Generating a Hash

The managed hash classes can hash either an array of bytes or a managed stream object. The following example uses the SHA1 hash algorithm to create a hash value for a string. The example uses the UnicodeEncoding class to convert the string into an array of bytes that are hashed using the SHA1Managed class. The hash value is then displayed to the console.

Imports System
Imports System.Security.Cryptography
Imports System.Text

Module Module1
    Sub Main()
        Dim HashValue() As Byte

        Dim MessageString As String = "This is the original message!"

        'Create a new instance of the UnicodeEncoding class to 
        'convert the string into an array of Unicode bytes.
        Dim UE As New UnicodeEncoding()

        'Convert the string into an array of bytes.
        Dim MessageBytes As Byte() = UE.GetBytes(MessageString)

        'Create a new instance of the SHA1Managed class to create 
        'the hash value.
        Dim SHhash As New SHA1Managed()

        'Create the hash value from the array of bytes.
        HashValue = SHhash.ComputeHash(MessageBytes)

        'Display the hash value to the console. 
        Dim b As Byte
        For Each b In HashValue
            Console.Write("{0} ", b)
        Next b
    End Sub
End Module
[C#]
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

class Class1
{
   static void Main(string[] args)
   {
      byte[] HashValue;

      string MessageString = "This is the original message!";

      //Create a new instance of the UnicodeEncoding class to 
      //convert the string into an array of Unicode bytes.
      UnicodeEncoding UE = new UnicodeEncoding();

      //Convert the string into an array of bytes.
     byte[] MessageBytes = UE.GetBytes(MessageString);

      //Create a new instance of the SHA1Managed class to create 
      //the hash value.
      SHA1Managed SHhash = new SHA1Managed();

      //Create the hash value from the array of bytes.
      HashValue = SHhash.ComputeHash(MessageBytes);

      //Display the hash value to the console. 
      foreach(byte b in HashValue)
      {
         Console.Write("{0} ", b);
      }
   }
}

This code will display the following string to the console:

59 4 248 102 77 97 142 201 210 12 224 93 25 41 100 197 213 134 130 135

See Also

Verifying a Hash | Ensuring Data Integrity with Hash Codes | Cryptographic Tasks | Cryptographic Services