Method-level security in Spring Boot - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is method-level security in Spring Boot?

Method-level security in Spring Boot means protecting individual methods in your code so only authorized users can run them. It controls access right where the action happens.

beginner

Which annotation is commonly used to secure methods by roles in Spring Boot?

The @PreAuthorize annotation is used to specify security rules before a method runs, like checking if a user has a certain role.

intermediate

How do you enable method-level security in a Spring Boot application?

You enable method-level security by adding @EnableMethodSecurity to a configuration class. This tells Spring to check security annotations on methods.

intermediate

What does @Secured annotation do in Spring Boot?

@Secured restricts method access to users with specific roles. It is simpler than @PreAuthorize but less flexible.

advanced

Why is method-level security useful compared to URL-based security?

Method-level security protects the actual business logic, so even if someone bypasses the web layer, they can't run protected methods. It adds a strong safety net.

Which annotation enables method-level security in Spring Boot?

A @EnableWebSecurity

B @EnableMethodSecurity

C @EnableGlobalMethodSecurity

D @EnableSecurity

Starting with Spring Security 6, @EnableMethodSecurity is used to enable method-level security.

What does @PreAuthorize("hasRole('ADMIN')") do?

A Allows only users with ADMIN role to run the method

B Prevents ADMIN users from running the method

C Runs the method before authorization

D Logs the ADMIN role before method execution

@PreAuthorize checks the user’s roles before allowing method execution.

Which annotation is simpler but less flexible than @PreAuthorize for method security?

A @Secured

B @RolesAllowed

C @PostAuthorize

D @PermitAll

@Secured only checks roles and is less flexible than @PreAuthorize which supports SpEL expressions.

Where do you place method-level security annotations?

A On entity classes

B Only on controller classes

C Only on configuration classes

D On service or controller methods

Method-level security annotations go on the methods you want to protect, often in service or controller classes.

Why use method-level security in addition to URL security?

A To avoid writing any URL security

B To speed up the application

C To protect business logic even if URL security is bypassed

D To allow all users access

Method-level security adds a second layer of protection directly on the code that does the work.

Explain how to secure a method in Spring Boot using annotations.

Think about what you add to your config and what you add to your methods.

Describe the benefits of method-level security compared to only URL-based security.

Consider what happens if someone tries to call methods without going through the web.

Practice

1. What is the main purpose of using @PreAuthorize in Spring Boot method-level security?

easy

A. To log method execution time

B. To restrict access to a method based on user roles or permissions

C. To automatically retry failed method calls

D. To inject dependencies into a method

Solution

1. Step 1: Understand the role of @PreAuthorize

   @PreAuthorize is an annotation used to secure methods by specifying access rules based on roles or permissions.

2. Step 2: Identify the correct purpose

   It restricts method access to users who meet the specified security expression, such as having a certain role.

3. Final Answer:

   To restrict access to a method based on user roles or permissions -> Option B

4. Quick Check:

   Method-level security = restrict access [OK]

Hint: Remember: @PreAuthorize controls who can call a method [OK]

Common Mistakes:

• Confusing @PreAuthorize with logging or retry mechanisms
• Thinking it injects dependencies
• Assuming it runs code before method execution without security checks

2. Which of the following is the correct syntax to restrict a method to users with role 'ADMIN' using @PreAuthorize?

easy

A. @PreAuthorize("checkRole('ADMIN')")

B. @PreAuthorize("hasPermission('ADMIN')")

C. @PreAuthorize("isUser('ADMIN')")

D. @PreAuthorize("hasRole('ADMIN')")

Solution

1. Step 1: Recall the correct expression for role checking

   The correct Spring Security expression to check a role is hasRole('ROLE_NAME').

2. Step 2: Match the syntax

   @PreAuthorize("hasRole('ADMIN')") uses hasRole('ADMIN'), which is the standard and correct syntax.

3. Final Answer:

   @PreAuthorize("hasRole('ADMIN')") -> Option D

4. Quick Check:

   Role check syntax = hasRole('ROLE') [OK]

Hint: Use hasRole('ROLE') inside @PreAuthorize for role checks [OK]

Common Mistakes:

• Using hasPermission instead of hasRole for roles
• Using non-existent expressions like isUser or checkRole
• Missing quotes or wrong method names

3. Given the method below, what will happen if a user without the 'USER' role calls getUserData()?

@PreAuthorize("hasRole('USER')")
public String getUserData() {
    return "User Data";
}

medium

A. The method returns null

B. The method returns "User Data" normally

C. AccessDeniedException is thrown and method is not executed

D. The method executes but logs a warning

Solution

1. Step 1: Understand the effect of @PreAuthorize with hasRole

   The annotation blocks method execution if the user does not have the required role.

2. Step 2: Identify the behavior when role is missing

   Spring Security throws an AccessDeniedException and prevents the method from running.

3. Final Answer:

   AccessDeniedException is thrown and method is not executed -> Option C

4. Quick Check:

   Missing role = AccessDeniedException [OK]

Hint: No role? Method blocked with AccessDeniedException [OK]

Common Mistakes:

• Thinking method returns null instead of throwing exception
• Assuming method runs but logs warning
• Believing method returns data regardless of role

4. Identify the error in the following method-level security annotation:

@PreAuthorize("hasRole(ADMIN)")
public void deleteUser() {
    // delete logic
}

medium

A. Missing quotes around 'ADMIN' in hasRole expression

B. Method should return a value, not void

C. Annotation should be @PostAuthorize instead of @PreAuthorize

D. No error, the code is correct

Solution

1. Step 1: Check the syntax of hasRole expression

   The role name must be a string inside quotes, like hasRole('ADMIN').

2. Step 2: Identify the missing quotes

   The code uses hasRole(ADMIN) without quotes, causing a syntax error.

3. Final Answer:

   Missing quotes around 'ADMIN' in hasRole expression -> Option A

4. Quick Check:

   Role names need quotes in hasRole [OK]

Hint: Always put role names in quotes inside hasRole() [OK]

Common Mistakes:

• Forgetting quotes around role names
• Confusing @PreAuthorize with @PostAuthorize
• Thinking void methods cannot be secured

5. You want to secure a method so that only users with role 'ADMIN' or with permission 'WRITE_PRIVILEGE' can access it. Which @PreAuthorize expression correctly implements this?

hard

A. @PreAuthorize("hasRole('ADMIN') or hasPermission('WRITE_PRIVILEGE')")

B. @PreAuthorize("hasRole('ADMIN') && hasPermission('WRITE_PRIVILEGE')")

C. @PreAuthorize("hasRole('ADMIN') xor hasPermission('WRITE_PRIVILEGE')")

D. @PreAuthorize("hasRole('ADMIN') and hasPermission('WRITE_PRIVILEGE')")

Solution

1. Step 1: Understand the requirement for access

   The method should allow access if the user has either the 'ADMIN' role or the 'WRITE_PRIVILEGE' permission.

2. Step 2: Choose the correct logical operator

   The logical OR operator or allows access if either condition is true, matching the requirement.

3. Step 3: Verify syntax correctness

   @PreAuthorize("hasRole('ADMIN') or hasPermission('WRITE_PRIVILEGE')") uses or and correct method calls with quotes, making it valid.

4. Final Answer:

   @PreAuthorize("hasRole('ADMIN') or hasPermission('WRITE_PRIVILEGE')") -> Option A

5. Quick Check:

   Use 'or' to allow either role or permission [OK]

Hint: Use 'or' to combine role and permission checks [OK]

Common Mistakes:

• Using 'and' instead of 'or' when either condition suffices
• Using '&&' which is invalid in SpEL expressions
• Confusing xor with or logic