Visual FoxPro

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. Visual FoxPro

LOCAL lnSuccess
LOCAL loSb

lnSuccess = 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"
*           },
*  ...
*  ...

loSb = CreateObject('Chilkat.StringBuilder')
lnSuccess = loSb.LoadFile("my_invoice.json","utf-8")
IF (lnSuccess = 0) THEN
    ? "Failed to load input file."
    RELEASE loSb
    CANCEL
ENDIF

*  Convert the contents of sb to the ITIDA canonical form.
*  Always pass utf-8 for the 2nd arg.
loSb.Encode("itida","utf-8")

*  Examine the canonicalized JSON
? loSb.GetAsString()

*  Compute the SHA256 hash and show the SHA256 in hex format
? "SHA256 hash: " + loSb.GetHash("sha256","hex","utf-8")

RELEASE loSb