SSH key pairs can be used for secure login to Linux server with out prompting for password. Puttygen is a very useful key generator which can be used to generate key pairs for login to Linux node on cloud or on premise using putty utility. It uses the private key in ppk format to login.
Instances use an SSH key pair instead of a password to authenticate a remote user. A key pair file contains a private key and public key. You keep the private key on your computer and provide the public key every time you launch an instance.
To create key pairs, you can use a third-party tool such as OpenSSH on UNIX-style systems (including Linux, Solaris, BSD, and OS X) or PuTTY Key Generator on Windows.
Before You Begin
- If you already have an SSH-2 RSA key pair, you can use your existing pair and skip this step. Proceed to Choosing a Compartment.
- If you're using a Linux distribution, you probably already have the
ssh-keygen
utility installed. To determine if it's installed, typessh-keygen
on the command line. If it's not installed, you can download OpenSSH for UNIX from http://www.openssh.com/portable.html and install it. - If you're using Windows and you don't already have the PuTTY Key Generator, download it from http://www.putty.org and install it.
Creating a Key Pair
Creating an SSH Key Pair on the Command Line- Open a shell or terminal for entering the commands.
At the prompt, enter
ssh-keygen
and provide a name and passphrase when prompted.The keys will be created with the default values: RSA keys of 2048 bits.
Alternatively, you can type a complete ssh-keygen
command, for example:
Bharya telugu serial actress name list. The command arguments are shown in the following table:
Argument | Description |
---|---|
-t rsa | Use the RSA algorithm. |
-N '<passphrase>' | A passphrase to protect the use of the key (like a password). If you don't want to set a passphrase, don't enter anything between the quotes. A passphrase is not required. You can specify one as a security measure to protect the private key from unauthorized use. |
-b 2048 | Generate a 2048-bit key. You don't have to set this if 2048 is acceptable, as 2048 is the default. A minimum of 2048 bits is recommended for SSH-2 RSA. |
-C '<key_name>' | A name to identify the key. |
-f <path/root_name> | The location where the key pair will be saved and the root name for the files. |
- Find
puttygen.exe
in the PuTTY folder on your computer, for example,C:Program Files (x86)PuTTY
. Double-clickputtygen.exe
to open it. Specify a key type of SSH-2 RSA and a key size of 2048 bits:
- In the Key menu, confirm that the default value of SSH-2 RSA key is selected.
- For the Type of key to generate, accept the default key type of RSA.
- Set the Number of bits in a generated key to 2048 if it is not already set.
- Click Generate.
Move your mouse around the blank area in the PuTTY window to generate random data in the key.
When the key is generated, it appears under Public key for pasting into OpenSSH authorized_keys file.
- A Key comment is generated for you, including the date and time stamp. You can keep the default comment or replace it with your own more descriptive comment.
- Leave the Key passphrase field blank.
Click Save private key, and then click Yes in the prompt about saving the key without a passphrase.
The key pair is saved in the PuTTY Private Key (PPK) format, which is a proprietary format that works only with the PuTTY tool set.
You can name the key anything you want, but use the
ppk
file extension. For example,mykey.ppk
.Select all of the generated key that appears under Public key for pasting into OpenSSH authorized_keys file, copy it using Ctrl + C, paste it into a text file, and then save the file in the same location as the private key.
(Do not use Save public key because it does not save the key in the OpenSSH format.)
You can name the key anything you want, but for consistency, use the same name as the private key and a file extension of
pub
. For example,mykey.pub
.- Write down the names and location of your public and private key files. You will need the public key when launching an instance. You will need the private key to access the instance via SSH.
What's Next
Now that you have a key pair, continue on with Choosing a Compartment.
These protocols are all used to run a remote session on a computer, over a network. PuTTY implements the client end of that session: the end at which the session is displayed, rather than the end at which it runs.
In really simple terms: you run PuTTY on a Windows machine, and tell it to connect to (for example) a Unix machine. PuTTY opens a window. Then, anything you type into that window is sent straight to the Unix machine, and everything the Unix machine sends back is displayed in the window. So you can work on the Unix machine as if you were sitting at its console, while actually sitting somewhere else.
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What's New:
- Security fix: prevent a nefarious SSH server or network attacker from crashing PuTTY at startup in three different ways by presenting a maliciously constructed public key and signature.
- Security fix: PuTTY no longer retains the private half of users' keys in memory by mistake after authenticating with them.
- Revamped the internal configuration storage system to remove all fixed arbitrary limits on string lengths. In particular, there should now no longer be an unreasonably small limit on the number of port forwardings PuTTY can store.
- Port-forwarded TCP connections which close one direction before the other should now be reliably supported, with EOF propagated independently in the two directions. This also fixes some instances of port-forwarding data corruption (if the corruption consisted of losing data from the very end of the connection) and some instances of PuTTY failing to close when the session is over (because it wrongly thought a forwarding channel was still active when it was not).
- The terminal emulation now supports xterm's bracketed paste mode (allowing aware applications to tell the difference between typed and pasted text, so that e.g. editors need not apply inappropriate auto-indent).
- You can now choose to display bold text by both brightening the foreground colour and changing the font, not just one or the other.
- PuTTYgen will now never generate a 2047-bit key when asked for 2048 (or more generally n−1 bits when asked for n).
- Some updates to default settings: PuTTYgen now generates 2048-bit keys by default (rather than 1024), and PuTTY defaults to UTF-8 encoding and 2000 lines of scrollback (rather than ISO 8859-1 and 200).
- Unix: PSCP and PSFTP now preserve the Unix file permissions, on copies in both directions.
- Unix: dead keys and compose-character sequences are now supported.
- Unix: PuTTY and pterm now permit font fallback (where glyphs not present in your selected font are automatically filled in from other fonts on the system) even if you are using a server-side X11 font rather than a Pango client-side one.
- Bug fixes too numerous to list, mostly resulting from running the code through Coverity Scan which spotted an assortment of memory and resource leaks, logic errors, and crashes in various circumstances.
Legal Warning: Use of PuTTY, PSCP, PSFTP and Plink is illegal in countries where encryption is outlawed. I believe it is legal to use PuTTY, PSCP, PSFTP and Plink in England and Wales and in many other countries, but I am not a lawyer and so if in doubt you should seek legal advice before downloading it. You may find this site useful (it's a survey of cryptography laws in many countries) but I can't vouch for its correctness.
Use of the Telnet-only binary (PuTTYtel) is unrestricted by any cryptography laws.
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