Zig

Combine Timestamp Reply and Content File into a TimeStampData

See more ASN.1 Examples

Demonstrates how to combine a timestamp reply (RFC 3161) with a data file (any type of file) to create a TimeStampData structure (RFC 5544). 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.

    // Also see this example:
    // Send a TimeStamp Request to a TimeStamp Authority and get the Response

    // Load a timestamp reply file
    const bd_tsr = try chilkat.BinData.init();
    defer bd_tsr.deinit();
    bd_tsr.loadFile("qa_data/tsd/sample.tsr") catch {
        std.debug.print("Failed to load timestamp reply file.\n", .{});
        return;
    };

    // Load the tsr into an ASN.1 object.
    const asn_tsr = try chilkat.Asn.init();
    defer asn_tsr.deinit();
    asn_tsr.loadEncoded(try bd_tsr.getEncoded(alloc, "base64"), "base64") catch {
        std.debug.print("{s}\n", .{try asn_tsr.getLastErrorText(alloc)});
        return;
    };

    // Get the timestamp reply as XML.
    const xml_tsr = try chilkat.Xml.init();
    defer xml_tsr.deinit();
    xml_tsr.loadXml(try asn_tsr.asnToXml(alloc)) catch {};

    // The timestamp reply XML begins like this:
    // We'll want to remove the 1st "sequence" subtree.

    //     <?xml version="1.0" encoding="utf-8"?>
    //     <sequence>
    //         <sequence>       <---- Remove this sub-tree.
    //             <int>00</int>
    //             <sequence>
    //                 <utf8>Operation Okay</utf8>
    //             </sequence>
    //         </sequence>
    //         <sequence>
    //             <oid>1.2.840.113549.1.7.2</oid>
    //             <contextSpecific tag="0" constructed="1">
    //             ...

    // Remove the 1st sub-tree..
    xml_tsr.removeChildByIndex(0);

    // In this example, the data file we're combining with the timestamp into a timestampData is a .p7m.
    // However, it can be any type of file (text or binary), it doesn't matter..
    const bd_content = try chilkat.BinData.init();
    defer bd_content.deinit();
    bd_content.loadFile("qa_data/tsd/sample.p7m") catch {
        std.debug.print("Failed to load content file.\n", .{});
        return;
    };

    // Begin building the TimeStampData.
    // We'll build as XML and then convert to ASN.1
    const xml = try chilkat.Xml.init();
    defer xml.deinit();
    xml.setTag("sequence");
    xml.updateChildContent("oid", "1.2.840.113549.1.9.16.1.31");
    xml.updateAttrAt("contextSpecific", true, "tag", "0") catch {};
    xml.updateAttrAt("contextSpecific", true, "constructed", "1") catch {};
    xml.updateChildContent("contextSpecific|sequence|int", "01");
    xml.updateChildContent("contextSpecific|sequence|octets", try bd_content.getEncoded(alloc, "base64"));
    xml.updateAttrAt("contextSpecific|sequence|contextSpecific", true, "tag", "0") catch {};
    xml.updateAttrAt("contextSpecific|sequence|contextSpecific", true, "constructed", "1") catch {};

    const x_context = try xml.getChildWithTag("contextSpecific|sequence|contextSpecific");
    defer x_context.deinit();
    x_context.addChildTree(xml_tsr) catch {};

    // Convert the XML to ASN.1
    const tsd = try chilkat.Asn.init();
    defer tsd.deinit();
    tsd.loadAsnXml(try xml.getXml(alloc)) catch {};

    // Write the timestamped data to a file.
    try tsd.writeBinaryDer("qa_output/sample.tsd");

    // Alternatively, get the tsd ASN.1 as base64..
    const tsd_base64 = try tsd.getEncodedDer(alloc, "base64_mime");
    std.debug.print("{s}\n", .{tsd_base64});
}