Sign a JWS with an HMAC Key

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetMacKey, which sets the symmetric MAC key for a signature. The key bytes are supplied in a named encoding such as hex or base64.

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

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

    --  Protected header specifying HMAC-SHA256.
    DECLARE @header int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @header OUT

    EXEC sp_OAMethod @header, 'UpdateString', @success OUT, 'alg', 'HS256'
    EXEC sp_OAMethod @jws, 'SetProtectedHeader', @success OUT, 0, @header
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @jws, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @jws
        EXEC @hr = sp_OADestroy @header
        RETURN
      END

    DECLARE @bIncludeBom int
    SELECT @bIncludeBom = 0
    EXEC sp_OAMethod @jws, 'SetPayload', @success OUT, 'This is the content to sign.', 'utf-8', @bIncludeBom
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @jws, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @jws
        EXEC @hr = sp_OADestroy @header
        RETURN
      END

    --  Set the symmetric MAC key for signature 0.  The key bytes are provided in the named encoding (here
    --  base64).  In production, obtain the key from a secure source rather than hard-coding it.
    DECLARE @base64Key nvarchar(4000)
    SELECT @base64Key = 'YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU='
    EXEC sp_OAMethod @jws, 'SetMacKey', @success OUT, 0, @base64Key, 'base64'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @jws, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @jws
        EXEC @hr = sp_OADestroy @header
        RETURN
      END

    DECLARE @jwsCompact nvarchar(4000)
    EXEC sp_OAMethod @jws, 'CreateJws', @jwsCompact OUT
    EXEC sp_OAGetProperty @jws, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 = 0
      BEGIN
        EXEC sp_OAGetProperty @jws, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @jws
        EXEC @hr = sp_OADestroy @header
        RETURN
      END

    PRINT @jwsCompact

    EXEC @hr = sp_OADestroy @jws
    EXEC @hr = sp_OADestroy @header


END
GO