SQL Server

Demonstrates the MacBytesENC Method

Demonstrates the MacBytesENC method to do HMAC-SHA256, HMAC-SHA1, and HMAC-MD5. 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)
    -- This example assumes Chilkat Crypt2 to have been previously unlocked.
    -- See Unlock Crypt2 for sample code.

    -- Demonstrates how to reproduce the following results found at
    -- https://en.wikipedia.org/wiki/Hash-based_message_authentication_code

    -- HMAC_SHA256("key", "The quick brown fox jumps over the lazy dog") = 0xf7bc83f430538424b13298e6aa6fb143ef4d59a14946175997479dbc2d1a3cd8
    -- HMAC_MD5("key", "The quick brown fox jumps over the lazy dog")    = 0x80070713463e7749b90c2dc24911e275
    -- HMAC_SHA1("key", "The quick brown fox jumps over the lazy dog")   = 0xde7c9b85b8b78aa6bc8a7a36f70a90701c9db4d9

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

    EXEC sp_OASetProperty @crypt, 'MacAlgorithm', 'hmac'
    EXEC sp_OASetProperty @crypt, 'EncodingMode', 'hex'
    DECLARE @success int
    EXEC sp_OAMethod @crypt, 'SetMacKeyString', @success OUT, 'key'
    DECLARE @sData nvarchar(4000)
    SELECT @sData = 'The quick brown fox jumps over the lazy dog'

    -- We're doing this in a convoluted, roundabout fashion to show syntax
    -- and data types for handling binary data.
    -- The straightforward way of doing an HMAC on a string is
    -- shown here: HMAC String

    DECLARE @binData int
    EXEC @hr = sp_OACreate 'Chilkat.BinData', @binData OUT

    EXEC sp_OAMethod @binData, 'AppendString', @success OUT, @sData, 'utf-8'
    EXEC sp_OAMethod @binData, 'GetBinary', @dataToHmac OUT

    EXEC sp_OASetProperty @crypt, 'HashAlgorithm', 'SHA-256'

    EXEC sp_OAMethod @crypt, 'MacBytesENC', @sTmp0 OUT, @dataToHmac
    PRINT 'HMAC_SHA256: ' + @sTmp0

    EXEC sp_OASetProperty @crypt, 'HashAlgorithm', 'MD5'

    EXEC sp_OAMethod @crypt, 'MacBytesENC', @sTmp0 OUT, @dataToHmac
    PRINT 'HMAC_MD5: ' + @sTmp0

    EXEC sp_OASetProperty @crypt, 'HashAlgorithm', 'SHA-1'

    EXEC sp_OAMethod @crypt, 'MacBytesENC', @sTmp0 OUT, @dataToHmac
    PRINT 'HMAC_SHA1: ' + @sTmp0

    -- The output is the same (ignore case)
    -- HMAC_SHA256: F7BC83F430538424B13298E6AA6FB143EF4D59A14946175997479DBC2D1A3CD8
    -- HMAC_MD5: 80070713463E7749B90C2DC24911E275
    -- HMAC_SHA1: DE7C9B85B8B78AA6BC8A7A36F70A90701C9DB4D9

    EXEC @hr = sp_OADestroy @crypt
    EXEC @hr = sp_OADestroy @binData


END
GO