Generate "Authorization: Basic authString"
in a HTTP request header to be forwarded to a server,
if it does not have an original Authorization field from a client.
The authString should be "userName:passWord".
The following special string stand for attributes of clients.
%u
-- user name got using Ident protocol
%h
-- host name of the client got from the socket
%i
-- host name of the network interface to the client
%I
-- like %i but use the value of "Host:" if given in HTTP
-- generated string by "CMAP=string:authgen:mapSpec"
%U
-- username part of client's [Proxy-]Authorization: username:password
%P
-- password part of client's [Proxy-]Authorization: username:password
Example:
When the firewall have two network interfaces and internal
and external hosts access from different interface, then
they can be distinguished by the name of interface.
A generated password is formatted as "passWord/%i" and
a DeleGate rejects incoming requests with an Authorization
field of such pattern. Thus forged password cannot pass the
DeleGate on the host "%i".