Tcl

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. Tcl

load ./chilkat.dll

set 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"
#          },
# ...
# ...

set sb [new_CkStringBuilder]

set success [CkStringBuilder_LoadFile $sb "my_invoice.json" "utf-8"]
if {$success == 0} then {
    puts "Failed to load input file."
    delete_CkStringBuilder $sb
    exit
}

# Convert the contents of sb to the ITIDA canonical form.
# Always pass utf-8 for the 2nd arg.
CkStringBuilder_Encode $sb "itida" "utf-8"

# Examine the canonicalized JSON
puts [CkStringBuilder_getAsString $sb]

# Compute the SHA256 hash and show the SHA256 in hex format
puts "SHA256 hash: [CkStringBuilder_getHash $sb sha256 hex utf-8]"

delete_CkStringBuilder $sb