How to extract token from HTTP header?

[miberecz]

Hello Everyone,

I have a set of data with a lot of HTTP requests, where I want to extract only the tokens highlighted below. 

header=Authorization=Basic MmQyXXXXXXXXNDVjOTlkNTJlM2M0ZjA1MzVjYTI4ZGZkMzJmNTBlMjk=

2022-05-13 10:07:07,772 INFO  [io.undertow.request.dump] (default task-13778) 
----------------------------REQUEST---------------------------
               URI=/auth/realms/Public/protocol/openid-connect/token
 characterEncoding=null
     contentLength=29
       contentType=[application/x-www-form-urlencoded;charset=UTF-8]
            header=Accept=application/json, application/x-www-form-urlencoded
            header=Cache-Control=no-cache
            header=Pragma=no-cache
            header=User-Agent=Java/11.0.4
            header=Connection=keep-alive
            header=Authorization=Basic MmQyXXXXXNDVjOTlkNTJlM2M0ZjA1MzVjYTI4ZGZkMzJmNTBlMjk=
            header=Content-Type=application/x-www-form-urlencoded;charset=UTF-8
            header=Content-Length=29

I tried with the Field Extractor wizard, but with no luck. 

Can you please advise, how to achieve this? 

[ITWhisperer]

Try something like this

| rex "header=Authorization=Basic\s(?<auth>\S*)"