Reading in Login info from outside

[ldpfrog]

I am currently writing a very simple encryption program for my friends and myself. I'm still learning VB, but am very familiar with programming itself. This is all irrelevant though, because this technique could be applied to any program which requires logging in.

I would like to be able to make a file (just a basic text file or spreadsheet to start would be fine) with Usernames and Passwords listed which will be accepted into my program. I currently just use If statements for two or three users, but will eventually probably distribute this to more of my friends, in which it would be much easier to host some sort of file for the program to connect to and read from.

I understand how to use the Login information, I am just not familiar with reading in information with VB. Once that is working I'd also like a suggestion as to how I could make it so only the program (or some sort of password protection) could access the login information file.

If we get this far, I would also like to be able to host it (which I can do) and have my program read from it on the web, so I could just change the file from my computer and it would work with whoever is using the software.

Thanks alot!
Frog

[Killer42]

If you have a look at the "Index of articles" at the top of the VB forum, there are links to a couple of samples showing how to read a text file in VB.

I don't know how you can restrict access to the file, but one simple precaution would be to store the passwords in their encrypted form. That way, if someone edits the file, unless they know your encryption method, the most they can do is to stop it working by messing up the stored details. If you encrypt the entire file contents, or at least include some sort of checksum, then your program could detect that it has been modified and refuse to run.

[ldpfrog]

I did see that but I don't understand how to use it. It essentially hands you a chunk of code and doesn't tell you how to use it

I have also been looking online and many are saying to use ADO, where you would use excel as opposed to a text file. I have been screwing around with this with no success =/.

[danp129]

I did see that but I don't understand how to use it. It essentially hands you a chunk of code and doesn't tell you how to use it

I have also been looking online and many are saying to use ADO, where you would use excel as opposed to a text file. I have been screwing around with this with no success =/.

Here's the article's code with the sub renamed (read makes more sense than dump) and an example to call it, and also a comment in the code. If you actually test the code with a file, it will be more apparent what's going on.

Private Sub Command1_Click()
    ReadFile_V01 ("c:\test.txt")
End Sub
 
 
Public Sub ReadFile_V01(ByVal FileName As String)
  Dim FileNo As Long
  Dim LineNo As Long
  Dim LineText As String
 
  FileNo = FreeFile ' Get next available file number.
 
  Open FileName For Input Access Read Shared As #FileNo
  Do Until EOF(FileNo) ' Repeat until end of file...
    Line Input #FileNo, LineText ' Read a line from the file.
 
 
    'put your code here to deal with the current line of text
    LineNo = LineNo + 1
    Debug.Print Format(LineNo, "00000"); ": "; LineText
 
 
 
    DoEvents ' Allow Windows to handle other tasks.
  Loop
  Close #FileNo
End Sub
 

If you want the password file hosted on a website you can use something like this to download the file:

Option Explicit
Private Sub Command1_Click()
    Dim sHTML
    sHTML = RequestText("http://news.google.com/")
 
    msgbox sHTML
 
End Sub
 
Private Function RequestText(sURL, Optional sMethod = "POST")
    'You may have caching issues using GET
    Dim XMLHTTP
    Set XMLHTTP = CreateObject("microsoft.XMLHTTP")
    sMethod = UCase(sMethod)
    XMLHTTP.Open sMethod, sURL, False
    XMLHTTP.send (Null) '"x=x"
    RequestText = XMLHTTP.responseText
    Set XMLHTTP = Nothing
End Function

[Killer42]

I did see that but I don't understand how to use it. It essentially hands you a chunk of code and doesn't tell you how to use it

I have also been looking online and many are saying to use ADO, where you would use excel as opposed to a text file. I have been screwing around with this with no success =/.

Hm... ADO and Excel... interesting. I haven't seen it done, but that doesn't prove anything I suppose. I guess both Excel and Access have the advantage of supporting some security measures.

As for the samples, yes they really are just code snippets for people to play with. We don't have anything much in the way of tutorials as yet. There are heaps of VB tutorials available on the web, though. However, let's assume you had a text file with a bunch of user IDs, each one followed on the next line by an encrypted password. Here's a sample I threw together which will prompt you for the name of the file then invoke a little "black box" function to return an array of user IDs and encrypted passwords from it.

This is the complete code module for the function...

Option Explicit
 
Public Type UserStuff
  ID As String
  Psw As String
End Type
 
Public Function GetUserDetailsFromFile(ByVal FileName As String) As UserStuff()
  Dim FileNo As Long
  'Dim LineNo As Long
  Dim LineText As String
  Dim TempUser() As UserStuff
  Dim UserNo As Long
  'Dim TempPsw() As String
 
  FileNo = FreeFile ' Get next available file number.
 
  Open FileName For Input Access Read Shared As #FileNo
  Do Until EOF(FileNo) ' Repeat until end of file...
    UserNo = UserNo + 1
    ReDim Preserve TempUser(1 To UserNo)
    Line Input #FileNo, TempUser(UserNo).ID
    Line Input #FileNo, TempUser(UserNo).Psw
    DoEvents ' Allow Windows to handle other tasks.
  Loop
  Close #FileNo
  GetUserDetailsFromFile = TempUser
End Function

And here's the code in my sample form to test it out...

Option Explicit
Dim MyUserDetails() As UserStuff
 
Private Sub Form_DblClick()
  MyUserDetails = GetUserDetailsFromFile(InputBox("Enter name (including path) of file with users"))
  Dim I As Long
  For I = LBound(MyUserDetails) To UBound(MyUserDetails)
    With MyUserDetails(I)
      Debug.Print "UserID:"; .ID, "Psw:"; .Psw
    End With
  Next
End Sub

Just run it, double-click the form and away you go. It just prints the results to the immediate window.

My sample file was just a text file I created in Notepad, containing these stupid values...

User01
%JFK ASEF:F$$W
User02
45v-98n3pytp4
User03
$%Y$%$K%JFK$$W

[ldpfrog]

Okay, thank you all alot for your help. This was the code that I came up with. I Created an array UInfo(999, 2). The X portion of this array is the maximum amount of usernames and passwords I could set, I could increase the amount but I doubt I'll have over 1000 users using this program. The Y portion is set up so if Y=1 then you are looking at a username, and if Y=2 then it is the password for the corresponding username.

In order for this to work, just create a multiline Textbox and a Command button, with the default VB6 names. I would be happy to explain to anybody who needs it because this is a very simple solution to having multiple usernames and passwords to your program without editing the actual code.

Dim nFileNum As Integer, UInfo(999, 2) As String, sNextLine As String, lLineCount As Long, NumLine As Integer, LCount As Integer, UnPw As Integer
 
Private Sub Command1_Click()
 
nFileNum = FreeFile
 
 
Open "C:\Documents and Settings\Matt\My Documents\testing.txt" For Input As nFileNum
lLineCount = 1
 
NumLine = 0
LCount = 1
UnPw = 0
Do While Not EOF(nFileNum)
   Line Input #nFileNum, sText
   LCount = LCount + 1
   If LCount Mod 2 <> 0 Then UnPw = 2
   If LCount Mod 2 = 0 Then
   NumLine = NumLine + 1
   UnPw = 1
   End If
  UInfo(NumLine, UnPw) = sText
 
Loop
UInfo(0, 1) = "UN"
UInfo(0, 2) = "PW"
For x = 0 To LCount
For y = 1 To 2
Text1.Text = Text1 & UInfo(x, y) + " "
Next y
Text1.Text = Text1 & vbCrLf
Next x
 
Close nFileNum
 
End Sub

[Killer42]

Glad to see you got it working.

Just one piece of general advice I would like to pass on. When you have two mutually exclusive possbilities (such as in lines 17-18 of your code) you should normally code it with an Else clause, as it makes the intention much more obvious. For instance...

If LCount Mod 2 <> 0 Then
  UnPw = 2
Else
  NumLine = NumLine + 1
  UnPw = 1
End If

[ldpfrog]

I know but I learned programming in TrueBasic and am not used to using 0 in arrays so I was afraid it would screw things up (which it did anyway). But thank you!

[Killer42]

I know but I learned programming in TrueBasic and am not used to using 0 in arrays so I was afraid it would screw things up (which it did anyway). But thank you!

I never use entry 0 in an array either. I hate zero-based arrays - they go completely against the way humans think, and try to force them to think like computers. They should be banned.

All I was talking about in this case is the structure of the IF tests. You are doing the equivalent of...

IF Condition Then
  ' Blah blah
End If
If Not Condition Then
  ' Blah blah
End If

In such a case, it's usually simpler to read if you code it as

IF condition Then
  ' Blah blah
Else
  ' Blah blah
End If

This is largely a personal choice, of course.

[ldpfrog]

Understood, thank you! Check out my other post about reading the file from the internet?