Sign in with AptosSign in with Aptos

import { getCookie, setCookie } from "hono/cookie";
import { Hono } from "hono";
import { z } from "zod";

const auth = new Hono();

auth.get("/auth/siwa", (c) => {
  const nonce = generateNonce();

  const input = {
    nonce,
    domain: "myapp.com",
    statement: "Sign into to get access to this demo application",
  } satisfies AptosSignInInput;

  setCookie(c, "siwa-input", JSON.stringify(input), {
    httpOnly: true,
    sameSite: "lax",
  });

  return c.json({ data: input });
});

auth.post(
  "/auth/siwa/callback",
  async (c) => {
    const { output } = c.req.valid("json");

    const expectedInput = getCookie(c, "siwa-input");
    if (!expectedInput) return c.json({ error: "input_not_found" }, 400);

    const deserializedOutput = deserializeSignInOutput(output);

    const signatureVerification = await verifySignInSignature(deserializedOutput);

    if (!signatureVerification.valid) {
      return c.json(
        { error: `${signatureVerification.errors.join(", ")}` },
        400,
      );
    }

    const messageVerification = await verifySignInMessage({
      input: deserializedOutput.input,
      expected: JSON.parse(expectedInput) as AptosSignInInput,
      publicKey: deserializedOutput.publicKey,
    );

    if (!messageVerification.valid) {
      return c.json(
        { error: `${messageVerification.errors.join(", ")}` },
        400,
      );
    }

    // ... Generate and store a session for the user

    return c.json({ data: true });
  }
);