MD5 HASH Encoding Problem

[Shaun Merrill]

This function doesn't seem to be giving me the appearance I expect. This
should appear more like
"1ba442ab45c8002a86d068d1c1748e44" but it looks really cryptic and screwy,
like "­óìØLÜzrVÊ%' \Y7".

Here is my code segment written in VB.NET Enterprise Architect:
--------
Public Function MD5File(ByVal Filename As String) As String
'
' Read a file, produce an MD5 hashed key value in a String.
'
With New Security.Cryptography.MD5CryptoServiceProvider
Dim result() As Byte = .ComputeHash( New
IO.StreamReader(Filename).BaseStream )
Dim Encoding As Text.Encoding = System.Text.Encoding.Default
Return Encoding.GetString(result)
Encoding = Nothing
.Clear()
End With
End Function
---------
Perhaps you can suggest a modification to my code which yields a more
hex-like string. I'm new to VB.NET, but I love it so far.
Thanks,
~ Shaun
near Seattle, WA

 

[Nak]

Hi there,

This is much easier done by loading the file into a byte array first,

Imports System.Security.Cryptography

Public Function createHash(ByVal iByteArray() As Byte) As String
Dim pBytHash() As Byte
pBytHash = New MD5CryptoServiceProvider().ComputeHash(iByteArray)
Return (BitConverter.ToString(pBytHash, 0, pBytHash.GetUpperBound(0)))
End Function

You can then use the above function to get an MD5 Hash of the data.

Nick.

 

[Guest]

Shaun,

The result you are getting is actually correct... it's just not formatted in
"nice-hex-format", you still have it as raw data.

Here's a quick code snippet that will take your raw data, and display it how
you want...

///
Dim strMD5 As String
For Each bytByte As Byte In result
strMD5 &= bytByte.ToString("x2")
Next
///

Now, strMD5 contains the nicely formatted MD5 hash. (Assuming 'result' is
your byte array).

Also, you have an unreachable code segment in your code:

Encoding = Nothing
.Clear()

These two lines will *never* be called, because they are preceeded with a
'Return' statement, which exits the method.

Hope this helps!

-- Tom Spink