How To Fix SFTP Error "FATAL ERROR: No supported authentication methods available"

FATAL ERROR: No supported authentication methods available 

FTP (File Transfer Protocol) has been a standard for transferring files over the internet for decades. However, it has several security issues that make it vulnerable to hacking and data theft. To address these issues, the Secure FTP (SFTP) protocol was introduced. SFTP is a secure version of FTP that uses encryption to protect the data being transferred. It's widely used by web administrators and developers to securely upload and download files to their servers.

However, despite its security benefits, SFTP can sometimes be a source of frustration for users. One common issue that users face when using SFTP is the 'FATAL ERROR: No supported authentication methods available' error. This error occurs when the SFTP client is unable to authenticate with the server, either due to incorrect login credentials or because the server does not support the authentication method being used.

In this blog, we will delve into the cause of this error and provide a step-by-step guide on how to resolve it. Whether you are a web administrator, developer, or simply someone who uses SFTP to transfer files, this guide will help you understand and overcome this error. From troubleshooting your login credentials to configuring the SFTP server, we will cover all the necessary steps to resolve the 'FATAL ERROR: No supported authentication methods available' error.

If you are seeing the following issue when attempting to SFTP to your server while SSH is functioning normally, we have you covered.

FATAL ERROR: No supported authentication methods available (server sent: publickey)
Error:     Could not connect to server

This is because SFTP settings in SSH configurations are disabled. Don't worry, we can quickly resolve this problem. 

Step 1

 Please login to your server via SSH as root. You need to edit the SSH configuration using a editor(in my case nano)

nano /etc/ssh/sshd_config

Scroll down to the line 'PasswordAuthentication,' and make sure its value is 'yes.' This line is required to allow password-based login, if you are utilising SSH key authentication, leave it on 'no'. Also, check the line 'ChallengeResponseAuthentication' or 'KbdInteractiveAuthentication' is set to 'yes' as well.

Step 2

Once you've made your changes, use 'ctrl+x' to edit, then 'y' to save and 'enter' to use the same file name. You need to restart SSH service to take effect.

service ssh restart

Now, try to login and check if it's working as expected.

Conclusion

In conclusion, the 'FATAL ERROR: No supported authentication methods available' error can be a frustrating experience for SFTP users. However, with the right approach and understanding of the root cause, it is possible to resolve this error and get back to securely transferring files. By following the steps outlined in this guide, you can troubleshoot and resolve the issue, whether it's due to incorrect login credentials or a misconfigured SFTP server.

In this digital age, it's essential to have a secure method of transferring files over the internet. SFTP provides an excellent solution to this need, but as with any technology, it's not immune to errors and problems. By understanding the cause of the 'FATAL ERROR: No supported authentication methods available' error and following the steps to resolve it, you can get back to securely transferring files with confidence.