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Reading a file into a buffer from in asp.net: error "Logon failure: unknown user name or bad password."

Hello experts!
We are facing an interesting problem.
We have some tiff image files located on a remote shared folder, say
\\172.23.45.66\Shared\Images
Only specific logins are given access to this folder.
Now, on my webpage, if I place an image control, and set its src value as follows:
myImg.Src = @"\\172.23.45.66\Shared\Images\tmpin.jpg";"

Then the code works and the image is displayed.
But, If we try to read the image into a buffer as follows:

byte[] buf = null;
System.IO.FileStream fs = new System.IO.FileStream(myImg.Src, System.IO.FileMode.Open, System.IO.FileAccess.Read);

buf = new byte[fs.Length];
fs.Read(buf, 0, buf.Length);
fs.Close();

then we get the following error:
"Logon failure: unknown user name or bad password. "

It is very important that we load the file into a buffer.
So, can some one suggest what could be the problem and how it can be solved?
Note that it is not possible for us to create additional shares or virtual Web folders for the file directory, because the address can be anything that the user has rights to: it is not necessarily one single folder.
So, we are looking for a generic solution to load a file into a buffer from an ASP .net page if the current windows user has rights to access the folder.
Looking forward to your help.
Thanks,
...Shu

AerosSaga

Dim r As New StreamReader(file1.PostedFile.InputStream())
Dim strBuffer As String = r.ReadToEnd

'DO SOMETHING HERE WITH strBuffer

r.Close()

AerosSaga

<form runat="server" enctype="multipart/form-data" ID="Form2">
<P>
<input type="file" id="file1" runat="server" NAME="file1">
</P>
<P>
<asp:Button id="btn1" runat="server" text="Upload" onclick="upload" />
</P>
</form>

--------------------------------------------------------------------------------------

Imports System.Data
Imports System.Data.SqlClient

Public Sub Upload(ByVal sender As Object, ByVal e As System.EventArgs)
Dim b(file1.PostedFile.InputStream.Length - 1) As Byte

file1.PostedFile.InputStream.Read(b, 0, file1.PostedFile.InputStream.Length)

Dim con As New SqlConnection(ConfigurationSettings.AppSettings("ConnectionStringSQL"))

Dim sql As String = "INSERT INTO MY_TABLE(MyID, DATABLOB) VALUES(1,@BlobData) "
Dim cmd As New SqlCommand(sql, con)

Dim parmBlob As New SqlParameter("@BlobData", SqlDbType.VarBinary, _
             b.Length, ParameterDirection.Input, False, 0, _
             0, Nothing, DataRowVersion.Current, b)

cmd.Parameters.Add(parmBlob)

con.Open()
cmd.ExecuteNonQuery()
con.Close()
End Sub

Aeros

praneetha

System.IO.FileStream fs = new System.IO.FileStream(@"\\172.23.45.66\Shared\Images\tmpin.jpg", System.IO.FileMode.Open, System.IO.FileAccess.Read);

try hardcoding it for a while...

also try (@"\\172.23.45.66\\Shared\\Images\\tmpin.jpg",

ASKER CERTIFIED SOLUTION

jnhorst

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snehanshu

ASKER

jnhorst,
Thanks for your comment.
Your comment helped us understand the problem and we have made changes to the design based on this understanding.
Thanks again,
...Shu

jnhorst

Glad to help.

John

snehanshu

ASKER

John,
May I ask a follow-up question please?
If I want to use option 3, can you tell me how to do it?
I would like to take take the windows username and password from a database and execute the file access code under that user (security context or whatever it is called).
I know that for windows based application, we have APIs to impersonate a certain user and execute parts of code as a different user. Are there any web-equivalents of this: that only certain part of my code is executed as a partucluar username/password that I know (have as string variables)?

...Shu

jnhorst

You can do this (having certain code running under a particular user's account) in a COM+ application that you instantiate in your web app, but I have not done this in .NET, only back in old school asp. But if you want to use a certain account for a web app (the whole app), you can do this:

<identity impersonate="true" username="userslogin" password="password" />

I do not like doing this (putting secure info in a clear text file that exists on the server) but it can be done.

John

snehanshu

ASKER

Thanks again John!
We will try this.
...Shu

Reading a file into a buffer from in asp.net: error &quot;Logon failure: unknown user name or bad password.&quot;

Reading a file into a buffer from in asp.net: error "Logon failure: unknown user name or bad password."