Breaking down the SkyDrive process (Updated)

Posted: January 7, 2015 in hacking, Microsoft, SkyDrive, Windows, Windows 8
Tags: , , , , , , , ,

I’ve been underwhelmed by Microsoft’s response for documentation regarding SkyDrive and its inner workings. So, I’m on a mission to break things down. I’ll update this blog post as I find more information. As always, any info provided here is used at your own risk. I take no responsibility if you hose a system.

In case you want to see all the SkyDrive process settings:

C:\Users\<your account name>\AppData\Local\Microsoft\Windows\SkyDrive\settings

There are two files of interest:

global.ini and ClientPolicy.ini

There were some settings that surprised me in ClientPolicy.ini:

  • MaxFileSizeBytes = 2147483647 Is the 2 GB max file size mentioned on MSFT’s site? They should probably mention that, since all shipping systems are 64-bit and video files and ISOs can be pretty big.
    • Update 7-Jan-2015: It appears Microsoft has upped this to 10 terabytes.
  • Tier1MaxFileSizeBytes = 2147483647 These would be Microsoft’s Office file types
  • Tier1FileInclusionList = |doc|docm|docx|dot|dotm|dotx|odc|odp|ods|odt|pot|potm|potx|pps|ppsm|ppsx|ppt|pptm|pptx|rtf|vdw|vdx|vsd|vsdm|vsdx|vssm|vssx|vst|vstm|vstx|vsw|vsx|vtx|xla|xlam|xlm|xls|xlsb|xlsm|xlsx|xlt|xltm|xltx|xlw|
  • MaxItemsInOneFolder = 150000 I wonder if this caused my earlier sync problems, since I had more than 150K files in a folder, and then I deleted the folder. Maybe that messed up Microsoft’s storage system in the cloud? When I finally had a Microsoft technician look at my account, things magically started working a day later. I didn’t change anything, but what happened on their end?
  • MaxClientMBTransferredPerDay = 131072
    • Update 7-Jan-2015: It appears Microsoft has upped this to over 250000. Makes sense, given average home broadband speeds.
  • MaxClientRequestsPerDay = 500000 So what happens if you reach your limit?
  • NumberOfConcurrentUploads = 3 I’d rather have more, but it appears the next setting helps here, even though it’s not accessible via the SkyDrive app.
  • AllowUserOverrideOfConcurrentUploads = true
  • SyncTelemetryURL = http://wlepsi3.redmond.corp.microsoft.com/SyncDiag.ashx This one bothers me a bit. What is this URL tracking? And why isn’t it over SSL?
  • LowDiskSpaceLimitMB = 3072 If you want to override the low disk space limit… I’m going to try this on my Dell Venue Pro 8. Update: It worked! Yay!
    • Update 7-Jan-2015: It appears Microsoft has lowered this to 200MB. Much better for tablets! Of course, in the future, tablets will probably have 64GB, 128GB or more by default due to lowered storage costs.
  • AutomaticVerboseLoggingEnabled = true I wonder where the log file is. There’s one in this folder, but it’s used by the SkyDrive process. I’ll play with that in a VM so I don’t mess anything up Smile

I’m also curious as to why SkyDrive.exe can’t be opened in a decompiler. If I request it, the file system says the file doesn’t exist. Is c:\windows\system32\SkyDrive.exe simply a shim? Very interesting.

Breaking down the SkyDrive process, I found what appears to be additional command line parameters. I have not tested these as of yet.

/shutdown
/register
/unregister
/installperfcounters
/uninstallperfcounters
/background
/watson

Until next time… enjoy!

Best,

-Auri

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