sha1 problem

[Linda]

I'm I'm trying to compare 2 hash values using sha1 one written in vb.net
and the other in Python.

The value I get in my vb.net code does not match the python code, or any
other hash calulator I have used.

Here is the .net code:
-----------------------------------------------
Dim UE As New UnicodeEncoding
Dim SHAhash As New SHA1Managed
Dim SHA1HASHValue() As Byte
Dim MessageBytes As Byte() = UE.GetBytes(TB_Input.Text)
SHA1HASHValue = SHAhash.ComputeHash(MessageBytes)
Dim b As Byte
Dim strHex As String
For Each b In SHA1HASHValue
strHex += String.Format("{0:x2}", b)
Next
LB_Output.Text = strHex
----------------------------------------------------------------------------
--------
example: If I use a text value of "a"
Run value in .net is: 0a04b971b03da607ce6c455184037b660ca89f78
compared to a hash calulator: 86f7e437faa5a7fce15d1ddcb9eaeaea377667b8
----------------------------------------------------------------------------
-----------------------------------
any ideas what is wrong here?

[Joe Kaplan \(MVP - ADSI\)]

I get the same value as your hash calculator when I use ASCIIEncoding or
UTF8Encoding. Therefore, the question is how is the python code converting
your string to an array of bytes. Each of those encodings will produce
different byte arrays, depending on what's in the source string. ASCII and
UTF8 will be the same for all ASCII characters, but all three will be
different for non-ASCII characters.

These string->Byte() conversion issues seem to cause the most problems for
people doing cryptography work.

Joe K.

"Linda" <lindan@analyticinnovations.com> wrote in message
news:uajwIkrtEHA.3628@tk2msftngp13.phx.gbl...

> I'm I'm trying to compare 2 hash values using sha1 one written in vb.net
> and the other in Python.
>
> The value I get in my vb.net code does not match the python code, or any
> other hash calulator I have used.
>
> Here is the .net code:
> -----------------------------------------------
> Dim UE As New UnicodeEncoding
> Dim SHAhash As New SHA1Managed
> Dim SHA1HASHValue() As Byte
> Dim MessageBytes As Byte() = UE.GetBytes(TB_Input.Text)
> SHA1HASHValue = SHAhash.ComputeHash(MessageBytes)
> Dim b As Byte
> Dim strHex As String
> For Each b In SHA1HASHValue
> strHex += String.Format("{0:x2}", b)
> Next
> LB_Output.Text = strHex
> ----------------------------------------------------------------------------
> --------
> example: If I use a text value of "a"
> Run value in .net is: 0a04b971b03da607ce6c455184037b660ca89f78
> compared to a hash calulator: 86f7e437faa5a7fce15d1ddcb9eaeaea377667b8
> ----------------------------------------------------------------------------
> -----------------------------------
> any ideas what is wrong here?
>
>