Add password-derived auth key flow for login and registration

Adds deriveAuthKeypair (scrypt-based) and deriveWalletEntropy utilities.
Login now attempts challenge-response auth via derived key before password
fallback. Registration requires password and derives authPubkey. Settings
derives authPubkey on password change.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

1 files changed, 51 insertions, 0 deletions

diff --git a/src/routes/(static)/login/+page.server.ts b/src/routes/(static)/login/+page.server.ts
index 68143d83..d402fdad 100644
--- a/src/routes/(static)/login/+page.server.ts
+++ b/src/routes/(static)/login/+page.server.ts
@@ -97,6 +97,57 @@ export const actions = {
     };
   },
 
+  passwordAuth: async ({ cookies, fetch, request }) => {
+    const form = await fd(request);
+    let { event, challenge, username, loginRedirect, recaptcha, token: twofa } = form;
+    if (loginRedirect === "null" || loginRedirect === "undefined") loginRedirect = undefined;
+    event = JSON.parse(event);
+
+    const maxAge = 380 * 24 * 60 * 60;
+
+    const res = await fetch(`${PUBLIC_COINOS_URL}/authKeyLogin`, {
+      method: "POST",
+      body: JSON.stringify({ event, challenge, username, recaptcha, twofa }),
+      headers: {
+        "content-type": "application/json",
+        accept: "application/json",
+        "cf-connecting-ip": request.headers.get("cf-connecting-ip") ?? "",
+        "x-forwarded-host": request.headers.get("host") ?? "",
+      },
+    });
+
+    const text = await res.text();
+
+    if (res.status === 401) {
+      if (text.startsWith("2fa")) throw new Error("2fa");
+      throw new Error(text);
+    }
+
+    if (!res.ok) {
+      let message;
+      try {
+        ({ message } = JSON.parse(text));
+      } catch {
+        message = text;
+      }
+      return fail(400, { error: message || "Login failed" });
+    }
+
+    const { user, token } = JSON.parse(text);
+    if (!token) return fail(400, { error: "Login failed" });
+    const { username: uname, language } = user;
+
+    const expires = new Date();
+    expires.setSeconds(expires.getSeconds() + maxAge);
+
+    const opts = { path: "/", expires };
+    if (language) cookies.set("lang", language, opts);
+    cookies.set("username", uname, opts);
+    cookies.set("token", token, opts);
+
+    redirect(307, loginRedirect || `/${uname}`);
+  },
+
   passkey: async ({ cookies, fetch, request }) => {
     const form = await fd(request);
     let { credential, challengeId, loginRedirect } = form;