PureBasic

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. PureBasic

IncludeFile "CkPrng.pb"

Procedure ChilkatExample()

    success.i = 0

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

    success = 0

    fortuna.i = CkPrng::ckCreate()
    If fortuna.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; 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 = CkPrng::ckAddEntropy(fortuna,"01020304","hex")
    success = CkPrng::ckAddEntropy(fortuna,"hello world","ascii")

    ; Generate some random data:
    strRandHex.s = CkPrng::ckGenRandom(fortuna,16,"hex")
    strRandBase64.s = CkPrng::ckGenRandom(fortuna,22,"base64")
    strRandBase58.s = CkPrng::ckGenRandom(fortuna,32,"base58")

    Debug "hex random bytes: " + strRandHex
    Debug "base64 random bytes: " + strRandBase64
    Debug "base58 random bytes: " + strRandBase58

    ; Try it again with a different object to verify that the same results are obtained:
    fortuna2.i = CkPrng::ckCreate()
    If fortuna2.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkPrng::ckAddEntropy(fortuna2,"01020304","hex")
    success = CkPrng::ckAddEntropy(fortuna2,"hello world","ascii")

    strRandHex = CkPrng::ckGenRandom(fortuna2,16,"hex")
    strRandBase64 = CkPrng::ckGenRandom(fortuna2,22,"base64")
    strRandBase58 = CkPrng::ckGenRandom(fortuna2,32,"base58")

    Debug "hex random bytes: " + strRandHex
    Debug "base64 random bytes: " + strRandBase64
    Debug "base58 random bytes: " + strRandBase58


    CkPrng::ckDispose(fortuna)
    CkPrng::ckDispose(fortuna2)


    ProcedureReturn
EndProcedure