irule to pass on User ID and Password

What is the authentication type (basic, ntlm, etc)? If you don't want to use source IP address, what component of the request would you want to use to know when to insert the credentials in a request?

For basic auth, you could insert the header using an iRule like this:

 
 when HTTP_REQUEST { 
  
     Check if some condition is true 
    if {$allow_access==1}{ 
  
        Insert the authorization header with the base64 encoded username:password 
       HTTP::header replace Authorization "Basic: dXNlcm5hbWU6cGFzc3dvcmQ=" 
    } 
 } 
 

Aaron