Imports System.Text.RegularExpressions

    Public Class HashValidator
        Public Enum ALGO As Integer
            CRC16 = 4
            CRC32 = 8
            MD5 = 32
            SHA1 = 40
            SHA256 = 64
            SHA384 = 96
            SHA512 = 128
        End Enum

        Public Shared Function IsValid(ByVal Expression As String, ByVal Algorythm As ALGO) As Boolean
            Dim Validator As Regex = Nothing

            Select Case Algorythm
                Case ALGO.CRC16 : Validator = New Regex("^([a-fA-F0-9]){4}$")
                Case ALGO.CRC32 : Validator = New Regex("^([a-fA-F0-9]){8}$")
                Case ALGO.MD5 : Validator = New Regex("^([a-fA-F0-9]){32}$")
                Case ALGO.SHA1 : Validator = New Regex("^([a-fA-F0-9]){40}$")
                Case ALGO.SHA256 : Validator = New Regex("^([a-fA-F0-9]){64}$")
                Case ALGO.SHA384 : Validator = New Regex("^([a-fA-F0-9]){96}$")
                Case ALGO.SHA512 : Validator = New Regex("^([a-fA-F0-9]){128}$")
            End Select

            Return Validator.IsMatch(Expression)
        End Function

        Public Shared Function IsValid(ByVal Expression() As Byte, ByVal Algorythm As ALGO) As Boolean
            Dim TmpValue As String = ""
            Dim HashString As String = ""

            For i As Integer = 0 To Expression.Length - 1
                TmpValue = Hex(Expression(i))
                If Len(TmpValue) = 1 Then TmpValue = "0" & TmpValue
                HashString &= TmpValue
            Next

            Return IsValid(HashString, Algorythm)
        End Function
    End Class