Contents
SSH connection with authentication using public key
Creation of public and private key pairs
Create a public/private key pair for a user connecting to the Linux server using OpenSSH.
Use ssh-keygen to create key pairs.
Creation of public/private key pairs is performed with remote login user privileges.
If you do not specify the destination and file name, id_rsa and id_rsa.pub will be created in /home/(user name)/.ssh/. On the way, enter the password for the key.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 |
# su - huong [huong@rocky~]$ /usr/bin/ssh-keygen -t rsa Generating public/private rsa key pair. Enter file in which to save the key (/home/huong/.ssh/id_rsa): [Enter] Created directory '/home/huong/.ssh'. Enter passphrase (empty for no passphrase): Password Enter same passphrase again: Again Password Your identification has been saved in /home/huong/.ssh/id_rsa. Your public key has been saved in /home/huong/.ssh/id_rsa.pub. The key fingerprint is: SHA256:/s3sLJJXH+7Ul01UDQplwwd/PkzQ6fqn7OmEWCen/6g huong@rocky The key's randomart image is: +---[RSA 3072]----+ | .o=oo.+| | o.+ooo| | ..o.o| | o= | | S o +oo| | . o.B.o+| | ....oo+o+| | o.o= =o+o| | o.oE=Xoo| +----[SHA256]-----+ |
1 |
$ cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys |
1 |
$ chmod 600 ~/.ssh/authorized_keys |
Save the created private key id_rsa to an appropriate location on windows using winSCP.
Start Winscp and click "New Session"
Host name : Server IP Address
Port number : SSH Port
User name : Server Login User
Password : Password for the same user
and then "Save".
Site name : Any name
Click "OK"
![](https://korodes.com/wp-content/uploads/2022/05/abc4ee692e8d523a6e67e53823c4028d.png)
After confirming the server, click "Login".
![](https://korodes.com/wp-content/uploads/2022/05/5337a463af46989de0d4cdcd3f2bea8a.png)
Click "Update" when the following screen appears
![](https://korodes.com/wp-content/uploads/2022/05/b0e75504c43c2dec9a5603379c9df40c.png)
Password of the logged-in user in the Password field
![](https://korodes.com/wp-content/uploads/2022/05/100978adf52d2777467003c4ddc335c2.png)
When connected, the right column is the server side and the left column is the PC (Windows) side.
Save the file "id_rsa" under /home/huong/.ssh on the server side to an appropriate location on Windows in the left column.
![](https://korodes.com/wp-content/uploads/2022/05/519270533f8142dce95588e29ab3d794.png)
Edit SSH configuration file
Edit the SSH configuration file to disable password authentication.
This time, instead of being an ordinary user, su - to become root.
1 2 3 4 5 6 7 |
$ su - Password: # vi /etc/ssh/sshd_config # Line 71 : Change to password authentication disabled PasswordAuthentication no # systemctl restart sshd |
How to connect with Tera Term
Start Tera Term, and select "File" menu "New connection"
![](https://korodes.com/wp-content/uploads/2022/05/a665f699dd994b53fffe9d6f0ef40826.png)
Host : Server IP Address
TCP port : SSH Port number
![](https://korodes.com/wp-content/uploads/2022/05/c1251b0fdd1def8a04f053e625d7a4e8.png)
If you get the following security warning "Replace...." and click "Continue".
![](https://korodes.com/wp-content/uploads/2022/05/2515e05dc3f751841e52139cdc53c3ec.png)
User name : Login User Name
Password : Password specified in the creation of a public/private key pair
Under "Use RSA/DSA/ECDSA/ED25519 key to log in", set "Private key file:" to "id_rsa" that you just saved in Windows. and click "OK".
![](https://korodes.com/wp-content/uploads/2022/05/560eab40d940a29d3b42587e6699d595.png)
Creating a private key using PuTTYgen
Start Winscp, select the appropriate server, and run Puttygen from "Tools".
Click "Load"
![](https://korodes.com/wp-content/uploads/2022/05/6b939ae51b37143f8e081e227bc17233.png)
Change the file type to [ All Files (*. *)] to read the private key id_rsa transferred from the Linux server.
The password is the password set in "Creating a public and private key pair" above
![](https://korodes.com/wp-content/uploads/2022/05/edd5c92218d4e538d5ecc61a0be164ef.png)
Click on "Save private key"
![](https://korodes.com/wp-content/uploads/2022/05/60dda6a69c9cdaa70a35c1d5b0f19aec.png)
Save the file with the extension ".ppk" in the same place as "id_rsa" saved earlier on the Windows side under the name "id_rsa.ppk".
Select the appropriate server and click "Edit"
Click on "Advanced"
Open the "Authentication" menu and specify "id_rsa.ppk" saved in Windows for "Private key file"
![](https://korodes.com/wp-content/uploads/2022/05/36497757c7297ff5f47021f59d4e273f.png)
Click "Save"
Click on "Login"
![](https://korodes.com/wp-content/uploads/2022/05/2b1ddb882ae31ad5b4ad29f2e3ba436a.png)
The password is the password set in "Creating a public and private key pair" above
![](https://korodes.com/wp-content/uploads/2022/05/e11b1bd8a4e89d286eb0564422f2841e.png)
When connecting with Tera Term
Use RSA/DSA/ECDSA/..." Specify "id_rsa.ppk" saved in windows in the "id_rsa.ppk" field.