1 files changed, 132 insertions, 0 deletions
diff --git a/app/routes/auth.login.tsx b/app/routes/auth.login.tsx
new file mode 100644
index 0000000..f8e9028
--- /dev/null
+++ b/app/routes/auth.login.tsx
@@ -0,0 +1,132 @@
+import { useState } from "react";
+import { redirect } from "react-router";
+import {
+  generateAuthenticationOptions,
+  verifyAuthenticationResponse,
+  type AuthenticationResponseJSON,
+  type AuthenticatorTransportFuture,
+} from "@simplewebauthn/server";
+import type { Route } from "./+types/auth.login";
+import { getSession, commitSession } from "~/lib/session.server";
+import { listCredentials, getCredentialById, updateCredentialCounter } from "~/lib/db.server";
+import { rpID, origin } from "~/lib/passkey.server";
+
+export async function loader({ request }: Route.LoaderArgs) {
+  const session = await getSession(request.headers.get("Cookie"));
+  if (session.get("authenticated")) return redirect("/");
+  if (listCredentials().length === 0) return redirect("/auth/register");
+  return {};
+}
+
+export async function action({ request }: Route.ActionArgs) {
+  const url = new URL(request.url);
+  const intent = url.searchParams.get("intent");
+  const session = await getSession(request.headers.get("Cookie"));
+
+  if (intent === "options") {
+    const credentials = listCredentials();
+    const options = await generateAuthenticationOptions({
+      rpID,
+      allowCredentials: credentials.map((c) => ({
+        id: c.id,
+        transports: c.transports
+          ? (JSON.parse(c.transports) as AuthenticatorTransportFuture[])
+          : undefined,
+      })),
+      userVerification: "required",
+    });
+    session.set("challenge", options.challenge);
+    return Response.json(options, {
+      headers: { "Set-Cookie": await commitSession(session) },
+    });
+  }
+
+  if (intent === "verify") {
+    const challenge = session.get("challenge") as string | undefined;
+    if (!challenge) return Response.json({ error: "セッション切れです" }, { status: 400 });
+
+    const body = (await request.json()) as AuthenticationResponseJSON;
+    const credential = getCredentialById(body.id);
+    if (!credential) return Response.json({ error: "パスキーが見つかりません" }, { status: 400 });
+
+    const verification = await verifyAuthenticationResponse({
+      response: body,
+      expectedChallenge: challenge,
+      expectedOrigin: origin,
+      expectedRPID: rpID,
+      credential: {
+        id: credential.id,
+        publicKey: new Uint8Array(Buffer.from(credential.public_key, "base64url")),
+        counter: credential.counter,
+        transports: credential.transports
+          ? (JSON.parse(credential.transports) as AuthenticatorTransportFuture[])
+          : undefined,
+      },
+    });
+
+    if (!verification.verified) {
+      return Response.json({ error: "認証に失敗しました" }, { status: 400 });
+    }
+
+    updateCredentialCounter(credential.id, verification.authenticationInfo.newCounter);
+    session.unset("challenge");
+    session.set("authenticated", true);
+    return redirect("/", {
+      headers: { "Set-Cookie": await commitSession(session) },
+    });
+  }
+
+  return Response.json({ error: "不正なリクエスト" }, { status: 400 });
+}
+
+export default function Login() {
+  const [status, setStatus] = useState<"idle" | "loading" | "error">("idle");
+  const [errorMsg, setErrorMsg] = useState("");
+
+  async function handleLogin() {
+    setStatus("loading");
+    setErrorMsg("");
+    try {
+      const { startAuthentication } = await import("@simplewebauthn/browser");
+
+      const optRes = await fetch("/auth/login?intent=options", { method: "POST" });
+      if (!optRes.ok) throw new Error("オプション取得に失敗しました");
+      const options = await optRes.json();
+
+      const authResponse = await startAuthentication({ optionsJSON: options });
+
+      const verRes = await fetch("/auth/login?intent=verify", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify(authResponse),
+      });
+      if (!verRes.ok) {
+        const err = await verRes.json();
+        throw new Error(err.error ?? "認証に失敗しました");
+      }
+
+      window.location.href = "/";
+    } catch (e) {
+      setStatus("error");
+      setErrorMsg(e instanceof Error ? e.message : "エラーが発生しました");
+    }
+  }
+
+  return (
+    <div className="wrap">
+      <header className="site-header">
+        <h1>log</h1>
+      </header>
+      <div className="auth-box">
+        <h2>ログイン</h2>
+        <p>登録済みのパスキーで認証します。</p>
+        <button className="btn" onClick={handleLogin} disabled={status === "loading"}>
+          {status === "loading" ? "認証中…" : "パスキーでログイン"}
+        </button>
+        {status === "error" && (
+          <p className="error-msg" style={{ marginTop: ".75rem" }}>{errorMsg}</p>
+        )}
+      </div>
+    </div>
+  );
+}