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