Zig

Export a Public Key as a JWK

Demonstrates the Chilkat PublicKey.GetJwk method, which returns the public key as a compact JWK (JSON Web Key). It takes no arguments; binary values use Base64url without padding and the member order is stable across calls.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: JWK is the JSON key format used across modern web security — JWT, OAuth, OpenID Connect. Exporting a public key to JWK is exactly what you do to publish it in a JWK Set (a jwks_uri endpoint) so others can verify your signatures. The stable member order matters because it makes the output reproducible, which is important when the JWK feeds into a thumbprint.

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Zig

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

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

    // Load a public key to export.  LoadFromFile inspects the content, so it accepts DER, PEM, XML,
    // JWK, and other supported representations.
    const pub_key = try chilkat.PublicKey.init();
    defer pub_key.deinit();
    pub_key.loadFromFile("qa_data/public.pem") catch {
        std.debug.print("{s}\n", .{try pub_key.getLastErrorText(alloc)});
        return;
    };

    // Export the public key as a compact JWK (JSON Web Key).  Binary values use Base64url without
    // padding, and the member order is stable across calls.
    const jwk = pub_key.getJwk(alloc) catch {
        std.debug.print("{s}\n", .{try pub_key.getLastErrorText(alloc)});
        return;
    };

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