Audit Trail Checksum type Comfort Panel

Hi,

I'm thinking of making my own Audit Viewer on WinCE Comfort Panel. There is one problem i do not know what Checksum calculation Audit Trail uses. I have build GUI and code to check other files, but Audit Trail add-on would be great.

Usually every encryption is mentioned e.g. SHA256, I cannot find this info on Audit Trail, maybe i just don't know how to look or maybe it is a big secret.

So does someone know how the checksum is calculated on Comfort Panel?

Hello K_Ohjus, 

K_Ohjus

Hi,

I'm thinking of making my own Audit Viewer on WinCE Comfort Panel. There is one problem i do not know what Checksum calculation Audit Trail uses. I have build GUI and code to check other files, but Audit Trail add-on would be great.

Usually every encryption is mentioned e.g. SHA256, I cannot find this info on Audit Trail, maybe i just don't know how to look or maybe it is a big secret.

So does someone know how the checksum is calculated on Comfort Panel?

just a hint, there is already an example for showing the Audit Trail on a panel:

WinCC Audit Trail Filter (filtering the operator actions on the SIMATIC Panel)

Relating the checksum calculation, it's a Siemens secret in order to prevent one modifies the file and also cheats the corresponding checksum which would make the recording non-compliant.

On the WinCC-DVD there is, besides the Audit Viewer, a tool to proof the checksum. But I never used that on a panel, only on a PC.

Regards,

Frink 

Hi Frink,

Thanks for the info, i have screen in WinCC(TIA) for viewing Audit Trail files. I have to check that link and project for improvements to my viewer.

Reason for my WinCE viewer is that it works with different manufactures HMI e.g. Rockwell, also i like using list box for file viewing, it is fast and looks good enough. Siemens PDFgenerating is notoriously slow, internet explorer looks like.. and AB FTW ME does not have any file handling.

I have other files with checksum, nothing fancy only fletcher's 16 and 32. I can view those and calculate file integrity, Audit would have been nice add to that.

Still i cannot understand what is the harm if i know encrypting method. Of course i can make line with same checksum easily, but line would not make any sense. And if i had proper skills to make line that is like original, but tampered, i would have skills to pull out the calculating method my self.  

Edit

And yes AB's or other manufacturers Audit checksum is most probably not the same as Siemens.