SQL Server

PBKDF2 Key Derivation

Demonstrates AES secret key derivation from a password using PBDKF2. SQL Server

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    -- This example assumes the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    DECLARE @crypt int
    EXEC @hr = sp_OACreate 'Chilkat.Crypt2', @crypt OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @password nvarchar(4000)
    SELECT @password = 'correcthorsebatterystaple'

    -- Derive from the utf-8 byte representation of the password.
    DECLARE @charset nvarchar(4000)
    SELECT @charset = 'utf-8'

    DECLARE @hashAlg nvarchar(4000)
    SELECT @hashAlg = 'sha256'

    EXEC sp_OASetProperty @crypt, 'EncodingMode', 'hex'
    DECLARE @saltHex nvarchar(4000)
    EXEC sp_OAMethod @crypt, 'GenRandomBytesENC', @saltHex OUT, 16

    DECLARE @iterationCount int
    SELECT @iterationCount = 310000

    -- Derive a 256-bit key from the password.
    DECLARE @outputBitLen int
    SELECT @outputBitLen = 256

    -- The derived key is returned as a hex or base64 encoded string.
    -- (Note: The salt argument must be a string that also uses
    -- the same encoding.)
    DECLARE @enc nvarchar(4000)
    SELECT @enc = 'hex'

    DECLARE @hexKey nvarchar(4000)
    EXEC sp_OAMethod @crypt, 'Pbkdf2', @hexKey OUT, @password, @charset, @hashAlg, @saltHex, @iterationCount, @outputBitLen, @enc


    PRINT @hexKey

    -- Sample output:
    -- 597734C894FF89CFD3B93D925462C24E97724BCB118F6FC919007F5ABC27E768

    EXEC @hr = sp_OADestroy @crypt


END
GO