Downloading a File Protected by NTLM/SSPI Without Prompting For Credentials Using Python on Win32?

Question

I need to download a file on a corporate Sharepoint site using CPython. Existing codebase prevents me from using Ironpython without porting the code, so .NET's WebClient library is out. I also want to download the file without prompting the user to save and without prompting the user for network credentials. I tried other libraries, but they all had short-comings:

• urllib2 plus python-ntlm: requires user/pass to be provided
• COM automation of Internet Explorer: requires the user to click 'Save'
• subprocess using wget or cURL: couldn't get either to authenticate without requesting user/pass

I couldn't find anything in pywin32 that looks like it hooks into urllib2 or provides equivalent functionality. So, is there a way to download the file without requesting credentials and without prompting the user to click 'Save'?

Answer 1

I ended up finding some VB code from a Microsoft support page that uses a function from urlmon.dll I replicated it with a single line of ctypes code and it accomplished exactly what I needed it to do.

ctypes.windll.urlmon.URLDownloadToFileA(0,url,local_file_name,0,0)

• url is the location of the resource (in this case, an Excel file on a Sharepoint site)
• local_file_name is the local path and name of the file to be saved.

This passed credentials across the wire with no prompts.