Accessing Third Party Network drive when using Azure Websites

Question

I am having problems trying to read a file that is stored on a network drive when hosting my website/request on a azure website.

The code works testing on a local machine and it also works on a Dedicated server that we have with another client and have full control of but it gets the following error when we try to read the file.

Access to the path '\\xxx.xxx.xxx.xxx\\abc\\abc.xml' is denied.

I wanted to know if Azure was locked down to prevent this behaviour that I didn't know about. Maybe ports closed or something.

The code I am using

if (impersonate.impersonateValidUser("username", "domain.com", "password"))
                    {
                        message = "impersonate ok";
                        if (!System.IO.File.Exists(file))
                        {
                            message = "no file";
                            impersonate.undoImpersonation();
                        }

                        using (StreamReader reader = File.OpenText(file))
                        {
                            message = "";
                            XmlSerializer deserializer = new XmlSerializer(typeof(TextModeSchema));
                            schema = (TextModeSchema)deserializer.Deserialize(reader);
                            reader.Close();
                        }
                    }

which is using a basic Impersonate class that we use in alot of places

public class Impersonate : IDisposable
    {
        public const int LOGON32_LOGON_INTERACTIVE = 2;
        public const int LOGON32_LOGON_NETWORK = 3;
        public const int LOGON32_LOGON_BATCH = 4;
        public const int LOGON32_LOGON_SERVICE = 5;
        public const int LOGON32_LOGON_UNLOCK = 7;
        public const int LOGON32_LOGON_NETWORK_CLEARTEXT = 8;
        public const int LOGON32_LOGON_NEW_CREDENTIALS = 9;


        public const int LOGON32_PROVIDER_DEFAULT    =0;
        public const int LOGON32_PROVIDER_WINNT35    =1;
        public const int LOGON32_PROVIDER_WINNT40    =2;
        public const int LOGON32_PROVIDER_WINNT50 = 3;

       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);

        public 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_NEW_CREDENTIALS,
                    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;
        }

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


        public void Dispose()
        {
            impersonationContext.Undo();
            GC.Collect();
        }
    }

If this is not allowed on azure, does anyone know of a way we can get around it without having to set up a full Virtual machine? I would like to keep with a azure website/webapp ideally.

Answer 1

Is this on a web role, worker role or a web application? I know that in case of a role, the remote host in your scenario has to be on the same private network than you role (It may also be true for a web app). Also, we had a similar scenario where we decided to use Azure Files which allows mounting shares on a role which you might want to try. http://blogs.msdn.com/b/windowsazurestorage/archive/2014/05/12/introducing-microsoft-azure-file-service.aspx