Zig

Sign String to create a CAdES-T Signature

See more CAdES Examples

This example will sign a string to create a CAdEST-T signature.

Note: This example requires Chilkat v9.5.0.78 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 requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

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

    // This example will use the certificate + private key currently inserted into a smartcard reader.
    const cert = try chilkat.Cert.init();
    defer cert.deinit();

    // If we wish to provide the smartcard PIN (otherwise the user will be prompted by the operating system).
    cert.setSmartCardPin("000000");
    cert.loadFromSmartcard("") catch {
        std.debug.print("{s}\n", .{try cert.getLastErrorText(alloc)});
        return;
    };

    // Note: It is also possible to use certs from .pfx/.p12, .pem, or other sources such as
    // pre-installed Windows certificates.

    try crypt.setSigningCert(cert);

    // Use SHA-256 rather than the default of SHA-1
    crypt.setHashAlgorithm("sha256");

    // Create JSON that tells Chilkat what signing attributes to include:
    const attrs = try chilkat.JsonObject.init();
    defer attrs.deinit();
    attrs.updateBool("contentType", true) catch {};
    attrs.updateBool("signingTime", true) catch {};
    attrs.updateBool("messageDigest", true) catch {};
    attrs.updateBool("signingCertificateV2", true) catch {};

    // A CAdES-T signature is one that includes a timestampToken created by an online TSA (time stamping authority).
    // We must include the TSA's URL, as well as a few options to indicate what is desired.
    // Except for the TSA URL, the options shown here are typically what you would need.
    attrs.updateBool("timestampToken.enabled", true) catch {};
    attrs.updateString("timestampToken.tsaUrl", "https://freetsa.org/tsr") catch {};
    attrs.updateBool("timestampToken.addNonce", false) catch {};
    attrs.updateBool("timestampToken.requestTsaCert", true) catch {};
    attrs.updateString("timestampToken.hashAlg", "sha256") catch {};

    crypt.setSigningAttributes(try attrs.emit(alloc));

    const str_to_sign = "THIS IS MY ID";

    const bd = try chilkat.BinData.init();
    defer bd.deinit();
    bd.appendString(str_to_sign, "utf-8") catch {};

    // This creates the CAdES-T signature.  During the signature creation, it
    // communicates with the TSA to get a timestampToken.
    // The contents of bd are signed and replaced with the CAdES-T signature (which embeds the original content).
    crypt.opaqueSignBd(bd) catch {
        std.debug.print("{s}\n", .{try crypt.getLastErrorText(alloc)});
        return;
    };

    // Get the signature in base64 format:
    std.debug.print("{s}\n", .{try bd.getEncoded(alloc, "base64_mime")});

    // Or save the signature to a file.
    bd.writeFile("qa_output/cades-t_sample.p7m") catch {};

    std.debug.print("Success.\n", .{});
}