[cups.general] Sharp MX3500N and user restrictions

[alet at librelogiciel.com]

Hi,

We've got a Sharp MX3500N copier/printer with PostScript option.

I'd like to make this printer available through CUPS.

Unfortunately user restrictions are in place, so in the native Windows
driver's print dialog box you must enter an username and password to be
allowed to print in color, and a different one for B&W.

Under MacOSX, the PPD file references manufacturer's plugins for these
and other settings, so it can be made to work just as fine as it works
from Windows.

But under GNU/Linux, even with the correct PPD file, it doesn't work
because the printer refuses the job (unknown user)

So I've captured a job coming from Windows, and modified the PPD file so
that the correct PJL settings for ACCOUNTLOGIN and ACCOUNTPASSWORD are
inserted into the print job.

The problem is this doesn't work with the login and password values
captured from the Windows print job, which are not in the clear but
encrypted, and doesn't work with clear text values either.

So I think the username and password which must be inserted into the PJL
statements is a combination of the username/password specified in the
printer's configuration, and of some other data (timestamp, job's size,
client hostname or whatever I don't know).

I'm pretty sure that the username and password present in a working
print job are a base64 encoding of an md5 hash, but md5 hashing the
username and/or password alone produce different final results, so
finally here's my question :

Does someone know how to compute these two values ACCOUNTLOGIN and
ACCOUNTPASSWORD, knowing the client's hostname, end user's name, and
username and password defined in the printer ?

Thanks in advance

PS : I've seen other people who had to enter an ID number instead of an
username and password and who succeeded to make this work with CUPS
because this information was passed in the clear in the PJL
settings. But if the approach is the same this is different because of
entryption.


Jerome Alet