SharePoint service account can't access its own temp directory

Question

I have a feature with a an event receiver that have to uncompress an archive (actually an Infopath Form), patch some data and recompress the archive (using Cab compression).

In order to "properly" clean up files, I have written this code :

private void FixArchive(SPWeb web, SPSite site)
{
    var myFile = web.GetFile("/pathtofile.xsn");

    var tempFolder = Path.Combine(Path.GetTempPath(), "tempFolder");
    var extractedPath = Path.Combine(tempFolder, "tempExtracted");
    var extractedTemplate = Path.Combine(tempFolder, myFile.Name);
    var extractor = new CabLib.Extract();
    var compactor = new CabLib.Compress();
    var manifestPath = Path.Combine(extractedPath, "manifest.xsf");
    try
    {
        Directory.CreateDirectory(tempFolder);
        Directory.CreateDirectory(extractedPath);
        File.WriteAllBytes(extractedTemplate, myFile.OpenBinary());
        extractor.ExtractFile(extractedTemplate, extractedPath);
        var manifestContent = File.ReadAllText(manifestPath);

        // Patch the file

        File.WriteAllText(manifestPath, newContent);
        compactor.CompressFolder(extractedPath, extractedTemplate, "*.*", true, true, 0);
        myFile.SaveBinary(File.ReadAllBytes(extractedTemplate));
    }
    catch
    {
        throw;
    }
    finally
    {
        if (Directory.Exists(tempFolder)) Directory.Delete(tempFolder, true);
    }
}

this code is working on dev computer, but not on production server.

In the ULS Logs I can see :

Feature receiver assembly 'MyProject, Version=1.0.0.0, Culture=neutral, PublicKeyToken=c02e9cbf6dab9cb0', class 'MyProject.MyEventReceiver', method 'FeatureActivated' for feature 'bc8d119e-6308-4292-9cab-f381ee9b35fe' threw an exception: System.UnauthorizedAccessException: Access to the path 'C:\Users\myserviceaccount\AppData\Local\Temp\tempFolder' is denied.

How is it possible that a service account can't create in its own temporary folder?

Is it the correct place to deal with temp files?

PS: of course, I check that the service account has full control on its temp directory

[EDIT] I don't why, but if I specify another inexisting folder (c:\test for example) instead of Path.GetTempPath(), the code works as expected...

Answer 1

It is possible that there is already a lock on the folder if it didn't finish successfully on a previous run as you are always using the same folder name. Try generating a new folder name using a Guid for example and clean that up so each time the code runs it is dealing with a unique folder.

Answer 2

To solve my issue, I have to specify another folder than the %temp% directory. I'm suspecting a weird setting in the user permission somewhere in the folder hirearchy to the %temp% leaf directory.