dotnet security: Hi All

I tried many times to convert the ff code to .NET but I fail to have
it converted.

How To Validate User Credentials from Visual Basic by Using SSPI
http://support.microsoft.com/default.aspx?scid=kb;en-us;279815

I would like to use the above link to authenticate the current user of
the computer in a windows 2000 platform.

I have a code that works with Windows XP using the Login API, but sad
to say, it fails at Windows 2000.

LogonAPI for VB.NET example:
Works only for Windows XP
http://support.microsoft.com/default.aspx?scid=kb;en-us;841699

Newsgroup said that giving the current user's rights set to SE_TCB_NAME
(Act As Part Of The Operating System), then the LogonAPI VB.NET example
will work under Windows 2000, but if that's the case, then the use will
have Admin rights, which in the company I work with will not do.


Anyone could help me on this dilema???

Does the above link actually work?
If the validating a user's Credentials using SSPI does work with
VB.NET, then my problems are solve.

And from what I've been reading, many other developers as well will
benefit from this effort.

Thanks,
Henry :)

Here was my attempt to convert it to VB.NET.
Just copy and paste the code below to a New Module.

How to use is easy.

Just call the function SSPValidateUser("username", "domain",
"password") or
SSPValidateUser(System.Environment.UserName,
System.Environment.UserDomainName, "password") to not type in username
and domain anymore.


I encounter 2 problems, I made a comment in my code where the problem
lies. "Problem #1", "Probelm #2".

'PROBLEM #1
ss = InitializeSecurityContext2(AuthSeq.hcred, 0, 0, 0,
0, SECURITY_NATIVE_DREP, 0, 0, AuthSeq.hctxt, sbdOut, fContextAttr,
tsExpiry)

'PROBLEM #2
ss = AcceptSecurityContext2(AuthSeq.hcred, 0, sbdIn, 0,
SECURITY_NATIVE_DREP, AuthSeq.hctxt, sbdOut, fContextAttr, tsExpiry)

The error message on both is :
An unhandled exception of type 'System.NullReferenceException' occurred
in UserAuthentication.exe

Additional information: Object reference not set to an instance of an
object.





'------------------
Option Explicit On

Module modSSPI

Private Declare Sub CopyMemoryInteger Lib "kernel32" Alias
"RtlMoveMemory" (ByRef Destination As Integer, ByRef Source As
SecBuffer, ByVal Length As Integer)
Private Declare Sub CopyMemorySecBuffer Lib "kernel32" Alias
"RtlMoveMemory" (ByRef Destination As SecBuffer, ByRef Source As
Integer, ByVal Length As Integer)
Private Declare Sub CopyMemorySecPkgInfo Lib "kernel32" Alias
"RtlMoveMemory" (ByRef Destination As SecPkgInfo, ByRef Source As
Integer, ByVal Length As Integer)
Private Declare Function NT4QuerySecurityPackageInfo Lib "security"
Alias "QuerySecurityPackageInfoA" (ByVal PackageName As String, ByRef
pPackageInfo As Integer) As Integer
Private Declare Function QuerySecurityPackageInfo Lib "secur32"
Alias "QuerySecurityPackageInfoA" (ByVal PackageName As String, ByRef
pPackageInfo As Integer) As Integer
Private Declare Function NT4FreeContextBuffer Lib "security" Alias
"FreeContextBuffer" (ByVal pvContextBuffer As Integer) As Integer
Private Declare Function FreeContextBuffer Lib "secur32" (ByVal
pvContextBuffer As Integer) As Integer
Private Declare Function NT4InitializeSecurityContext Lib
"security" Alias "InitializeSecurityContextA" (ByRef phCredential As
SecHandle, ByRef phContext As SecHandle, ByVal pszTargetName As
Integer, ByVal fContextReq As Integer, ByVal Reserved1 As Integer,
ByVal TargetDataRep As Integer, ByRef pInput As SecBufferDesc, ByVal
Reserved2 As Integer, ByRef phNewContext As SecHandle, ByRef pOutput As
SecBufferDesc, ByRef pfContextAttr As Integer, ByRef ptsExpiry As
TimeStamp) As Integer
Private Declare Function InitializeSecurityContext Lib "secur32"
Alias "InitializeSecurityContextA" (ByRef phCredential As SecHandle,
ByRef phContext As SecHandle, ByVal pszTargetName As Integer, ByVal
fContextReq As Integer, ByVal Reserved1 As Integer, ByVal TargetDataRep
As Integer, ByRef pInput As SecBufferDesc, ByVal Reserved2 As Integer,
ByRef phNewContext As SecHandle, ByRef pOutput As SecBufferDesc, ByRef
pfContextAttr As Integer, ByRef ptsExpiry As TimeStamp) As Integer
Private Declare Function NT4InitializeSecurityContext2 Lib
"security" Alias "InitializeSecurityContextA" (ByRef phCredential As
SecHandle, ByVal phContext As Integer, ByVal pszTargetName As Integer,
ByVal fContextReq As Integer, ByVal Reserved1 As Integer, ByVal
TargetDataRep As Integer, ByVal pInput As Integer, ByVal Reserved2 As
Integer, ByRef phNewContext As SecHandle, ByRef pOutput As
SecBufferDesc, ByRef pfContextAttr As Integer, ByRef ptsExpiry As
TimeStamp) As Integer
Private Declare Function InitializeSecurityContext2 Lib "secur32"
Alias "InitializeSecurityContextA" (ByRef phCredential As SecHandle,
ByVal phContext As Integer, ByVal pszTargetName As Integer, ByVal
fContextReq As Integer, ByVal Reserved1 As Integer, ByVal TargetDataRep
As Integer, ByVal pInput As Integer, ByVal Reserved2 As Integer, ByRef
phNewContext As SecHandle, ByRef pOutput As SecBufferDesc, ByRef
pfContextAttr As Integer, ByRef ptsExpiry As TimeStamp) As Integer
Private Declare Function NT4AcquireCredentialsHandle Lib "security"
Alias "AcquireCredentialsHandleA" (ByVal pszPrincipal As Integer, ByVal
pszPackage As String, ByVal fCredentialUse As Integer, ByVal pvLogonId
As Integer, ByRef pAuthData As SEC_WINNT_AUTH_IDENTITY, ByVal pGetKeyFn
As Integer, ByVal pvGetKeyArgument As Integer, ByRef phCredential As
SecHandle, ByRef ptsExpiry As TimeStamp) As Integer
Private Declare Function AcquireCredentialsHandle Lib "secur32"
Alias "AcquireCredentialsHandleA" (ByVal pszPrincipal As Integer, ByVal
pszPackage As String, ByVal fCredentialUse As Integer, ByVal pvLogonId
As Integer, ByRef pAuthData As SEC_WINNT_AUTH_IDENTITY, ByVal pGetKeyFn
As Integer, ByVal pvGetKeyArgument As Integer, ByRef phCredential As
SecHandle, ByRef ptsExpiry As TimeStamp) As Integer
Private Declare Function NT4AcquireCredentialsHandle2 Lib
"security" Alias "AcquireCredentialsHandleA" (ByVal pszPrincipal As
Integer, ByVal pszPackage As String, ByVal fCredentialUse As Integer,
ByVal pvLogonId As Integer, ByVal pAuthData As Integer, ByVal pGetKeyFn
As Integer, ByVal pvGetKeyArgument As Integer, ByRef phCredential As
SecHandle, ByRef ptsExpiry As TimeStamp) As Integer
Private Declare Function AcquireCredentialsHandle2 Lib "secur32"
Alias "AcquireCredentialsHandleA" (ByVal pszPrincipal As Integer, ByVal
pszPackage As String, ByVal fCredentialUse As Integer, ByVal pvLogonId
As Integer, ByVal pAuthData As Integer, ByVal pGetKeyFn As Integer,
ByVal pvGetKeyArgument As Integer, ByRef phCredential As SecHandle,
ByRef ptsExpiry As TimeStamp) As Integer
Private Declare Function NT4AcceptSecurityContext Lib "security"
Alias "AcceptSecurityContext" (ByRef phCredential As SecHandle, ByRef
phContext As SecHandle, ByRef pInput As SecBufferDesc, ByVal
fContextReq As Integer, ByVal TargetDataRep As Integer, ByRef
phNewContext As SecHandle, ByRef pOutput As SecBufferDesc, ByRef
pfContextAttr As Integer, ByRef ptsExpiry As TimeStamp) As Integer
Private Declare Function AcceptSecurityContext Lib "secur32" (ByRef
phCredential As SecHandle, ByRef phContext As SecHandle, ByRef pInput
As SecBufferDesc, ByVal fContextReq As Integer, ByVal TargetDataRep As
Integer, ByRef phNewContext As SecHandle, ByRef pOutput As
SecBufferDesc, ByRef pfContextAttr As Integer, ByRef ptsExpiry As
TimeStamp) As Integer
Private Declare Function NT4AcceptSecurityContext2 Lib "security"
Alias "AcceptSecurityContext" (ByRef phCredential As SecHandle, ByVal
phContext As Integer, ByRef pInput As SecBufferDesc, ByVal fContextReq
As Integer, ByVal TargetDataRep As Integer, ByRef phNewContext As
SecHandle, ByRef pOutput As SecBufferDesc, ByRef pfContextAttr As
Integer, ByRef ptsExpiry As TimeStamp) As Integer

Hello henrycortezwu@gmail.com,

LogonUser on Windows 2000 is a highly privileged operation - which needs
the privilege you talked about.

This is fixed on XP and W2K3.

---------------------------------------
Dominick Baier - DevelopMentor
http://www.leastprivilege.com

[quoted text, click to view]

Hello henrycortezwu@gmail.com,

you'll find a fully functional library with source here:
http://www.develop.com/technology/resourcedetail.aspx?id=ee929f0b-1f9d-4a2a-92a1-911706bd7b52



---------------------------------------
Dominick Baier - DevelopMentor
http://www.leastprivilege.com

[quoted text, click to view]