(SQL Server) Generating Repeatable Random Data for Testing/Debugging

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

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- All Chilkat classes can be unlocked at once at the beginning of a program
    -- by calling UnlockBundle.  It requires a Bundle unlock code.
    DECLARE @chilkatGlob int
    -- Use "Chilkat_9_5_0.Global" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Global', @chilkatGlob OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @success int
    EXEC sp_OAMethod @chilkatGlob, 'UnlockBundle', @success OUT, 'Anything for 30-day trial.'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @chilkatGlob, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @chilkatGlob
        RETURN
      END

    DECLARE @fortuna int
    -- Use "Chilkat_9_5_0.Prng" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Prng', @fortuna OUT

    -- 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.
    EXEC sp_OAMethod @fortuna, 'AddEntropy', @success OUT, '01020304', 'hex'
    EXEC sp_OAMethod @fortuna, 'AddEntropy', @success OUT, 'hello world', 'ascii'

    -- Generate some random data:
    DECLARE @strRandHex nvarchar(4000)
    EXEC sp_OAMethod @fortuna, 'GenRandom', @strRandHex OUT, 16, 'hex'
    DECLARE @strRandBase64 nvarchar(4000)
    EXEC sp_OAMethod @fortuna, 'GenRandom', @strRandBase64 OUT, 22, 'base64'
    DECLARE @strRandBase58 nvarchar(4000)
    EXEC sp_OAMethod @fortuna, 'GenRandom', @strRandBase58 OUT, 32, 'base58'


    PRINT 'hex random bytes: ' + @strRandHex

    PRINT 'base64 random bytes: ' + @strRandBase64

    PRINT 'base58 random bytes: ' + @strRandBase58

    -- Try it again with a different object to verify that the same results are obtained:
    DECLARE @fortuna2 int
    -- Use "Chilkat_9_5_0.Prng" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Prng', @fortuna2 OUT

    EXEC sp_OAMethod @fortuna2, 'AddEntropy', @success OUT, '01020304', 'hex'
    EXEC sp_OAMethod @fortuna2, 'AddEntropy', @success OUT, 'hello world', 'ascii'

    EXEC sp_OAMethod @fortuna2, 'GenRandom', @strRandHex OUT, 16, 'hex'
    EXEC sp_OAMethod @fortuna2, 'GenRandom', @strRandBase64 OUT, 22, 'base64'
    EXEC sp_OAMethod @fortuna2, 'GenRandom', @strRandBase58 OUT, 32, 'base58'


    PRINT 'hex random bytes: ' + @strRandHex

    PRINT 'base64 random bytes: ' + @strRandBase64

    PRINT 'base58 random bytes: ' + @strRandBase58

    EXEC @hr = sp_OADestroy @chilkatGlob
    EXEC @hr = sp_OADestroy @fortuna
    EXEC @hr = sp_OADestroy @fortuna2


END
GO