Oct 24, 2006  Generating public/private rsa key pair. Enter file in which to save the key (/root/.ssh/idrsa): (It's safe to press enter here, as the /root/.ssh is the default and recommended directory to hold.

Usually a public SSH key is generated at the same time as a private key.

Unlike a private SSH key, it is acceptable to lose a public key as it can be generated again from a private key at any time.

Generate Ssh Public Key From Private Key

In this small note i am showing how to create a public SSH key from a private one using ssh-keygen command-line tool.

Cool Tip: Remove delay during SSH login! Read more →

Extracting public RSA key from a private key from the command line. Command line comparison to show there is no difference between a public RSA key and an extracted key if you ignore whitespace. Diff public key with 'extractedpublickey' file ignoring white space. From the 'man ssh-keygen' -y This option will read a private OpenSSH format file and print an OpenSSH public key to stdout. Specify the private key with the -f option, yours might be dsa instead of rsa. The name of your private key probably contains which you used. To generate the public/private key pair, enter this in the Command Prompt: ssh-keygen At the first prompt, “Enter file in which to save the key,” press Enter to save it in the default location. Extracting public RSA key from a private key from the command line. Command line comparison to show there is no difference between a public RSA key and an extracted key if you ignore whitespace. Diff public key with 'extractedpublickey' file ignoring white space. Save the public and private keys by clicking the Save public key and Save private key buttons. From the Public key for pasting into OpenSSH authorizedkeys file field at the top of the window, copy all the text (starting with ssh-rsa ) to your clipboard by pressing Ctrl-C.

Get Public SSH Key from Private

Use the following command to read a private SSH key from a file and print a public key:

Short explanation:

Generate Rsa Ssh Key

As an example, let’s generate a public SSH key from a private key ~/.ssh/id_rsa and save it to the file ~/.ssh/id_rsa.pub:

Several tools exist to generate SSH public/private key pairs. The following sections show how to generate an SSH key pair on UNIX, UNIX-like and Windows platforms.

Generating an SSH Key Pair on UNIX and UNIX-Like Platforms Using the ssh-keygen Utility

Generate Public Ssh Key Windows

UNIX and UNIX-like platforms (including Solaris and Linux) include the ssh-keygen utility to generate SSH key pairs.

1. Navigate to your home directory:
2. Run the ssh-keygen utility, providing as filename your choice of file name for the private key:

   The ssh-keygen utility prompts you for a passphrase for the private key.

3. Enter a passphrase for the private key, or press Enter to create a private key without a passphrase:

   Note:

   While a passphrase is not required, you should specify one as a security measure to protect the private key from unauthorized use. When you specify a passphrase, a user must enter the passphrase every time the private key is used.

   The ssh-keygen utility prompts you to enter the passphrase again.

4. Enter the passphrase again, or press Enter again to continue creating a private key without a passphrase:
5. The ssh-keygen utility displays a message indicating that the private key has been saved as filename and the public key has been saved as filename.pub. It also displays information about the key fingerprint and randomart image.

Generating an SSH Key Pair on Windows Using the PuTTYgen Program

The PuTTYgen program is part of PuTTY, an open source networking client for the Windows platform.

1. Download and install PuTTY or PuTTYgen.

   To download PuTTY or PuTTYgen, go to http://www.putty.org/ and click the You can download PuTTY here link.

2. Run the PuTTYgen program.
3. Set the Type of key to generate option to SSH-2 RSA.
4. In the Number of bits in a generated key box, enter 2048.
5. Click Generate to generate a public/private key pair.

   As the key is being generated, move the mouse around the blank area as directed.

6. (Optional) Enter a passphrase for the private key in the Key passphrase box and reenter it in the Confirm passphrase box.

   Note:

   While a passphrase is not required, you should specify one as a security measure to protect the private key from unauthorized use. When you specify a passphrase, a user must enter the passphrase every time the private key is used.

7. Click Save private key to save the private key to a file. To adhere to file-naming conventions, you should give the private key file an extension of .ppk (PuTTY private key).

   Note:

   The .ppk file extension indicates that the private key is in PuTTY's proprietary format. You must use a key of this format when using PuTTY as your SSH client. It cannot be used with other SSH client tools. Refer to the PuTTY documentation to convert a private key in this format to a different format.
8. Select all of the characters in the Public key for pasting into OpenSSH authorized_keys file box.

   Make sure you select all the characters, not just the ones you can see in the narrow window. If a scroll bar is next to the characters, you aren't seeing all the characters. /download-free-microsoft-office-2010-product-key-generator.html.

9. Right-click somewhere in the selected text and select Copy from the menu.
10. Open a text editor and paste the characters, just as you copied them. Start at the first character in the text editor, and do not insert any line breaks.
11. Save the text file in the same folder where you saved the private key, using the .pub extension to indicate that the file contains a public key.
12. If you or others are going to use an SSH client that requires the OpenSSH format for private keys (such as the ssh utility on Linux), export the private key:
    1. On the Conversions menu, choose Export OpenSSH key.
    2. Save the private key in OpenSSH format in the same folder where you saved the private key in .ppk format, using an extension such as .openssh to indicate the file's content.