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Create Egypt ITIDA CAdES-BES Signature with Automatic JSON Canonicalization

See more Egypt ITIDA Examples

Demonstrates how to create a .p7s signature that fits Egypt's ITIDA requirements where Chilkat automatically does the ITIDA JSON canonicalization.

Note: This example requires Chilkat v9.5.0.75 or greater.

Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    const crypt = try chilkat.Crypt2.init();
    defer crypt.deinit();
    crypt.setVerboseLogging(true);

    const cert = try chilkat.Cert.init();
    defer cert.deinit();
    cert.setVerboseLogging(true);

    // Set the smart card PIN, which will be needed for signing.
    cert.setSmartCardPin("12345678");

    // There are many ways to load the certificate.
    // This example was created for a customer using an ePass2003 USB token.
    // Assuming the USB token is the only source of a hardware-based private key..
    cert.loadFromSmartcard("") catch {
        std.debug.print("{s}\n", .{try cert.getLastErrorText(alloc)});
        return;
    };

    // Tell the crypt class to use this cert.
    crypt.setSigningCert(cert) catch {
        std.debug.print("{s}\n", .{try crypt.getLastErrorText(alloc)});
        return;
    };

    const cms_options = try chilkat.JsonObject.init();
    defer cms_options.deinit();
    // Setting "DigestData" causes OID 1.2.840.113549.1.7.5 (digestData) to be used.
    cms_options.updateBool("DigestData", true) catch {};
    cms_options.updateBool("OmitAlgorithmIdNull", true) catch {};

    // Indicate that we are passing normal JSON and we want Chilkat do automatically
    // do the ITIDA JSON canonicalization:
    cms_options.updateBool("CanonicalizeITIDA", true) catch {};

    crypt.setCmsOptions(try cms_options.emit(alloc));

    // The CadesEnabled property applies to all methods that create CMS/PKCS7 signatures.
    // To create a CAdES-BES signature, set this property equal to true.
    crypt.setCadesEnabled(true);

    crypt.setHashAlgorithm("sha256");

    const json_signing_attrs = try chilkat.JsonObject.init();
    defer json_signing_attrs.deinit();
    json_signing_attrs.updateInt("contentType", 1) catch {};
    json_signing_attrs.updateInt("signingTime", 1) catch {};
    json_signing_attrs.updateInt("messageDigest", 1) catch {};
    json_signing_attrs.updateInt("signingCertificateV2", 1) catch {};
    crypt.setSigningAttributes(try json_signing_attrs.emit(alloc));

    // By default, all the certs in the chain of authentication are included in the signature.
    // If desired, we can choose to only include the signing certificate:
    crypt.setIncludeCertChain(false);

    // Pass a JSON document such as the following.  Chilkat will do the ITIDA canonicalization.
    // (It is the canonicalized JSON that gets signed.)

    //       {
    //          "issuer":{
    //             "address":{
    //                "branchID":"0",
    //                "country":"EG",
    //                "regionCity":"Cairo",
    //                "postalCode":"",
    //                "buildingNumber":"0",
    //                "street":"123rd Street",
    //                "governate":"GOVERNATE"
    //             },
    //             "type":"B",
    //             "id":"209999899",
    //             "name":"Xyz SAE"
    //          },
    //          "receiver":{
    //             "address":{
    //                "country":"EG",
    //                "regionCity":"CAIRO",
    //                "postalCode":"11435",
    //                "buildingNumber":"0",
    //                "street":"Autostrad Road Abc",
    //                "governate":"GOVERNATE"
    //             },
    //             "type":"B",
    //             "id":"999999999",
    //             "name":"XYZ EGYPT FOR TRADE"
    //          },
    //          "documentType":"I",
    //          "documentTypeVersion":"1.0",
    //          "dateTimeIssued":"2020-11-15T11:04:53Z",
    //          "taxpayerActivityCode":"1073",
    //          "internalID":"ZZZZ999",
    //          "purchaseOrderReference":"2009199918",
    //          "salesOrderReference":"",
    //          "payment":{
    //             "bankName":"",
    //             "bankAddress":"",
    //             "bankAccountNo":"",
    //             "bankAccountIBAN":"",
    //             "swiftCode":"",
    //             "terms":""
    //          },
    //          "delivery":{
    //             "approach":"",
    //             "packaging":"",
    //             "dateValidity":"",
    //             "exportPort":"",
    //             "countryOfOrigin":"EG",
    //             "grossWeight":0,
    //             "netWeight":0,
    //             "terms":""
    //          },
    //          "invoiceLines":[
    //             {
    //                "description":"CDM Widget 48GX99X12BA",
    //                "itemType":"GS1",
    //                "itemCode":"7622213335056",
    //                "unitType":"CS",
    //                "quantity":1.00,
    //                "unitValue":{
    //                   "currencySold":"EGP",
    //                   "amountEGP":588.67,
    //                   "amountSold":0,
    //                   "currencyExchangeRate":0
    //                },
    //                "salesTotal":588.67,
    //                "total":603.97,
    //                "valueDifference":0,
    //                "totalTaxableFees":0,
    //                "netTotal":529.8,
    //                "itemsDiscount":0,
    //                "discount":{
    //                   "rate":10.00,
    //                   "amount":58.87
    //                },
    //                "taxableItems":[
    //                   {
    //                      "taxType":"T1",
    //                      "amount":74.17,
    //                      "subType":"No sub",
    //                      "rate":14.00
    //                   }
    //                ],
    //                "internalCode":"9099994"
    //             }
    //          ],
    //          "totalSales":588.67,
    //          "totalSalesAmount":588.67,
    //          "totalDiscountAmount":58.87,
    //          "netAmount":529.80,
    //          "taxTotals":[
    //             {
    //                "taxType":"T1",
    //                "amount":74.17
    //             }
    //          ],
    //          "extraDiscountAmount":0,
    //          "totalItemsDiscountAmount":0,
    //          "totalAmount":603.97,
    //       }
    //

    const json = try chilkat.JsonObject.init();
    defer json.deinit();
    json.loadFile("qa_data/itida/sdk.invoicing.eta.gov.eg/files/one-doc.json") catch {
        std.debug.print("{s}\n", .{try json.getLastErrorText(alloc)});
        return;
    };

    json.setEmitCompact(false);

    // Create the CAdES-BES signature.
    crypt.setEncodingMode("base64");

    // Make sure we sign the utf-8 byte representation of the JSON string
    crypt.setCharset("utf-8");

    const sig_base64 = crypt.signStringENC(alloc, try json.emit(alloc)) catch {
        std.debug.print("{s}\n", .{try crypt.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("Base64 signature:\n", .{});
    std.debug.print("{s}\n", .{sig_base64});

    // Add the signature to the JSON.
    json.updateString("signatures[0].signatureType", "I") catch {};
    json.updateString("signatures[0].value", sig_base64) catch {};

    std.debug.print("JSON with signature added:\n", .{});
    std.debug.print("{s}\n", .{try json.emit(alloc)});
}