Zig

Create JWT Using ECC (ES256, ES384, or ES512)

See more JSON Web Token (JWT) Examples

Demonstrates how to create a JWT using an ECC private key. This is for JOSE headers with an "alg" of ES256, ES384, or ES512. When ECC is used, the private key signs (creates) the JWT, and the public key is for verification.

This example also demonstrates how to include time constraints:

• nbf: Not Before Time
• exp: Expiration Time
• iat: Issue At Time

Zig

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

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

    // Demonstrates how to create a JWT using an ECC private key.

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

    const priv_key = try chilkat.PrivateKey.init();
    defer priv_key.deinit();

    // Load an ECC private key from a PEM file.
    priv_key.loadPemFile("qa_data/pem/ecc_privKey.pem") catch {
        std.debug.print("{s}\n", .{try priv_key.getLastErrorText(alloc)});
        return;
    };

    const jwt = try chilkat.Jwt.init();
    defer jwt.deinit();

    // Build the JOSE header
    const jose = try chilkat.JsonObject.init();
    defer jose.deinit();
    // Use ES256.  Pass the string "ES384" or "ES512" to use ECC with SHA-384 or SHA-512.
    try jose.appendString("alg", "ES256");
    try jose.appendString("typ", "JWT");

    // Now build the JWT claims (also known as the payload)
    const claims = try chilkat.JsonObject.init();
    defer claims.deinit();
    try claims.appendString("iss", "http://example.org");
    try claims.appendString("sub", "John");
    try claims.appendString("aud", "http://example.com");

    // Set the timestamp of when the JWT was created to now.
    const cur_date_time = jwt.genNumericDate(0);
    try claims.addIntAt(-1, "iat", cur_date_time);

    // Set the "not process before" timestamp to now.
    try claims.addIntAt(-1, "nbf", cur_date_time);

    // Set the timestamp defining an expiration time (end time) for the token
    // to be now + 1 hour (3600 seconds)
    try claims.addIntAt(-1, "exp", cur_date_time + 3600);

    // Produce the smallest possible JWT:
    jwt.setAutoCompact(true);

    // Create the JWT token.  This is where the ECC signature is created.
    const token = try jwt.createJwtPk(alloc, try jose.emit(alloc), try claims.emit(alloc), priv_key);

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

    // Example output:
    // eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJodHRwOi8vZXhhbXBsZS5vcmciLCJzdWIiOiJKb2huIiwiYXVkIjoiaHR0cDovL2V4YW1wbGUuY29tIiwiaWF0IjoxNDg1NzA4NzkyLCJuYmYiOjE0ODU3MDg3OTIsImV4cCI6MTQ4NTcxMjM5Mn0.wqsuyJpxJ073ox-lOiLFqG1lQocXe4hGf2XGZJRrO3qn0UusxI_bu3Gzky8gBsH4sA4u9TWZn5M-1wYMMIJk6Q
}