Convert from hexadecimal to binary -and vice versa

CREATE FUNCTION dbo.cHex2Bin 
(
@hex varchar(50) 
)

RETURNS varchar(200)

AS

BEGIN

set @hex=replace (@hex,'1','0001')
set @hex=replace (@hex,'2','0010')
set @hex=replace (@hex,'3','0011')
set @hex=replace (@hex,'4','0100')
set @hex=replace (@hex,'5','0101')
set @hex=replace (@hex,'6','0110')
set @hex=replace (@hex,'7','0111')
set @hex=replace (@hex,'8','1000')
set @hex=replace (@hex,'9','1001')
set @hex=replace (@hex,'A','1010')
set @hex=replace (@hex,'B','1011')
set @hex=replace (@hex,'C','1100')
set @hex=replace (@hex,'D','1101')
set @hex=replace (@hex,'E','1110')
set @hex=replace (@hex,'F','1111')

--get rif od leading 0

while charindex('x0','x'+@hex)>0 
set @hex=replace ('x'+@hex,'x0','')

RETURN @hex
END
GO 

--Convert from binary to hexadecimal 
SET QUOTED_IDENTIFIER ON 
GO
SET ANSI_NULLS ON 
GO

CREATE FUNCTION cBin2Hex 
(
@Hex varchar(100)
)
RETURNS varchar(50)
AS
BEGIN
DECLARE @bin as varchar(50)
select @bin=''
set @Hex='000'+@Hex
while len(@HEx)>3

begin
select @bin= case right(@hex,4)
   when '1111' then 'F'
   when '1110' then 'E'
   when '1101' then 'D'
   when '1100' then 'C'
   when '1011' then 'B'
   when '1010' then 'A'
   when '1001' then '9'
   when '1000' then '8'
   when '0111' then '7'
   when '0110' then '6'
   when '0101' then '5'
   when '0100' then '4'
   when '0011' then '3'
   when '0010' then '2'
   when '0001' then '1'
   when '0000' then '0'
end +@bin

set @hex=left(@hex,Len(@hex)-4)

end
RETURN @bin

END

GO
SET QUOTED_IDENTIFIER OFF 
GO
SET ANSI_NULLS ON 
GO