SQL Server

Hash Binary Data (SHA256 and other hash algorithms)

Demonstrates how to hash binary bytes using SHA256, SHA384, SHA512, MD2, MD5, HAVAL, RIPEMD, etc. 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
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

    -- This example requires the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    -- Let's load a binary file to get the bytes..
    DECLARE @jpgData int
    EXEC @hr = sp_OACreate 'Chilkat.BinData', @jpgData OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    EXEC sp_OAMethod @jpgData, 'LoadFile', @success OUT, 'qa_data/jpg/starfish.jpg'
    IF @success <> 1
      BEGIN

        PRINT 'Failed to load file.'
        EXEC @hr = sp_OADestroy @jpgData
        RETURN
      END

    EXEC sp_OAMethod @jpgData, 'GetBinary', @jpgBytes OUT

    DECLARE @crypt int
    EXEC @hr = sp_OACreate 'Chilkat.Crypt2', @crypt OUT

    -- Choose the hash algorithm.
    -- Can be  "sha1", "sha256", "sha384", "sha512", "md2", "md5", "haval", "ripemd128", "ripemd160","ripemd256", or "ripemd320".
    EXEC sp_OASetProperty @crypt, 'HashAlgorithm', 'sha256'

    EXEC sp_OAMethod @crypt, 'HashBytes', @hashBytes OUT, @jpgBytes

    -- Let's examine the hash as a hex string.
    DECLARE @sb int
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sb OUT

    EXEC sp_OAMethod @sb, 'AppendEncoded', @success OUT, @hashBytes, 'hex'

    EXEC sp_OAMethod @sb, 'GetAsString', @sTmp0 OUT
    PRINT 'SHA256 hash = ' + @sTmp0

    -- We could alternatively hash the bytes and receive the hex result directly:
    EXEC sp_OASetProperty @crypt, 'EncodingMode', 'hex'
    DECLARE @hashHexStr nvarchar(4000)
    EXEC sp_OAMethod @crypt, 'HashBytesENC', @hashHexStr OUT, @jpgBytes

    PRINT 'SHA256 hash = ' + @hashHexStr

    EXEC @hr = sp_OADestroy @jpgData
    EXEC @hr = sp_OADestroy @crypt
    EXEC @hr = sp_OADestroy @sb


END
GO