Sign a JWS with an HMAC Key

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetMacKey, which sets the symmetric MAC key for a signature. The key bytes are supplied in a named encoding such as hex or base64.

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

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

    const jws = try chilkat.Jws.init();
    defer jws.deinit();

    // Protected header specifying HMAC-SHA256.
    const header = try chilkat.JsonObject.init();
    defer header.deinit();
    header.updateString("alg", "HS256") catch {};
    jws.setProtectedHeader(0, header) catch {
        std.debug.print("{s}\n", .{try jws.getLastErrorText(alloc)});
        return;
    };

    const b_include_bom = false;
    jws.setPayload("This is the content to sign.", "utf-8", b_include_bom) catch {
        std.debug.print("{s}\n", .{try jws.getLastErrorText(alloc)});
        return;
    };

    // Set the symmetric MAC key for signature 0.  The key bytes are provided in the named encoding (here
    // base64).  In production, obtain the key from a secure source rather than hard-coding it.
    const base64_key = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU=";
    jws.setMacKey(0, base64_key, "base64") catch {
        std.debug.print("{s}\n", .{try jws.getLastErrorText(alloc)});
        return;
    };

    const jws_compact = jws.createJws(alloc) catch {
        std.debug.print("{s}\n", .{try jws.getLastErrorText(alloc)});
        return;
    };

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