Testing Password Length Requirements: Reevaluating Common Techniques for Modern Applications

When developing applications, ensuring user passwords meet specific length requirements is a critical step in securing user data. A common requirement might be for a user to enter a password of at least 11 characters. However, simply applying traditional testing techniques such as Equivalence Class Partitioning (ECP), Boundary Value Analysis (BVA), or Error Guessing without considering the broader context of the application might not fully address the vulnerabilities.

Context and Challenges

The requirement that a password must be at least 11 characters places a focus on edge cases. For instance, how does the system handle inputs that are just 10 characters (below the minimum)? Exactly 11 characters (the minimum requirement)? Or inputs that have more than 11 characters (just above the minimum)? These edge cases can be effectively tested using Boundary Value Analysis (BVA).

Boundary Value Analysis (BVA)

Boundary Value Analysis focuses on testing at the edges of input ranges. This technique is particularly useful when dealing with boundary conditions, such as the minimum and maximum values for password lengths. For the password length requirement of at least 11 characters, the boundary values would be 10 and 11 characters.

10 characters: One character less than the minimum 11 characters: Exactly the minimum requirement 12 or more characters: One character more than the minimum

By generating test cases for these boundary values, testers can ensure that the system correctly handles inputs right at the boundary of the requirement. This helps in identifying potential issues early on, thereby ensuring the system behaves as expected within these limits.

Equivalence Class Partitioning (ECP)

Equivalence Class Partitioning can also be used to categorize inputs into partitions and test representative values from each partition. However, for this specific requirement, ECP might be less effective. While it can help in organizing test cases, it does not as effectively target the critical boundary conditions where the edge cases lie.

Error Guessing

Error Guessing is a technique based on the tester's intuition and experience to guess potential problem areas. While it can complement other techniques, it is not systematic and may not specifically target the boundary condition as effectively as BVA.

Reevaluating Testing Techniques for Modern Applications

While traditional testing techniques are valuable, they should not be blindly applied without considering the broader context. The phrase "11 characters" means little when you consider the full scope of potential issues that must be addressed:

Should passwords include alphanumeric characters? Are spaces allowed? Do special characters have to be included? Does the user receive a clear and helpful hint to use accepted characters? What is the happy path for legitimate users attempting to create a password? Are there any specific password formats or patterns that the product owner wants to avoid? What happens if the user attempts a "bad" password? Does the user receive a meaningful error message? What happens if the first attempt is bad, but the next attempt with an acceptable password is successful? How does the password get sent to the application? How is the password validation implemented? Is it possible to bypass the validation and send an "incorrect" password to the server?

Instead of adhering strictly to traditional techniques, it is important to think about the ways in which users, both good and bad, might interact with the application. Consider the various problems that could occur and identify potential issues before they become larger problems. Techniques like BVA are just one piece of the testing puzzle and should not bound you to specific methods if they do not directly address the underlying issues.

In conclusion, while traditional techniques such as BVA, ECP, and Error Guessing are useful, they should be part of a broader testing strategy that considers the full range of user behavior and potential vulnerabilities. By taking a more holistic approach, testers can ensure that their applications are secure and robust.