Imports System
Imports System.Security.Cryptography
Imports System.Text
Module Example
' Hash an input string and return the hash as
' a 32 character hexadecimal string.
Function getMd5Hash(ByVal input As String) As String
' Create a new instance of the MD5 object.
Dim md5Hasher As MD5 = MD5.Create()
' Convert the input string to a byte array and compute the hash.
Dim data As Byte() = md5Hasher.ComputeHash(Encoding.Default.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
' Verify a hash against a string.
Function verifyMd5Hash(ByVal input As String, ByVal hash As String) As Boolean
' Hash the input.
Dim hashOfInput As String = getMd5Hash(input)
' Create a StringComparer an comare the hashes.
Dim comparer As StringComparer = StringComparer.OrdinalIgnoreCase
If 0 = comparer.Compare(hashOfInput, hash) Then
Return True
Else
Return False
End If
End Function
Sub Main()
Dim source As String = "Hello World!"
Dim hash As String = getMd5Hash(source)
Console.WriteLine("The MD5 hash of " + source + " is: " + hash + ".")
Console.WriteLine("Verifying the hash...")
If verifyMd5Hash(source, hash) Then
Console.WriteLine("The hashes are the same.")
Else
Console.WriteLine("The hashes are not same.")
End If
End Sub
End Module
' This code example produces the following output:
'
' The MD5 hash of Hello World! is: ed076287532e86365e841e92bfc50d8c.
' Verifying the hash...
' The hashes are the same.