Digest authentication: Impossible to authenticate to DB and IIS Webserver
April 26, 2006
Posted by Roel in : Technical , add a comment
Due to some technical issues (i’ll show you below) it is impossible to authenticate using Digest Authentication for authenticating the user against an Database/LDAP and the webserver itself. I did this before with Basic authentication, which works fine.
Example1:
It is possible to authenticate with basic authentication against a Database, simply write a 401 header to the client, wait until the client responses, decode the response with a Base64Decode function and query a database table with that username and password. When you decode the client response with a Base64Decode function, you get the ‘username:pasword’ (separated by a colon). (more…)
[VBScript/ASP] About Isnull and =null
April 26, 2006
Posted by Roel in : Technical , 1 comment so far
Expressions in VBScript/ASP with "null" in it, will always return FALSE. See the examples below:
Dim test
If (test=null) Then Response.Write "True" Else Response.Write "False" End If
If Not(test=null) Then Response.Write "True" Else Response.Write "False" End If
Both will show "False". Because "null" is in the expression, none of them will ever return True.
This is because any expression containing a Null is itself Null and therefore False.
Too make it more confusing, look at this example:
test_avc = null
Response.Write IsNull(test_avc)
If (test_avc=null) Then response.write "True" Else Response.Write "False" End If
This will return "True … False".
See the VBScript IsNull Reference:
"Use the IsNull function to determine whether an expression contains a Null value. Expressions that you might expect to evaluate to True under some circumstances, such as If Var = Null and If Var <> Null, are always False. This is because any expression containing a Null is itself Null, and therefore, False."
