SQL Server

ITIDA Canonicalize JSON and Compute SHA256 Hash

See more Egypt ITIDA Examples

Demonstrates creating the canonical (ITIDA) version of a JSON document, and then computes the SHA256 hash of the canonicalized JSON. 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 assumes the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    -- Load the JSON containing the document to be signed.

    -- The JSON file should look like this:
    -- NOTE: The JSON should NOT begin with "{ "documents" : [ ..."

    --       {
    --          "issuer":{
    --             "address":{
    --                "branchID":"0",
    --                "country":"EG",
    --                "regionCity":"Cairo",
    --                "postalCode":"",
    --                "buildingNumber":"0",
    --                "street":"123rd Street",
    --                "governate":"GOVERNATE"
    --             },
    --             "type":"B",
    --             "id":"209999899",
    --             "name":"Xyz SAE"
    --          },
    -- ...
    -- ...

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

    EXEC sp_OAMethod @sb, 'LoadFile', @success OUT, 'my_invoice.json', 'utf-8'
    IF @success = 0
      BEGIN

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

    -- Convert the contents of sb to the ITIDA canonical form.
    -- Always pass utf-8 for the 2nd arg.
    EXEC sp_OAMethod @sb, 'Encode', @success OUT, 'itida', 'utf-8'

    -- Examine the canonicalized JSON
    EXEC sp_OAMethod @sb, 'GetAsString', @sTmp0 OUT
    PRINT @sTmp0

    -- Compute the SHA256 hash and show the SHA256 in hex format

    EXEC sp_OAMethod @sb, 'GetHash', @sTmp0 OUT, 'sha256', 'hex', 'utf-8'
    PRINT 'SHA256 hash: ' + @sTmp0

    EXEC @hr = sp_OADestroy @sb


END
GO