The AUTHZR_TOKEN_USER structure identifies the user associated with a token.

 typedef struct _AUTHZR_TOKEN_USER {
     AUTHZR_SID_AND_ATTRIBUTES User;
 } AUTHZR_TOKEN_USER;
  
  

User:  Contains an AUTHZR_SID_AND_ATTRIBUTES structure (section 2.2.3.8) representing the user associated with the access token.