Enabling Password Authentication

For accessing the SSH server, password authentication is a crucial step. A solution for fixing the permission denied error is to enable password login in the sshd_config file on Linux systems.

A Step-by-step process for it is:

Step 1:

Open the sshd_config file in a text editor, popular and common text editor includes vi, vim etc. for linux based systems. An example of opening the file is given below.

sudo nano /etc/ssh/sshd_config

Step 2: After opening the file, find the “PasswordAuthentication” line in the text editor and ensure that the the line ends with yes. Shown in Screenshot below.

Step 3:

Also in the file, check for “ChallengeResponseAuthentication” and disable it with writing no.

If lines are commented out, remove the hash sign # to uncomment them.

Step 4: Save the file and exit. In case of using Nano type Ctrl+S and Ctrl+X to save and exit.

Step 5: Restart the SSH service by typing the following command:

sudo systemctl restart sshd

SSH, also known as Secure Shell, is a commonly used method for securely sending commands to a computer network over an unsecured computer network. It uses a cryptographic network protocol for authenticating and encrypting connections between devices. SSH allows for tunneling, or port forwarding, which allows the transfer of data packets across networks. It was developed as a replacement for other unsecured and vulnerable protocols like telnet for seamless solutions for remote access, file transfer, and command-line execution.

SSH operates generally on a client-server architecture, in which a server program accepts or rejects incoming connections, and a client program requests the server for information. Typically, the default port of SSH is 22.

SSH uses public key cryptography to authenticate the remote computer, or, if necessary, allows it to authenticate the server. When a public-private key is generated by the user, authentication is performed when the key pair is generated, and the session will be opened with any password input from the client.