| Class | Description | 
|---|---|
| CSRFTokenValidator | This is a utility class containing static methods for handling creation and
 validation of security tokens used for preventing from CSRF attacks. | 
| HMAC | A class to generate Hashed Message Authentication Codes. | 
| SessionSwap | SessionSwap, a class to handle secure data manipulations in a way
 consistent with SessionSwap from the perl codebase. | 
| Exception | Description | 
|---|---|
| CSRFTokenException | RuntimeException to indicate failure during validation of CSRF tokens. | 
| PermissionException | A RuntimeException indicating that the user has attempted something he or she does
 not have permissions for. | 
| SessionSwapTamperException | A given session swap token had an invalid signature |