[IPP] Proper encoding to be used in "job-password" when "job-password-encryption" is not "none"

[IPP] Proper encoding to be used in "job-password" when "job-password-encryption" is not "none"

Michael Sweet msweet at apple.com
Mon Apr 24 20:04:54 UTC 2017


Smith,

Yes, that is correct (although for plain-text job-password values are typically 4 to 6 digit PINs...)

> On Apr 24, 2017, at 3:40 PM, Kennedy, Smith (Wireless Architect) <smith.kennedy at hp.com> wrote:
> 
> Thanks Mike! So to put this all together:
> 
> 	• RFC 8011 section 5.1.11 defines octetString as being simply a collection of octets
> 	• "job-password" is defined in PWG 5100.11 as "job-password (octetString(255))" which means its value will be raw octets
> 	• If "job-password-encryption" is "none" then there is no hashing, so presumably the plain octets are passed along (which is a bad security choice and also makes it possible for encoding confusion in the absence of "job-password-repertoire")
> 	• If "job-password-encryption" is one of the other keywords identifying a particular hashing algorithm, then the raw octets of the out put of that hashing algorithm are to be used.
> 
> Did I get that right?
> 
> Smith
> 
> 
> 
>> On Apr 21, 2017, at 4:12 PM, Michael Sweet <msweet at apple.com> wrote:
>> 
>> Smith,
>> 
>> The octetString syntax is a BLOB type, so the raw MD5 bytes are transferred, not the ASCII representation.
>> 
>>> On Apr 21, 2017, at 1:28 PM, Kennedy, Smith (Wireless Architect) <smith.kennedy at hp.com> wrote:
>>> 
>>> Greetings,
>>> 
>>> Given the following scenario:
>>> 	• An IPP Printer has reported via Get-Printer-Attributes:
>>> 		• "job-password-supported" = 32
>>> 		• "job-password-encryption-supported" = 'none', 'md5'
>>> 		• (going to ignore "job-password-repertoire-configured" and "job-password-length-supported" for now...)
>>> 	• An IPP Client acquires from the User a job password "beeblebrox"
>>> 
>>> If the Client chooses 'none', then it should send in a Validate-Job operation
>>> 
>>> "job-password-encryption" = 'none'
>>> "job-password" = 'beeblebrox'
>>> 
>>> However, if the Client chooses 'md5', how does it encode the md5 hash octets? Does it encode it as hex-ascii in 32 octets like so?
>>> 
>>> "job-password-encryption" = 'none'
>>> "job-password" = '3f73fde3af41b6a50c84a75f84892b85'
>>> 
>>> Or since 'job-password' is defined in 5100.11 as "job-password (octetString(255))", is it reasonable for it to provide the raw binary value? I cannot find any statement in PWG 5100.11, RFC 8010, or wp-job-password-repertoire-20160101.pdf that makes this clear. Is the Printer expected to handle both scenarios?
>>> 
>>> Thoughts?
>>> 
>>> Smith
>>> 
>>> /**
>>>    Smith Kennedy
>>>    Wireless Architect - Client Software - IPG-PPS
>>>    Standards - IEEE ISTO PWG / Bluetooth SIG / Wi-Fi Alliance / NFC Forum / USB IF
>>>    Chair, IEEE ISTO Printer Working Group
>>>    HP Inc.
>>> */
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> ipp mailing list
>>> ipp at pwg.org
>>> https://www.pwg.org/mailman/listinfo/ipp
>> 
>> _________________________________________________________
>> Michael Sweet, Senior Printing System Engineer
>> 
> 

_________________________________________________________
Michael Sweet, Senior Printing System Engineer



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