clsCrypto.vb

Imports System.Text
Imports System.Security.Cryptography

Public Class clsCrypto
    Shared Function GetMd5Hash(ByVal md5Hash As MD5, ByVal input As String) As String

        ' Convert the input string to a byte array and compute the hash.
        Dim data As Byte() = md5Hash.ComputeHash(Encoding.UTF8.GetBytes(input))

        ' Create a new Stringbuilder to collect the bytes
        ' and create a string.
        Dim sBuilder As New StringBuilder()

        ' Loop through each byte of the hashed data 
        ' and format each one as a hexadecimal string.
        Dim i As Integer
        For i = 0 To data.Length - 1
            sBuilder.Append(data(i).ToString("x2"))
        Next i

        ' Return the hexadecimal string.
        Return sBuilder.ToString()

    End Function 'GetMd5Hash


    ' Verify a hash against a string.
    Shared Function VerifyMd5Hash(ByVal md5Hash As MD5, ByVal input As String, ByVal hash As String) As Boolean
        ' Hash the input.
        Dim hashOfInput As String = GetMd5Hash(md5Hash, input)

        ' Create a StringComparer an compare the hashes.
        Dim comparer As StringComparer = StringComparer.OrdinalIgnoreCase

        If 0 = comparer.Compare(hashOfInput, hash) Then
            Return True
        Else
            Return False
        End If

    End Function 'VerifyMd5Hash
End Class