Is possible but the current system which is a mixture of Access and SQL
Server back ends with Access front ends is due to be replaced by my
current project. The dll to be called from Access is a stop gap measure
to address an identified security flaw. I will be basing all my work on
Windows authentication and will be using NetSQLAzMan for application
authorisation.
The idea of having a 'Staff' table to authenticate a user when one can
use AD in a secure way is not really tenable. It might have been the
only way possible when the Access solution was first written but
thankfully this is no longer the case.
Regards Peter
On 9/03/2010 6:34 AM, Arjang Assadi wrote:
What about windows authetication? is there a way to use that from
Access instead?
Alternative idea : Throw away the Access front end and do it all C#,
call it the next version of the software.
Regards
On 8 March 2010 21:35, Peter Maddin<[email protected]> wrote:
Hi Ian
Thanks for the Code Project link. It looks really great.
I searched CodeProject and did not find this page.
I am fairly certain I have MS Access using my C# COM aware dll.
I have tested it and it works great.
To morrow I will pass it over to the the person who supports Access at our
site.
Personally I can't stand Access but they needed a function they could call
from VBA to protect passwords that they
store in a database table. I though a hash would be easier than a symmetric
cipher. I tend to shy away using reversible symmetric ciphers within
insecure code. It is just too easy to bypass most of the security features
in Access.
Its really just a one off to try and make their access front end
applications a bit more secure.
Regards Peter.
On 8/03/2010 3:33 PM, Ian Thomas wrote:
Peter
Did you try the sample code, with Excel? The GUID in the C# or Vb.NET will
be different for Excel, Access.
Have a read of this article (CodeProject) for an overview -
http://www.codeproject.com/KB/COM/cominterop.aspx
________________________________
Ian Thomas
Victoria Park, Western Australia
________________________________
From: [email protected] [mailto:[email protected]]
On Behalf Of Maddin, Peter
Sent: Monday, 8 March 2010 2:34 PM
To: ozDotNet
Subject: RE: Calling a class library C# method from ms access
Thanks Ian
I ma having trouble translating this from Vb.NET to C#.
I built the class library and then used reflector to see the c# code.
Tried cutting and pasting but the VS Editor did not like it.
Googling other material, locates code that only vaguely resembles that in
your link below.
I am venturing into unchartered territory never having had much to with Com
before (and being told it was dead)
The latest one has no GUIDs at all
http://www.codeproject.com/KB/office/ParallelMsAccess.aspx
My project is tiny
using System;
using System.Runtime.InteropServices;
using System.Security.Cryptography;
using System.Text;
namespace PathWest
{
[ComVisible(true)]
public interface HashInterface
{
string Md5Hash(string passwordValue);
}
[ComVisible(true)]
[ClassInterface(ClassInterfaceType.None)]
public class GetHash : HashInterface
{
public string Md5Hash(string passwordValue)
{
byte[] hashValue = new
MD5CryptoServiceProvider().ComputeHash(Encoding.ASCII.GetBytes(passwordValue));
return Encoding.ASCII.GetString(hashValue);
}
}
}
I do see one in the Assembly.cs file though
// Setting ComVisible to false makes the types in this assembly not visible
// to COM components. If you need to access a type in this assembly from
// COM, set the ComVisible attribute to true on that type.
[assembly: ComVisible(true)]
// The following GUID is for the ID of the typelib if this project is
exposed to COM
[assembly: Guid("b92f832a-3887-412b-a126-e58f35041f2d")]
Regards Peter Maddin
Applications Development Officer
PathWest Laboratory Medicine WA
Phone : +618 9473 3944
Fax : +618 9473 3982
E-Mail : [email protected]
The contents of this e-mail transmission outside of the WAGHS network are
intended solely for the named recipient's), may be confidential, and may be
privileged or otherwise protected from disclosure in the public interest.
The use, reproduction, disclosure or distribution of the contents of this
e-mail transmission by any person other than the named recipient(s) is
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immediately.
From: [email protected] [mailto:[email protected]]
On Behalf Of Ian Thomas
Sent: Monday, 8 March 2010 11:13 AM
To: 'ozDotNet'
Subject: RE: Calling a class library C# method from ms access
http://support.microsoft.com/kb/317535
________________________________
Ian Thomas
Victoria Park, Western Australia
________________________________
From: [email protected] [mailto:[email protected]]
On Behalf Of Maddin, Peter
Sent: Monday, 8 March 2010 10:49 AM
To: [email protected]
Subject: Calling a class library C# method from ms access
I need to call a C# method from MS Access 2003.
I need to pass in a string and return a string.
I have spent some trying to do this in Delphi but am now sure I need to use
COM so I might as well use C#.
I have wasted a couple of days almost getting it working only to find that
it was too flaky with Access crashing.
Does anyone have a simple code example they would be willing to share?
The goal is to pass in a string (which will be a password) and return a hash
of that string using MD5 or something similar.
Generating the hash is no problem its just writing the class and method so
Access will be able to call it, setting up the MS Access declaration and
calling the method passing in a string and returning a string.
I believe one needs to make the assembly ‘Com-Visible”.
Also the Access declaration needs to specify the TLB and not the dll.
One needs to register the dll (? And tlb) using regasm.
Is there anything else required?
Regards Peter Maddin
Applications Development Officer
PathWest Laboratory Medicine WA
Phone : +618 9473 3944
Fax : +618 9473 3982
E-Mail : [email protected]
The contents of this e-mail transmission outside of the WAGHS network are
intended solely for the named recipient's), may be confidential, and may be
privileged or otherwise protected from disclosure in the public interest.
The use, reproduction, disclosure or distribution of the contents of this
e-mail transmission by any person other than the named recipient(s) is
prohibited. If you are not a named recipient please notify the sender
immediately.
