(SQL Server) Adding Entropy to a PRNG

Demonstrates how system entropy is automatically added when the application does not explicitly add entropy prior to generating the 1st random data. Also demonstrates how additional entropy can be added at anytime during the lifetime of the PRNG object.

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

    --  The simplest way to use the Chilkat PRNG is to instantiate the object
    --  and generate random data.  This skips the explicit step of getting system entropy
    --  and adding it (via get AddEntropy method).  When no entropy is explicitly added,
    --  Chilkat will automatically add 32-bytes of system entropy on the first request
    --  for random data.

    --  Generate some random data.
    --  The 1st call to GenRandom implicitly adds 32 bytes of system entropy to seed the PRNG.
    EXEC sp_OAMethod @fortuna, 'GenRandom', @sTmp0 OUT, 16, 'hex'
    PRINT @sTmp0

    --  Note: An application can get additional system entropy and add it at any point
    --  during the lifetime of the PRNG.  For example:
    EXEC sp_OAMethod @fortuna, 'GenRandom', @sTmp0 OUT, 16, 'hex'
    PRINT @sTmp0
    EXEC sp_OAMethod @fortuna, 'GenRandom', @sTmp0 OUT, 16, 'hex'
    PRINT @sTmp0
    EXEC sp_OAMethod @fortuna, 'GenRandom', @sTmp0 OUT, 16, 'hex'
    PRINT @sTmp0
    EXEC sp_OAMethod @fortuna, 'GetEntropy', @sTmp0 OUT, 16, 'hex'
    EXEC sp_OAMethod @fortuna, 'AddEntropy', @success OUT, @sTmp0, 'hex'
    EXEC sp_OAMethod @fortuna, 'GenRandom', @sTmp0 OUT, 16, 'hex'
    PRINT @sTmp0
    EXEC sp_OAMethod @fortuna, 'GenRandom', @sTmp0 OUT, 16, 'hex'
    PRINT @sTmp0
    EXEC sp_OAMethod @fortuna, 'GenRandom', @sTmp0 OUT, 16, 'hex'
    PRINT @sTmp0
    EXEC sp_OAMethod @fortuna, 'GetEntropy', @sTmp0 OUT, 16, 'hex'
    EXEC sp_OAMethod @fortuna, 'AddEntropy', @success OUT, @sTmp0, 'hex'
    EXEC sp_OAMethod @fortuna, 'GenRandom', @sTmp0 OUT, 16, 'hex'
    PRINT @sTmp0
    EXEC sp_OAMethod @fortuna, 'GenRandom', @sTmp0 OUT, 16, 'hex'
    PRINT @sTmp0
    EXEC sp_OAMethod @fortuna, 'GenRandom', @sTmp0 OUT, 16, 'hex'
    PRINT @sTmp0
    EXEC sp_OAMethod @fortuna, 'GetEntropy', @sTmp0 OUT, 16, 'hex'
    EXEC sp_OAMethod @fortuna, 'AddEntropy', @success OUT, @sTmp0, 'hex'
    EXEC sp_OAMethod @fortuna, 'GenRandom', @sTmp0 OUT, 16, 'hex'
    PRINT @sTmp0
    EXEC sp_OAMethod @fortuna, 'GenRandom', @sTmp0 OUT, 16, 'hex'
    PRINT @sTmp0
    EXEC sp_OAMethod @fortuna, 'GenRandom', @sTmp0 OUT, 16, 'hex'
    PRINT @sTmp0

    EXEC @hr = sp_OADestroy @chilkatGlob


END
GO