RE: MIC calculation discrepancy?

Hi Phil, it's been a while. Escaped the interops? I've seen the same thing
that you have with regards to MD5 but every once in a while I see MDN's with
bad MIC's returned for customers using SHA. If Michael is seeing different
MICs for every retransmission then it's probably his software but if it's
every once in a while I believe it could very well be iSoft. I'm still
trying to get data from customers to nail this down but once they
re-transmit and get a good MDN back they move on.

Tim
 
-----Original Message-----
From: Phil Arcuri [mailto:[email protected]] 
Sent: Wednesday, August 27, 2003 12:06 PM
To: Michael Milner; [email protected]
Subject: RE: MIC calculation discrepancy?


Michael,

We have many customers who trade with Walmart, and might be
able to help.  Walmart's AS2 vendor chose not to support MD5,
and we have seen very peculiar behaviour when messages signed
with MD5 are sent to Walmart.  Are you using MD5 in your test 
messages?  If not, someone in our Support group who regularly
handles issues with Walmart/AS2 communications can work with
you (at least for a little while...).  Can you provide a
copy of the test message sent to Walmart?

- Phil

Phil Arcuri, D.Phil.
Director, Desktop Applications Development
bTrade, Inc.
2324 Gateway Drive
Irving, TX 75063
972-580-2916 

-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Michael Milner
Sent: Wednesday, August 27, 2003 10:24 AM
To: [email protected]
Subject: MIC calculation discrepancy?



Hello, I am hoping someone can help me... we are
testing some in-house software to do AS2
communications, and we have had problems connecting to
Walmart. We can send signed and encrypted messages
just fine and we receive a proper MDN; however we are
not able to verify the Message Integrity Check
returned in Walmart's MDN. In particular if we sign,
encrypt, and send the same test message repeatedly we
get a different value for the MIC each time!

I am a bit confused as to how this could be, as RFC
3335 and the AS2 spec indicate that the MIC should be
calculated over the original EDI data and MIME header.
Moreover we have not had this issue connecting with
other servers. Is this a known issue with Wal-Mart's
EDI solution? Or am I doing something wrong?

Thank you!

Best regards,

Michael Milner


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