[RESOLVED] Getting Hash of File in VB.net -- Code does not produce same hash as certutil.exe

[walt4]

I am looking to verify the integrity of some files in a VB.net program and have encountered something strange.

Originally, I was using the attached class to produce a hash, but during testing noticed that it does not produce the same hash for any given file as Windows certutil.exe.

Clearly I am missing something. Does anyone know what is missing? Or is there a better way to get the hash of a file in VB.net? I could use a process to run certutil.exe, but would prefer to avoid a process if possible.


Class:

Imports System.Text
Imports System.Security.Cryptography

Public Class SHA

    Public Shared Function GenerateSHA512String(ByVal inputString) As String
        Dim sha512 As SHA512 = SHA512Managed.Create()
        Dim bytes As Byte() = Encoding.UTF8.GetBytes(inputString)
        Dim hash As Byte() = sha512.ComputeHash(bytes)
        Dim stringBuilder As New StringBuilder()

        For i As Integer = 0 To hash.Length - 1
            stringBuilder.Append(hash(i).ToString("X2"))
        Next

        Return stringBuilder.ToString()
    End Function

End Class

[walt4]

I have been able to resolve the problem with the following changes to the class:

Imports System
Imports System.IO
Imports System.Text
Imports System.Security.Cryptography

Public Class SHA

    Public Shared Function GenerateSHA512String(ByVal inputString As String) As String
        Using SHA512 As SHA512 = SHA512Managed.Create()

            Using fileStream As FileStream = File.OpenRead(inputString)
                Return BitConverter.ToString(SHA512.ComputeHash(fileStream)).Replace("-", "").ToLowerInvariant()
            End Using

        End Using
    End Function

End Class

Now, the hash generated is the same hash as shown when using certutil.exe.