How to Mask Password Input in Windows Terminal using C

Learn to effectively mask password input in your C programs running in the Windows Terminal while avoiding common pitfalls.
---
This video is based on the question https://stackoverflow.com/q/68151171/ asked by the user 'Ayush Kumar' ( https://stackoverflow.com/u/16327242/ ) and on the answer https://stackoverflow.com/a/68152100/ provided by the user 'Ayush Kumar' ( https://stackoverflow.com/u/16327242/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: masking password input in windows terminal in C

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/licensing
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Masking Password Input in Windows Terminal using C

When creating a program that requires user input, particularly for sensitive information like passwords, masking the input is essential. Without proper masking, users may feel uncomfortable typing their passwords knowing that anyone nearby could see what they are entering. In this guide, we'll explore a common issue faced when trying to implement this in C on a Windows Terminal and provide a well-structured solution to effectively mask password input.

Understanding the Problem

In the initial attempt to mask password input, the user faced several issues:

Backspace Issue: When pressing backspace at the beginning of the input, the printed prompt would show characters being deleted. This is undesired behavior as it confuses the user.

Key Press Detection: The implementation captured additional unwanted input when trying to exit the terminal using keys like Alt+ F4. Instead of simply cancelling the input, the additional key presses were being registered.

These issues are common when handling keyboard input directly in C, especially using functions like getch(). Therefore, we need a better approach to ensure the program behaves as expected.

An Improved Solution

After some troubleshooting and inspiration from existing C+ + code, we can implement a robust solution that tackles the above problems head-on. Here's how we can accomplish this step-by-step:

Key Features of the Revised Code

Input Handling: The code intelligently ignores whitespace and certain special key presses (like Esc and arrow keys).

Backspace Functionality: It handles the backspace key correctly by not allowing it to delete characters when no input is present.

Termination Keys: It properly terminates input when either Enter or Tab is pressed.

Masking: Whenever a character is input, the program displays an asterisk (*) to maintain confidentiality.

Code Implementation

Here’s the revised code that incorporates all these features:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Code

Header Inclusions: The program includes conio.h for console input functionalities and stdio.h for standard input/output operations.

Input Mechanism: It uses getch() to read a character at a time without displaying it immediately. This way, we can manage how it’s displayed (or not displayed) based on user actions.

Control Structures: The use of if-else statements effectively filters out unwanted inputs, ensuring only valid password characters are processed.

Character Masking: As each character is entered, an asterisk is printed in place of the actual character for visual confirmation of input without revealing sensitive information.

Conclusion

By following the above guidance, you can successfully implement a password input mechanism in your C programs that is both functional and user-friendly. With proper input handling, users can feel secure knowing their passwords aren't visible to someone looking over their shoulder.

If you have further questions or need clarification, feel free to reach out! Happy coding!

Видео How to Mask Password Input in Windows Terminal using C канала vlogize