature.
Create Your Public/Private Key Pair and Revocation Certificate
Use
gpg --full-gen-key
command to generate your key pair.It asks you what kind of key you want. Notice there’re four options. The default is to create a RSA public/private key pair and also a RSA signing key. Let’s hit Enter to select the default.
Next it asks you the key length. The default is 2048 bits long. 1024 RSA key is obsolete. The longer 4096 RSA key will not provide more security than 2048 RSA key. So hit Enter to select the default.
After that it asks you how long the key should be valid, 2 years is fine. You can always update the expiration time later on.
Now it asks you if it’s correct. Notice that the default is No. So press
y
then Enter to confirm it’s correct.And now we need to provide some user identification information for the key. This is important because this information will be included in our key. It’s one way of indicating who is owner of this key. The email address is a unique identifier for a person. You can leave Comment blank.
Select Okay.
Now it asks you to enter a passphrase to protect your private key. Enter a good and long passphrase and remember it. Because if you forget this passphrase, you won’t be able to unlock you private key.
Once you enter and confirm your passphrase. GPG will generate your keys.
It will take a while for GPG to generate your keys. So you can now do other stuff.
It took about 4 minutes on my system to generate my key pair.
This first line tells us that GPG created a unique identifier for public key. This unique identifier is in hex format. When someone wants to download you public key, they can refer to you public key via your email address or this hex value.
The third line tells us that GPG created a revocation certificate and its directory.Your should never share you private key with anyone.If you private key is compromised, you can use revocateion certificate to revoke your key. That means you tell the rest of the world that the old public key shall not be used any more.I suggest that you open this revocation certificate with your text editor to see what’s inside there.
Let’s look at the last three lines. They tell us the public key is 2048 bits using RSA algorithm. The public key ID 4F0BDACC matchs the last 8 bits of key fingerprint. The key fingerprint is a hash of your public key.
It also lists our user ID information: your name and your email address. And it also indicates the subkey which is 2048 bits using RSA algorithm and the unique identifier of the subkey.
Now you can find that there are two files created under ~/.gnupg/private-keys-v1.d/ directory. These two files are binary files with .key extension.
Export Your Public Key
Others need your public key to send encrypted message to you and only your private key can decrypt it. Use the following command to export your public key.
--armor
option means that the output is ASCII armored. The default is to create the binary OpenPGP format. user-id
is your email address.The exported public key is written to
pubkey.asc
file.Export Your Private Key
Issue the following command to export your private key.
The exported key is written to
privkey.asc
file.Protect Your Private Key and Revocation Certificate
Your private key should be kept in a safe place, like an encrypted flash drive. Treat it like your house key. Only you can have it and don’t lose it. And you must remember your passphrase, otherwise you can’t unlock your private key.
You should also protect your revocation certificate. If others have your revocation certificate, they can immediately revoke your public/private keypair and generate a fake public/priavte keypair.
In part 2 we will look at how to encrypt message with your public key and how to decrypt it with your private key. Take care!
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HGenerate Rsa Key Pair
ow do I generate ssh keys under Linux / UNIX / Mac OS X and *BSD operating systems for remote login?SSH uses public-key cryptography to authenticate the remote computer and allow the remote computer to authenticate the user, if required. You can create ssh keys as follows on any Linux or UNIX-like operating systems including Mac OS X.[donotprint][/donotprint]
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ssh-keygen command to Generate SSH Keys
The ssh-keygen command generates, manages and converts authentication keys for ssh client and server usage. Type the following command to generate ssh keys (open terminal and type the command):
Generate SSH keys looks as follows:
$ ssh-keygen
Generate SSH keys looks as follows:
The above command creates ~/.ssh/ directory. So if your user name is vivek, than all files are stored in /home/vivek/.ssh/ or $HOME/.ssh/ directory as follows:
- $HOME/.ssh/id_rsa – Your private key. Do not share this file with anyone. Keep it private
- $HOME/.ssh/id_rsa.pub– Your public key.
Please note that the passphrase must be different from your current password and do not share keys or passphrase with anyone. Also, make sure you have correct and secure permissions on $HOME/.ssh/ directory:
SSH Keys Are Generated, What Next?
You need to copy $HOME/.ssh/id_rsa.pub file to remote server so that you can login using keys instead of the password. Use any one of the following command to copy key to remote server called vpn22.nixcraft.net.in for vivek user:
On some *nix system such as OS X ssh-copy-id command may not be installed, use the following commands (when prompted provide the password for remote user account called vivek) to install/append the public key on remote host:
To login simply type:
The following command will help to remember passphrase
ssh-copy-id [email protected]
On some *nix system such as OS X ssh-copy-id command may not be installed, use the following commands (when prompted provide the password for remote user account called vivek) to install/append the public key on remote host:
ssh [email protected] 'umask 077; mkdir .ssh'
cat $HOME/.ssh/id_rsa.pub | ssh [email protected] 'cat >> .ssh/authorized_keys'
To login simply type:
ssh [email protected]
The following command will help to remember passphrase
exec ssh-agent $SHELL
ssh-add
ssh [email protected]
Optional ssh-keygen command syntax for advance users
The following syntax specifies the 4096 of bits in the RSA key to creation (default 2048):
Where,
ssh-keygen -t rsa -b 4096 -f ~/.ssh/aws.key -C 'My AWs cloud key'
Where,
- -t rsa : Specifies the type of key to create. The possible values are “rsa1” for protocol version 1 and “dsa”, “ecdsa”, “ed25519”, or “rsa” for protocol version 2.
- -b 4096 : Specifies the number of bits in the key to create.
- -f ~/.ssh/aws.key : Specifies the filename of the key file.
- -C 'My AWs cloud key' : Set a new comment.
Now install the ~/.ssh/aws.key, run:
Test it with the ssh command:
See “How To Set up SSH Keys on a Linux / Unix System” for more info.
ssh-copy-id -i ~/.ssh/aws.key user@aws-server-ip
Test it with the ssh command:
ssh -i ~/.ssh/aws.key ec2-user@aws-server-ip
See “How To Set up SSH Keys on a Linux / Unix System” for more info.
Conclusion
You learned how to create and generate ssh keys using the ssh-keygen command.
Linux Generate Rsa Key 2048 Free
- Howto Linux / UNIX setup SSH with DSA public key authentication (password less login)
- sshpass: Login To SSH Server / Provide SSH Password Using A Shell Script
- keychain: Set Up Secure Passwordless SSH Access For Backup Scripts
- Openssh man pages here
- Man pages – ssh-keygen(1)
Linux Generate Rsa Key 2048 Download
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