Creating a private/public key pair on Ubuntu Last updated: 04 Jun 2012. There are many reasons you might want to create a key pair on Linux, more specifically on Ubuntu. For more information about key pairs, see this. If your server is an Amazon EC2 Server Instance, you might want to look at more specific information here. Public-key ciphers were invented to avoid the key-exchange problem entirely. A public-key cipher uses a pair of keys for sending messages. The two keys belong to the person receiving the message. One key is a public key and may be given to anybody. The other key is a private key and is kept secret by the owner. A sender encrypts a message using.

1. Generating Public Key In Html Code
2. Generating Public Key In Html File
3. Public Key Definition

Generating Public Key In Html Code

Generating a Public and Private X.509 Key Pair You need to generate a public and private X.509 key pair that will be used to sign a kernel module after it has been built. The corresponding public key will be used to authenticate the kernel module when it is loaded. Generating a Public/Private Key Pair. You need to programmatically create a public/private key pair using the RSA algorithm with a minimum key strength of 2048 bits. The method you use to generate this key pair may differ depending on platform and programming language. Generating a public/private key pair by using OpenSSL library.

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

Generating Public Key In Html File

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

Public 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.

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 hereMicrosoft office 2016 key generator free download. 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.

To access your instances using SSH, generate an SSH key pair, associate the public key with your instances, and use the private key to log in to the instances using SSH.

Note:

You can’t use SSH keys to log in to a Windows instance. To log in to your Windows instance using RDP, see Accessing a Windows Instance Using RDP.

Caution:

Keep your SSH keys secure. Lay down policies to ensure that the keys aren’t lost or compromised when employees leave the organization or move to other departments. If you lose your private key, then you can’t access your instances. For business continuity, ensure that the SSH keys of at least two IT system administrators are added to your instances.

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Generating an SSH Key Pair on UNIX and UNIX-Like Systems

Use the following procedure to generate an SSH key pair on UNIX and UNIX-like systems:

1. Run the ssh-keygen command.

   You can use the -t option to specify the type of key to create.

   For example, to create an RSA key, run:

   You can use the -t option to specify the length (bit size) of the key, as shown in the following example:

2. The command prompts you to enter the path to the file in which you want to save the key.

   A default path and file name are suggested in parentheses. For example: /home/user_name/.ssh/id_rsa. To accept the default path and file name, press Enter. Otherwise, enter the required path and file name, and then press Enter.

3. The command prompts you to enter a passphrase.

   The passphrase is not mandatory if you want to log in to an instance created using an Oracle-provided image. However, it is recommended that you specify a passphrase to protect your private key against unauthorized use.

   Note:

   With some images provided on Oracle Marketplace, the use of a passphrase might be mandatory.

4. When prompted, enter the passphrase again to confirm it.

The command generates an SSH key pair consisting of a public key and a private key, and saves them in the specified path. The file name of the public key is created automatically by appending .pub to the name of the private key file. For example, if the file name of the SSH private key is id_rsa, the file name of the public key would be id_rsa.pub.

Make a note of the path and file names of the private and public keys. When you create an instance, you must specify the SSH public key value. When you log in to an instance, you must provide the path to the corresponding SSH private key and you must enter the passphrase when prompted.

Generating an SSH Key Pair on Windows

You can generate an SSH key pair on a Microsoft Windows machine by using an application such as PuTTY. See the tutorial, Creating SSH Keys for Use with Oracle Cloud Services.