VB.NET

Generating Repeatable Random Data for Testing/Debugging

See more PRNG Examples

Demonstrates how to use the Fortuna PRNG to generate random-looking but repeatable non-random data for the purpose of testing and debugging. VB.NET

Dim success As Boolean = False

' This example assumes the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

success = False

Dim fortuna As New Chilkat.Prng

' Normally an application would seed the PRNG with entropy from
' some real random source.  However, sometimes we want the same
' random sequence of bytes for testing and debugging purposes.
' This a reason why GetEntropy and AddEntropy are two different methods.
' An application could omit the call to GetEntropy, and instead pass
' non-random data to AddEntropy. For example:

' Seed the PRNG with non-entropy, so we get a repeatable sequence.
' Note: AddEntropy can be called any number of times.
success = fortuna.AddEntropy("01020304","hex")
success = fortuna.AddEntropy("hello world","ascii")

' Generate some random data:
Dim strRandHex As String = fortuna.GenRandom(16,"hex")
Dim strRandBase64 As String = fortuna.GenRandom(22,"base64")
Dim strRandBase58 As String = fortuna.GenRandom(32,"base58")

Debug.WriteLine("hex random bytes: " & strRandHex)
Debug.WriteLine("base64 random bytes: " & strRandBase64)
Debug.WriteLine("base58 random bytes: " & strRandBase58)

' Try it again with a different object to verify that the same results are obtained:
Dim fortuna2 As New Chilkat.Prng

success = fortuna2.AddEntropy("01020304","hex")
success = fortuna2.AddEntropy("hello world","ascii")

strRandHex = fortuna2.GenRandom(16,"hex")
strRandBase64 = fortuna2.GenRandom(22,"base64")
strRandBase58 = fortuna2.GenRandom(32,"base58")

Debug.WriteLine("hex random bytes: " & strRandHex)
Debug.WriteLine("base64 random bytes: " & strRandBase64)
Debug.WriteLine("base58 random bytes: " & strRandBase58)