homebrew01 (4/5/2010)

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Will BlowFish or TwoFish work with image data ?? I downloaded the latest SQL toolkit and Tried running TwoFish after modifying it to handle image data converted to varbinary(max). The data came back as NULL, instead of encrypted. Either I did something wrong (very likely), or there's some limitation in the DLL for length, or there's some other problem I don't understand.

--modified fn_encrypt_twofish in the hopes it will work with bigger data

CREATE FUNCTION [dbo].[fn_encrypt_twofish_max] (@plaintext VARBINARY(max),

@localkeyname VARCHAR(128),

@password VARCHAR(128),

@keybits INT)

RETURNS VARBINARY(max)

AS

BEGIN

DECLARE @masterkey VARBINARY(64)

DECLARE @localkey VARBINARY(80)

SELECT @masterkey = m.[Key], @localkey = l.[Key]

FROM dbo.Local_Key_Vault l, dbo.Master_Key_Vault m

WHERE l.[name] = @localkeyname

AND l.[master_key_name] = m.[name]

DECLARE @enctext VARBINARY(max)

EXEC dbo.xp_encrypt_twofish @plaintext, @enctext OUTPUT, @password, @masterkey, @localkey, @keybits

RETURN @enctext

END

and then ran

-- Encrypt data

UPDATE MyTable

SET VoiceData = cast(master.dbo.fn_encrypt_twofish_max(VoiceData ,

'Local Key 1', NULL, 32) AS VARBINARY(max))

Thoughts ?

TIA