Refactor XOR CSRF Token Encoding into Separate Encoder Class with Unit Tests #17969
      
        
          +257
        
        
          −65
        
        
          
        
      
    
  
  Add this suggestion to a batch that can be applied as a single commit.
  This suggestion is invalid because no changes were made to the code.
  Suggestions cannot be applied while the pull request is closed.
  Suggestions cannot be applied while viewing a subset of changes.
  Only one suggestion per line can be applied in a batch.
  Add this suggestion to a batch that can be applied as a single commit.
  Applying suggestions on deleted lines is not supported.
  You must change the existing code in this line in order to create a valid suggestion.
  Outdated suggestions cannot be applied.
  This suggestion has been applied or marked resolved.
  Suggestions cannot be applied from pending reviews.
  Suggestions cannot be applied on multi-line comments.
  Suggestions cannot be applied while the pull request is queued to merge.
  Suggestion cannot be applied right now. Please check back later.
  
    
  
    
Description
This PR refactors the XOR-based CSRF token encoding and decoding logic out of the XorCsrfTokenRequestAttributeHandler class into a new dedicated class named XorCsrfTokenEncoder.
Key Changes
Extracted XOR encode/decode logic into the XorCsrfTokenEncoder class with public methods
Updated XorCsrfTokenRequestAttributeHandler to delegate encoding and decoding to the new encoder
Introduced a CsrfTokenEncoder interface to define the encoding/decoding contract
Added comprehensive unit tests for XorCsrfTokenEncoder to ensure reliability
Supported injection of a custom SecureRandom instance for improved flexibility
Preserved existing behavior and encoding mechanism
This refactor improves code modularity and testability, making maintenance easier and future enhancements more straightforward.
Closes #17968