How to hash a UTF-8 string in Classic ASP

Question

I\'ve been looking for a Classic ASP script that allows me to hash a string using the MD5 algorithm. I need to match this hashed string against the same string in an ASP.NET

Answer 1

If you are using UTF-8 on both .Net and Classic ASP you should be able to borrow the .Net implementation.

Something like this;

<%
Dim asc, enc, bytes, instr, outstr, pos

instr = "muñeca"

Set asc = CreateObject("System.Text.UTF8Encoding")
Set enc = CreateObject("System.Security.Cryptography.MD5CryptoServiceProvider")

bytes = asc.GetBytes_4(instr)
bytes = enc.ComputeHash_2((bytes))

outstr = ""

'Convert the Byte Array to a Hex string
For pos = 1 To LenB(bytes)
 outstr = outstr & LCase(Right("0" & Hex(AscB(MidB(bytes, pos, 1))), 2))
Next

Response.Write outstr
%>

Output:

ea07bec1f37f4b56ebe368355d1c058f

This is the only valid method I've found for Classic ASP because all other implementations assume ANSI encoding and you end up with an incorrect hash.

Credit to: Replicating PHP’s sha1() in VBScript for helping me finally find a solution.