Objective-C

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. Objective-C

#import <CkoStringBuilder.h>

BOOL success = NO;

// 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"
//          },
// ...
// ...

CkoStringBuilder *sb = [[CkoStringBuilder alloc] init];
success = [sb LoadFile: @"my_invoice.json" charset: @"utf-8"];
if (success == NO) {
    NSLog(@"%@",@"Failed to load input file.");
    return;
}

// Convert the contents of sb to the ITIDA canonical form.
// Always pass utf-8 for the 2nd arg.
[sb Encode: @"itida" charset: @"utf-8"];

// Examine the canonicalized JSON
NSLog(@"%@",[sb GetAsString]);

// Compute the SHA256 hash and show the SHA256 in hex format
NSLog(@"%@%@",@"SHA256 hash: ",[sb GetHash: @"sha256" encoding: @"hex" charset: @"utf-8"]);