ISAPI Extension cannot write temp files [Answered]RSS

6 replies

Last post Mar 11, 2019 10:34 AM by RolandSmith

  • ISAPI Extension cannot write temp files

    Mar 10, 2019 03:05 AM|RolandSmith|LINK

    I have two Windows 10 Home computers. On my laptop I developed an ISAPI Extension (in regular C) which among other things writes data to a temp file.

    Everything works fine on the laptop. In fact it worked the first time. Now I am trying to get it setup on the other computer and the file write feature isn't working.

    I have a custom Application Pool using ApplicationPoolIdentity. I have tried writing the file to several different locations and have given permissions to IUSR but I still can't write the file. I've tried the system temp folder, C:\Temp, and others.

  • Re: ISAPI Extension cannot write temp files

    Mar 10, 2019 05:57 AM|lextm|LINK

    Lex Li
    https://lextudio.com
    ---------------------------
    This posting is provided "AS IS" with no warranties, and confers no rights.
  • Re: ISAPI Extension cannot write temp files

    Mar 10, 2019 12:49 PM|RolandSmith|LINK

    Yes it is and that link does not say anything about it.

    On my laptop where it is working, I am able to write to folders that I have not made any changes to security. On the one that does not work, I started with C:\Windows\Temp then tried C:\Temp.

    There must be some other reason why it works on one and not the other.

  • Re: ISAPI Extension cannot write temp files

    Mar 10, 2019 04:23 PM|lextm|LINK

    RolandSmith

    Yes it is and that link does not say anything about it.

    For example, if you create an application pool with the name "MyNewAppPool," a security identifier with the name "MyNewAppPool" is created in the Windows Security system.

    Lex Li
    https://lextudio.com
    ---------------------------
    This posting is provided "AS IS" with no warranties, and confers no rights.
  • Re: ISAPI Extension cannot write temp files

    Mar 10, 2019 11:42 PM|RolandSmith|LINK

    I've already tried assigning security on folders to the custom AppPool name. On the laptop where writing files works, I didn't have to do anything to get it to work, it just worked perfectly the first try.

    There must be something else missing. I first tried C:\Windows\Temp, then I created C:\Temp, then I tried the folder where the ISAPI dll is installed under C:\Program Files (x86). I've tried assigning write access to IUSR, IIS_USRS, and the AppPool name.

  • Re: ISAPI Extension cannot write temp files

    Mar 11, 2019 02:22 AM|lextm|LINK

    There is something called Process Monitor, https://docs.microsoft.com/en-us/sysinternals/downloads/procmon 

    Lex Li
    https://lextudio.com
    ---------------------------
    This posting is provided "AS IS" with no warranties, and confers no rights.
  • Re: ISAPI Extension cannot write temp files

    Mar 11, 2019 10:34 AM|RolandSmith|LINK

    As it turns out, there was a missing dll in the ISAPI extension's runtime folder. It wasn't effecting the output in the web browser so I didn't notice earlier.

    Thanks!