Read file from network location with credentials in asp.net code

Question

I want to read files from a folder that exists on the network.

When I try to access this folder manually (from run command giving a path like \\ABCServer\Documents ) it ask me for credentials (username and password). After giving the correct credentials I am able to access/read files.

When I try to read the same files from C# code in ASP.NET it gives me an error:

Login Failure: unkown username or bad password

How can I pass credentials via C# code during reading file?

Below is a part of the code that I am using:

Stream s = File.OpenRead(filePath);
byte[] buffer = new byte[s.Length];            
try
{
    s.Read(buffer, 0, (Int32)s.Length);
}            
finally 
{ 
    s.Close();
}

Note:

The code works fine
I'm using ASP.NET 4.0 with C#
IIS version is 7.5

sounds like you may want to look at using Impersonation.. if so checkout this stackoverflow posting with links http://platinumdogs.me/2008/10/30/net-c-impersonation-with-network-credentials/ — MethodMan, Dec 17 '12 at 18:48

score 4 · Accepted Answer · edited Jul 22 '15 at 20:41

4

This is from http://support.microsoft.com/kb/306158

public const int LOGON32_LOGON_INTERACTIVE=2;
public const int LOGON32_PROVIDER_DEFAULT=0;

WindowsImpersonationContext impersonationContext;

[DllImport("advapi32.dll")]
public static extern int LogonUserA(String lpszUserName,
    String lpszDomain,
    String lpszPassword,
    int dwLogonType,
    int dwLogonProvider,
    ref IntPtr phToken);

[DllImport("advapi32.dll", CharSet=CharSet.Auto, SetLastError=true)]
public static extern int DuplicateToken(IntPtr hToken,
    int impersonationLevel,
    ref IntPtr hNewToken);

[DllImport("advapi32.dll", CharSet=CharSet.Auto, SetLastError=true)]
public static extern bool RevertToSelf();

[DllImport("kernel32.dll", CharSet=CharSet.Auto)]
public static extern bool CloseHandle(IntPtr handle);

private bool impersonateValidUser(String userName, String domain, String password) {
  WindowsIdentity tempWindowsIdentity;
  IntPtr token=IntPtr.Zero;
  IntPtr tokenDuplicate=IntPtr.Zero;

  if(RevertToSelf()) {
    if(LogonUserA(userName, domain, password, LOGON32_LOGON_INTERACTIVE,
      LOGON32_PROVIDER_DEFAULT, ref token)!=0) {
        if(DuplicateToken(token, 2, ref tokenDuplicate)!=0) {
          tempWindowsIdentity=new WindowsIdentity(tokenDuplicate);
        impersonationContext=tempWindowsIdentity.Impersonate();
        if(impersonationContext!=null) {
          CloseHandle(token);
          CloseHandle(tokenDuplicate);
          return true;
        }
      }
    }
  }
  if(token!=IntPtr.Zero)
    CloseHandle(token);
  if(tokenDuplicate!=IntPtr.Zero)
    CloseHandle(tokenDuplicate);
  return false;
}

private void undoImpersonation() {
  impersonationContext.Undo();
}

edited Jul 22 '15 at 20:41

Holly

1,305
2
15
30

answered Dec 17 '12 at 20:05

Dan OConnell

217
1
8

LogonUserA(userName, domain, password, LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT, ref token)!=0 gives me error code '1326', when I enter the same credential manually then it works fine. – Ali Dec 18 '12 at 20:29
I hate saying this, but it ran fine on my machine. Are you sure the domain is right? I tried it with the good password and a bad one, worked with the good, failed with the bad. – Dan OConnell Dec 19 '12 at 04:08
Thanks for the edit weloytty, btw, did you used to work at AOL, I seem to remember a Bill Loytty(tho I thought it was spelled differently) when I was there – Dan OConnell Dec 19 '12 at 04:08
first of all thanks for your reply.server where files exists is part of other domain,for instance - if my system is part of DomainA and files that I have needed exists in system which is part of DomainB.I successfully access these files via run command as well as browser – Ali Dec 19 '12 at 17:28
Are you sending in the domain, or using "\\domain\user" for the user, I'd try both, sorry I don't have a separate domain to test right now. – Dan OConnell Dec 19 '12 at 19:34
got it,need to build trust between domains in case of different domains.[view](http://stackoverflow.com/questions/993418/logonuser-works-only-for-my-domain) thanks – Ali Dec 19 '12 at 19:35

score 1 · Answer 2 · edited May 23 '17 at 12:14

1

You can do this using impersonation. Here is a question and answers of how it is done.

edited May 23 '17 at 12:14

Community

1
1

answered Dec 17 '12 at 18:50

Mark Avenius

13,679
6
42
50

Read file from network location with credentials in asp.net code

2 Answers2

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