Microsoft Access 97 MDW files

Does anyone know if there is a document that describes the algorithm used to scramble the password found in Microsoft Access MDW files? I've tried my luck with the archives here, and on Google, and I don't believe that this is a topic that has been discussed.

I'm particularily concerned with the Password column in the MSysAccounts table. At first glance I can see only 64 bits of entropy:

Here is a snippet from two columns copied and pasted into notepad, one per line, saved, and then converted to hex:

fffedd2bb1bf52e1e4926952ad67f3d5e1e60d000a006952ad67f3d5e1e66952a d67f3d5e1e6

>From this I've guessed that "fffe" is a unicode header, which
gives me:

dd2bb1bf52e1e4926952ad67f3d5e1e60d000a006952ad67f3d5e1e66952ad67f 3d5e1e6

Since the rows are CR/LF delimited we get:

dd2bb1bf52e1e4926952ad67f3d5e1e6
0d000a00
6952ad67f3d5e1e66952ad67f3d5e1e6

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This file is also stored little-endian, so we get:

2bddbfb1e15292e4526967add5f3e6e1
526967add5f3e6e1526967add5f3e6e1

The first is a row that contains a password, the second row contains a password of "" (0 length string)

If we separate the rows where the data matches we get:

2bddbfb1e15292e4 526967add5f3e6e1
526967add5f3e6e1 526967add5f3e6e1

It seems that the LS = RS on the empty password line, and RS = RS between the two lines. I've tried putting in a single character password, but it seems to modify many bits in the LS. Based on this information, it seems that a 64-bit hash function is used to calculate the left side, and the right side is used to obfuscate the result of the function via XOR (which yeilds a result of 0 when LS = RS). I also presume that the value of obfuscating the results of the hash function is so that the output is not noticably predictable at a glance?

Does anyone have information that they can share to help the progression of this train of thought, or documentation to point me
in the right direction?

Thanks,
Derek Received on Tue Jun 17 17:47:30 2003

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