Nov 10, 2011 4. Your public and private SSH key should now be generated. Open the file manager and navigate to the.ssh directory. You should see two files: idrsa and idrsa.pub. Upload the idrsa.pub file to the home folder of your remote host (assuming your remote host is running Linux as well).

Since OpenSSL is a collection of modules we specify genpkey to generate a private key. The -algorithm option specifies which algorithm we want to use to generate the key (RSA in this case), -out specifies the name of the output file, and -pkeyopt allows us to set the value for specific key options. In this case the length of the RSA key in bits. How to generate public/private key in C#. Asymmetric cryptography also known as public-key encryption uses a public/private key pair to encrypt and decrypt data. In.NET, the RSACryptoServiceProvider and DSACryptoServiceProvider classes are used for asymmetric encryption.

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.

To generate the missing public key again from the private key, the following command will generate the public key of the private key provided with the -f option. $ ssh-keygen -y -f /.ssh/idrsa /.ssh/idrsa.pub Enter passphrase: The -y option will read a private SSH key file and prints an SSH public key to stdout. If you can, disable password logins in your “sshdconfig” file (on the server) and use keys instead. In case you travel and can’t carry your laptop with you, just keep your private key on a USB stick and attach it to your physical keychain. Your server will be much safer this way. Generate Public/Private SSH Key Pair. While Encrypting a File with a Password from the Command Line using OpenSSL is very useful in its own right, the real power of the OpenSSL library is its ability to support the use of public key cryptograph for encrypting or validating data in an unattended manner (where the password is not required to encrypt) is done with public keys.

Generate Public Key And Private Key Using Rsa Code

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

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

Private Key Definition

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.

Generate Public Key From Private Key Rsa

Symmetric Key

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.

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.